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1.  Elevated Soluble Lectin-like Oxidized LDL Receptor 1 (LOX-1) Levels in Obese Postmenopausal Women 
Obesity (Silver Spring, Md.)  2008;16(6):1454-1456.
We investigated the association between soluble lectin-like oxidized LDL receptor 1 (sLOX-1) levels and obesity in older women. Fifty-one (10 lean, 22 overweight, and 19 obese) postmenopausal women were included in this small retrospective analysis. Plasma sLOX-1 levels were measured using a chemiluminescent ELISA. Plasma levels of sLOX-1 were significantly higher in obese women (55.33±4.49 pg/mL) compared to lean (30.91±6.19 pg/mL, p=0.002) and overweight women (38.31±4.18 pg/mL, p=0.017). Plasma sLOX-1 levels were positively associated with body weight, BMI, total body fat, and trunk fat. The relationship between sLOX-1 and BMI was attenuated after adjustment for age, HRT, and body fat. In conclusion, obese women have higher sLOX-1 levels, which may reflect increased LOX-1 expression in adipose tissue.
PMCID: PMC2677801  PMID: 18388896
obesity; postmenopausal women; receptors
2.  Variation in the Lectin-like Oxidized LDL Receptor 1 (LOX-1) Gene Is Associated With Plasma Soluble LOX-1 Levels 
Experimental physiology  2008;93(9):1085-1090.
The lectin-like ox-LDL receptor 1 (LOX-1) expressed on vascular cells plays a major role in atherogenesis by internalizing and degrading oxidized LDL. LOX-1 can be cleaved from the cell surface and released as soluble LOX-1 (sLOX-1), and elevated sLOX-1 levels may be indicative of atherosclerotic plaque instability. We examined associations between the LOX-1 3′UTR-C/T and G501C polymorphisms and plasma sLOX-1 levels in 97 healthy older men and women. The frequencies for the 3′UTR-T and 501C alleles were 46% and 10%, respectively. Plasma sLOX-1 levels were significantly higher in the 3′UTR CC genotype group compared to both the CT (p=0.02) and TT (p=0.002) genotype groups. Plasma sLOX-1 were also significantly higher in the 501GC genotype group compared to the GG genotype group (p=0.004). In univariate analyses, sLOX-1 levels were significantly associated with both the 3′UTR-C/T and G501 C polymorphisms. These associations remained significant after adjusting for age, gender, race, and BMI. In conclusion, variation in the LOX-1 gene is associated with plasma sLOX-1 levels in older men and women.
PMCID: PMC2652129  PMID: 18469066
receptor; cardiovascular; gene expression
3.  Pregnancy Followed by Delivery May Affect Circulating Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 Levels in Women of Reproductive Age 
Mediators of Inflammation  2012;2012:837375.
Background/Objective. It is known that menopause or lack of endogenous estrogen is a risk factor for endothelial dysfunction and CAD. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is involved inmultiple phases of vascular dysfunction.The purpose of the current study was to determine the association between soluble LOX-1 (sLOX-1) and pregnancy followed by delivery in women of reproductive age. Materials/Methods. Sixty-eight subjects with pregnancy followed by delivery (group 1) and 57 subjects with nongravidity (group 2) were included in this study. Levels of sLOX-1 were measured in serum by EL SA. Results. Plasma levels of sLOX-1 were significantly lower in Group 1 than Group 2 in women of reproductive age (0.52 ± 0.18 ng/mL and 0.78 ± 0.13, resp., P < 0.001). There were strong correlations between sLOX-1 levels and the number of gravida (r = −0.645, P < 0.001). The levels of sLOX-1 highly correlated with the number of parous (r = −0.683, P < 0.001). Conclusion. Our study demonstrated that serum sLOX-1 levels were associated with pregnancy followed by delivery that might predict endothelial dysfunction. We conclude that pregnancy followed by delivery may delay the beginning and progress of arteriosclerosis and its clinical manifestations in women of reproductive age.
PMCID: PMC3350984  PMID: 22619487
4.  Soluble Lectin-Like Oxidized Low Density Lipoprotein Receptor-1 as a Biochemical Marker for Atherosclerosis-Related Diseases 
Disease markers  2013;35(5):413-418.
Lectin-like oxidized low density lipoprotein receptor-1 (LOX-1), the main oxidized low-density lipoprotein (OxLDL) in endothelial cells, is upregulated in atherosclerotic lesions and is involved in several cellular processes that regulate the pathogenesis of atherosclerosis. The LOX-1 expressed on the cell surface can be proteolytically cleaved and released in a soluble form (sLOX-1) in the circulation under pathological conditions. Serum levels of sLOX-1, in fact, are elevated at the early stages of acute coronary syndrome and are associated with coronary plaque vulnerability and with the presence of multiple complex coronary lesions. Moreover, in subjects with stable CAD, levels of serum sLOX-1 are associated with the presence of lesions in the proximal and mid-segments of the left anterior descending artery that are the most prone to rupture; in subjects undergoing percutaneous coronary intervention, baseline preprocedural serum sLOX-1 levels are associated with the incidence of periprocedural myocardial infarction. Altogether, these findings suggest that circulating levels of sLOX-1 might be a diagnostic and prognostic marker for atherosclerotic-related events.
PMCID: PMC3809739  PMID: 24198442
5.  Effects of a caloric restriction weight loss diet and exercise on inflammatory biomarkers in overweight/obese postmenopausal women: a randomized controlled trial 
Cancer Research  2012;72(9):2314-2326.
Obese and sedentary persons have increased risk for cancer; inflammation is a hypothesized mechanism. We examined the effects of a caloric restriction weight loss diet and exercise on inflammatory biomarkers in 439 women. Overweight and obese postmenopausal women were randomized to 1-year: caloric restriction diet (goal of 10% weight loss, N=118), aerobic exercise (225 minutes/week of moderate-to-vigorous activity, N=117), combined diet+exercise (N=117) or control (N=87). Baseline and 1-year high-sensitivity C-reactive protein (hs-CRP), serum amyloid A (SAA), interleukin-6 (IL-6), leukocyte and neutrophil levels were measured by investigators blind to group. Inflammatory biomarker changes were compared using generalized estimating equations. Models were adjusted for baseline body mass index (BMI), race/ethnicity and age. 438 (N=1 in diet+exercise group was excluded) were analyzed. Relative to controls, hs-CRP decreased by geometric mean (95% confidence interval, p-value) 0.92mg/L (0.53–1.31, P<0.001) in the diet and 0.87mg/L (0.51–1.23, P<0.0001) in the diet+exercise groups. IL-6 decreased by 0.34pg/ml (0.13–0.55, P=0.001) in the diet and 0.32pg/ml (0.15–0.49, P<0.001) in the diet+exercise groups. Neutrophil counts decreased by 0.31×109/L (0.09–0.54, P=0.006) in the diet and 0.30×109/L (0.09–0.50, P=0.005) in the diet+exercise groups. Diet and diet+exercise participants with ≥5% weight loss reduced inflammatory biomarkers (hs-CRP, SAA, and IL-6) compared to controls. The diet and diet+exercise groups reduced hs-CRP in all subgroups of baseline BMI, waist circumference, CRP level, and fasting glucose. Our findings indicate that a caloric restriction weight loss diet with or without exercise reduces biomarkers of inflammation in postmenopausal women, with potential clinical significance for cancer risk reduction.
PMCID: PMC3342840  PMID: 22549948
inflammation; postmenopausal women; obesity; exercise; dietary weight loss
6.  Effects of individual and combined dietary weight loss and exercise interventions in postmenopausal women on adiponectin and leptin levels 
Journal of internal medicine  2013;274(2):163-175.
Excess body weight and a sedentary lifestyle are associated with the development of several diseases, including cardiovascular disease, diabetes, and cancer in women. One proposed mechanism linking obesity to chronic diseases is an alteration in adipose-derived adiponectin and leptin levels. We investigated the effects of 12-month reduced calorie, weight loss and exercise interventions on adiponectin and leptin concentrations.
Overweight/obese postmenopausal women (n=439) were randomized as follows: 1) a reduced calorie, weight loss diet (diet; N=118); 2) moderate-to-vigorous intensity aerobic exercise (exercise; N=117); 3) a combination of a reduced calorie, weight loss diet and moderate-to-vigorous intensity aerobic exercise (diet+exercise; N=117); or 4) control (N=87). The reduced calorie diet had a 10% weight loss goal. The exercise intervention consisted of 45 minutes of moderate-to-vigorous aerobic activity 5 days/week. Adiponectin and leptin levels were measured at baseline and after 12 months of intervention using a radioimmunoassay.
Adiponectin increased by 9.5 % in the diet group and 6.6 % in the diet+exercise group (both p≤0.0001 vs. control). Compared with controls, leptin decreased with all interventions (diet+exercise, −40.1%, p<0.0001; diet, −27.1%, p<0.0001; exercise, −12.7%, p=0.005). The results were not influenced by the baseline body mass index (BMI). The degree of weight loss was inversely associated with concentrations of adiponectin (diet, p-trend=0.0002; diet+exercise, p-trend=0.0005) and directly associated with leptin (diet, p-trend<0.0001; diet+exercise, p-trend<0.0001).
Weight loss through diet or diet+exercise increased adiponectin concentrations. Leptin concentrations decreased in all of the intervention groups, but the greatest reduction occurred with diet+exercise. Weight loss and exercise exerted some beneficial effects on chronic diseases via effects on adiponectin and leptin.
PMCID: PMC3738194  PMID: 23432360
adiponectin; leptin; randomized controlled trial; diet and exercise intervention
7.  Dietary Weight-Loss and Exercise Effects on Insulin Resistance in Postmenopausal Women 
Comprehensive lifestyle interventions are effective in preventing diabetes and restoring glucose regulation; however, the key stimulus for change has not been identified and effects in older individuals are not established. The aim of the study was to investigate the independent and combined effects of dietary weight-loss and exercise on insulin sensitivity and restoration of normal fasting glucose in mid-aged and older women.
Four-arm RCT, conducted between 2005 and 2009 and data analyzed in 2010.
439 inactive, overweight/obese postmenopausal women. Interventions: Women were assigned to: dietary weight loss (n=118), exercise (n=117), exercise+diet (n=117), or control (n=87). The diet intervention was a group-based reduced-calorie program with a 10% weight-loss goal. The exercise intervention was 45 min/day, 5 days/week of moderate-to-vigorous intensity aerobic activity.
Main outcome measures
12-month change in serum insulin, C-peptide, fasting glucose, and whole body insulin resistance (HOMA-IR).
A significant improvement in HOMA-IR was detected in the diet (−24%, p<0.001) and exercise+ diet (−26%, p<0.001) groups, but not in the exercise (−9%, p=0.22) group compared to controls (−2%); these effects were similar in middle-aged (50–60 years) and older women (aged 60–75 years). Among those with impaired fasting glucose (5.6–6.9 mmol/L) at baseline (n=143; 33%), the odds (95% CI) of regressing to normal fasting glucose after adjusting for weight loss and baseline levels were: 2.5 (0.8, 8.4), 2.76 (0.8, 10.0), and 3.1 (1.0, 9.9) in the diet, exercise+diet, and exercise group, respectively, compared to controls.
Dietary weight loss, with or without exercise, significantly improved insulin resistance. Older women derived as much benefit as did the younger postmenopausal women.
PMCID: PMC3185302  PMID: 21961463
8.  Procoagulant activity of circulating microparticles is associated with the presence of moderate calcified plaque burden detected by multislice computed tomography 
Circulating microparticles (MPs) have been reported to be associated with coronary artery disease (CAD). In this study, we explored the relationship between MPs procoagulant activity and characteristics of atherosclerotic plaque detected by 64-slice computed tomography angiography (CTA).
In 127 consecutive patients with CAD but without acute coronary syndrome and who underwent 64-slice CTA, MPs procoagulant activity in plasma (by a thrombin generation test), soluble form of lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) and N(epsilon)-(carboxymethyl) lysine (CML) circulating levels (by ELISA) were measured. A quantitative volumetric analysis of the lumen and plaque burden of the vessel wall (soft and calcific components), for the three major coronary vessels, was performed. The patients were classified in three groups according to the presence of calcium volume: non-calcified plaque (NCP) group (calcium volume (%) = 0), moderate calcified plaque (MCP) group (0 < calcium volume (%) < 1), and calcified plaque (CP) group (calcium volume (%) ≥ 1).
MPs procoagulant activity and CML levels were higher in MCP group than in CP or NCP group (P = 0.009 and P = 0.027, respectively). MPs procoagulant activity was positively associated with CML (r = 0.317, P < 0.0001) and sLOX-1 levels (r = 0.216, P = 0.0025).
MPs procoagulant activity was higher in the MCP patient group and correlated positively with sLOX-1 and CML levels, suggesting that it may characterize a state of blood vulnerability that may locally precipitate plaque instability and increase the risk of subsequent major cardiovascular events.
PMCID: PMC3981978  PMID: 24748876
Computed tomography; Microparticles; Low density lipoprotein; Lysine; Coronary artery disease
9.  Adipose tissue endocannabinoid system gene expression: depot differences and effects of diet and exercise 
Alterations of endocannabinoid system in adipose tissue play an important role in lipid regulation and metabolic dysfunction associated with obesity. The purpose of this study was to determine whether gene expression levels of cannabinoid type 1 receptor (CB1) and fatty acid amide hydrolase (FAAH) are different in subcutaneous abdominal and gluteal adipose tissue, and whether hypocaloric diet and aerobic exercise influence subcutaneous adipose tissue CB1 and FAAH gene expression in obese women.
Thirty overweight or obese, middle-aged women (BMI = 34.3 ± 0.8 kg/m2, age = 59 ± 1 years) underwent one of three 20-week weight loss interventions: caloric restriction only (CR, N = 9), caloric restriction plus moderate-intensity aerobic exercise (CRM, 45-50% HRR, N = 13), or caloric restriction plus vigorous-intensity aerobic exercise (CRV, 70-75% HRR, N = 8). Subcutaneous abdominal and gluteal adipose tissue samples were collected before and after the interventions to measure CB1 and FAAH gene expression.
At baseline, FAAH gene expression was higher in abdominal, compared to gluteal adipose tissue (2.08 ± 0.11 vs. 1.78 ± 0.10, expressed as target gene/β-actin mRNA ratio × 10-3, P < 0.05). Compared to pre-intervention, CR did not change abdominal, but decreased gluteal CB1 (Δ = -0.82 ± 0.25, P < 0.05) and FAAH (Δ = -0.49 ± 0.14, P < 0.05) gene expression. CRM or CRV alone did not change adipose tissue CB1 and FAAH gene expression. However, combined CRM and CRV (CRM+CRV) decreased abdominal adipose tissue FAAH gene expression (Δ = -0.37 ± 0.18, P < 0.05). The changes in gluteal CB1 and abdominal FAAH gene expression levels in the CR alone and the CRM+CRV group were different (P < 0.05) or tended to be different (P = 0.10).
There are depot differences in subcutaneous adipose tissue endocannabinoid system gene expression in obese individuals. Aerobic exercise training may preferentially modulate abdominal adipose tissue endocannabinoid-related gene expression during dietary weight loss.
Trial Registration NCT00664729.
PMCID: PMC3213035  PMID: 22035053
Cannabinoid Type 1 Receptor; Fatty Acid Amide Hydrolase; Fat Depots; Diet; Exercise
10.  A Yearlong Exercise Intervention Decreases CRP among Obese Postmenopausal Women 
Medicine and science in sports and exercise  2009;41(8):10.1249/MSS.0b013e31819c7feb.
To investigate the effect of a yearlong moderate-intensity aerobic exercise intervention on C-reactive protein (CRP), serum amyloid A (SAA), and interleukin 6 (IL-6) among overweight or obese postmenopausal women.
In a randomized controlled trial, 115 postmenopausal, overweight or obese, sedentary women, aged 50-75 years were randomized to an aerobic exercise intervention of moderate-intensity (60-75% observed maximal heart rate), for ≥45 min/day, 5 days/week (n=53), or to a 1 day/week stretching control (n=62), on an intent-to-treat basis. CRP, SAA, and IL-6 were measured at baseline, 3-months, and 12-months.
From baseline to 12-months, CRP decreased 10% in exercisers and increased 12% in controls (p=0.01); no effects were observed for SAA and IL-6. Among participants at baseline who were obese (BMI≥30kg/m2) or had abdominal obesity (waist circumference (WC)≥88cm), exercise resulted in a more pronounced reduction in CRP (BMI≥30kg/m2: p=0.002; WC≥88cm: p<0.0001), borderline for SAA (BMI≥30kg/m2: p=0.08; WC≥88cm: p=0.04); no intervention effects were observed among women who did not have these characteristics. Overall, weight loss was minimal in the exercise intervention (~1.8kg). Linear trends were observed between CRP and 12-month changes in: aerobic fitness (ptrend = 0.006), exercise adherence (ptrend = 0.004), percentage body fat (ptrend = 0.002), body weight (ptrend = 0.002), waist circumference (ptrend = 0.02), and intra-abdominal fat (ptrend = 0.03).
A moderate-intensity exercise intervention reduced CRP over 12-months among women who were obese at baseline. These findings support the role of exercise in modulating inflammatory processes that are related to increased risk of chronic disease among obese women.
PMCID: PMC3850754  PMID: 19568208
overweight; inflammation; C-reactive protein; physical activity; randomized controlled trial; serum amyloid A
11.  Effects of Dietary Weight Loss and Exercise on Insulin-Like Growth Factor-1 and Insulin-Like Growth Factor Binding Protein-3 in Postmenopausal Women: A Randomized Controlled Trial 
High levels of insulin-like growth factor (IGF)-1 may increase the risk of common cancers in humans. We hypothesized that weight loss induced by diet and/or exercise would reduce IGF-1 in postmenopausal women. Four hundred and thirty nine overweight or obese (BMI ≥25kg/m2) women (50–75 y) were randomly assigned to: i) exercise (N=117), ii) dietary weight-loss (N=118), iii) diet + exercise (N=117), or iv) control (n=87). The diet intervention was a group-based program with a 10% weight loss goal. The exercise intervention was 45 min/day, 5 days/week of moderate-to-vigorous intensity activity. Fasting serum insulin-like growth factor (IGF)-1 and insulin-like growth factor binding protein (IGFBP)-3 were measured at baseline and 12 months by radioimmunoassay. Higher baseline BMI was associated with lower IGF-1 and IGF-1/IGFBP-3 molar ratio. While no significant changes in either IGF-1 or IGFBP-3 were detected in any intervention arm compared to control, the IGF-1/IGFBP-3 ratio increased significantly in the diet (+5.0%, p<0.01) and diet + exercise (+5.4%, p<0.01) groups compared to control. Greater weight loss was positively associated with change in both IGF-1 (ptrend=0.017) and IGF-1/IGFBP-3 ratio (ptrend<0.001) in the diet group, but inversely with change in IGFBP-3 in the diet + exercise group (ptrend=0.01). No consistent interaction effects with baseline BMI were detected. Modified IGF-1 bioavailability is unlikely to be a mechanism through which caloric restriction reduces cancer risk in postmenopausal women.
PMCID: PMC3732802  PMID: 23756654
lifestyle; intervention; obesity; energy balance; insulin
12.  Design of the SHAPE-2 study: the effect of physical activity, in addition to weight loss, on biomarkers of postmenopausal breast cancer risk 
BMC Cancer  2013;13:395.
Physical inactivity and overweight are two known risk factors for postmenopausal breast cancer. Former exercise intervention studies showed that physical activity influences sex hormone levels, known to be related to postmenopausal breast cancer, mainly when concordant loss of body weight was achieved. The question remains whether there is an additional beneficial effect of physical activity when weight loss is reached.
The aim of this study is to investigate the effect attributable to exercise on postmenopausal breast cancer risk biomarkers, when equivalent weight loss is achieved compared with diet-induced weight loss.
The SHAPE-2 study is a three-armed, multicentre trial. 243 sedentary, postmenopausal women who are overweight or obese (BMI 25–35 kg/m2) are enrolled. After a 4-6 week run-in period, wherein a baseline diet is prescribed, women are randomly allocated to (1) a diet group, (2) an exercise group or (3) a control group. The aim of both intervention groups is to lose an amount of 5–6 kg body weight in 10–14 weeks. The diet group follows an energy restricted diet and maintains the habitual physical activity level. The exercise group participates in a 16-week endurance and strength training programme of 4 hours per week. Furthermore, they are prescribed a moderate caloric restriction. The control group is asked to maintain body weight and continue the run-in baseline diet.
Measurements include blood sampling, questionnaires, anthropometrics (weight, height, waist and hip circumference), maximal cycle exercise test (VO2peak), DEXA-scan (body composition) and abdominal MRI (subcutaneous and visceral fat). Primary outcomes are serum levels of oestradiol, oestrone, testosterone and sex hormone binding globulin (SHBG).
This study will give insight in the potential attributable effect of physical activity on breast cancer risk biomarkers and whether this effect is mediated by changes in body composition, in postmenopausal women. Eventually this may lead to the design of specific lifestyle guidelines for prevention of breast cancer.
Trial registration
The SHAPE-2 study is registered in the register of, Identifier: NCT01511276.
PMCID: PMC3765586  PMID: 23972905
13.  Lean Mass Loss Is Associated with Low Protein Intake during Dietary-Induced Weight Loss in Postmenopausal Women 
The health and quality-of-life implications of overweight and obesity span all ages in the United States. We investigated the association between dietary protein intake and loss of lean mass during weight loss in postmenopausal women through a retrospective analysis of a 20-week randomized, controlled diet and exercise intervention in women aged 50 to 70 years. Weight loss was achieved by differing levels of caloric restriction and exercise. The diet-only group reduced caloric intake by 2,800 kcal/week, and the exercise groups reduced caloric intake by 2,400 kcal/week and expended ~400 kcal/week through aerobic exercise. Total and appendicular lean mass was measured using dual energy x-ray absorptiometry. Linear regression analysis was used to examine the association between changes in lean mass and appendicular lean mass and dietary protein intake. Average weight loss was 10.8±4.0 kg, with an average of 32% of total weight lost as lean mass. Protein intake averaged 0.62 g/kg body weight/day (range=0.47 to 0.8 g/kg body weight/day). Participants who consumed higher amounts of dietary protein lost less lean mass and appendicular lean mass r(=0.3, P=0.01 and r=0.41, P<0.001, respectively). These associations remained significant after adjusting for intervention group and body size. Therefore, inadequate protein intake during caloric restriction may be associated with adverse body-composition changes in postmenopausal women.
PMCID: PMC3665330  PMID: 18589032
14.  Effect of diet and exercise, alone or combined, on weight and body composition in overweight-to-obese post-menopausal women 
Obesity (Silver Spring, Md.)  2011;20(8):1628-1638.
Lifestyle interventions for weight loss are the cornerstone of obesity therapy, yet their optimal design is debated. This is particularly true for postmenopausal women; a population with a high prevalence of obesity yet towards whom fewer studies are targeted. We conducted a year-long, 4-arm randomized trial among 439 overweight-to-obese postmenopausal sedentary women to determine the effects of a calorie-reduced, low-fat diet (D), a moderate-intensity, facility-based aerobic exercise program (E), or the combination of both interventions (D+E), vs. a no-lifestyle-change control (C) on change in body weight and composition. The group-based dietary intervention had a weight-reduction goal of ≥10%, and the exercise intervention consisted of a gradual escalation to 45 min aerobic exercise 5 d/wk. Participants were predominantly non-Hispanic Whites (85%) with a mean age of 58.0±5.0 years, a mean BMI of 30.9±4.0 kg/m2 and an average of 47.8±4.4% body fat. Baseline and 12-month weight and adiposity measures were obtained by staff blinded to participants’ intervention assignment. 399 women completed the trial (91% retention). Using an intention-to-treat analysis, average weight loss at 12 months was −8.5% for the D group (P<0.0001 vs. C), −2.4% for the E group (P=0.03 vs. C), and −10.8% for the D+E group (P<0.0001 vs. C), while the C group experienced a non-significant −0.8% decrease. BMI, waist circumference, and % body fat were also similarly reduced. Among postmenopausal women, lifestyle change involving diet, exercise, or both combined over 1 year improves body weight and adiposity, with the greatest change arising from the combined intervention.
PMCID: PMC3406229  PMID: 21494229
Body weight; body composition; weight-reducing diet; exercise intervention; women
15.  Influence of diet, exercise and serum vitamin D on sarcopenia in post-menopausal women 
To investigate the effects of 12 months of dietary weight loss and/or aerobic exercise on lean mass and the measurements defining sarcopenia in postmenopausal women, and to examine the potential moderating effect of serum 25-hydroxyvitamin D (25(OH)D) and age.
439 overweight and obese postmenopausal women were randomized to: diet modification (N=118); exercise (N=117), diet+exercise (N=117), or control (N=87). The diet intervention was a group-based program with a 10% weight loss goal. The exercise intervention was 45 mins/day, 5 days/week of moderate-to-vigorous intensity aerobic activity. Total and appendicular lean mass were quantified by dual Xray absorptiometry (DXA) at baseline and 12 months. A skeletal muscle index (SMI=appendicular lean mass (kg)/m2) and the prevalence of sarcopenia (SMI<5.67 kg/m2) were calculated. Serum 25(OH)D was assayed using a competitive chemiluminescent immunoassay.
Dietary weight loss resulted in a significant decrease in lean mass, and a borderline significant decrease in appendicular lean mass and SMI compared to controls. In contrast, aerobic exercise significantly preserved appendicular lean mass and SMI. Diet + exercise attenuated the loss of appendicular lean mass and SMI compared to diet alone, and did not result in significant loss of total- or appendicular lean mass compared to controls. Neither serum 25(OH)D nor age were significant moderators of the intervention effects.
Aerobic exercise added to dietary weight loss can attenuate the loss of appendicular lean mass during weight loss, and may be effective for the prevention and treatment of sarcopenia among overweight and obese postmenopausal women.
PMCID: PMC3594522  PMID: 23190588
caloric restriction; weight loss; 25-hydroxyvitamin D; ageing
16.  Independent and Combined Effects of Dietary Weight Loss and Exercise on Leukocyte Telomere Length in Postmenopausal Women 
Obesity (Silver Spring, Md.)  2013;21(12):10.1002/oby.20509.
Investigate the effects of 12 months of dietary weight loss and/or aerobic exercise on leukocyte telomere length in postmenopausal women.
Design and Methods
439 overweight or obese women (50–75 y) were randomized to: i) dietary weight loss (N=118); ii) aerobic exercise (N=117), iii) diet + exercise (N=117), or iv) control (N=87). The diet intervention was a group-based program with a 10% weight loss goal. The exercise intervention was 45 mins/day, 5 days/week of moderate-to-vigorous aerobic activity. Fasting blood samples were taken at baseline and 12 months. DNA was extracted from isolated leukocytes and telomere length was measured by quantitative-polymerase chain reaction (qPCR). Mean changes were compared between groups (intent-to-treat) using generalized estimating equations.
Baseline telomere length was inversely associated with age (r=−0.12 p<0.01) and positively associated with maximal oxygen uptake (r=0.11, p=0.03), but not with BMI or %body fat. Change in telomere length was inversely correlated with baseline telomere length (r=−0.47, p<0.0001). No significant difference in leukocyte telomere length was detected in any intervention group compared to controls, nor was the magnitude of weight loss associated with telomere length at 12 months.
Twelve-months of dietary weight loss and exercise did not change telomere length in postmenopausal women.
PMCID: PMC3786031  PMID: 23640743
caloric restriction; physical activity; lifestyle; ageing; chromosomes
17.  Dietary weight loss and exercise interventions effects on quality of life in overweight/obese postmenopausal women: a randomized controlled trial 
Although lifestyle interventions targeting multiple lifestyle behaviors are more effective in preventing unhealthy weight gain and chronic diseases than intervening on a single behavior, few studies have compared individual and combined effects of diet and/or exercise interventions on health-related quality of life (HRQOL). In addition, the mechanisms of how these lifestyle interventions affect HRQOL are unknown. The primary aim of this study was to examine the individual and combined effects of dietary weight loss and/or exercise interventions on HRQOL and psychosocial factors (depression, anxiety, stress, social support). The secondary aim was to investigate predictors of changes in HRQOL.
This study was a randomized controlled trial. Overweight/obese postmenopausal women were randomly assigned to 12 months of dietary weight loss (n = 118), moderate-to-vigorous aerobic exercise (225 minutes/week, n = 117), combined diet and exercise (n = 117), or control (n = 87). Demographic, health and anthropometric information, aerobic fitness, HRQOL (SF-36), stress (Perceived Stress Scale), depression [Brief Symptom Inventory (BSI)-18], anxiety (BSI-18) and social support (Medical Outcome Study Social Support Survey) were assessed at baseline and 12 months. The 12-month changes in HRQOL and psychosocial factors were compared using analysis of covariance, adjusting for baseline scores. Multiple regression was used to assess predictors of changes in HRQOL.
Twelve-month changes in HRQOL and psychosocial factors differed by intervention group. The combined diet + exercise group improved 4 aspects of HRQOL (physical functioning, role-physical, vitality, and mental health), and stress (p ≤ 0.01 vs. controls). The diet group increased vitality score (p < 0.01 vs. control), while HRQOL did not change differently in the exercise group compared with controls. However, regardless of intervention group, weight loss predicted increased physical functioning, role-physical, vitality, and mental health, while increased aerobic fitness predicted improved physical functioning. Positive changes in depression, stress, and social support were independently associated with increased HRQOL, after adjusting for changes in weight and aerobic fitness.
A combined diet and exercise intervention has positive effects on HRQOL and psychological health, which may be greater than that from exercise or diet alone. Improvements in weight, aerobic fitness and psychosocial factors may mediate intervention effects on HRQOL.
PMCID: PMC3215656  PMID: 22026966
health-related quality of life; exercise; dietary weight loss; postmenopausal women
18.  Moderate Exercise Attenuates the Loss of Skeletal Muscle Mass That Occurs With Intentional Caloric Restriction–Induced Weight Loss in Older, Overweight to Obese Adults 
Aging is associated with a loss of muscle mass and increased body fat. The effects of diet-induced weight loss on muscle mass in older adults are not clear.
This study examined the effects of diet-induced weight loss, alone and in combination with moderate aerobic exercise, on skeletal muscle mass in older adults.
Twenty-nine overweight to obese (body mass index = 31.8 ± 3.3 kg/m2) older (67.2 ± 4.2 years) men (n = 13) and women (n = 16) completed a 4-month intervention consisting of diet-induced weight loss alone (WL; n = 11) or with exercise (WL/EX; n = 18). The WL intervention consisted of a low-fat, 500–1,000 kcal/d caloric restriction. The WL/EX intervention included the WL intervention with the addition of aerobic exercise, moderate-intensity walking, three to five times per week for 35–45 minutes per session. Whole-body dual-energy x-ray absorptiometry, thigh computed tomography (CT), and percutaneous muscle biopsy were performed to assess changes in skeletal muscle mass at the whole-body, regional, and cellular level, respectively.
Mixed analysis of variance demonstrated that both groups had similar decreases in bodyweight (WL, −9.2% ± 1.0%; WL/EX, −9.1% ± 1.0%) and whole-body fat mass (WL, −16.5%, WL/EX, −20.7%). However, whole-body fat-free mass decreased significantly (p < .05) in WL (−4.3% ± 1.2%) but not in WL/EX (−1.1% ± 1.0%). Thigh muscle cross-sectional area by CT decreased in both groups (WL, −5.2% ± 1.1%; WL/EX, −3.0% ± 1.0%) and was not statistically different between groups. Type I muscle fiber area decreased in WL (−19.2% ± 7.9%, p = .01) but remained unchanged in WL/EX (3.4% ± 7.5%). Similar patterns were observed in type II fibers (WL, −16.6% ± 4.0%; WL/EX, −0.2% ± 6.5%).
Diet-induced weight loss significantly decreased muscle mass in older adults. However, the addition of moderate aerobic exercise to intentional weight loss attenuated the loss of muscle mass.
PMCID: PMC2800807  PMID: 19276190
Weight loss; Aerobic exercise; Obese; Muscle
19.  History of weight cycling does not impede future weight loss or metabolic improvements in postmenopausal women 
Given that the repetitive loss and regain of body weight, termed weight cycling, is a prevalent phenomenon that has been associated with negative physiological and psychological outcomes, the purpose of this study was to investigate weight change and physiological outcomes in women with a lifetime history of weight cycling enrolled in a 12-month diet and/or exercise intervention.
439 overweight, inactive, postmenopausal women were randomized to: i) dietary weight loss with a 10% weight loss goal (N=118); ii) moderate-to-vigorous intensity aerobic exercise for 45 min/day, 5 days/week (n=117); ii) both dietary weight loss and exercise (n=117); or iv) control (n=87). Women were categorized as non-, moderate-(≥3 losses of ≥4.5 kg), or severe-cyclers (≥3 losses of ≥9.1 kg). Trend tests and linear regression were used to compare adherence and changes in weight, body composition, blood pressure, insulin, C-peptide, glucose, insulin resistance (HOMA-IR), C-reactive protein, leptin, adiponectin, and interleukin-6 between cyclers and non-cyclers.
Moderate (n=103) and severe (n=77) cyclers were heavier and had less favorable metabolic profiles than non-cyclers at baseline. There were, however, no significant differences in adherence to the lifestyle interventions. Weight-cyclers (combined) had a greater improvement in HOMA-IR compared to non-cyclers participating in the exercise only intervention (p=0.03), but no differences were apparent in the other groups.
A history of weight cycling does not impede successful participation in lifestyle interventions or alter the benefits of diet and/or exercise on body composition and metabolic outcomes.
PMCID: PMC3514598  PMID: 22898251
lifestyle intervention; insulin resistance; inflammation; adipokines
20.  Changes in weight loss, body composition and cardiovascular disease risk after altering macronutrient distributions during a regular exercise program in obese women 
Nutrition Journal  2010;9:59.
This study's purpose investigated the impact of different macronutrient distributions and varying caloric intakes along with regular exercise for metabolic and physiological changes related to weight loss.
One hundred forty-one sedentary, obese women (38.7 ± 8.0 yrs, 163.3 ± 6.9 cm, 93.2 ± 16.5 kg, 35.0 ± 6.2 kg•m-2, 44.8 ± 4.2% fat) were randomized to either no diet + no exercise control group (CON) a no diet + exercise control (ND), or one of four diet + exercise groups (high-energy diet [HED], very low carbohydrate, high protein diet [VLCHP], low carbohydrate, moderate protein diet [LCMP] and high carbohydrate, low protein [HCLP]) in addition to beginning a 3x•week-1 supervised resistance training program. After 0, 1, 10 and 14 weeks, all participants completed testing sessions which included anthropometric, body composition, energy expenditure, fasting blood samples, aerobic and muscular fitness assessments. Data were analyzed using repeated measures ANOVA with an alpha of 0.05 with LSD post-hoc analysis when appropriate.
All dieting groups exhibited adequate compliance to their prescribed diet regimen as energy and macronutrient amounts and distributions were close to prescribed amounts. Those groups that followed a diet and exercise program reported significantly greater anthropometric (waist circumference and body mass) and body composition via DXA (fat mass and % fat) changes. Caloric restriction initially reduced energy expenditure, but successfully returned to baseline values after 10 weeks of dieting and exercising. Significant fitness improvements (aerobic capacity and maximal strength) occurred in all exercising groups. No significant changes occurred in lipid panel constituents, but serum insulin and HOMA-IR values decreased in the VLCHP group. Significant reductions in serum leptin occurred in all caloric restriction + exercise groups after 14 weeks, which were unchanged in other non-diet/non-exercise groups.
Overall and over the entire test period, all diet groups which restricted their caloric intake and exercised experienced similar responses to each other. Regular exercise and modest caloric restriction successfully promoted anthropometric and body composition improvements along with various markers of muscular fitness. Significant increases in relative energy expenditure and reductions in circulating leptin were found in response to all exercise and diet groups. Macronutrient distribution may impact circulating levels of insulin and overall ability to improve strength levels in obese women who follow regular exercise.
PMCID: PMC3000832  PMID: 21092228
21.  The effect of 12 weeks of aerobic, resistance or combination exercise training on cardiovascular risk factors in the overweight and obese in a randomized trial 
BMC Public Health  2012;12:704.
Evidence suggests that exercise training improves CVD risk factors. However, it is unclear whether health benefits are limited to aerobic training or if other exercise modalities such as resistance training or a combination are as effective or more effective in the overweight and obese. The aim of this study is to investigate whether 12 weeks of moderate-intensity aerobic, resistance, or combined exercise training would induce and sustain improvements in cardiovascular risk profile, weight and fat loss in overweight and obese adults compared to no exercise.
Twelve-week randomized parallel design examining the effects of different exercise regimes on fasting measures of lipids, glucose and insulin and changes in body weight, fat mass and dietary intake. Participants were randomized to either: Group 1 (Control, n = 16); Group 2 (Aerobic, n = 15); Group 3 (Resistance, n = 16); Group 4 (Combination, n = 17). Data was analysed using General Linear Model to assess the effects of the groups after adjusting for baseline values. Within-group data was analyzed with the paired t-test and between-group effects using post hoc comparisons.
Significant improvements in body weight (−1.6%, p = 0.044) for the Combination group compared to Control and Resistance groups and total body fat compared to Control (−4.4%, p = 0.003) and Resistance (−3%, p = 0.041). Significant improvements in body fat percentage (−2.6%, p = 0.008), abdominal fat percentage (−2.8%, p = 0.034) and cardio-respiratory fitness (13.3%, p = 0.006) were seen in the Combination group compared to Control. Levels of ApoB48 were 32% lower in the Resistance group compared to Control (p = 0.04).
A 12-week training program comprising of resistance or combination exercise, at moderate-intensity for 30 min, five days/week resulted in improvements in the cardiovascular risk profile in overweight and obese participants compared to no exercise. From our observations, combination exercise gave greater benefits for weight loss, fat loss and cardio-respiratory fitness than aerobic and resistance training modalities. Therefore, combination exercise training should be recommended for overweight and obese adults in National Physical Activity Guidelines.
This clinical trial was registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), registration number: ACTRN12609000684224.
PMCID: PMC3487794  PMID: 23006411
Obesity; Overweight; Cardiovascular risk factors; Exercise training
22.  Dose–response effects of exercise training on the subjective sleep quality of postmenopausal women: exploratory analyses of a randomised controlled trial 
BMJ Open  2012;2(4):e001044.
To investigate whether a dose–response relationship existed between exercise and subjective sleep quality in postmenopausal women. This objective represents a post hoc assessment that was not previously considered.
Parallel-group randomised controlled trial.
Clinical exercise physiology laboratory in Dallas, Texas.
437 sedentary overweight/obese postmenopausal women.
Participants were randomised to one of four treatments, each of 6 months of duration: a non-exercise control treatment (n=92) or one of three dosages of moderate-intensity exercise (50% of VO2peak), designed to meet 50% (n=151), 100% (n=99) or 150% (n=95) of the National Institutes of Health Consensus Development Panel physical activity recommendations. Exercise dosages were structured to elicit energy expenditures of 4, 8 or 12 kilocalories per kilogram of body weight per week (KKW), respectively. Analyses were intent to treat.
Primary outcome measures
Continuous scores and odds of having significant sleep disturbance, as assessed by the Sleep Problems Index from the 6-item Medical Outcomes Study Sleep Scale. Outcome assessors were blinded to participant randomisation assignment.
Change in the Medical Outcomes Study Sleep Problems Index score at 6 months significantly differed by treatment group (control: −2.09 (95% CI −4.58 to 0.40), 4 KKW: −3.93 (−5.87 to −1.99), 8 KKW: −4.06 (−6.45 to −1.67), 12 KKW: −6.22 (−8.68 to −3.77); p=0.04), with a significant dose–response trend observed (p=0.02). Exercise training participants had lower odds of having significant sleep disturbance at postintervention compared with control (4 KKW: OR 0.37 (95% CI 0.19 to 0.73), 8 KKW: 0.36 (0.17 to 0.77), 12 KKW: 0.34 (0.16 to 0.72)). The magnitude of weight loss did not differ between treatment conditions. Improvements in sleep quality were not related to changes in body weight, resting parasympathetic control or cardiorespiratory fitness.
Exercise training induced significant improvement in subjective sleep quality in postmenopausal women, with even a low dose of exercise resulting in greatly reduced odds of having significant sleep disturbance.
Trial registration number identifier: NCT00011193.
Article summary
Article focus
Sleep disturbance is prevalent in postmenopausal women, with 35%–60% reporting significant sleep problems.
Effective, safe and easily available treatment options for disturbed sleep in postmenopausal women are lacking.
There has been equivocal evidence as to whether exercise improves sleep in postmenopausal women, though possible dose–response effects have been noted.
Key messages
Exercise resulted in significant improvement in subjective sleep quality in postmenopausal women, with reduced odds of having sleep disturbance at postintervention with even 50% of the recommended dose of exercise for adults.
The effects of exercise on sleep quality were independent of changes in body weight, resting parasympathetic control or cardiorespiratory fitness.
Strengths and limitations of this study
The study constitutes the largest randomised controlled trial on exercise and sleep quality, using a structured dose of exercise and a validated measure of sleep quality.
Only self-reported sleep was assessed; objective measurement of sleep, with either actigraphy or polysomnography, was not conducted.
Despite the high prevalence of sleep disturbance in the sample, participants were not selected on the basis of sleep complaints.
PMCID: PMC3400065  PMID: 22798253
23.  Adiposity changes after a 1-year aerobic exercise intervention among postmenopausal women: a randomized controlled trial 
We examined the effects of an aerobic exercise intervention on adiposity outcomes that may be involved in the association between physical activity and breast cancer risk.
This study was a two-centre, two-armed, randomized controlled trial. The 1-year-long exercise intervention included 45 min of moderate-to-vigorous aerobic exercise five times per week, with at least three of the sessions being facility based. The control group was asked not to change their activity and both groups were asked not to change their diet.
A total of 320 postmenopausal, sedentary, normal weight-to-obese women aged 50–74 years who were cancer-free, nondiabetic and nonhormone replacement therapy users were included in this study.
Anthropometric measurements of height, weight and waist and hip circumferences; dual energy X-ray absorptiometry measurements of total body fat; and computerized tomography measurements of abdominal adiposity were carried out.
Women in the exercise group exercised a mean of 3.6 days (s.d.=1.3) per week and 178.5 min (s.d.=76.1) per week. Changes in all measures of adiposity favored exercisers relative to controls (P<0.001). The mean difference between groups was: −1.8 kg for body weight; −2.0 kg for total body fat; −14.9 cm2 for intra-abdominal fat area; and −24.1 cm2 for subcutaneous abdominal fat area. A linear trend of greater body fat loss with increasing volume of exercise was also observed.
A 1-year aerobic exercise program consistent with current public health guidelines resulted in reduced adiposity levels in previously sedentary postmenopausal women at higher risk of breast cancer.
PMCID: PMC3061001  PMID: 20820172
clinical trial; exercise; body weight; breast neoplasms; biological mechanisms
24.  Weight and metabolic effects of dietary weight loss and exercise interventions in postmenopausal antidepressant medication users and non-users: a randomized controlled trial 
Preventive medicine  2013;57(5):525-532.
Antidepressants may attenuate the effects of diet and exercise programs. We compared adherence and changes in body measures and biomarkers of glucose metabolism and inflammation between antidepressant users and non-users in a 12-month randomized controlled trial.
Overweight or obese, postmenopausal women were assigned to: diet (10% weight loss goal, N=118); moderate-to-vigorous aerobic exercise (225 minutes/week, N=117); diet+exercise (N=117); and control (N=87) in Seattle, WA 2005–2009. Women using antidepressants at baseline were classified as users (N=109). ANCOVA and generalized estimating equation approaches, respectively, were used to compare adherence (exercise amount, diet session attendance, and changes in percent calorie intake from fat, cardiopulmonary fitness, and pedometer steps) and changes in body measures (weight, waist and percent body fat) and serum biomarkers (glucose, insulin, homeostasis assessment-insulin resistance, and high-sensitivity C-reactive protein) between users and non-users. An interaction term (intervention × antidepressant use) tested effect modification.
There were no differences in adherence except diet session attendance was lower among users in the diet+exercise group (P<0.05 vs. non-users). Changes in body measures and serum biomarkers did not differ by antidepressant use (Pinteraction>0.05).
Dietary weight loss and exercise improved body measures and biomarkers of glucose metabolism and inflammation independent of antidepressant use.
PMCID: PMC3800227  PMID: 23859929
Obesity; weight loss intervention; antidepressants; diet; exercise
25.  Bariatric Surgery 
Executive Summary
To conduct an evidence-based analysis of the effectiveness and cost-effectiveness of bariatric surgery.
Obesity is defined as a body mass index (BMI) of at last 30 kg/m2.1 Morbid obesity is defined as a BMI of at least 40 kg/m2 or at least 35 kg/m2 with comorbid conditions. Comorbid conditions associated with obesity include diabetes, hypertension, dyslipidemias, obstructive sleep apnea, weight-related arthropathies, and stress urinary incontinence. It is also associated with depression, and cancers of the breast, uterus, prostate, and colon, and is an independent risk factor for cardiovascular disease.
Obesity is also associated with higher all-cause mortality at any age, even after adjusting for potential confounding factors like smoking. A person with a BMI of 30 kg/m2 has about a 50% higher risk of dying than does someone with a healthy BMI. The risk more than doubles at a BMI of 35 kg/m2. An expert estimated that about 160,000 people are morbidly obese in Ontario. In the United States, the prevalence of morbid obesity is 4.7% (1999–2000).
In Ontario, the 2004 Chief Medical Officer of Health Report said that in 2003, almost one-half of Ontario adults were overweight (BMI 25–29.9 kg/m2) or obese (BMI ≥ 30 kg/m2). About 57% of Ontario men and 42% of Ontario women were overweight or obese. The proportion of the population that was overweight or obese increased gradually from 44% in 1990 to 49% in 2000, and it appears to have stabilized at 49% in 2003. The report also noted that the tendency to be overweight and obese increases with age up to 64 years. BMI should be used cautiously for people aged 65 years and older, because the “normal” range may begin at slightly above 18.5 kg/m2 and extend into the “overweight” range.
The Chief Medical Officer of Health cautioned that these data may underestimate the true extent of the problem, because they were based on self reports, and people tend to over-report their height and under-report their weight. The actual number of Ontario adults who are overweight or obese may be higher.
Diet, exercise, and behavioural therapy are used to help people lose weight. The goals of behavioural therapy are to identify, monitor, and alter behaviour that does not help weight loss. Techniques include self-monitoring of eating habits and physical activity, stress management, stimulus control, problem solving, cognitive restructuring, contingency management, and identifying and using social support. Relapse, when people resume old, unhealthy behaviour and then regain the weight, can be problematic.
Drugs (including gastrointestinal lipase inhibitors, serotonin norepinephrine reuptake inhibitors, and appetite suppressants) may be used if behavioural interventions fail. However, estimates of efficacy may be confounded by high rates of noncompliance, in part owing to the side effects of the drugs. In addition, the drugs have not been approved for indefinite use, despite the chronic nature of obesity.
The Technology
Morbidly obese people may be eligible for bariatric surgery. Bariatric surgery for morbid obesity is considered an intervention of last resort for patients who have attempted first-line forms of medical management, such as diet, increased physical activity, behavioural modification, and drugs.
There are various bariatric surgical procedures and several different variations for each of these procedures. The surgical interventions can be divided into 2 general types: malabsorptive (bypassing parts of the gastrointestinal tract to limit the absorption of food), and restrictive (decreasing the size of the stomach so that the patient is satiated with less food). All of these may be performed as either open surgery or laparoscopically. An example of a malabsorptive technique is Roux-en-Y gastric bypass (RYGB). Examples of restrictive techniques are vertical banded gastroplasty (VBG) and adjustable gastric banding (AGB).
The Ontario Health Insurance Plan (OHIP) Schedule of Benefits for Physician Services includes fee code “S120 gastric bypass or partition, for morbid obesity” as an insured service. The term gastric bypass is a general term that encompasses a variety of surgical methods, all of which involve reconfiguring the digestive system. The term gastric bypass does not include AGB. The number of gastric bypass procedures funded and done in Ontario, and funded as actual out-of-country approvals,2 is shown below.
Number of Gastric Bypass Procedures by Fiscal Year: Ontario and Actual Out-of-Country (OOC) Approvals
Data from Provider Services, MOHLTC
Courtesy of Provider Services, Ministry of Health and Long Term Care
Review Strategy
The Medical Advisory Secretariat reviewed the literature to assess the effectiveness, safety, and cost-effectiveness of bariatric surgery to treat morbid obesity. It used its standard search strategy to retrieve international health technology assessments and English-language journal articles from selected databases. The interventions of interest were bariatric surgery and, for the controls, either optimal conventional management or another type of bariatric procedure. The outcomes of interest were improvement in comorbid conditions (e.g., diabetes, hypertension); short- and long-term weight loss; quality of life; adverse effects; and economic analysis data. The databases yielded 15 international health technology assessments or systematic reviews on bariatric surgery.
Subsequently, the Medical Advisory Secretariat searched MEDLINE and EMBASE from April 2004 to December 2004, after the search cut-off date of April, 2004, for the most recent systematic reviews on bariatric surgery. Ten studies met the inclusion criteria. One of those 10 was the Swedish Obese Subjects study, which started as a registry and intervention study, and then published findings on people who had been enrolled for at least 2 years or at least 10 years. In addition to the literature review of economic analysis data, the Medical Advisory Secretariat also did an Ontario-based economic analysis.
Summary of Findings
Bariatric surgery generally is effective for sustained weight loss of about 16% for people with BMIs of at least 40 kg/m2 or at least 35 kg/m2 with comorbid conditions (including diabetes, high lipid levels, and hypertension). It also is effective at resolving the associated comorbid conditions. This conclusion is largely based on level 3a evidence from the prospectively designed Swedish Obese Subjects study, which recently published 10-year outcomes for patients who had bariatric surgery compared with patients who received nonsurgical treatment. (1)
Regarding specific procedures, there is evidence that malabsorptive techniques are better than other banding techniques for weight loss and resolution of comorbid illnesses. However, there are no published prospective, long-term, direct comparisons of these techniques available.
Surgery for morbid obesity is considered an intervention of last resort for patients who have attempted first-line forms of medical management, such as diet, increased physical activity, behavioural modification, and drugs. In the absence of direct comparisons of active nonsurgical intervention via caloric restriction with bariatric techniques, the following observations are made:
A recent systematic review examining the efficacy of major commercial and organized self-help weight loss programs in the United States concluded that the evidence to support the use of such programs was suboptimal, except for one trial on Weight Watchers. Furthermore, the programs were associated with high costs, attrition rates, and probability of regaining at least 50% of the lost weight in 1 to 2 years. (2)
A recent randomized controlled trial reported 1-year outcomes comparing weight loss and metabolic changes in severely obese patients assigned to either a low-carbohydrate diet or a conventional weight loss diet. At 1 year, weight loss was similar for patients in each group (mean, 2–5 kg). There was a favourable effect on triglyceride levels and glycemic control in the low-carbohydrate diet group. (3)
A decision-analysis model showed bariatric surgery results in increased life expectancy in morbidly obese patients when compared to diet and exercise. (4)
A cost-effectiveness model showed bariatric surgery is cost-effective relative to nonsurgical management. (5)
Extrapolating from 2003 data from the United States, Ontario would likely need to do 3,500 bariatric surgeries per year. It currently does 508 per year, including out-of-country surgeries.
PMCID: PMC3382415  PMID: 23074460

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