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.
obesity; postmenopausal women; receptors
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.
receptor; cardiovascular; gene expression
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.
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.
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.
The human cutaneous circulation is an accessible and representative regional circulation for investigating mechanisms of microvascular dysfunction, a systemic disease process occurring early in the pathogenesis of atherosclerosis. Elevated concentrations of low-density lipoproteins ([LDL]) are highly atherogenic and independently associated with the severity of coronary atherosclerosis through their actions on the lectin-like oxidized LDL receptors (LOX-1). We hypothesized that cutaneous microvascular dysfunction, as measured by a decrement in endothelial nitric oxide- (NO-) dependent vasodilation during local heating, would be correlated with serum [LDL], oxidized [LDL], and soluble LOX-1 receptors [sLOX-1]. Intradermal microdialysis fibers were placed in the skin of 53 otherwise healthy men and women (aged 52±8 years) whose serum [LDL] ranged from 72 to 233 mg/dL. Skin blood flow was measured by laser Doppler flowmetry over a local forearm skin site as it was heated (42 °C) to induce sustained local vasodilation. After flux plateaued, L-NAME was infused to block endothelial NO synthase in order to determine the NO-dependent portion of the vasodilatory response. Data were normalized to maximal cutaneous vascular conductance (CVC). NO-dependent vasodilation was reduced as a linear function of [LDL] (R2=0.303, p<0.001), oxidized [LDL] (R2=0.214, p<0.001), and [sLOX-1] (R2=0.259, p=0.026) but was unrelated to high-density lipoprotein (HDL) concentration (R2=0.003, p=0.68). Hypercholesterolemia-induced microvascular dysfunction is related to various LDL markers and involves a reduction in NO-dependent vasodilation that appears to be a progressive process measurable in the skin microcirculation.
This study determined whether performing a single moderate- or vigorous-intensity exercise bout impacts daily physical activity energy expenditure (PAEE, by accelerometer). Overweight/obese postmenopausal women underwent a 5-month caloric restriction and moderate- (n = 18) or vigorous-intensity (n = 18) center-based aerobic exercise intervention. During the last month of intervention, in women performing moderate-intensity exercise, PAEE on days with exercise (577.7 ± 219.7 kcal·d−1) was higher (P = .011) than on days without exercise (450.7 ± 140.5 kcal·d−1); however, the difference (127.0 ± 188.1 kcal·d−1) was much lower than the energy expended during exercise. In women performing vigorous-intensity exercise, PAEE on days with exercise (450.6 ± 153.6 kcal·d−1) was lower (P = .047) than on days without exercise (519.2 ± 127.4 kcal·d−1). Thus, women expended more energy on physical activities outside of prescribed exercise on days they did NOT perform center-based exercise, especially if the prescribed exercise was of a higher intensity.
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.
inflammation; postmenopausal women; obesity; exercise; dietary weight loss
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.
Cannabinoid Type 1 Receptor; Fatty Acid Amide Hydrolase; Fat Depots; Diet; Exercise
Advancing age and adiposity contribute to musculoskeletal degenerative diseases and the development of sarcopenic obesity. The etiology of muscle loss is multifactorial, and includes inflammation, oxidative stress and hormonal changes, and is worsened by activity avoidance due to fear of pain. The risk for mobility disability and functional impairment rises with severity of obesity in the older adult. Performance measures of walking distance, walking speed, chair rise, stair climb, body transfers and ability to navigate obstacles on a course are adversely affected in this population, and this reflects decline in daily physical functioning. Exercise training is an ideal intervention to counteract the effects of aging and obesity. The 18 randomized controlled trials of exercise studies with or without diet components reviewed here indicate that 3–18 month programs that included aerobic and strengthening exercise (2–3 days per week) with caloric restriction (typically 750 kcal deficit/day), induced the greatest change in functional performance measures compared with exercise or diet alone. Importantly, resistance exercise attenuates muscle mass loss with the interventions. These interventions can also combat factors that invoke sarcopenia, including inflammation, oxidative stress and insulin resistance. Therefore, regular multimodal exercise coupled with diet appears to be very effective for counteracting sarocpenic obesity and improving mobility and function in the older, obese adult.
Obesity; Aging; Physical function; Mobility; Strength
It has been suggested that exercise training results in compensatory mechanisms that attenuate weight loss. However, this has only been examined with large doses of exercise. The goal of this analysis was to examine actual weight loss compared to predicted weight loss (compensation) across different doses of exercise in a controlled trial of sedentary, overweight or obese postmenopausal women (n = 411).
Participants were randomized to a non-exercise control (n = 94) or 1 of 3 exercise groups; exercise energy expenditure of 4 (n = 139), 8 (n = 85), or 12 (n = 93) kcal/kg/week (KKW). Training intensity was set at the heart rate associated with 50% of each woman's peak VO2 and the intervention period was 6 months. All exercise was supervised. The main outcomes were actual weight loss, predicted weight loss (exercise energy expenditure/ 7700 kcal per kg), compensation (actual minus predicted weight loss) and waist circumference. The study sample had a mean (SD) age 57.2 (6.3) years, BMI of 31.7 (3.8) kg/m2, and was 63.5% Caucasian. The adherence to the intervention was >99% in all exercise groups. The mean (95% CI) weight loss in the 4, 8 and 12 KKW groups was −1.4 (−2.0, −0.8), −2.1 (−2.9, −1.4) and −1.5 (−2.2, −0.8) kg, respectively. In the 4 and 8 KKW groups the actual weight loss closely matched the predicted weight loss of −1.0 and −2.0 kg, respectively, resulting in no significant compensation. In the 12 KKW group the actual weight loss was less than the predicted weight loss (−2.7 kg) resulting in 1.2 (0.5, 1.9) kg of compensation (P<0.05 compared to 4 and 8 KKW groups). All exercise groups had a significant reduction in waist circumference which was independent of changes in weight.
In this study of previously sedentary, overweight or obese, postmenopausal women we observed no difference in the actual and predicted weight loss with 4 and 8 KKW of exercise (72 and 136 minutes respectively), while the 12 KKW (194 minutes) produced only about half of the predicted weight loss. However, all exercise groups had a significant reduction in waist circumference which was independent of changes in weight.
ClinicalTrials.gov NCT 00011193
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.
Weight loss; Aerobic exercise; Obese; Muscle
The study investigated the effectiveness of home-based exercise combined with a slight caloric restriction on weight change during 12 months in non obese women.
A randomized clinical trial with a factorial design was conducted from 2003 to 2005. Two hundred three middle-aged women (Rio de Janeiro/Brazil), 25–45 years, were randomly assigned to one of two groups: control (CG) and home-based exercise (HB). The HB group received a booklet on aerobic exercise that could be practiced at home (3 times/week - 40 min/session), in low-moderate intensity, during 12 months. Both groups received dietary counseling aimed at a slight energy restriction of 100–300 calories per day.
The HB experienced a greater weight loss in the first 6 months (−1.4 vs. −0.8 kg; p=0.04), but after 12 months there was no differences between groups (−1.1 vs. −1.0; p=0.20). Of the serum biochemical markers, HDL-cholesterol showed major change, with an increase at month 12 of 18.3 mg/dl in the HB compared to 9.5 in the CG (p<0.01).
Home-based exercise promoted greater weight reduction during the first six months after which no further benefits are observed. Continuous favorable changes in HDL-cholesterol after 1 year suggest that home-based exercise promote health benefits.
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.
health-related quality of life; exercise; dietary weight loss; postmenopausal women
Estrogens and androgens are elevated in obesity and associated with increased postmenopausal breast cancer risk, but the effect of weight loss on these biomarkers is unknown. We evaluated the individual and combined effects of a reduced-calorie weight loss diet and exercise on serum sex hormones in overweight and obese postmenopausal women.
Patients and Methods
We conducted a single-blind, 12-month, randomized controlled trial from 2005 to 2009. Participants (age 50 to 75 years; body mass index > 25.0 kg/m2, exercising < 100 minutes/wk) were randomly assigned using a computer-generated sequence to (1) reduced-calorie weight loss diet (“diet”; n = 118), (2) moderate- to vigorous-intensity aerobic exercise (“exercise”; n = 117), (3) combined reduced-calorie weight loss diet and moderate- to vigorous-intensity aerobic exercise (“diet + exercise”; n = 117), or (4) control (n = 87). Outcomes were estrone concentration (primary) and estradiol, free estradiol, total testosterone, free testosterone, androstenedione, and sex hormone–binding globulin (SHBG) concentrations (secondary).
Mean age and body mass index were 58 years and 30.9 kg/m2, respectively. Compared with controls, estrone decreased 9.6% (P = .001) with diet, 5.5% (P = .01) with exercise, and 11.1% (P < .001) with diet + exercise. Estradiol decreased 16.2% (P < .001) with diet, 4.9% (P = .10) with exercise, and 20.3% (P < .001) with diet + exercise. SHBG increased 22.4% (P < .001) with diet and 25.8% (P < .001) with diet + exercise. Free estradiol decreased 21.4% (P < .001) with diet and 26.0% (P < .001) with diet + exercise. Free testosterone decreased 10.0% (P < .001) with diet and 15.6% (P < .001) with diet + exercise. Greater weight loss produced stronger effects on estrogens and SHBG.
Weight loss significantly lowered serum estrogens and free testosterone, supporting weight loss for risk reduction through lowering exposure to breast cancer biomarkers.
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.
Body weight; body composition; weight-reducing diet; exercise intervention; women
Patients diagnosed with obesity are usually offered group-based behavior interventions which include dietary advice and exercise programs. In particular, high-intensity training—combining weight lifting with aerobic exercising—has been proven effective for losing weight. Moreover, recent studies have shown that persons participating in high-intensity training are more likely to maintain their weight loss compared to persons with lower levels of physical activity. However, most of the research in the field has made use of quantitative methods focusing on the measurable effect of such interventions. Therefore, the aim of this study was to show how the training is experienced from a first-person perspective, namely the patients themselves. Our hope was to shed some new light on the process of weight loss that concerns more than the measurable “impacts” of the training. A qualitative approach was used based on interviews with five women selected from a primary healthcare clinic in Norway. Our results show that experiences of training are connected to the participants' general experience of being overweight. Both relationships to other people and earlier experiences are important for how the training is carried out and perceived. Five themes were identified supporting this line of argument: (1) the gaze of others; (2) a common ground; (3) dependence of close-follow up; (4) bodily discomfort as painful; and (5) aiming for results—an ambivalent experience. The results highlight the importance of finding the proper context and support for each patient's needs.
Obesity; weight reduction; exercise; qualitative study; group treatment
Elevated C-reactive protein (CRP) is associated with an increased risk of cardiovascular disease. Physical activity has been inversely associated with CRP. However, the clinical trials examining the effect of exercise training have produced conflicting results.
The purpose of this study was to examine the influence an exercise training program on CRP in postmenopausal women.
Sedentary, overweight/obese, postmenopausal women with elevated systolic blood pressure (120.0 to 159.9 mm Hg) (N= 464) were randomized into 1 of 4 groups: a non-exercise control or 1 of 3 aerobic exercise groups; exercise energy expenditure of 4, 8, or 12 kcal/kg/week (KKW), for 6 months at a training intensity of 50% of peak VO2.
Complete data was available of 421 participants and mean baseline CRP was 5.7 (5.5) mg/L with no significant differences across groups. While VO2 increased in a dose response manner, there were no significant changes in CRP in any of the exercise intervention groups compared to the control group. Change in fitness was not associated with change in CRP, whereas change in weight was significantly associated with change in CRP.
Despite increasing fitness, six months of aerobic exercise training did not improve CRP. However, improvements in CRP were associated with reductions in weight.
exercise; inflammation; female; weight
Abnormally elevated exercise blood pressure is associated with increased risk of cardiovascular disease. Aerobic exercise training has been shown to reduce exercise blood pressure. However, it is unknown if these improvements occur in a dose dependent manner. The purpose of the present study is to determine the effect of different doses of aerobic exercise training on exercise blood pressure in obese postmenopausal women.
Participants (n=404) were randomized to one of 4 groups: 4, 8, or 12 kilocalories per kilogram of energy expenditure per week (kcal/kg/week) or the non-exercise control group for 6 months. Exercise blood pressure was obtained during the 50 watts stage of a cycle ergometer maximal exercise test.
There was a significant reduction in systolic blood pressure at 50 watts in the 4 kcal/kg/week (−10.9 mmHg, p< 0.001), 8 kcal/kg/week (−9.9 mmHg, p= 0.022), and 12 kcal/kg/week (−13.7 mmHg, p<0.001) compared to control (−4.2 mmHg). Only the highest exercise training dose significantly reduced diastolic blood pressure (−4.3 mmHg, p= 0.033) compared to control. Additionally, resting blood pressure was not altered following exercise training (p>0.05) compared to control, and was not associated with changes in exercise systolic (r=0.09, p=0.09) or diastolic (r=0.10, p=0.08) blood pressure.
Aerobic exercise training reduces exercise blood pressure and may be more modifiable than changes in resting blood pressure. A high dose of aerobic exercise is recommended to successfully reduce both exercise systolic and diastolic blood pressure, and therefore may attenuate the CVD risk associated with abnormally elevated exercise blood pressure.
Postmenopausal; Exercise Training; Exercise Blood Pressure; Dose Response; Hypertension
The metabolic syndrome is a complex clustering of metabolic defects associated with physical inactivity, abdominal adiposity, and aging.
To examine the effects of exercise training intensity on abdominal visceral fat (AVF) and body composition in obese women with the metabolic syndrome.
Twenty-seven middle-aged, obese women (mean ± SD; age: 51 ± 9 years and body mass index: 34 ± 6 kg/m2) with the metabolic syndrome completed one-of-three 16-week aerobic exercise interventions: (i) No Exercise Training (Control): Seven participants maintained their existing levels of physical activity, (ii) Low-Intensity Exercise Training (LIET): eleven participants exercised 5 days · week-1 at an intensity ≤ lactate threshold (LT) (iii) High-Intensity Exercise Training (HIET): nine participants exercised 3 days · week-1 at an intensity > LT and 2 days ·week-1 ≤ LT. Exercise time was adjusted to maintain caloric expenditure (400 kcal·session-1). Single-slice computed tomography scans obtained at the L4-L5 disc-space and mid-thigh were used to determine abdominal fat and thigh muscle cross-sectional areas. Percent body fat was assessed by air displacement plethysmography.
HIET significantly reduced total abdominal fat (p<0.001), abdominal subcutaneous fat (p=0.034) and AVF (p=0.010). There were no significant changes observed in any of these parameters within the Control or LIET conditions.
The present data indicate that body composition changes are affected by intensity of exercise training with HIET more effective for reducing total abdominal fat, subcutaneous abdominal fat and AVF in obese women with the metabolic syndrome.
Physical Activity; Weight Loss; Metabolic Syndrome; Diabetes; Cardiovascular; Human
Obesity is associated with an atherogenic lipid profile characterized by a predominance of small LDL and HDL particles. Weight loss, by dietary restriction or exercise, increases LDL particle size. Whether these interventions can augment HDL size in conjunction with LDL size remains unknown.
This study compared the effects of alternate day fasting (ADF), calorie restriction (CR), and endurance exercise on LDL and HDL particle size in overweight and obese subjects.
In a 12-week parallel-arm trial, adult subjects (n = 60) were randomized to 1 of 4 groups: 1) ADF (75% energy restriction for 24-h alternated with ad libitum feeding for 24-h), 2) CR (25% energy restriction every day), 3) exercise (moderate intensity training 3 x/week), or 4) control.
Body weight was reduced (P < 0.001) by ADF, CR, and exercise (5.2 ± 1.1%, 5.0 ± 1.4%, 5.1 ± 0.9%, respectively). Plasma LDL cholesterol decreased (P < 0.05) with ADF (10 ± 4%) and CR (8 ± 4%), whereas HDL cholesterol increased (P < 0.05) with exercise (16 ± 5%). Integrated LDL particle size was augmented (P = 0.01) by ADF and CR. The proportion of small LDL particles decreased (P = 0.04) with ADF only, and the proportion of large HDL particles increased (P = 0.03) with exercise only.
These results indicate that dietary restriction increases LDL particle size, while endurance training augments HDL particle size, with minimal weight loss. None of these interventions concomitantly increased both LDL and HDL particle size, however.
Calorie restriction; alternate day fasting; endurance exercise; weight loss; LDL particle size; HDL particle size; cholesterol; obese adults
Context: The effect of weight loss by diet alone or diet in conjunction with exercise on low-grade inflammation in non-obese (overweight) individuals is not known. Objective: Test the hypothesis that 24 weeks of moderate calorie restriction (CR; 25%) by diet only or with aerobic exercise would reduce markers of systemic inflammation and attenuate inflammation gene expression in subcutaneous adipose tissue. Design: Randomized controlled trial. Setting: Institutional Research Center. Participants: Thirty-five overweight (body mass index: 27.8 ± 0.7 kg/m2) but otherwise healthy participants (16M/19F) completed the study. Intervention: Participants were randomized to either CR (25% reduction in energy intake, n = 12), caloric restriction + exercise (CR + EX: 12.5% reduction in energy intake + 12.5% increase in exercise energy expenditure, n = 12), or control (healthy weight-maintenance diet, n = 11) for 6 months. Main outcome measures: Fasting serum markers of inflammation [leptin, highly sensitive C-reactive protein (hsCRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), adiponectin] and inflammation-related genes [CD68, IL-6, TNF-α, macrophage migration inhibitory factor (MIF), monocyte chemoattractant protein-1 (MCP-1), adiponectin, plasminogen activator inhibitor-1 (PAI-1)] in subcutaneous adipose tissue. Results: CR and CR + EX lost similar amounts of body weight (–10 ± 1%), fat mass (–24 ± 3%), visceral fat (–27 ± 3%), and had increased insulin sensitivity (CR: 40 ± 20%, CR + EX: 66 ± 22%). Leptin was significantly decreased from baseline (p < 0.001) in both groups however TNF-α and IL-6 were not changed. hsCRP was decreased in CR + EX. There was no change in the expression of genes involved in macrophage infiltration (CD68, MIF MCP-1, PAI-1) or inflammation (IL-6, TNF-α, adiponectin) in either CR or CR + EX. Conclusion: A 10% weight loss with a 25% CR diet alone or with exercise did not impact markers of systemic inflammation or the expression of inflammation-related adipose genes in overweight individuals.
caloric restriction; inflammation; subcutaneous fat; exercise; aging; immune function
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.
Exercise is recommended by public health agencies for weight management; however, the role of exercise is generally considered secondary to energy restriction. Few studies exist that have verified completion of exercise, measured the energy expenditure of exercise, and prescribed exercise with equivalent energy expenditure across individuals and genders.
The objective of this study was to evaluate aerobic exercise, without energy restriction, on weight loss in sedentary overweight and obese men and women.
Design and Methods
This investigation was a randomized, controlled, efficacy trial in 141 overweight and obese participants (body mass index, 31.0 ± 4.6 kg/m2; age 22.6 ± 3.9 years). Participants were randomized (2:2:1 ratio) to exercise at either 400 kcal/session or 600 kcal/session or to a non-exercise control. Exercise was supervised, 5 days/week, for 10 months. All participants were instructed to maintain usual ad libitum diets. Due to the efficacy design, completion of ≥ 90% of exercise sessions was an a priori definition of per protocol, and these participants were included in the analysis.
Weight loss from baseline to 10 months for the 400 and 600 kcal/session groups was 3.9 ± 4.9kg (4.3%) and 5.2 ± 5.6kg (5.7%), respectively compared to weight gain for controls of 0.5 ± 3.5kg (0.5%) (p<0.05). Differences for weight loss from baseline to 10 months between the exercise groups and differences between men and women within groups were not statistically significant.
Supervised exercise, with equivalent energy expenditure, results in clinically significant weight loss with no significant difference between men and women.
This study compared the effects of 12 weeks of caloric restriction and interval exercise (INT) and caloric restriction and continuous aerobic exercise (CON) on physiological outcomes in an obese population. Forty-four individuals (BMI ≥ 30 kg·m-2) were randomised into the INT or CON group. Participant withdrawal resulted in 12 and 14 participants in the INT and CON groups, respectively. All participants were on a strict monitored diet. Exercise involved two 15-min bouts of walking performed on five days per week. Interval exercise consisted of a 2:1 min ratio of low-intensity (40-45% VO2peak) and high- intensity (70-75% VO2peak) exercise, while the CON group exercised between 50-55% VO2peak. Exercise duration and average intensity (%VO2peak) were similar between groups. There were no significant differences (p > 0.05) between the two groups for any variable assessed apart from very low density lipoprotein (VLDL-C), which significantly decreased over time in the INT group only (p < 0.05, d = 1.03). Caloric restriction and interval exercise compared to caloric restriction and continuous aerobic exercise resulted in similar outcome measures apart from VLDL-C levels, which significantly improved in the INT group only.
Twelve weeks of interval exercise and caloric restriction resulted in significant improvement in very low density lipoprotein cholesterol in an obese population, as compared to continuous aerobic exercise and caloric restriction.
Twelve weeks of either interval exercise or continuous exercise resulted in similar improvements in aerobic fitness in an obese population.
Interval training; body fat; fitness; metabolism