Results of prospective studies examining the association between 25 hydroxyvitamin D
(25[OH]D) levels and cognitive decline have been inconsistent. We tested the hypothesis
that lower 25(OH)D levels are associated with a greater likelihood of cognitive
impairment and risk of cognitive decline.
The study is a cross-sectional and longitudinal analysis of a prospective cohort of
6,257 community-dwelling elderly women followed for 4 years. Global cognitive function
was measured by the Modified Mini-Mental State Examination and executive function was
measured by Trail Making Test Part B (Trails B). Cognitive impairment at baseline was
defined as a score >1.5 SD below the sample mean; cognitive decline
was defined as decline from baseline to follow-up >1 SD from mean
change in score.
Women with very low vitamin D levels had an increased odds of global cognitive
impairment at baseline: odds ratio (95% confidence interval), 1.60 (1.05–2.42) for
women with 25(OH)D <10 ng/mL (25 nmol/L) compared with those with 25(OH)D levels
≥30 ng/mL (75 nmol/L). Compared with women with baseline 25(OH)D level ≥30 ng/mL
(75 nmol/L), women with lower levels had an increased risk of global cognitive decline:
odds ratio (95% confidence interval), 1.58(1.12–2.22) for women with levels <10
ng/mL (25 nmol/L), and 1.31 (1.04–1.64) for those with levels 10–19.9 ng/mL
(25–49 nmol/L). Levels of 25(OH)D were not associated with executive cognitive
Low 25(OH)D levels among older women were associated with a higher odds of global
cognitive impairment and a higher risk of global cognitive decline.
Vitamin D; Cognitive decline; Executive function; Cohort studies; Risk factors in epidemiology
To examine the association of metabolic syndrome (MetS) with objective measures of physical performance.
Cross-sectional analysis of the cohort study, the Osteoporotic Fractures in Men Study.
Six clinical sites in the US.
5,457 ambulatory men (mean (±SD), age, 73.6 (5.9) years).
Physical performance assessed by grip strength, narrow walk speed, walking speed, and time to complete five repeated chair stands. Individual scores were converted to quintiles (worst  to best ; unable to complete=0) and summed for an overall score (mean (±SD), 11.6 (4.3), range, 1–20). MetS was defined by World Health Organization criteria that include evidence of glucose dysregulation (insulin resistance, diabetes, or hyperinsulinemia), and at least two additional characteristics: high blood pressure, low high density lipoprotein cholesterol, high triglycerides, or obesity.
26.3% of participants met criteria for MetS. In separate linear regression models, four of five MetS components were related to performance (P<.001); only high blood pressure was unrelated. Men with MetS had a 1.11-point lower performance score (mean (95% confidence interval (CI)) =10.81 (10.61, 11.00)) than men without MetS (mean (95% CI) =11.92 (11.81, 12.03)) (P<.001), adjusting for age, race, education and site. With further covariate adjustment this difference was reduced but remained significant (β=−0.78, P<.001). A graded association was observed between number of MetS components (0, 1, 2, or 3+) and performance (P for trend <.001). Findings were similar excluding men with diabetes or obese men.
Metabolic dysregulation is related to objectively-assessed poorer physical performance among relatively healthy older men.
aged; men; metabolic syndrome; physical function; physical performance
To determine whether nurse case management with a therapeutic algorithm could effectively improve rates of control for hypertension, hyperglycemia, and hyperlipidemia compared with usual care among veterans with diabetes.
RESEARCH DESIGN AND METHODS
A randomized controlled trial of diabetic patients that had blood pressure (BP) >140/90 mmHg, hemoglobin A1c (HbA1c) >9.0%, or LDL >100 mg/dL. Intervention patients received case management (n = 278) versus usual care (n = 278) over a 1-year period. The primary outcome was the percentage of patients achieving simultaneous control of all three parameters (defined by BP <130/80 mmHg, HbA1c <8.0%, and LDL <100 mg/dL) at 1 year. Secondary outcomes included improvements within each individual component of the composite primary outcome. Differences between groups were analyzed using t tests, Pearson χ2 tests, and linear and logistic regression.
A greater number of individuals assigned to case management achieved the primary study outcome of having all three outcome measures under control (61 [21.9%] compared with 28 [10.1%] in the usual care group [P < 0.01]). In addition, a greater number of individuals assigned to the intervention group achieved the individual treatment goals of HbA1c <8.0% (73.7 vs. 65.8%, P = 0.04) and BP <130/80 mmHg (45.0 vs. 25.4%, P < 0.01), but not for LDL <100 mg/dL (57.6 vs. 55.4%, P = 0.61), compared with those in the usual care group.
In patients with diabetes, nurse case managers using a treatment algorithm can effectively improve the number of individuals with control of multiple cardiovascular risk factors at 1 year.
The National Heart, Lung and Blood Institute currently defines a blood pressure under 120/80 as “normal.”
To examine the independent effects of diastolic (DBP) and systolic blood pressure (SBP) on mortality and to estimate the number of Americans affected by accounting for these effects in the definition of “normal.”
DESIGN, PARTICIPANTS AND MEASURES
Data on adults (age 25–75) collected in the early 1970s in the first National Health and Nutrition Examination Survey were linked to vital status data through 1992 (N = 13,792) to model the relationship between blood pressure and mortality rate adjusting for age, sex, race, smoking status, BMI, cholesterol, education and income. To estimate the number of Americans in each blood pressure category, nationally representative data collected in the early 1960s (as a proxy for the underlying distribution of untreated blood pressure) were combined with 2008 population estimates from the US Census.
The mortality rate for individuals over age 50 began to increase in a stepwise fashion with increasing DBP levels of over 90. However, adjusting for SBP made the relationship disappear. For individuals over 50, the mortality rate began to significantly increase at a SBP ≥140 independent of DBP. In individuals ≤50 years of age, the situation was reversed; DBP was the more important predictor of mortality. Using these data to redefine a normal blood pressure as one that does not confer an increased mortality risk would reduce the number of American adults currently labeled as abnormal by about 100 million.
DBP provides relatively little independent mortality risk information in adults over 50, but is an important predictor of mortality in younger adults. Conversely, SBP is more important in older adults than in younger adults. Accounting for these relationships in the definition of normal would avoid unnecessarily labeling millions of Americans as abnormal.
blood pressure; hypertension; guidelines; mortality
A number of new biological markers are being studied as predictors of disease or adverse medical events among those who already have a disease. Systematic reviews of this growing literature can help determine whether the available evidence supports use of a new biomarker as a prognostic test that can more accurately place patients into different prognostic groups to improve treatment decisions and the accuracy of outcome predictions. Exemplary reviews of prognostic tests are not widely available, and the methods used to review diagnostic tests do not necessarily address the most important questions about prognostic tests that are used to predict the time-dependent likelihood of future patient outcomes. We provide suggestions for those interested in conducting systematic reviews of a prognostic test. The proposed use of the prognostic test should serve as the framework for a systematic review and to help define the key questions. The outcome probabilities or level of risk and other characteristics of prognostic groups are the most salient statistics for review and perhaps meta-analysis. Reclassification tables can help determine how a prognostic test affects the classification of patients into different prognostic groups, hence their treatment. Review of studies of the association between a potential prognostic test and patient outcomes would have little impact other than to determine whether further development as a prognostic test might be warranted.
prognosis; predictive accuracy; reclassification; review
In this paper, we discuss common challenges in and principles for conducting systematic reviews of genetic tests. The types of genetic tests discussed are those used to 1). determine risk or susceptibility in asymptomatic individuals; 2). reveal prognostic information to guide clinical management in those with a condition; or 3). predict response to treatments or environmental factors. This paper is not intended to provide comprehensive guidance on evaluating all genetic tests. Rather, it focuses on issues that have been of particular concern to analysts and stakeholders and on areas that are of particular relevance for the evaluation of studies of genetic tests. The key points include:The general principles that apply in evaluating genetic tests are similar to those for other prognostic or predictive tests, but there are differences in how the principles need to be applied or the degree to which certain issues are relevant.A clear definition of the clinical scenario and an analytic framework is important when evaluating any test, including genetic tests.Organizing frameworks and analytic frameworks are useful constructs for approaching the evaluation of genetic tests.In constructing an analytic framework for evaluating a genetic test, analysts should consider preanalytic, analytic, and postanalytic factors; such factors are useful when assessing analytic validity.Predictive genetic tests are generally characterized by a delayed time between testing and clinically important events.Finding published information on the analytic validity of some genetic tests may be difficult. Web sites (FDA or diagnostic companies) and gray literature may be important sources.In situations where clinical factors associated with risk are well characterized, comparative effectiveness reviews should assess the added value of using genetic testing along with known factors compared with using the known factors alone.For genome-wide association studies, reviewers should determine whether the association has been validated in multiple studies to minimize both potential confounding and publication bias. In addition, reviewers should note whether appropriate adjustments for multiple comparisons were used.
genetic test; systematic review methods; predictive tests; prognostic tests; risk
Sleep-disordered breathing(SDB) may be deleterious to the cardiovascular system and other organs, including the kidney. Although older men are at increased risk for both kidney disease and SDB, it is unknown whether SDB is associated with higher urinary albumin excretion in this population.
We examined 507 community-dwelling men age ≥67 years(mean 76.0±5.3) enrolled in the MrOS Sleep study who underwent overnight polysomnography and gave a spot urine sample. SDB severity was categorized using the respiratory disturbance index and percent total sleep time <90% oxygen saturation(%time O2<90). Urinary albumin excretion was expressed using the albumin-to-creatinine ratio(ACR).
There was a graded association between respiratory disturbance index and ACR (age and race-adjusted mean ACR=9.35 mg/gCr for respiratory disturbance index≥30 versus 6.72 mg/gCr for respiratory disturbance index<5, p=0.007). This association was attenuated after further adjustment for body mass index(BMI), hypertension and diabetes and no longer reached significance(p=0.129). However, even after adjustment for age, race, BMI, hypertension and diabetes, greater %time O2<90 was associated with higher ACR(10.35 mg/gCr for ≥10%time O2<90 versus 7.45 mg/gCr for <1%time O2<90, p=0.046).
SDB, measured by elevated respiratory disturbance index or nocturnal hypoxemia, was associated with higher ACR. The relationship between respiratory disturbance index and ACR was partially explained by higher BMI and greater prevalence of hypertension and diabetes among men with SDB. However, greater nocturnal hypoxemia was independently associated with higher ACR, suggesting that the hypoxia component of SDB may mediate any detrimental effect of SDB on the kidney.
Albuminuria; sleep-disordered breathing; chronic kidney disease; nocturnal hypoxemia
The new US National Osteoporosis Foundation's (NOF's) Clinician's Guide to Prevention and Treatment of Osteoporosis includes criteria for recommending pharmacologic treatment based on history of hip or vertebral fracture, femoral neck or spine bone mineral density (BMD) T-scores of −2.5 or less, and presence of low bone mass at the femoral neck or spine plus a 10-year risk of hip fracture of 3% or greater or of major osteoporotic fracture of 20% or greater. The proportion of men who would be recommended for treatment by these guidelines is not known. We applied the NOF criteria for treatment to men participating in the Osteoporotic Fractures in Men Study (MrOS). To determine how the MrOS population differs from the general US population of Caucasian men aged 65 years and older, we compared men in MrOS with men who participated in the National Health and Nutrition Examination Survey (NHANES) III on criteria included in the NOF treatment guidelines that were common to both cohorts. Compared with NHANES III, men in MrOS had higher femoral neck BMD values. Application of NOF guidelines to MrOS data estimated that at least 34% of US white men aged 65 years and older and 49% of those aged 75 years and older would be recommended for drug treatment. Application of the new NOF guidelines would result in recommending a very large proportion of white men in the United States for pharmacologic treatment of osteoporosis, for many of whom the efficacy of treatment is unknown. © 2010 American Society for Bone and Mineral Research.
osteoporosis; men; treatment; guidelines; epidemiology; bone density
To examine the association of kidney function with cognitive impairment and decline in elderly men.
Observational prospective cohort.
5529 community dwelling men, aged 65 years or older (mean age 73.6 ± 5.9).
Estimated Glomerular filtration rate (eGFR) calculated using the standardized Modification of Diet in Renal Disease (MDRD) equation; cognitive function assessed with Modified Mini-Mental State Examination (3MS) and Trail Making Test B (Trails B).
At baseline, 148 (2.7%) and 494 (9.1%) men were classified as cognitively impaired and, in the 5-year prospective analysis, 931 (23%) and 432 (11.6%) met the criteria for cognitive decline at follow-up defined by 3MS and Trails B performance, respectively. In unadjusted analysis, the odds of prevalent cognitive impairment and risk of cognitive decline were significantly higher among men with eGFR of <45 and 45–59 mL/min/1.73m2, compared to men with eGFR ≥60 mL/min/1.73m2. These associations were largely explained by difference in age, race, and education between the eGFR categories, with the exception of the association between reduced renal function and higher odds of impairment based on Trails B test score which persisted despite adjustment for multiple potential confounders.
This study found evidence of an independent association between mild to moderate reductions in kidney function and poor executive function at baseline, but not with global cognitive impairment or risk of cognitive decline in older men.
kidney function; cognition; elderly
Prior studies have suggested an increased risk of CVD-related mortality in older adults with disturbed circadian rest/activity rhythms (RARs). The objective goal of this study was to examine the association between disrupted RARs and risk of cardiovascular disease (CVD) events in older men. A total of 2,968 men aged 67 yrs and older wore wrist actigraphs for 115±18 consecutive hours. RAR parameters were computed from wrist actigraphy data and expressed as quartiles (Q). CVD events consisted of a composite outcome of coronary heart disease (CHD), stroke, and peripheral vascular disease (PVD) events. Secondary analyses examined associations between RARs and individual components of the composite outcome (CHD, stroke, and PVD). There were 490 CVD events over an average of 4.0±1.2 yrs. Overall, reduced amplitude (HR = 1.31, 95%CI 1.01–1.71 for Q2 vs. Q4) and greater minimum (HR = 1.33, 95%CI 1.01–1.73 for Q4 vs. Q1) were associated with an increased risk of CVD events in multivariable-adjusted models. In secondary analyses, there was an independent association between reduced amplitude (HR = 1.36, 95%CI 1.00–1.86) and greater minimum activity counts (HR = 1.39, 95%CI 1.02–1.91) with increased risk of CHD events. Reduced F-value (HR = 2.88, 95%CI 1.41–5.87 for Q1 vs. Q4 and HR = 2.71, 95%CI 1.34–5.48 for Q2 vs. Q4) and later occurring acrophase of the RAR (HR = 1.65, 95%CI 1.04–2.63 for Q4 vs. Q2–3) were associated with an increased risk of PVD events. Results were similar in men without a history of CVD events. The findings revealed among older men, measures of decreased circadian activity rhythm robustness (reduced amplitude and greater minimum activity) were associated with an increased risk of CVD events, primarily through increased risk of CHD or stroke events, whereas measures of reduced circadian activity rhythm robustness were not associated with risk of CVD events overall, but were associated with an increased risk of PVD events. These results should be confirmed in other populations.
Rest/activity rhythm; Circadian rhythms; Sleep; Elderly; Cardiovascular disease
The purpose of these analyses was to explore whether physical activity score, leg power or grip strength were associated with tibia and radius estimates of bone strength, cortical density, or total bone area. Peripheral quantitative computed tomography (pQCT) was used to compare tibial and radial bone volumetric density (vBMD, mg/cm3), total (ToA, mm2) and cortical (CoA, mm2) bone area, and estimates of bone compressive strength (bone strength index, BSI) and bending strength (polar strength strain index, SSIp) in a subset (n=1171) of men (≥ 65 years) who participated in the multi-site Osteoporotic Fractures in Men (MrOS) study. Physical activity was assessed by questionnaire (PASE), leg power by Nottingham Power Rig, and grip strength by a hand-held Dynamometer. Participants were categorized into quartiles of PASE, grip strength or leg power. The model was adjusted for age, race, clinic, weight, and limb length. In the tibia, BSI (+7%) and SSIp (+4%) were highest in the most active physically quartile compared to the least active (p<0.05). At the 4% site of the tibia, men with the greatest leg power had both greater ToA (+5%, p<0.001) and BSI (+5.3%, p=0.086) compared to men with the least leg power. At the 66% site of the tibia, the men with the highest leg power, compared to the men with the lowest leg power, had greater ToA (+3%, p=0.045) SSIp (+5%, p=0.008). Similar results were found at both the distal and midshaft of the radius. The findings of this study suggest the importance of maintaining levels of physical activity and muscle strength in older men to prevent bone fragility.
Older men; Physical activity; Bone strength; Bone geometry; Peripheral quantitative computed tomography
The effects of type 2 diabetes mellitus (T2DM) on bone volumetric density, bone geometry, and estimates of bone strength are not well established. We used peripheral quantitative computed tomography (pQCT) to compare tibial and radial bone volumetric density (vBMD, mg/cm3), total (ToA, mm2) and cortical (CoA, mm2) bone area and estimates of bone compressive and bending strength in a subset (n = 1171) of men (≥65 years of age) who participated in the multisite Osteoporotic Fractures in Men (MrOS) study. Analysis of covariance–adjusted bone data for clinic site, age, and limb length (model 1) and further adjusted for body weight (model 2) were used to compare data between participants with (n = 190) and without (n = 981) T2DM. At both the distal tibia and radius, patients with T2DM had greater bone vBMD (+2% to +4%, model 1, p < .05) and a smaller bone area (ToA −1% to −4%, model 2, p < .05). The higher vBMD compensated for lower bone area, resulting in no differences in estimated compressive bone strength at the distal trabecular bone regions. At the mostly cortical bone midshaft sites of the radius and tibia, men with T2DM had lower ToA (−1% to −3%, p < .05), resulting in lower bone bending strength at both sites after adjusting for body weight (−2% to −5%, p < .05) despite the lack of difference in cortical vBMD at these sites. These data demonstrate that older men with T2DM have bone strength that is low relative to body weight at the cortical-rich midshaft of the radius despite no difference in cortical vBMD. © 2010 American Society for Bone and Mineral Research
bone geometry; osteoporosis; peripheral quantitative computed tomography; diabetes mellitus
A web-based risk assessment tool (FRAX®) using clinical risk factors with and without femoral neck bone mineral density (BMD) has been incorporated into clinical guidelines regarding treatment to prevent fractures. Our objective is to determine whether prediction with FRAX® models is superior to that based on parsimonious models.
We conducted a prospective cohort study in 6252 women aged ≥65 years and compared the value of FRAX® models that include BMD to parsimonious models based on age and BMD alone for prediction of fractures. We also compared FRAX® models without BMD to simple models based on age and fracture history alone. Fractures (hip, major osteoporotic [hip, clinical vertebral, wrist, or humerus], and any clinical fracture) were ascertained during 10 years of follow-up. Area under the curve (AUC) statistics from receiver operating characteristic (ROC) curve analysis were compared between FRAX® models and simple models.
AUC comparisons revealed no differences between FRAX® models with BMD versus simple models with age and BMD alone in discriminating hip (AUC=0.75 for FRAX® model and 0.76 for simple model, p=0.26); major osteoporotic (AUC=0.68 for FRAX® model and 0.69 for simple model, p=0.51); or clinical fracture (AUC=0.64 for FRAX® model and 0.63 for simple model, p=0.16). Similarly, performance of parsimonious models containing age and fracture history alone was nearly identical to that of FRAX® models without BMD. The proportion of women in each quartile of predicted risk who actually experienced a fracture outcome did not differ between FRAX® and simple models (p≥0.16).
Simple models based on age and BMD alone or age and fracture history alone predicted 10-year risk of hip, major osteoporotic, and clinical fracture as well as more complex FRAX® models.
An association between increased risk of mortality and disruptions in rest/activity circadian rhythms (RAR) has been shown among adults with dementia and with metastatic colorectal cancer. However the association among a more general population of older adults has not been studied.
Study population consisted of 2964 men aged 67 and older enrolled in the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) Study. Rest/activity patterns were measured with wrist actigraphy. RAR parameters were computed and expressed as quintiles, and included acrophase (time of peak activity level), amplitude (peak-to-nadir difference), mesor (middle of the peak), pseudo F-value (overall circadian rhythmicity), beta (steepness) and alpha (peak-to-trough width).
After adjustment for multiple potential confounders, men in the lowest quintile of pseudo F-value had a 57% higher mortality rate (Hazard ratio [HR]=1.57, 95%CI, 1.03–2.39) compared with men in the highest quintile. This association was even stronger with increased risk of cardiovascular disease-related mortality (CVD) (HR=2.32, 95%CI, 1.04–5.22). Additionally, men in the lowest quintile of acrophase had a 2.8-fold higher rate of CVD-related mortality (HR=2.84, 95%CI, 1.29–6.24). There was no evidence of independent associations with amplitude, mesor, alpha, beta and risk of mortality.
Older men with less robust RAR and earlier acrophase timing, have modestly higher all-cause and CVD-related mortality rates. Further research should examine potential biological mechanisms underlying this association.
rest/activity rhythms; circadian rhythms; mortality; elderly; sleep
To compare validity of a parsimonious frailty index (components: weight loss, inability to rise from a chair, and poor energy [SOF index]) with that of the more complex CHS index (components: unintentional weight loss, low grip strength, poor energy, slowness, and low physical activity) for prediction of adverse outcomes in older men.
Prospective cohort study
Six U.S. centers
3132 men ≥67 years
Men classified as robust, intermediate stage or frail using SOF index and criteria similar to those used in CHS index. Falls reported tri-annually for 1 year. Disability (≥1 new impairment in performing IADL) ascertained at 1 year. Fractures and deaths ascertained during 3 years of follow-up. Area under the curve (AUC) statistics from receiver operating characteristic curve analysis compared for models containing SOF index versus CHS index.
Greater evidence of frailty as defined by either index was associated with increased risks of adverse outcomes. Frail men had a higher age-adjusted risk of recurrent falls (odds ratio [OR] 3.0–3.6), disability (OR 5.3–7.5), nonspine fracture (hazards ratio [HR] 2.2–2.3), and death (HR 2.5–3.5) (P<0.001 for all models). AUC comparisons revealed no differences between models with SOF index versus models with CHS index in discriminating falls (AUC=0.63, P= 0.97), disability (AUC=0.68, P=0.86), nonspine fracture (AUC=0.63, P=0.90), or death (AUC=0.71 for model with SOF index and 0.72 for model with CHS index, P=0.19).
The simple SOF index predicts risk of falls, disability, fracture and mortality in men as well as the more complex CHS index.
frailty; older men; hip fracture; mortality
Carbohydrate and lipid metabolism disorders may affect adults with spinal cord injuries (SCIs) differently than able-bodied individuals because of reduced physical activity in the SCI population. The objective of this study was to conduct a systematic review to determine the effectiveness of exercise to improve carbohydrate and lipid metabolism disorders in adults with chronic SCI.
Studies were identified in MEDLINE (1996–2008), Cochrane Library, bibliographies of identified articles, and expert recommendations. English language articles were included if they evaluated adults with chronic SCI; evaluated exercise; and reported carbohydrate-, lipid-, and/or cardiovascular disease-related outcomes.
Twenty-two studies met inclusion criteria, including 15 intervention case-series and 7 cross-sectional surveys using self-reported physical activity measures. Intervention protocols involved active (n = 7) or electrically stimulated (n = 7) exercise or an educational program (n = 1) from 8 to 52 weeks in duration. Frequency of exercise was typically 2 to 3 sessions/week, lasting 30 to 60 minutes/session. Totals of 150 and 369 subjects participated in studies with carbohydrate (n = 12) or lipid and cardiovascular (n = 16) outcomes, respectively; 78% were men. Level of SCI ranged from C4 to L5 and included both incomplete and complete lesions. Outcomes measures included fasting and postload blood glucose and insulin concentrations and serum cholesterol levels. Small sample sizes and variations in study design, intervention, SCI characteristics, and reported outcomes precluded quantitative pooling of results or reliable assessment of metabolic efficacy. No intervention studies assessed cardiovascular outcomes.
Evidence is insufficient to determine whether exercise improves carbohydrate and lipid metabolism disorders among adults with SCI. Expert consensus, based on the preliminary evidence, is needed to inform future studies.
Spinal cord injuries; Tetraplegia; Paraplegia; Exercise; Functional electrical stimulation; Lipid metabolism; Carbohydrate metabolism; Systematic review; Outcomes research
Background. Sleep-disordered breathing (SDB) is common in severe chronic kidney disease (CKD) and may contribute to morbidity and mortality in this population. However, the association between mild to moderate CKD and likelihood of SDB is uncertain.
Methods. We studied 2696 men ≥65 years (mean 73.0 ± 5.5) enrolled in the Outcomes of Sleep Disorders in Older Men (MrOS Sleep) study who had serum creatinine (SCr) measured 3.4 years prior to overnight polysomnography (PSG). CKD was expressed as quartiles of estimated glomerular filtration rate (eGFR) using the four-variable Modification of Diet in Renal Disease (MDRD) formula. SDB was assessed using the respiratory disturbance index (RDI) with ≥4% oxygen desaturation.
Results. Mean SCr was 0.99 ± 0.20 mg/dl; 14.8% had eGFR <60 ml/min/1.73 m2. Median RDI was 7.4 events/hour (inter-quartile range 2.6–15.8). Lower eGFR was not associated with higher mean RDI in the unadjusted model (P for trend = 0.180). There was evidence of an interaction between eGFR and age for the prediction of RDI; an association between lower eGFR and higher RDI was evident only among men ≤72 (median) years. Among this age group, however, the association was not statistically significant after further adjustment for body mass index (BMI) (P for trend = 0.278).
Conclusions. In this cohort of older community-dwelling men, reduced renal function was not associated with greater evidence of SDB, except among younger old men. However, this association was largely explained by higher BMI at lower eGFR. Further prospective study in younger populations is needed to clarify our findings.
chronic kidney disease; kidney dysfunction; sleep disorders
The purpose of this study was to examine the association of the alpha-actinin-3 (ACTN3) R577X polymorphism on muscle function and physical performance in older adults.
We measured knee extensor torque, midthigh muscle cross-sectional area, muscle quality, short physical performance battery score, and 400-meter walk time at baseline and after 5 years in white older adults aged 70–79 years in the Health, Aging and Body Composition Study cohort (n = 1367). Incident persistent lower extremity limitation (PLL) over 5 years was additionally assessed. We also examined white men in the Osteoporotic Fractures in Men Study, a longitudinal, observational cohort (n = 1152) of men 65 years old or older as a validation cohort for certain phenotypes.
There were no significant differences between genotype groups in men or women for adjusted baseline phenotypes. Male X-homozygotes had a significantly greater adjusted 5-year increase in their 400-meter walk time compared to R-homozygotes and heterozygotes (p = .03). In women, X-homozygotes had a ~35% greater risk of incident PLL compared to R-homozygotes (hazard ratio = 0.65, 95% confidence interval = 0.44–0.94). There were no other significant associations between any of the phenotypes and ACTN3 genotype with aging in either cohort.
The ACTN3 polymorphism may influence declines in certain measures of physical performance with aging in older white adults, based on longitudinal assessments. However, the influence of the ACTN3 R577X polymorphism does not appear to have a strong effect on skeletal muscle–related phenotypes based on the strength and consistency of the associations and lack of replication with regard to specific phenotypes.
Genetics; Elderly; Sarcopenia; Skeletal muscle
Peripheral arterial disease (PAD) and osteoporosis are chronic illnesses that increase in prevalence with aging and certain metabolic disorders. The association between PAD, rates of bone loss, and fracture risk in older men is uncertain.
Methods and Results
We sought to test the hypothesis that PAD is associated with higher rates of bone loss and increased fracture risk. We analyzed data from a prospective cohort study involving 6 US centers and 5781 men at least 65 years of age. We assessed ankle-brachial index and hip bone mineral density, followed up prospectively for changes in hip bone mineral density and fractures. PAD was defined as a baseline ankle-brachial index <0.9. Hip bone mineral density was measured with dual x-ray absorptiometry at baseline and again an average of 4.6 years later. Incident nonspine fractures were ascertained by self-report and confirmed with radiography reports during an average of 5.4 years of follow-up. At baseline, the prevalence of PAD was 6.2%. After adjustment for age, race, site, and baseline bone mineral density, the mean annualized rate of bone loss at the total hip was −0.66% per year (95% confidence interval −0.78 to −0.54) in men with PAD compared with −0.34% per year (95% confidence interval −0.36 to −0.31) in men without PAD (P<0.001). After further adjustment for multiple potential confounders, the difference was attenuated (−0.49% in men with PAD versus −0.35% in men without PAD) but remained significant (P=0.02). Findings were similar at hip subregions. Twelve percent of men with PAD and 7.9% of those without PAD experienced an incident nonspine fracture (hazard ratio adjusted for age, race, and site=1.47, 95% confidence interval 1.07 to 2.04); this association was not altered substantially by further adjustment for multiple confounders.
In community-dwelling older men, PAD was associated with higher rates of hip bone loss and increased risk of nonspine fractures. Further research should examine the biological mechanisms underlying the association between reduced limb blood flow and fractures.
peripheral arterial disease; bone loss; fractures
To examine the fracture pattern in older women whose bone mineral density (BMD) T-score criteria for osteoporosis at hip and spine disagree, hip and spine BMD were measured in Study of Osteoporotic Fractures participants using dual energy x-ray absorptiometry (DXA). Hip osteoporosis was defined as T-score ≤-2.5 at femoral neck or total hip, and spine osteoporosis as T-score ≤-2.5 at lumbar spine. Incident clinical fractures were self-reported and centrally adjudicated. Incident radiographic spine fractures were defined morphometrically. Compared to women with osteoporosis at neither hip nor spine, those osteoporotic only at hip had a 3.0-fold age and weight-adjusted increased risk for hip fracture (95%CI 2.4-3.6), and smaller increases in risk of nonhip nonspine (HR=1.6), clinical spine (OR=2.2), and radiographic spine fractures (OR=1.5). Women osteoporotic only at spine had a 2.8-fold increased odds of radiographic spine fracture (95%CI 2.1-3.8), and smaller increases in risk of clinical spine (OR=1.4), nonhip nonspine (HR=1.6), and hip fractures (HR=1.2). Discordant BMD results predict different fracture patterns. DXA fracture risk estimation in these patients should be site-specific. Women osteoporotic only at spine would not have been identified from hip BMD measurement alone, and may have a sufficiently high fracture risk to warrant preventive treatment.
Osteoporosis; bone density; fractures; prospective studies; DXA
To determine if loop diuretic use is associated with hip bone loss, and increased risk of falls and fractures in older women.
Prospective cohort study from August 1992 to April 2004.
Four regions in the US from the Study of Osteoporotic Fractures (SOF).
Women aged 65 and older (N = 8127) with medication use data who participated in the 4th SOF examination, from which 3 study cohorts were derived.
1) Bone mineral density (BMD) of the total hip assessed by dual-energy x-ray absorptiometry at the 4th and 6th examinations (N = 2980); 2) recurrent (2 or more) falls in the year following the 4th examination (N = 6244); and 3) incident fracture including nonspine (N = 6778) and hip fractures (N = 7272).
After multivariable-adjustment, loop diuretic users had greater loss of total hip BMD compared to nonusers (mean annualized % BMD −0.87 vs. −0.71, p=0.03) after a mean of 4.4 years (+/− 0.6). The risks of recurrent falls (OR 0.99, 95% CI 0.71 to 1.39), nonspine (RR 1.04, 95% CI 0.90 to 1.21) and hip fracture (RR 1.03, 95% CI 0.81 to 1.31) were not increased among loop diuretic users compared with nonusers.
In this cohort of older women, loop diuretic use was associated with a small, but significantly higher rate of hip bone loss compared to nonuse after a mean duration of 4.4 years. However the risk of falls or fracture did not differ between the two groups.
loop diuretics; osteoporosis; falls; fractures
Sleep-disordered breathing (SDB) may increase the risk of cardiovascular disease (CVD) and death in chronic kidney disease (CKD). However, the association between mild reductions in renal function and SDB is uncertain.
We studied 508 community-dwelling men aged ≥67 years (mean 76.0 ± 5.3) who were enrolled at the Minnesota site for the Minneapolis center of the Outcomes of Sleep Disorders in Older Men (MrOS) sleep study and had serum cystatin-C and creatinine measured coincident with overnight polysomnography. CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m2 using Cockcroft-Gault (CG), modification of diet in renal disease (MDRD) and Mayo Clinic formulae. SDB was defined by a respiratory disturbance index (RDI) ≥15 events/h.
Mean cystatin-C was 1.21 ± 0.30 mg/L, and mean creatinine was 1.09 ± 0.23 mg/dL. Median RDI was 7.0 events/h (range 0-73). Higher quartiles of cystatin-C were associated with higher mean RDI (p for trend = 0.007). This association persisted after adjustment for age and race (p for trend = 0.03), but not after adjustment for body mass index (BMI, p for trend = 0.34). After adjusting for age, race, BMI, diabetes, hypertension, and CVD, CKD defined by the Mayo Clinic formula, but not CG or MDRD, was associated with a higher odds of SDB [odds ratio (OR) 1.95, 95% confidence interval (CI) 1.04-3.65, p = 0.04].
Older men with reduced renal function as defined by higher cystatin-C concentration have higher average RDI. This effect is explained by higher BMI in men with higher cystatin-C. CKD defined by the Mayo Clinic formula is independently associated with twofold higher odds for SDB. Therefore, reduced renal function may be associated with SDB in older men.
Chronic kidney disease; Kidney dysfunction; Cystatin-C; Sleep disorders; Sleep-disordered breathing; Sleep apnea syndromes
To examine the association between depressive symptoms, subjective and objective measures of sleep in community-dwelling older men.
Six US clinical centers
3051 men aged 67 and older
Depressive symptoms assessed using the 15-item Geriatric Depression Scale and categorized as 0–2 (normal, referent group), 3–5 (some depressive symptoms) and 6–15 (depressed). Objective sleep measures ascertained using wrist actigraphy (mean duration 5.2 nights), and subjective sleep measures assessed using the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS).
There was a strong multivariable adjusted association between level of depressive symptoms and subjective sleep disturbances (p-trend<0.001). For example, compared with normal men, the odds of reporting poor sleep quality were 3.7-fold (95% CI 2.5 to 5.3) higher for depressed men, and 2.1-fold (95% CI 1.7 to 2.6) higher for men with some depressive symptoms. For objectively measured sleep disturbances, men with a greater level of depressive symptoms had an increased odds of sleep latency ≥1 hour (p-trend=0.006). There was no association between levels of depressive symptoms and reduced sleep efficiency, increased awakening after sleep onset, multiple long-wake episodes or total sleep time. Excluding 384 men taking antidepressants, benzodiazepines or other anxiolytic/hypnotics did not alter the results.
Depressive symptoms have a strong, graded association with subjective sleep disturbances; and are moderately associated with objectively measured prolonged sleep latency. Future studies should address temporality of depression and sleep disturbances.
depression; depressive symptoms; sleep; elderly; actigraphy
Candidate osteoporosis gene variants were examined for associations with fracture risk and bone mineral density (BMD). A total of 9704 white women were recruited at four U.S. clinical centers and enrolled into the Study of Osteoporotic Fractures, a longitudinal cohort study. Genotyping of 31 polymorphisms from 18 candidate osteoporosis genes was performed in 6752 women. Incident radiographic fractures were identified at the third and eighth examinations compared with the baseline examination. BMD was measured at the total hip by dual-energy X-ray absorptiometry. Analyses were adjusted for age, clinic site, and self-reported ethnicity. During a mean follow-up of 14.5 years, a total of 849 hip, 658 vertebral, and 2496 nonhip/nonvertebral fractures occurred in 6752 women. Women carrying the ALOX15_G48924T T/T genotype had a higher rate of hip fracture (hazard ratio [HR] = 1.33;95% confidence interval [95% CI] = 1.00–1.77) compared with the G/G genotype. Compared with those carrying the PRL_T228C T/T genotype, women with either the C/C (HR = 0.80; 95% CI = 0.67–0.95) or C/T (HR = 0.81; 95% CI = 0.68–0.97) genotype had a lower rate of nonvertebral/nonhip fractures. Women carrying theBMP2_A125611G G/G genotype had a higher rate of vertebral fracture (odds ratio [OR] = 1.51; 95% CI = 1.03–2.23) compared with the A/A genotype. Women with the ESR1_C1335G G/G genotype had a higher rate of vertebral fracture (OR = 1.64; 95% CI = 1.07–2.50) compared with the C/C genotype. Compared with those with the MMP2_C595T C/C genotype, women with the C/T (OR = 0.79; 95% CI = 0.65–0.96) or T/T (OR = 0.44; 95% CI = 0.27–0.72) genotype had a lower rate of vertebral fracture. In conclusion, polymorphisms in several candidate genes were associated with hip, vertebral, and nonhip/nonvertebral fractures but not with total hip BMD in this large population based cohort study.
Genetics; Polymorphism; Osteoporosis; BMD; Fracture
Reduced sleep has been reported to predict obesity in children and young adults. However, studies based on self-report have been unable to identify an association in older populations. In this study, the cross-sectional associations between sleep duration measured objectively and measures of weight and body composition were assessed in two cohorts of older adults.
Wrist actigraphy was performed for a mean (SD) of 5.2 (0.9) nights in 3055 men (age: 67–96 years) participating in the Osteoporotic Fractures in Men Study (MrOS) and 4.1 (0.8) nights in 3052 women (age: 70–99 years) participating in the Study of Osteoporotic Fractures (SOF). A subgroup of 2862 men and 455 women also underwent polysomnography to measure sleep apnea severity.
Compared to those sleeping an average of 7–8 hours per night, and after adjusting for multiple risk factors and medical conditions, a sleep duration of less than 5 hours was associated with a body mass index (BMI) that was on average 2.5 kg/m2 (95% CI: 2.0–2.9) greater in men and 1.8 kg/m2 (95%CI: 1.1–2.4) greater in women. The odds of obesity (BMI ≥ 30 kg/m2) was 3.7-fold greater (95% CI: 2.7–5.0) in men and 2.3-fold greater in women (95% CI: 1.6–3.1) who slept less than 5 hours. Short sleep was also associated with central body fat distribution and increased percent body fat. These associations persisted after adjusting for sleep apnea, insomnia, and daytime sleepiness.
In older men and women, actigraphy-ascertained reduced sleep durations are strongly associated with greater adiposity.
sleep duration; sleep deprivation; obesity; central obesity; geriatrics; insomnia; sleepiness