Factors associated with fall risk increasing drug use in older black and white men and women: the Health ABC Study.

BACKGROUND: Most older adults use medications that may increase falls, often defined as fall risk increasing drugs or "FRIDs". Two definitions for FRIDs, the Centers for Disease Control and Prevention's (CDC) Stopping Elderly Accidents, Deaths & Injuries (STEADI-Rx) and Swedish National Board of Health and Welfare (SNBHW) definitions, are widely accepted, though include different FRIDs in their definitions. Whether factors associated with FRID use in older adults differ by definition is unknown. METHODS: We hypothesized that factors for FRID use will vary by FRID definition in 1,352 community-dwelling older Black and White adults with medication information in the Health, Aging and Body Composition Study (Health ABC; 2007-08 clinic visit; 83.4 ± 2.8 years; 54.1% women; 65.1% White). Multivariable logistic regression and multivariable negative binomial regression, progressively entering groups of covariates (demographics, lifestyle/behavior factors, and multimorbidity), modeled FRID use (yes/no) and count. RESULTS: Of 87.0% participants using SNBHW FRIDs, 82.9% used cardiac medications, with lower use of all other FRIDs (range:1.1-12.4%). Of 86.6% participants using STEADI-Rx FRIDs, 80.5% used cardiac medications, with lower use of all other FRIDs (range:1.1-16.1%). Participants with FRID use by either definition were more likely to have chronic health conditions, a hospitalization in the prior year, higher non-FRIDs medication counts, higher Center for Epidemiologic Studies Depression Scale (CES-D) scores, and less physical activity (all p < 0.05). Participants with STEADI-Rx FRID use had poorer vision and higher Modified Mini-Mental State (3MS) scores. In multivariable logistic regression for SNBHW use, hypertension, body mass index (BMI), 3MS scores, and non-FRID count were positively associated with FRID use and poorer vision and Digit Symbol Substitution Test (DSST) scores were negatively associated. In addition to SNBHW factors, higher CES-D scores were associated with STEADI-Rx FRID use. In multivariable negative binomial regression, hypertension, higher BMI, CES-D scores, and non-FRID count were associated with higher FRID count and sleep problems with lower FRID count for both definitions. Higher 3MS and lower DSST scores were associated with higher STEADI-Rx FRID count. Women had lower SNBHW FRID count after adjustments. CONCLUSIONS: Risk factors for FRID use in older adults differ slightly by STEADI-Rx and SNBHW FRIDs definition, but are largely similar.

Effects of Weight Loss on Obstructive Sleep Apnea Severity. Ten-Year Results of the Sleep AHEAD Study.

Rationale: Weight loss is recommended to treat obstructive sleep apnea (OSA).Objectives: To determine whether the initial benefit of intensive lifestyle intervention (ILI) for weight loss on OSA severity is maintained at 10 years.Methods: Ten-year follow-up polysomnograms of 134 of 264 adults in Sleep AHEAD (Action for Health in Diabetes) with overweight/obesity, type 2 diabetes mellitus, and OSA were randomized to ILI for weight loss or diabetes support and education (DSE).Measurements and Main Results: Change in apnea-hypopnea index (AHI) was measured. Mean ± SE weight losses of ILI participants of 10.7 ± 0.7, 7.4 ± 0.7, 5.1 ± 0.7, and 7.1 ± 0.8 kg at 1, 2, 4, and 10 years, respectively, were significantly greater than the 1-kg weight loss at 1, 2, and 4 years and 3.5 ± 0.8 kg weight loss at 10 years for the DSE group (P values ≤ 0.0001). AHI was lower with ILI than DSE by 9.7, 8.0, and 7.9 events/h at 1, 2, and 4 years, respectively (P values ≤ 0.0004), and 4.0 events/h at 10 years (P = 0.109). Change in AHI over time was related to amount of weight loss, baseline AHI, visit year (P values < 0.0001), and intervention independent of weight change (P = 0.01). OSA remission at 10 years was more common with ILI (34.4%) than DSE (22.2%).Conclusions: Participants with OSA and type 2 diabetes mellitus receiving ILI for weight loss had reduced OSA severity at 10 years. No difference in OSA severity was present between ILI and DSE groups at 10 years. Improvement in OSA severity over the 10-year period with ILI was related to change in body weight, baseline AHI, and intervention independent of weight change.

Persistent polypharmacy and fall injury risk: the Health, Aging and Body Composition Study.

BACKGROUND: Older adults receive treatment for fall injuries in both inpatient and outpatient settings. The effect of persistent polypharmacy (i.e. using multiple medications over a long period) on fall injuries is understudied, particularly for outpatient injuries. We examined the association between persistent polypharmacy and treated fall injury risk from inpatient and outpatient settings in community-dwelling older adults. METHODS: The Health, Aging and Body Composition Study included 1764 community-dwelling adults (age 73.6 ± 2.9 years; 52% women; 38% black) with Medicare Fee-For-Service (FFS) claims at or within 6 months after 1998/99 clinic visit. Incident fall injuries (N = 545 in 4.6 ± 2.9 years) were defined as the initial claim with an ICD-9 fall E-code and non-fracture injury, or fracture code with/without a fall code from 1998/99 clinic visit to 12/31/08. Those without fall injury (N = 1219) were followed for 8.1 ± 2.6 years. Stepwise Cox models of fall injury risk with a time-varying variable for persistent polypharmacy (defined as ≥6 prescription medications at the two most recent consecutive clinic visits) were adjusted for demographics, lifestyle characteristics, chronic conditions, and functional ability. Sensitivity analyses explored if persistent polypharmacy both with and without fall risk increasing drugs (FRID) use were similarly associated with fall injury risk. RESULTS: Among 1764 participants, 636 (36%) had persistent polypharmacy over the follow-up period, and 1128 (64%) did not. Fall injury incidence was 38 per 1000 person-years. Persistent polypharmacy increased fall injury risk (hazard ratio [HR]: 1.31 [1.06, 1.63]) after adjusting for covariates. Persistent polypharmacy with FRID use was associated with a 48% increase in fall injury risk (95%CI: 1.10, 2.00) vs. those who had non-persistent polypharmacy without FRID use. Risks for persistent polypharmacy without FRID use (HR: 1.22 [0.93, 1.60]) and non-persistent polypharmacy with FRID use (HR: 1.08 [0.77, 1.51]) did not significantly increase compared to non-persistent polypharmacy without FRID use. CONCLUSIONS: Persistent polypharmacy, particularly combined with FRID use, was associated with increased risk for treated fall injuries from inpatient and outpatient settings. Clinicians may need to consider medication management for FRID and other fall prevention strategies in community-dwelling older adults with persistent polypharmacy to reduce fall injury risk.

Does physical performance and muscle strength predict future personal and nursing care services in community-dwelling older adults aged 75+?

AIM: The objective of this study was to investigate if grip strength or the short physical performance battery could predict the rate of receiving two different types of home care services: (a) personal care and (b) home nursing care for community-dwelling older adults aged 75+ years. METHODS: A secondary data analysis of a prospective cohort study including 323 community-dwelling older adults. Measures of grip strength and the short physical performance battery were incorporated in a nationally regulated preventive home visit programme. Referral to personal and home nursing care were obtained from an administrative database with an average follow-up of 4.1 years. The rate of receiving the individual home care services and the study measures were determined using multivariable Cox proportional hazards models controlling for a priori selected covariates (age, sex, living status, obesity, smoking and prior use of home care). RESULTS: The mean age was 81.7 years with 58.8% being women. The rate of receiving personal care differed between the short physical performance battery groups but not between the grip strength groups after adjusting for all covariates with hazard ratios (95% confidence intervals) of 1.90 (1.29-2.81) and 1.41 (0.95-2.08), respectively. The rate of receiving home nursing care differed between both the short physical performance battery and grip strength groups after adjusting for all covariates with hazard ratios of 2.03 (1.41-2.94) and 1.48 (1.01-2.16), respectively. CONCLUSIONS: The short physical performance battery was associated with the rate of receiving both personal care and home nursing care. The short physical performance battery can be used to predict home care needs of community-dwelling older adults aged 75+ years.

Swallowing impairment in older adults: association with sensorimotor peripheral nerve function from the Health, Aging and Body Composition study.

BACKGROUND: The purpose of this study was to examine whether impairments in sensorimotor peripheral nerve function are associated with a higher likelihood of swallowing impairment in older adults. METHODS: Health, Aging and Body Composition participants (n = 607, age = 75.8 ± 2.7 years, 55.8% women, 32.3% black) underwent peripheral nerve testing at Year 4 and 11 with swallowing difficulty assessed at Year 4 and 15. Nerve conduction amplitude and velocity were measured at the peroneal motor nerve. Sensory nerve function was assessed with the vibration detection threshold and monofilament (1.4-g/10-g) testing at the big toe. Symptoms of lower extremity peripheral neuropathy and difficulty swallowing were collected by self-report. Data analysis was performed using a hierarchical approach. Odds ratios (ORs) were estimated using non-conditional logistic regression. RESULTS: At Year 15 108 (17.8%) participants had swallowing impairments. In fully adjusted models, the peripheral nerve impairments associated with swallowing impairment were numbness (OR 4.67; 95%CI 2.24-9.75) and poor motor nerve conduction velocity (OR 2.26; 95%CI 1.08-4.70). Other peripheral nerve impairments were not related to swallowing. CONCLUSIONS: The association between slow motor nerve conduction velocity and numbness and a higher likelihood of swallowing difficulties a decade later in our prospective study identifies an important area for further investigation in older adults.

Cardiometabolic risk factors as determinants of peripheral nerve function: the Maastricht Study.

AIMS/HYPOTHESIS: We aimed to examine associations of cardiometabolic risk factors, and (pre)diabetes, with (sensorimotor) peripheral nerve function. METHODS: In 2401 adults (aged 40-75 years) we previously determined fasting glucose, HbA1c, triacylglycerol, HDL- and LDL-cholesterol, inflammation, waist circumference, blood pressure, smoking, glucose metabolism status (by OGTT) and medication use. Using nerve conduction tests, we measured compound muscle action potential, sensory nerve action potential amplitudes and nerve conduction velocities (NCVs) of the peroneal, tibial and sural nerves. In addition, we measured vibration perception threshold (VPT) of the hallux and assessed neuropathic pain using the DN4 interview. We assessed cross-sectional associations of risk factors with nerve function (using linear regression) and neuropathic pain (using logistic regression). Associations were adjusted for potential confounders and for each other risk factor. Associations from linear regression were presented as standardised regression coefficients (ß) and 95% CIs in order to compare the magnitudes of observed associations between all risk factors and outcomes. RESULTS: Hyperglycaemia (fasting glucose or HbA1c) was associated with worse sensorimotor nerve function for all six outcome measures, with associations of strongest magnitude for motor peroneal and tibial NCV, ßfasting glucose = -0.17 SD (-0.21, -0.13) and ßfasting glucose = -0.18 SD (-0.23, -0.14), respectively. Hyperglycaemia was also associated with higher VPT and neuropathic pain. Larger waist circumference was associated with worse sural nerve function and higher VPT. Triacylglycerol, HDL- and LDL-cholesterol, and blood pressure were not associated with worse nerve function; however, antihypertensive medication usage (suggestive of history of exposure to hypertension) was associated with worse peroneal compound muscle action potential amplitude and NCV. Smoking was associated with worse nerve function, higher VPT and higher risk for neuropathic pain. Inflammation was associated with worse nerve function and higher VPT, but only in those with type 2 diabetes. Type 2 diabetes and, to a lesser extent, prediabetes (impaired fasting glucose and/or impaired glucose tolerance) were associated with worse nerve function, higher VPT and neuropathic pain (p for trend <0.01 for all outcomes). CONCLUSIONS/INTERPRETATION: Hyperglycaemia (including the non-diabetic range) was most consistently associated with early-stage nerve damage. Nonetheless, larger waist circumference, inflammation, history of hypertension and smoking may also independently contribute to worse nerve function.

Associations between novel jump test measures, grip strength, and physical performance: the Osteoporotic Fractures in Men (MrOS) Study.

BACKGROUND/AIMS: Weight-bearing jump tests measure lower extremity muscle power, velocity, and force, and may be more strongly related to physical performance than grip strength. However, these relationships are not well described in older adults. METHODS: Participants were 1242 older men (mean age 84 ± 4 years) in the Osteoporotic Fractures in Men (MrOS) Study. Jump peak power (Watts/kg body weight), force (Newton/kg body weight) at peak power, and velocity (m/s) at peak power were measured by jump tests on a force plate. Grip strength (kg/kg body weight) was assessed by hand-held dynamometry. Physical performance included 400 m walk time (s), 6 m usual gait speed (m/s), and 5-repeated chair stands speed (#/s). RESULTS: In adjusted Pearson correlations, power/kg and velocity moderately correlated with all performance measures (range r = 0.41-0.51; all p < 0.001), while correlations for force/kg and grip strength/kg were weaker (range r = 0.20-0.33; all p < 0.001). Grip strength/kg moderately correlated with power/kg (r = 0.44; p < 0.001) but not velocity or force/kg. In adjusted linear regression with standardized ßs, 1 SD lower power/kg was associated with worse: 400 m walk time (ß = 0.47), gait speed (ß = 0.42), and chair stands speed (ß = 0.43) (all p < 0.05). Associations with velocity were similar (400 m walk time: ß = 0.42; gait speed: ß = 0.38; chair stands speed: ß = 0.37; all p < 0.05). Force/kg and grip strength/kg were more weakly associated with performance (range ß = 0.18-0.28; all p < 0.05). CONCLUSIONS/DISCUSSION: Jump power and velocity had stronger associations with physical performance than jump force or grip strength. This suggests lower extremity power and velocity may be more strongly related to physical performance than lower extremity force or upper extremity strength in older men.

Chronic kidney disease and peripheral nerve function in the Health, Aging and Body Composition Study.

BACKGROUND: Chronic kidney disease (CKD) is associated with poor mobility. Peripheral nerve function alterations play a significant role in low mobility. We tested the hypothesis that early CKD is associated with altered sensory, motor and autonomic nerve function. METHODS: Participants in the Health, Aging and Body Composition cohort who had kidney function measures in Year 3 (1999-2000) and nerve function measurements at Year 4 (2000-01) were analyzed (n = 2290). Sensory (vibration threshold, monofilament insensitivity to light and standard touch), motor [compound motor action potentials (CMAPs), nerve conduction velocities (NCVs)] and autonomic (heart rate response and recovery after a 400-m walk test) nerve function as well as participant characteristics were compared across cystatin C- and creatinine-based estimated glomerular filtration rate categorized as ≤60 (CKD) or >60 mL/min/1.73 m2 (non-CKD). The association between CKD and nerve function was examined with logistic regression adjusted for covariates. RESULTS: Participants with CKD (n = 476) were older (77 ± 3 versus 75 ± 3 years; P < 0.05) and had a higher prevalence of diabetes (20.6% versus 13.1%; P < 0.001). CKD was associated with higher odds for vibration detection threshold {odds ratio [OR] 1.7 [95% confidence interval (CI) 1.1-2.7]} and light touch insensitivity [OR 1.4 (95% CI 1.1-1.7)]. CMAPs and NCVs were not significantly different between CKD and non-CKD patients. In adjusted analyses, participants with CKD had higher odds of an abnormal heart rate response [OR 1.6 (95% CI 1.1-2.2)] and poor heart rate recovery [OR 1.5 (95% CI 1.1-2.0)]. CONCLUSIONS: CKD is associated with changes in sensory and autonomic nerve function, even after adjustment for demographics and comorbidities, including diabetes. Longitudinal studies in CKD are needed to determine the contribution of nerve impairments to clinically important outcomes.

Effects of a lifestyle intervention on REM sleep-related OSA severity in obese individuals with type 2 diabetes.

The aim of this study was to determine if an intensive lifestyle intervention (ILI) reduces the severity of obstructive sleep apnea (OSA) in rapid-eye movement (REM) sleep, and to determine if longitudinal changes in glycaemic control are related to changes in OSA severity during REM sleep over a 4-year follow-up. This was a randomized controlled trial including 264 overweight/obese adults with type 2 diabetes (T2D) and OSA. Participants were randomized to an ILI targeted to weight loss or a diabetes support and education (DSE) control group. Measures included anthropometry, apnea-hypopnea index (AHI) during REM sleep (REM-AHI) and non-REM sleep (NREM-AHI) and glycated haemoglobin (HbA1c) at baseline and year 1, year 2 and year 4 follow-ups. Mean baseline values of REM-AHI were significantly higher than NREM-AHI in both groups. Both REM-AHI and NREM-AHI were reduced significantly more in ILI versus DSE, but these differences were attenuated slightly after adjustment for weight changes. Repeated-measure mixed-model analyses including data to year 4 demonstrated that changes in HbA1c were related significantly to changes in weight, but not to changes in REM-AHI and NREM-AHI. Compared to control, the ILI reduced REM-AHI and NREM-AHI during the 4-year follow-up. Weight, as opposed to REM-AHI and NREM-AHI, was related to changes in HbA1c. The findings imply that weight loss from a lifestyle intervention is more important than reductions in AHI for improving glycaemic control in T2D patients with OSA.

Physical activity trajectories during midlife and subsequent risk of physical functioning decline in late mid-life: The Study of Women's Health Across the Nation (SWAN).

The purpose of this study was to examine the importance of midlife physical activity on physical functioning in later life. Data are from 1771 Study of Women's Health Across the Nation (SWAN) participants, aged 42-52 (46.4±2.7) years at baseline (1996-97). Latent class growth analysis was used to identify physical activity trajectory groups using reported sports and exercise index data collected at seven time-points from baseline to Visit 13 (2011-13); objective measures of physical functioning performance were collected at Visit 13. The sports and exercise index (henceforth: physical activity) is a measure of moderate to vigorous intensity physical activity during discretionary periods of the day. Multivariable linear regression analyses were used to model each continuous physical performance measure as a function of the physical activity trajectory class. Across midlife, five physical activity trajectory classes emerged, including: lowest (26.2% of participants), increasing (13.4%), decreasing (22.4%), middle (23.9%), and highest (14.1%) physical activity. After full adjustment, women included in the middle and highest physical activity groups demonstrated ≥5% better physical functioning performance than those who maintained low physical activity levels (all comparisons; p<0.05). Statistically significant differences were also noted when physical activity trajectory groups were compared to the increasing physical activity group. Results from the current study support health promotion efforts targeting increased (or maintenance of) habitual physical activity in women during midlife to reduce future risk of functional limitations and disability. These findings have important public health and clinical relevance as future generations continue to transition into older adulthood.

Antidepressant Use and Recurrent Falls in Community-Dwelling Older Adults: Findings From the Health ABC Study.

BACKGROUND: Few studies have compared the risk of recurrent falls across various antidepressant agents-using detailed dosage and duration data-among community-dwelling older adults, including those who have a history of a fall/fracture. OBJECTIVE: To examine the association of antidepressant use with recurrent falls, including among those with a history of falls/fractures, in community-dwelling elders. METHODS: This was a longitudinal analysis of 2948 participants with data collected via interview at year 1 from the Health, Aging and Body Composition study and followed through year 7 (1997-2004). Any antidepressant medication use was self-reported at years 1, 2, 3, 5, and 6 and further categorized as (1) selective serotonin reuptake inhibitors (SSRIs), (2) tricyclic antidepressants, and (3) others. Dosage and duration were examined. The outcome was recurrent falls (≥2) in the ensuing 12-month period following each medication data collection. RESULTS: Using multivariable generalized estimating equations models, we observed a 48% greater likelihood of recurrent falls in antidepressant users compared with nonusers (adjusted odds ratio [AOR] = 1.48; 95% CI = 1.12-1.96). Increased likelihood was also found among those taking SSRIs (AOR = 1.62; 95% CI = 1.15-2.28), with short duration of use (AOR = 1.47; 95% CI = 1.04-2.00), and taking moderate dosages (AOR = 1.59; 95% CI = 1.15-2.18), all compared with no antidepressant use. Stratified analysis revealed an increased likelihood among users with a baseline history of falls/fractures compared with nonusers (AOR = 1.83; 95% CI = 1.28-2.63). CONCLUSION: Antidepressant use overall, SSRI use, short duration of use, and moderate dosage were associated with recurrent falls. Those with a history of falls/fractures also had an increased likelihood of recurrent falls.

Sensorimotor Peripheral Nerve Function and the Longitudinal Relationship With Endurance Walking in the Health, Aging and Body Composition Study.

OBJECTIVES: To determine whether lower extremity sensorimotor peripheral nerve deficits are associated with reduced walking endurance in older adults. DESIGN: Prospective cohort study with 6 years of follow-up. SETTING: Two university research clinics. PARTICIPANTS: Community-dwelling older adults enrolled in the Health, Aging and Body Composition Study from the 2000-2001 annual clinical examination (N=2393; mean age ± SD, 76.5±2.9y; 48.2% men; 38.2% black) and a subset with longitudinal data (n=1178). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants underwent peripheral nerve function examination in 2000-2001, including peroneal motor nerve conduction amplitude and velocity, vibration perception threshold, and monofilament testing. Symptoms of lower extremity peripheral neuropathy included numbness or tingling and sudden stabbing, burning, pain, or aches in the feet or legs. The Long Distance Corridor Walk (LDCW) (400 m) was administered in 2000-2001 and every 2 years afterward for 6 years to assess endurance walking performance over time. RESULTS: In separate, fully adjusted linear mixed models, poor vibration threshold (>130 µm), 10-g and 1.4-g monofilament insensitivity were each associated with a slower 400-m walk completion time (16.0 s, 14.4s, and 6.9 s slower, respectively; P<.05 for each). Poor motor amplitude (<1 mV), poor vibration perception threshold, and 10-g monofilament insensitivity were related to greater slowing per year (4.7, 4.2, and 3.8 additional seconds per year, respectively; P<.05), although poor motor amplitude was not associated with initial completion time. CONCLUSIONS: Poorer sensorimotor peripheral nerve function is related to slower endurance walking and greater slowing longitudinally. Interventions to reduce the burden of sensorimotor peripheral nerve function impairments should be considered to help older adults maintain walking endurance-a critical component for remaining independent in the community.

Sensorimotor Peripheral Nerve Function and Physical Activity in Older Men.

We determined whether sensorimotor peripheral nerve (PN) function was associated with physical activity (PA) in older men. The Osteoporotic Fractures in Men Study Pittsburgh, PA, site (n = 328, age 78.8 ± 4.7 years) conducted PN testing, including: peroneal motor and sural sensory nerve conduction (latencies, amplitudes: CMAP and SNAP for motor and sensory amplitude, respectively), 1.4g/10g monofilament (dorsum of the great toe), and neuropathy symptoms. ANOVA and multivariate linear regression modeled PN associations with PA (Physical Activity Scale for the Elderly [PASE] and SenseWear Armband). After multivariable adjustment, better motor latency was associated with higher PASE scores (160.5 ± 4.8 vs. 135.6 ± 6.7, p < .01). Those without versus with neuropathy symptoms had higher PASE scores (157.6 ± 5.3 vs. 132.9 ± 7.1, p < .01). Better versus worse SNAP was associated with slightly more daily vigorous activity (9.5 ± 0.8 vs. 7.3 ± 0.7, p = .05). Other PN measures were not associated with PA. Certain PN measures were associated with lower PA, suggesting a potential pathway for disability.

Anticholinergic Use and Recurrent Falls in Community-Dwelling Older Adults: Findings From the Health ABC Study.

BACKGROUND: Although it is generally accepted that anticholinergic use may lead to a fall, results from studies assessing the association between anticholinergic use and falls are mixed. In addition, direct evidence of an association between use of anticholinergic medications and recurrent falls among community-dwelling elders is not available. OBJECTIVE: To assess the association between anticholinergic use across multiple anticholinergic subclasses, including over-the-counter medications, and recurrent falls. METHODS: This was a longitudinal analysis of 2948 participants, with data collected via interview at year 1 from the Health, Aging and Body Composition study and followed through year 7 (1997-2004). Self-reported use of anticholinergic medication was identified at years 1, 2, 3, 5, and 6 as defined by the list from the 2015 American Geriatrics Society Beers Criteria. Dosage and duration were also examined. The main outcome was recurrent falls (≥2) in an ensuing 12-month period from each medication data collection. RESULTS: Using multivariable generalized estimating equation models, controlling for demographic, health status/behaviors, and access-to-care factors, a 34% increase in likelihood of recurrent falls in anticholinergic users (adjusted odds ratio = 1.34; 95% CI = 0.93-1.93) was observed, but the results were not statistically significant; similar results were found with higher doses and longer duration of use. CONCLUSION: Increased point estimates suggest an association of anticholinergic use with recurrent falls, but the associations did not reach statistical significance. Future studies are needed for more definitive evidence and to examine other measures of anticholinergic burden and associations with more intermediate adverse effects such as cognitive function.

Performance on fast- and usual-paced 400-m walk tests in older adults: are they comparable?

BACKGROUND AND AIMS: Fast- and usual-paced 400-m walking tests are often used to assess physical fitness or function, respectively, though it is not known how performance converges on these tests. This study aims to determine whether performance on the fast- and usual-paced 400-m walks varies based upon age and physical function. METHODS: Participants (26 men, 38 women aged 70-92) completed a fast- and usual-paced 400-m walk. The Short Physical Performance Battery was used to assess function (score range 0-12). Body mass index and health history were also assessed. RESULTS: Finish times for the fast- and usual-paced 400-m walks were 333.3 and 380.3 s, respectively (P < 0.0001), and highly correlated (r = 0.88, P < 0.001). Higher functioning participants (SPPB > 10) had greater differences between tests compared to lower functioning participants (SPPB ≤ 10) (52.9 vs. 26.2 s, P = 0.005), as did younger participants (age < 80) compared to those age 80 and older (56.8 vs. 32.8 s, P = 0.003). DISCUSSION: Older and lower functioning participants had greater convergence on the fast- and usual-paced 400-m walks. Potentially some of these lower functioning and older adults may have already performed at their maximal capacity during the usual-paced walk, while the younger and higher functioning participants were able to walk substantially faster when asked. CONCLUSIONS: Choice of walking test should consider the age and functional capacity of the population as well as whether function or fitness is of interest.

Subclinical thyroid dysfunction and fracture risk: a meta-analysis.

IMPORTANCE: Associations between subclinical thyroid dysfunction and fractures are unclear and clinical trials are lacking. OBJECTIVE: To assess the association of subclinical thyroid dysfunction with hip, nonspine, spine, or any fractures. DATA SOURCES AND STUDY SELECTION: The databases of MEDLINE and EMBASE (inception to March 26, 2015) were searched without language restrictions for prospective cohort studies with thyroid function data and subsequent fractures. DATA EXTRACTION: Individual participant data were obtained from 13 prospective cohorts in the United States, Europe, Australia, and Japan. Levels of thyroid function were defined as euthyroidism (thyroid-stimulating hormone [TSH], 0.45-4.49 mIU/L), subclinical hyperthyroidism (TSH <0.45 mIU/L), and subclinical hypothyroidism (TSH ≥4.50-19.99 mIU/L) with normal thyroxine concentrations. MAIN OUTCOME AND MEASURES: The primary outcome was hip fracture. Any fractures, nonspine fractures, and clinical spine fractures were secondary outcomes. RESULTS: Among 70,298 participants, 4092 (5.8%) had subclinical hypothyroidism and 2219 (3.2%) had subclinical hyperthyroidism. During 762,401 person-years of follow-up, hip fracture occurred in 2975 participants (4.6%; 12 studies), any fracture in 2528 participants (9.0%; 8 studies), nonspine fracture in 2018 participants (8.4%; 8 studies), and spine fracture in 296 participants (1.3%; 6 studies). In age- and sex-adjusted analyses, the hazard ratio (HR) for subclinical hyperthyroidism vs euthyroidism was 1.36 for hip fracture (95% CI, 1.13-1.64; 146 events in 2082 participants vs 2534 in 56,471); for any fracture, HR was 1.28 (95% CI, 1.06-1.53; 121 events in 888 participants vs 2203 in 25,901); for nonspine fracture, HR was 1.16 (95% CI, 0.95-1.41; 107 events in 946 participants vs 1745 in 21,722); and for spine fracture, HR was 1.51 (95% CI, 0.93-2.45; 17 events in 732 participants vs 255 in 20,328). Lower TSH was associated with higher fracture rates: for TSH of less than 0.10 mIU/L, HR was 1.61 for hip fracture (95% CI, 1.21-2.15; 47 events in 510 participants); for any fracture, HR was 1.98 (95% CI, 1.41-2.78; 44 events in 212 participants); for nonspine fracture, HR was 1.61 (95% CI, 0.96-2.71; 32 events in 185 participants); and for spine fracture, HR was 3.57 (95% CI, 1.88-6.78; 8 events in 162 participants). Risks were similar after adjustment for other fracture risk factors. Endogenous subclinical hyperthyroidism (excluding thyroid medication users) was associated with HRs of 1.52 (95% CI, 1.19-1.93) for hip fracture, 1.42 (95% CI, 1.16-1.74) for any fracture, and 1.74 (95% CI, 1.01-2.99) for spine fracture. No association was found between subclinical hypothyroidism and fracture risk. CONCLUSIONS AND RELEVANCE: Subclinical hyperthyroidism was associated with an increased risk of hip and other fractures, particularly among those with TSH levels of less than 0.10 mIU/L and those with endogenous subclinical hyperthyroidism. Further study is needed to determine whether treating subclinical hyperthyroidism can prevent fractures.

Fracture risk in diabetic elderly men: the MrOS study.

AIMS/HYPOTHESIS: Diabetes mellitus is associated with increased fracture risk in women but few studies are available in men. To evaluate the relationship between diabetes and prospective non-vertebral fractures in elderly men, we used data from the Osteoporotic Fractures in Men (MrOS) study. METHODS: The MrOS enrolled 5,994 men (aged ≥65 years). Diabetes (ascertained by self-report, the use of medication for diabetes or an elevated fasting glucose level) was reported in 881 individuals, 80 of whom were using insulin. Hip and spine bone mineral density (BMD) was measured using dual x-ray absorptiometry (DXA). After recruitment, the men were followed for incident non-vertebral fractures using a triannual (3 yearly) questionnaire for an average of 9.1 (SD 2.7) years. The Cox proportional hazards model was used to assess the incident risk of fractures. RESULTS: In models adjusted for age, race, clinic site and total hip BMD, the risk of non-vertebral fracture was higher in men with diabetes compared with normoglycaemic men (HR 1.30, 95% CI 1.09, 1.54) and was elevated in men using insulin (HR 2.46, 95% CI 1.69, 3.59). Men with impaired fasting glucose did not have a higher risk of fracture compared with normoglycaemic men (HR 1.04, 95% CI 0.89, 1.21). After multivariable adjustment, the risk of non-vertebral fracture remained higher only among men with diabetes who were using insulin (HR 1.74, 95% CI 1.13, 2.69). CONCLUSIONS/INTERPRETATION: Men with diabetes who are using insulin have an increased risk of non-vertebral fracture for a given age and BMD.

Genome-wide association analysis identifies TYW3/CRYZ and NDST4 loci associated with circulating resistin levels.

Resistin is a polypeptide hormone that was reported to be associated with insulin resistance, inflammation and risk of type 2 diabetes and cardiovascular disease. We conducted a genome-wide association (GWA) study on circulating resistin levels in individuals of European ancestry drawn from the two independent studies: the Nurses' Health Study (n = 1590) and the Health, Aging and Body Composition Study (n = 1658). Single-nucleotide polymorphisms (SNPs) identified in the GWA analysis were replicated in an independent cohort of Europeans: the Gargano Family Study (n = 659). We confirmed the association with a previously known locus, the RETN gene (19p13.2), and identified two novel loci near the TYW3/CRYZ gene (1p31) and the NDST4 gene (4q25), associated with resistin levels at a genome-wide significant level, best represented by SNP rs3931020 (P = 6.37 × 10(-12)) and SNP rs13144478 (P = 6.19 × 10(-18)), respectively. Gene expression quantitative trait loci analyses showed a significant cis association between the SNP rs3931020 and CRYZ gene expression levels (P = 3.68 × 10(-7)). We also found that both of these two SNPs were significantly associated with resistin gene (RETN) mRNA levels in white blood cells from 68 subjects with type 2 diabetes (both P = 0.02). In addition, the resistin-rising allele of the TYW3/CRYZ SNP rs3931020, but not the NDST4 SNP rs13144478, showed a consistent association with increased coronary heart disease risk [odds ratio = 1.18 (95% CI, 1.03-1.34); P = 0.01]. Our results suggest that genetic variants in TYW3/CRYZ and NDST4 loci may be involved in the regulation of circulating resistin levels. More studies are needed to verify the associations of the SNP rs13144478 with NDST4 gene expression and resistin-related disease.

Peripheral nerve function and lower extremity muscle power in older men.

OBJECTIVE: To assess whether sensorimotor peripheral nerve function is associated with muscle power in community-dwelling older men. DESIGN: Longitudinal cohort study with 2.3±0.3 years of follow-up. SETTING: One clinical site. PARTICIPANTS: Participants (n=372; mean age ± SD, 77.2±5.1y; 99.5% white; body mass index, 27.9±3.7kg/m(2); power, 1.88±0.6W/kg) at 1 site of the Osteoporotic Fractures in Men Study (N=5994). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: A nerve function ancillary study was performed 4.6±0.4 years after baseline. Muscle power was measured using a power rig. Peroneal motor nerve conduction amplitude, distal motor latency, and mean f-wave latency were measured. Sensory nerve function was assessed using 10-g and 1.4-g monofilaments and sural sensory nerve conduction amplitude and distal latency. Peripheral neuropathy symptoms at the leg and feet were assessed by self-report. RESULTS: After adjustments for age, height, and total body lean and fat mass, 1 SD lower motor (ß=-.07, P<.05) and sensory amplitude (ß=-.09, P<.05) and 1.4-g (ß=-.11, P<.05) and 10-g monofilament insensitivity (ß=-.17, P<.05) were associated with lower muscle power/kg. Compared with the effect of age on muscle power (ß per year, -.05; P<.001), this was equivalent to aging 1.4 years for motor amplitude, 1.8 years for sensory amplitude, 2.2 years for 1.4-g monofilament detection, and 3.4 years for 10-g detection. Baseline 1.4-g monofilament detection predicted a greater decline in muscle power/kg. Short-term change in nerve function was not associated with concurrent short-term change in muscle power/kg. CONCLUSIONS: Worse sensory and motor nerve function were associated with lower muscle power/kg and are likely important for impaired muscle function in older men. Monofilament sensitivity was associated with a greater decline in muscle power/kg, and screening may identify an early risk for muscle function decline in late life, which has implications for disability.