Jw Fell

A prospective study of the associations between 25-hydroxy-vitamin D, sarcopenia progression and physical activity in older adults.

Objective  Low 25‐hydroxyvitamin D (25OHD) levels may be associated with both sarcopenia (the age‐related decline in muscle mass and function) and low physical activity (PA). Our objective was to describe prospective associations between 25OHD, muscle parameters, and PA in community‐dwelling older adults.

Associations Between Dietary Nutrient Intake and Muscle Mass and Strength in Community-Dwelling Older Adults: The Tasmanian Older Adult Cohort Study

OBJECTIVES: To describe associations between dietary nutrient intake and progression of sarcopenia, the age‐related loss of muscle mass and strength.

Statin therapy, muscle function and falls risk in community-dwelling older adults

BACKGROUND Statin therapy can cause myopathy, however it is unclear whether this exacerbates age-related muscle function declines. AIM To describe differences between statin users and non-users in muscle mass, muscle function and falls risk in a group of community-dwelling older adults. DESIGN A prospective, population-based cohort study with a mean follow-up of 2.6 years. METHODS Total 774 older adults [48% female; mean (standard deviation) age = 62 (7) years] were examined at baseline and follow-up. Differences in percentage appendicular lean mass (%ALM), leg strength, leg muscle quality (LMQ; specific force) and falls risk were compared for statin users and non-users. RESULTS There were 147 (19%) statin users at baseline and 179 (23%) at follow-up. Longitudinal analyses revealed statin use at baseline predicted increased falls risk scores over 2.6 years (0.14, 95% CI 0.01 to 0.27) and a trend towards increased %ALM (0.45%, 95% CI -0.01 to 0.92). Statin users at both time points demonstrated decreased leg strength (-5.02 kg, 95% CI -9.65 to -0.40) and LMQ (-0.30 kg/kg, 95% CI -0.59 to -0.01), and trended towards increased falls risk (0.13, 95% CI -0.01 to 0.26) compared to controls. Finally, statin users at both baseline and follow-up demonstrated decreased leg strength (-16.17 kg, 95% CI -30.19 to -2.15) and LMQ (-1.13 kg/kg, 95% CI -2.02 to -0.24) compared to those who had ceased statin use at follow-up. CONCLUSION Statin use may exacerbate muscle performance declines and falls risk associated with aging without a concomitant decrease in muscle mass, and this effect may be reversible with cessation.

A randomized controlled study investigating static and dynamic balance in older adults after training with Pilates.

OBJECTIVE To evaluate effects of a Pilates intervention on balance and function in community-dwelling older (aged >60y) adults. DESIGN Randomized crossover study design lasting 16 weeks. SETTING University exercise clinic. PARTICIPANTS Ambulatory older community-dwelling adults (N=32) were recruited, and 27 (mean ± SD age, 67.3±6.5y) completed the program. INTERVENTION Participants were allocated to either 5 weeks of a group Pilates training intervention or 5 weeks of usual activity (control). After a 6-week washout period, participants performed the alternate intervention. MAIN OUTCOME MEASURES Static and dynamic balance measures (mediolateral sway range, Four Square Step Test, Timed Up and Go Test) and leg strength were recorded at 4 times before and after each intervention (baseline [t1], interim time immediately after the first group intervention [t2], after 5-week washout [before the second intervention period] [t3], and at study conclusion after the second group intervention [t4]). RESULTS There were no significant differences between the Pilates and control groups for any measured variables (P>.05) despite static and dynamic balance significantly improving during the study and from pre- to post-Pilates (P<.05) without significant changes occurring during the control phase. Improvements that occurred during Pilates between t1 and t2 did not return to baseline after the washout period (t3). There were no changes in leg strength. Mediolateral sway range standing on a foam cushion with eyes closed improved -1.64cm (95% confidence interval, -2.47 to -0.82) and had the largest effect size post-Pilates (d=.72). CONCLUSIONS Although there were no significant between-group differences, participation in the Pilates component of the study led to improved static and dynamic balance. The absence of differences between conditions may be a result of small sample size or the crossover study design because Pilates may produce neuromuscular adaptations of unknown resilience.

Prospective study of self-reported pain, radiographic osteoarthritis, sarcopenia progression, and falls risk in community-dwelling older adults

To examine the potential role of self‐reported joint pain, stiffness, and dysfunction, and radiographic osteoarthritis (ROA), in sarcopenia progression and falls risk in older adults.

The epidemiology of sarcopenia in community living older adults: what role does lifestyle play?

BackgroundSarcopenia, the age-related decline in skeletal muscle mass and function, is a relatively poorly understood process which may play an important role in the incidence of physical disability and falls in older adults. Evidence demonstrates that both genetic and environmental factors contribute to increased susceptibility for sarcopenia development, yet some of these factors may represent unavoidable consequences of ageing.MethodsA review of literature, generally from epidemiological research, was performed to examine the influence that potentially modifiable lifestyle factors (general physical activity, dietary nutrient intake and sun exposure), as well as chronic disease and medication use, may have on sarcopenia progression.ResultsThe review demonstrated that while physical activity, nutrient intake and sun exposure often decline during ageing, each may have important but differing benefits for the prevention of muscle mass and functional declines in older adults. Conversely, age-related increases in the prevalence of chronic diseases and the subsequent prescription of pharmacotherapy may exacerbate sarcopenia progression.ConclusionsThe prevalence of poor physical activity, diet and sun exposure, as well as chronic disease and medication use, within older adult populations may be modifiable through simple lifestyle and health care interventions. As such, these factors may represent the most effective targets for sarcopenia prevention during the ageing process.

Ambulatory activity, body composition, and lower-limb muscle strength in older adults.

PURPOSE It is unclear how the amount of ambulatory activity (AA) participated in by older adults relates to body composition or leg strength. The aim of this study was to describe associations of pedometer-determined AA with body fat and leg muscle parameters in community-dwelling 50- to 79-yr-olds. METHODS A cross-sectional study of 982 randomly recruited subjects was conducted (51% female; mean age = 62 +/- 7 yr). Dual-energy x-ray absorptiometry measured body composition, including total body fat, trunk fat, and leg lean mass. Isometric strength of the quadriceps and hip flexors was measured using a dynamometer. Leg muscle quality was calculated as kilograms of leg strength per kilogram of leg lean mass. Individual AA was recorded over seven d using a pedometer. RESULTS Average AA was 9622 +/- 4004 steps per day. There was no evidence of a threshold model between AA and body fat, leg lean mass, or leg strength. Multivariable regression analyses adjusting for age revealed that AA was negatively associated with total body fat (overall beta = -0.54, P < 0.001; partial R2 = 0.06) and trunk fat mass (overall beta = -0.28, P < 0.001; partial R2 = 0.05). In women only, a significant positive association between AA and both leg strength (beta = 0.71, P = 0.016; partial R2 = 0.01) and leg muscle quality (beta = 0.08, P = 0.001; partial R2 = 0.02) was observed. CONCLUSIONS These results suggest that pedometer-determined AA is a major determinant of body fat in community-dwelling older adults and is also involved in the maintenance of leg strength and muscle quality in older women.

Exploring the Popularity, Experiences, and Beliefs Surrounding Gluten-Free Diets in Nonceliac Athletes

Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popular despite a paucity of supportive medical or ergogenic evidence. This study aimed to quantify the demographics of NCA and determine associated experiences, perceptions, and sources of information related to GFD. Athletes (n = 910, female = 528, no gender selected = 5) completed a 17-question online survey. Forty-one percent of NCA respondents, including 18-world and/or Olympic medalists, follow a GFD 50-100% of the time (GFD > 50): only 13% for treatment of reported medical conditions with 57% self-diagnosing their gluten sensitivity. The GFD > 50 group characteristics included predominantly endurance sport athletes (70.0%) at the recreationally competitive level (32.3%), between 31 and 40 years of age (29.1%). Those who follow a GFD > 50 reported experiencing, abdominal/gastrointestinal (GI) symptoms alone (16.7%) or in conjunction with two (30.7%) or three (35.7%) additional symptoms (e.g., fatigue) believed to be triggered by gluten. Eighty-four percent of GFD > 50 indicated symptom improvement with gluten-removal. Symptom-based and non-symptom-based self-diagnosed gluten-sensitivity (56.7%) was the primary reason for adopting a GFD. Leading sources of GFD information were online (28.7%), trainer/coach (26.2%) and other athletes (17.4%). Although 5-10% of the general population is estimated to benefit clinically from a GFD a higher prevalence of GFD adherence was found in NCA (41.2%). Prescription of a GFD among many athletes does not result from evidence-based practice suggesting that adoption of a GFD in the majority of cases was not based on medical rationale and may be driven by perception that gluten removal provides health benefits and an ergogenic edge in NCA.

Effect of combined β-alanine and sodiumbicarbonate supplementation on cycling performance

PURPOSE The purpose of this study was to investigate the effects of 28 d of β-alanine supplementation on 4-min cycling time trial performance and to determine whether there was an additive effect of combined β-alanine and sodium bicarbonate (NaHCO3) supplementation on high-intensity cycling performance. METHODS Fourteen highly trained cyclists (mean ± SD: age = 25.4 ± 7.2 yr, mass = 71.1 ± 7.1 kg, V˙O(2max) = 66.6 ± 5.7 mL·kg·min) supplemented for 28 d with β-alanine (65 mg·kg body mass each day) or placebo. A maximal 4-min bout of cycling was performed before supplementation (baseline) and twice after supplementation: after ingestion of NaHCO3 (300 mg·kg body mass) and ingestion of a placebo using a randomized crossover design with 2 d between trials. Blood pH and HCO3 concentration were determined before loading (postsupplementation trials) and at pretest and posttest. RESULTS In the acute NaHCO3 loading trials, blood pH and HCO3 were elevated from before loading to pretest, and the magnitude of the change in HCO3 from pretest to posttest was significantly greater compared with the acute placebo loading trial (P < 0.001). Average power output in the 4-min cycling performance trial was increased in placebo + NaHCO3 (+3.1% ± 1.8%) and β-alanine + NaHCO3 (+3.3% ± 3.0%) compared with baseline (P < 0.05). β-alanine + placebo did not significantly improve average power output compared with baseline (+1.6% ± 1.7%, P = 0.20); however, magnitude-based inferences demonstrated that β-alanine + placebo was associated with a 37% likelihood of producing average power improvements. CONCLUSIONS In trained cyclists, β-alanine supplementation did not significantly improve 4-min cycling performance; however, there may be a small meaningful improvement in performance. Acute NaHCO3 supplementation significantly improved 4-min cycling performance. There seemed to be a minimal additive effect of combined β-alanine and NaHCO3 supplementation.

Validity and reliability of central blood pressure estimated by upper arm oscillometric cuff pressure

BACKGROUND Noninvasive central blood pressure (BP) independently predicts mortality, but current methods are operator-dependent, requiring skill to obtain quality recordings. The aims of this study were first, to determine the validity of an automatic, upper arm oscillometric cuff method for estimating central BP (O(CBP)) by comparison with the noninvasive reference standard of radial tonometry (T(CBP)). Second, we determined the intratest and intertest reliability of O(CBP). METHODS To assess validity, central BP was estimated by O(CBP) (Pulsecor R6.5B monitor) and compared with T(CBP) (SphygmoCor) in 47 participants free from cardiovascular disease (aged 57 ± 9 years) in supine, seated, and standing positions. Brachial mean arterial pressure (MAP) and diastolic BP (DBP) from the O(CBP) device were used to calibrate in both devices. Duplicate measures were recorded in each position on the same day to assess intratest reliability, and participants returned within 10 ± 7 days for repeat measurements to assess intertest reliability. RESULTS There was a strong intraclass correlation (ICC = 0.987, P < 0.001) and small mean difference (1.2 ± 2.2 mm Hg) for central systolic BP (SBP) determined by O(CBP) compared with T(CBP). Ninety-six percent of all comparisons (n = 495 acceptable recordings) were within 5 mm Hg. With respect to reliability, there were strong correlations but higher limits of agreement for the intratest (ICC = 0.975, P < 0.001, mean difference 0.6 ± 4.5 mm Hg) and intertest (ICC = 0.895, P < 0.001, mean difference 4.3 ± 8.0 mm Hg) comparisons. CONCLUSIONS Estimation of central SBP using cuff oscillometry is comparable to radial tonometry and has good reproducibility. As a noninvasive, relatively operator-independent method, O(CBP) may be as useful as T(CBP) for estimating central BP in clinical practice.