Severity of sarcopenia is associated with postural balance and risk of falls in community-dwelling older women

Background/Study context: Falls represent the leading cause of accidental deaths in the elderly. Sarcopenia is a geriatric syndrome defined as the loss of muscle mass and strength. However, the association between falls and sarcopenia is still unclear. Thus, the aim of the present study was to investigate the association between different stages of sarcopenia and postural balance, risk of falls, and fear of falling in community-dwelling older women. Methods: A total of 196 women (68.6 ± 6.5 years) underwent body composition (Dual-energy X-ray Absorptiometry), muscle strength (isokinetic), and functional (Timed Up-and-Go) assessments. Sarcopenia was classified according to European Working Group on Sarcopenia in Older People. Center of pressure (CoP) sway, risk, and fear of falling were assessed through force platform, QuickScreen, and Falls Efficacy Scale, respectively. ANOVA models and chi-squared were used to compare groups. Results: Severe sarcopenic subjects presented higher risk of falling when compared to the other stages (p < 0.01). Regarding CoP sway, both mean speed and mediolateral range were significantly higher in severe sarcopenia when compared to both nonsarcopenia and presarcopenia (p < 0.05). Fear of falling was higher in all sarcopenia stages when compared to nonsarcopenic individuals (p < 0.05). Conclusion: Sarcopenia negatively affects balance, and both risk and fear of falling in community-dwelling older women. Moreover, this study provides evidence that sarcopenia severity is further associated to reduced balance and imposes an even greater risk of falls in the elderly.     

Alternative definitions of sarcopenia, lower extremity performance, and functional impairment with aging in older men and women

OBJECTIVES: To compare two methods for classifying an individual as sarcopenic for predicting decline in physical function in the Health, Aging and Body Composition Study. DESIGN: Observational cohort study with 5 years of follow-up. SETTING: Communities in Memphis, Tennessee, and Pittsburgh, Pennsylvania. PARTICIPANTS: Men and women aged 70 to 79 (N=2,976, 52% women, 41% black). MEASUREMENTS: Appendicular lean mass (aLM) was measured using dual energy x-ray absorptiometry, and participants were classified as sarcopenic first using aLM divided by height squared and then using aLM adjusted for height and body fat mass (residuals). Incidence of persistent lower extremity limitation (PLL) was measured according to self-report, and change in objective lower extremity performance (LEP) measures were observed using the Short Physical Performance Battery. RESULTS: There was a greater risk of incident PLL in women who were sarcopenic using the residuals sarcopenia method than in women who were not sarcopenic (hazard ratio (HR)=1.34, 95% confidence interval (CI)=1.11-1.61) but not in men. Those defined as sarcopenic using the aLM/ht(2) method had lower incident PLL than nonsarcopenic men (HR=0.76, 95% CI=0.60-0.96) and women (HR=0.75, 95% CI=0.60-0.93), but these were no longer significant with adjustment for body fat mass. Using the residuals method, there were significantly poorer LEP scores in sarcopenic men and women at baseline and Year 6 and greater 5-year decline, whereas sarcopenic men defined using the aLM/ht(2) method had lower 5-year decline. Additional adjustment for fat mass attenuated this protective effect. CONCLUSION: These findings suggest that sarcopenia defined using the residuals method, a method that considers height and fat mass together, is better for predicting disability in an individual than the aLM/ht(2) method, because it considers fat as part of the definition.     

Bilateral deficit in explosive force related to sit-to-stand performance in older postmenopausal women

The purpose of this study was to determine whether the bilateral deficit (BLD) for maximal voluntary force (MVF) and rate of force development (RFD) influences sit-to-stand in older postmenopausal women. Fourteen women performed unilateral and bilateral maximal voluntary contractions during isometric leg-extension. The MVF and RFD over consecutive 50 ms periods (0–50, 50–100 and 100–150 ms) after force onset and the time to sit-to-stand test were calculated. There was only a BLD for RFD 0–50 ms and 50–100 ms. The time of sit-to-stand was moderately correlated to BLD for RFD 0–50 ms (r = 0.505; 95% CI: −0.035 to 0.817; P = 0.06), but after controlling for physical activity level the relationship was stronger and statistically significant (r = 0.605; 95% CI: 0.109 to 0.859; P = 0.029). These results suggest that the BLD for explosive force (0–50 ms) might represent a performance-limiting factor for sit-to-stand transfer in postmenopausal women and could be dependent of the physical activity level.Trial registered at Clinical Trials Gov.: NCT02434185.     

Vitamin D receptor genotype is associated with fat-free mass and sarcopenia in elderly men

We investigated the association of vitamin D receptor (VDR) genotype with fat-free mass (FFM) in a cohort of 302 older (aged 58-93 years) Caucasian men who underwent body composition analysis by dual-energy X-ray absorptiometry, and completed questionnaires addressing comorbidities, physical activity, and dietary intake. All participants were genotyped for a VDR translation start site (FokI) polymorphism [FF (37.7%), Ff (48.4%), and ff (13.9%)] and the previously studied BsmI polymorphism [BB (24.9%), Bb (37.7%), and bb (37.4%)]. The BsmI polymorphism was not associated with FFM in any analysis; however, the FokI polymorphism was significantly associated with total FFM, appendicular FFM, and relative (kg/m(2)) appendicular FFM (all p <.05), with the FF group demonstrating significantly lower FFM than the Ff and ff groups (e.g., total FFM: FF = 57.6 +/- 0.4, Ff = 59.4 +/- 0.4, ff = 59.4 +/- 0.7 kg; p <.02). Age-adjusted logistic regression revealed a 2.17-fold higher risk for sarcopenia (defined previously as appendicular FFM <7.26 kg/m(2)) in FF homozygotes (95% CI [confidence interval] = 1.19-3.85; p =.03) compared to men with one or more f alleles. The VDR translation start site (FokI) polymorphism is significantly associated with FFM and sarcopenia in this cohort of older Caucasian men.     

Prevalence of sarcopenia and predictors of skeletal muscle mass in healthy,older men and women

BACKGROUND: Sarcopenia refers to the loss of skeletal muscle mass with age. The objective of this study was to determine the prevalence of sarcopenia in a population of older, community-dwelling research volunteers. METHODS: Appendicular skeletal muscle mass was measured by dual x-ray absorptiometry in 195 women aged 64 to 93 years and 142 men aged 64 to 92 years. We defined sarcopenia as appendicular skeletal muscle mass/height(2) (square meters) less than 2 standard deviations below the mean for young, healthy reference populations. We used two different reference populations and compared prevalence in our population to that reported in previous studies. Body mass index (BMI) was calculated and physical activity and performance were measured with the Physical Activity Scale for the Elderly, the Short Physical Performance Battery, and the Physical Performance Test. We measured health-related quality of life by using the SF-36 general health survey. Serum estrone, estradiol, sex hormone-binding globulin, parathyroid hormone, and 25-hydroxy vitamin D were measured in all participants and bioavailable testosterone was measured only in men. Leg press strength and leg press power were determined in men. RESULTS: The prevalence of sarcopenia in our cohort was 22.6% in women and 26.8% in men. A subgroup analysis of women and men 80 years or older revealed prevalence rates of 31.0% and 52.9%, respectively. In women, skeletal muscle mass correlated significantly with BMI and levels of serum estrone, estradiol, and 25-hydroxy vitamin D; in men, it correlated significantly with BMI, single leg stance time, leg press strength, leg press power, SF-36 general health score, Physical Performance Test total score, and bioavailable testosterone levels. With the use of linear regression analysis, BMI was the only predictor of appendicular skeletal muscle mass in women, accounting for 47.9% of the variance (p <.05). In men, BMI accounted for 50.1%, mean strength accounted for 10.3%, mean power accounted for 4.1%, and bioavailable testosterone accounted for 2.6% of the variance in appendicular skeletal muscle mass (p <.05). CONCLUSIONS: Sarcopenia is common in adults over the age of 65 years and increases with age. BMI is a strong predictor of skeletal muscle mass in women and men. Strength, power, and bioavailable testosterone are further contributors in men. These data suggest that interventions to target nutrition, strength training, and testosterone replacement therapy should be further investigated for their role in preventing muscle loss with age.     

Prevalence of site-specific thigh sarcopenia in Japanese men and women

The purpose of this study was to compare the prevalence of severe sarcopenia detected by total skeletal muscle mass (SM) index and of site-specific thigh sarcopenia for differing age groups in men and women. Japanese nonobese men and women aged 20 to 85 (n = 1,994, 55 % women) had muscle thickness (MTH) measured by ultrasound at six sites on the anterior and posterior aspects of the body. SM was estimated from ultrasound-derived prediction equations. Site-specific thigh sarcopenia was calculated using ultrasound-measured MTH at the anterior and posterior aspects of the thigh (MTH ratio, anterior 50 %/posterior 50 % thigh MTH (A50/P50 MTH)). Sarcopenia was defined as a SM index (SM divided by height²) of >2 standard deviations (SD) below the mean for young adults. Site-specific thigh sarcopenia was defined as a ratio of A50/P50 MTH of >2 SD below the mean for young adults. Age was inversely correlated to SM index and A50/P50 MTH in men (r = −0.480 and r = −0.522) and women (r = −0.243 and r = −0.516). The prevalence rate of sarcopenia was less than 3 % for women under the age of 60, 7 % for ages 60–69, and 24 % for ages 70–80. In men, the prevalence rate of sarcopenia was less than 7 % under the age of 50, 18 % for ages 50–59, 33 % for ages 60–69, and 47 % for ages 70–85. Compared to the sarcopenia estimated by SM index, there was a higher prevalence of site-specific thigh sarcopenia observed in both sexes. These results suggest that site-specific thigh sarcopenia appears before it is able to be detected at the whole body level.     

FABP2 genotype is associated with insulin sensitivity in older women

This study determined whether sequence variations in genes related to glucose and insulin metabolism are associated with insulin sensitivity in postmenopausal women after accounting for habitual physical activity levels, body composition, and hormone-replacement therapy (HRT). Eighteen sedentary, 19 physically active, and 23 athletic postmenopausal white women underwent a frequently sampled intravenous glucose tolerance test to determine insulin sensitivity (S(I)) and dual-energy x-ray absorptiometry to determine body composition. After accounting for the effects of body composition, habitual physical activity levels, and HRT status, S(I) was 26% lower in subjects with the Thr54 fatty acid-binding protein 2 (FABP2) allele compared with Ala54 homozygotes (4.3 +/- 0.5 v 5.8 +/- 0.6 microU x 10(-4)/min/mL; P <.05). Angiotensin-converting enzyme genotype was not significantly associated with S(I). There were no significant associations between Gln27Glu beta(2)-adrenergic receptor or Pro12Ala peroxisome proliferator-activated receptor gamma variants and glucose or insulin kinetic parameters. It was concluded that FABP2 genotype influences insulin sensitivity independent of body composition, habitual physical activity levels, and HRT status in postmenopausal white women.     

Echo intensity is negatively associated with functional capacity in older women

Muscle quality is an important component of the functional profile of the elderly, and previous studies have shown that both muscle quantity and quality independently contribute to muscle strength of the elderly. This study aimed to verify the association between quadriceps femoris muscle quality, analyzed by specific tension and echo intensity (EI), and rate of torque development (RTD) of the knee extensor muscles with the functional performance in elderly active women. Forty-five healthy, active elderly women (70.28 ± 6.2) volunteered to participate in this study. Quadriceps femoris muscle thickness and EI were determined by ultrasonography. Knee extension isometric peak torque and RTD were obtained from maximal isometric voluntary contraction curves. The 30-s sit-to-stand-up (30SS) test and usual gait speed (UGS) test were applied to evaluate functional performance. Rectus femoris EI presented a significant negative correlation with 30SS (r = −0.505, P < 0.01), UGS (r_s = −0.347, P < 0.05), and isometric peak torque (r = −0.314, P < 0.05). The quadriceps femoris EI correlated negatively with 30SS (r = −0.493, P < 0.01) and isometric peak torque (r = −0.409, P < 0.01). The EI of the quadriceps femoris and all quadriceps muscle portions significantly correlated with RTD. RTD significantly correlated with physical performance in both functional tests (30SS = r = 0.340, P < 0.05; UGS = r_s = 0.371, P < 0.05). We concluded that muscle EI may be an important predictor of functional performance and knee extensor power capacity in elderly, active women.     

Hematocrit is associated with carotid atherosclerosis in men but not in women

BACKGROUND: It is known that blood and plasma viscosities are associated with clinical manifestations of atherosclerosis, though evidence is not conclusive particularly in women. OBJECTIVE: To verify whether hematocrit and blood and plasma viscosities are independently associated with carotid atherosclerosis and whether their measurement can improve the definition of the global coronary heart disease (CHD) risk. METHOD: Eight hundred and ninety-two participants in a cardiovascular disease prevention campaign were examined with regard to conventional CHD risk factors (age, blood pressure, lipids, glucose, body mass index, waist/hip ratio, cigarette smoking and diabetes), hematocrit and blood and plasma viscosities. According to the degree of carotid atherosclerosis, investigated by echo-Doppler, participants were divided in three groups: those without atherosclerosis, those with a low degree of atherosclerosis and those with a high degree of atherosclerosis. RESULTS: In men, age, blood pressure, intima-media thickness (IMT), hematocrit (47.4+/-3.7%, 47.8+/-3.7%, 48.4+/-3.7%, P<0.05) and blood viscosity (4.69+/-0.51 cP, 4.77+/-0.55 cP, 4.82+/-0.51 cP, P=0.05) increased with increasing degree of carotid atherosclerosis. In women, age, blood pressure, total cholesterol and low-density lipoprotein-cholesterol, IMT and plasma viscosity (1.42+/-0.12 cP, 1.44+/-0.11 cP, 1.46+/-0.13 cP, P<0.05) increased with increasing carotid score. Analysis of covariance (ANCOVA) showed that after adjusting for hematocrit, blood viscosity was no longer different in the three groups. In discriminant analysis, hematocrit, among the hemorheological variables investigated, was independently associated with carotid score in men (F=3.66, P<0.05). Neither hematocrit nor blood and plasma viscosities were significantly associated with carotid score in women. CONCLUSION: These findings suggest that in men, both hematocrit and blood viscosity are related to carotid atherosclerosis but hematocrit would appear to have an independent effect over and above that mediated by viscosity.     

Total and regional bone mineral density are associated with cellular health in older men and women

ObjectiveThis study aimed to investigate the relationship between crude bioimpedance variables with bone mineral density (BMD) in older adults.MethodOne hundred eighty-four older men and women (≥ 60 years old) composed the sample. BMD (whole-body) was measured through dual-energy X-ray absorptiometry. Bioimpedance spectroscopy was used to estimate whole-body resistance and reactance as well as to calculate the phase angle (PhA) and fat-free mass (FFM). Age, gender, body mass, FFM, height, calcium intake, vitamin D intake, number of fractures, number of diseases, and number of medications were included as covariates in the regression analyses.ResultsBMD fractions were significantly (P < 0.01) associated with PhA (femur: r = 0.524; neck: r = 0.450; and forearm: r = 0.437). Independently of age, body mass, FFM, calcium intake, vitamin D, number of diseases, fratures and medications, PhA remains a significant explanator of the variability of total (β = 0.22; P < 0.001), femur (β = 0.10; P = 0.018), and neck BMD (β = 0.07; P = 0.05) for men, and total (β = 0.08; P = 0.002), femur (β = 0.06; P = 0.005), neck (β = 0.04; P = 0.03), and forearm BMD (β = 0.05; P = 0.004) for women.ConclusionOur results suggest that a higher PhA is associated with BMD in older men and women fractions regardless of relevant covariates highlighting the biological meaning of this simple and crude bioimpedance-based measure in the elderly population.     

Diet-induced weight loss is associated with an improvement in beta-cell function in older men

Although weight loss in older subjects has been shown to improve insulin sensitivity, it is unclear what effect this lifestyle intervention has on beta-cell function. To determine whether diet-induced weight loss can improve beta-cell function in older subjects, we studied 19 healthy male subjects (age, 65.4 +/- 0.9 yr; body mass index, 30.9 +/- 0.6 kg/m2; mean +/- SEM) before and after a 3-month 1200-kcal/d diet. The insulin sensitivity index (SI) was quantified using Bergman's minimal model. The acute insulin response to glucose (AIRg) and the maximal glucose-potentiated insulin response (AIRmax) were determined and then adjusted for SI (SI x AIRg and SI x AIRmax), thus providing measures of beta-cell function. Subjects demonstrated significant weight loss (95.6 +/- 2.4 to 86.1 +/- 2.5 kg; P < 0.001). Both fasting plasma glucose [97.3 +/- 1.6 to 95.1 +/- 1.3 mg/dl (5.4 +/- 0.09 to 5.3 +/- 0.07 mM); P = 0.05] and insulin [18.5 +/- 1.3 to 12.2 +/- 1.0 microU/ml (110.9 +/- 7.7 to 73.5 +/- 5.9 pM); P < 0.001] levels decreased. With weight loss, SI increased [1.59 +/- 0.24 to 2.49 +/- 0.32 x 10(-4) min(-1)/(microU/ml) (2.65 +/- 0.4 to 4.15 +/- 0.5 x 10(-5) min(-1)/pM); P < 0.001], whereas both AIRg [63.4 +/- 13.4 to 51.0 +/- 10.7 microU/ml (380 +/- 80 to 306 +/- 64 pM); P < 0.05] and AIRmax [314 +/- 31.4 to 259.9 +/- 33.4 microU/ml (1886 +/- 188 to 1560 +/- 200 pM); P < 0.05] decreased. Overall beta-cell function improved (SI x AIRg, 9.63 +/- 2.28 to 12.78 +/- 2.58 x 10(-3) min(-1), P < 0.05; and SI x AIRmax, 51.01 +/- 9.2 to 72.69 +/- 13.4 x 10(-3) min(-1), P < 0.05). Thus, the weight loss-associated improvements in both insulin sensitivity and beta-cell function may explain the beneficial effects of a lifestyle intervention on delaying the development of diabetes in older subjects.     

Effect of leg muscle contraction velocity on functional performance in older men and women

OBJECTIVES: To explore the relationship between impairment (skeletal muscle strength and contraction velocity) and function in community-dwelling older adults. DESIGN: Cross-sectional. SETTING: University-based human physiology laboratory. PARTICIPANTS: One hundred one men and women (aged 75-90). MEASUREMENTS: Muscle strength and contraction velocity during bilateral leg press (LP) were calculated during one-repetition maximum (1RM) and 40% 1RM. A short physical performance battery (SPPB) and gait speed (GS) from a 400-m self-paced walk assessed function. Sex differences in LP strength and contraction velocity (at 40% 1RM) were assessed. The relationship between these variables and function was also examined. RESULTS: Lower extremity strength and contraction velocity were significantly associated with GS (P=.02 and P=.005, respectively) and SPPB (P<.001 and P=.009, respectively) in men only. Contraction velocity, but not muscle strength, was significantly associated with GS (P<.001) and SPPB (P=.02) in women. CONCLUSION: Sex differences exist in the relationship between impairment (muscle strength and contraction velocity) and function. Older men and women may employ different strategies to achieve success on different functional tasks. These findings may have important implications for clinicians practicing geriatric rehabilitation.