Mail-Based Intervention for Sarcopenia Prevention Increased Anabolic Hormone and Skeletal Muscle Mass in Community-Dwelling Japanese Older Adults: The INE (Intervention by Nutrition and Exercise) Study

The effects of exercise on muscle strength, body composition, physical functioning and the inflammatory profile of older adults: a systematic review

PURPOSE OF REVIEW

This systematic review reports the most recent literature regarding the effects of physical exercise on muscle strength, body composition, physical functioning and inflammation in older adults. All articles were assessed for methodological quality and where possible effect size was calculated.

RECENT FINDINGS

Thirty-four articles were included - four involving frail, 24 healthy and five older adults with a specific disease. One reported on both frail and nonfrail patients. Several types of exercise were used: resistance training, aerobic training, combined resistance training and aerobic training and others. In frail older persons, moderate-to-large beneficial exercise effects were noted on inflammation, muscle strength and physical functioning. In healthy older persons, effects of resistance training (most frequently investigated) on inflammation or muscle strength can be influenced by the exercise modalities (intensity and rest interval between sets). Muscle strength seemed the most frequently used outcome measure, with moderate-to-large effects obtained regardless the exercise intervention studied. Similar effects were found in patients with specific diseases.

SUMMARY

Exercise has moderate-to-large effects on muscle strength, body composition, physical functioning and inflammation in older adults. Future studies should focus on the influence of specific exercise modalities and target the frail population more.

Exercise Intervention for Anti-Sarcopenia in Community-Dwelling Older People

Sarcopenia is an age-related health problem in general communities. Effective exercise programs against sarcopenia remain necessary for community-dwelling older people. In order to summarize the available knowledge on this subject, we collected English articles from a MEDLINE/Pubmed database examining the effects of exercise interventions on sarcopenia-related outcome measures in community-dwelling older people. When nine articles, including eight randomized controlled trials, were reviewed, most studies demonstrated significant improvements in some outcome measures. Indeed, a significant improvement in the muscle mass in one study, muscle strength in two studies and physical performance in two studies was reported among five studies using exercise (E) alone. A significant improvement in the muscle mass in two studies, muscle strength in one study and physical performance in two studies was also reported among four studies using exercise plus nutritional supplementation (EN). Notably, the EN studies appeared to have less extensive exercise interventions than the E studies. One EN study further exhibited significant improvements in all outcome measures. Collectively, exercise could be used as anti-sarcopenic strategies and nutritional interventions when combined with exercise might play a compensated or perhaps a comprehensive role among community-dwelling older people. Limited studies exist and more studies are required for the optimum programs in the community settings.

Higher Daily Physical Activities Continue to Preserve Muscle Strength After Mid-Life, But Not Muscle Mass After Age of 75

The objective of this study is to explore the impact of aging and daily physical activities (PA) on muscle mass and muscle strength among community-dwelling people in Taiwan.The design is a cross-sectional study. Setting is a population-based community study.One thousand eight hundred thirty-nine community-dwelling people aged 50 years and older in Taiwan participated in the study.Measurements include demographic characteristics, Charlson Comorbidity Index (CCI) for multimorbidity, mini-nutritional assessment (MNA) for nutritional evaluation, functional autonomy measurement system (SMAF) for functional capacity, Chinese version mini mental state examination (MMSE), 5-item Taiwan Geriatric Depression Scale (TGDS-5), Chinese version of International Physical Activity Questionnaire (IPAQ), height-adjusted skeletal muscle index (SMI) by dual-energy X-ray absorptiometry, handgrip strength, timed 6-m walking test for usual gait speed. Laboratory measurements include testosterone, sex-hormone binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEA-S), insulin-like growth factor-1 (IGF-1), high-sensitivity C-reactive protein (hsCRP), 25-OH vitamin D, and insulin resistance.After adjusted for age, the lowest PA tertile was associated with multimorbidity, poorer functional capacity and nutritional status, more depressive symptoms, lower SMI and lower handgrip strength, and lower free androgen index (FAI) in men. The negative association between PA and low SMI was more significant among subjects aged younger than 65 and the association decreased with older age. For subjects aged younger than 65, moderate daily PA (Q2) group had lower risk of low SMI compared with Q1 participants (OR: 0.62, 95% CI = 0.39-0.98, P = 0.040). For muscle strength, higher daily PA was associated with lower risk of low handgrip strength after age of 65 and the effect was dose-dependent. The effect was attenuated by potential confounders during age 65 to 74, while after age 75, the result was almost unchanged in fully adjusted model (OR = 0.37, 95% CI = 0.18-0.79, P = 0.010).Older age may attenuate the protective effects of higher daily PA on preventing muscle loss, but higher daily PA continues to preserve muscle strength at different age groups, even after the age of 75. The prognostic role of daily PA may be mediated by muscle strength instead of muscle mass among people aged 75 years and older.

Sex-specific differences in risk factors for sarcopenia amongst community-dwelling older adults

With considerable variation including potential sex-specific differential rate of skeletal muscle loss, identifying modifiable factors for sarcopenia will be pivotal to guide targeted interventions. This study seeks to identify clinical and biological correlates of sarcopenia in community-dwelling older adults, with emphasis on the role of anabolic and catabolic stimuli, and special reference to gender specificity. In this cross-sectional study involving 200 community-dwelling and functionally independent older adults aged ≥50 years, sarcopenia was defined using the Asian Working Group for Sarcopenia criteria. Comorbidities, cognitive and functional performance, physical activity and nutritional status were routinely assessed. Biochemical parameters included haematological indices, lipid panel, vitamin D level, anabolic hormones [insulin-like growth factor-1 (IGF-1), free testosterone (males only)] and catabolic markers [inflammatory markers (interleukin-6, C-reactive protein) and myostatin]. Multiple logistic regression was performed to identify independent predictors for sarcopenia. Age was associated with sarcopenia in both genders. Malnutrition conferred significantly higher odds for sarcopenia in women (OR = 5.71, 95% CI 1.13-28.84.44, p = 0.035) while higher but acceptable range serum triglyceride was protective in men (OR = 0.05, 95% CI 0.00-0.52, p = 0.012). Higher serum myostatin independently associated with higher odds for sarcopenia in men (OR = 1.11, 95% CI 1.00-1.24, p = 0.041). Serum IGF-1 was significantly lower amongst female sarcopenic subjects, with demonstrable trend for protective effect against sarcopenia in multiple regression models, such that each 1 ng/ml increase in IGF-1 was associated with 1% decline in odds of sarcopenia in women (p = 0.095). Our findings support differential pathophysiological mechanisms for sarcopenia that, if corroborated, may have clinical utility in guiding sex-specific targeted interventions for community-dwelling older adults.