A 3-month static stretching intervention was found to improve vascular endothelial function, and an additional 3-month intervention also improved arterial stiffness. However, these effects were reversed by detraining.

SummaryBackground/PurposeIrisin is a skeletal muscle myokine that causes the brown coloration of white fat, promotes fat burning, inhibits weight gain and may be useful for treatment of obesity. Irisin is also related to glucose/lipid metabolism and may prevent onset of diabetes, but a consensus on irisin secretion has not been reached. The purpose of this study was to determine the relationships between serum irisin levels and physical factors in untreated Japanese men and women with obesity.MethodsThe subjects were 66 untreated patients with obesity (body mass index ≥30 kg m−2) who visited our obesity clinic. The subjects included 19 men and 47 women with a mean age of 45.7 ± 13.4 years, mean body weight of 93.8 ± 17.6 kg, and mean body mass index of 36.5 ± 4.7 kg m−2. At the initial visit, blood sampling was performed, body composition was evaluated using dual energy X‐ray absorptiometry, and exercise tolerance was determined in a cardiopulmonary exercise test. Homeostasis model of assessment – insulin resistance (HOMA‐IR), an index of insulin resistance, and the serum level of irisin were measured.ResultsIn men, serum irisin was positively correlated with fasting blood glucose (r = 0.491, P < 0.05), immunoreactive insulin (r = 0.536, P < 0.05), HOMA‐IR (r = 0.635, P < 0.01), body weight (r = 0.491, P < 0.05), lean body mass of the trunk (r = 0.579, P < 0.05) and whole lean body mass (r = 0.489, P < 0.05). In women, serum irisin was positively correlated with immunoreactive insulin (r = 0.502, P < 0.01) and HOMA‐IR (r = 0.385, P < 0.01). In both sexes, HOMA‐IR was an independent variable associated with obesity (men: β = 0.635, R2 = 0.369, P < 0.01; women: β = 0.385, R2 = 0.129, P < 0.01).ConclusionThe serum level of irisin was positively correlated with HOMA‐IR in Japanese patients with obesity of both sexes. This suggests that compensatory enhancement of irisin secretion may occur in response to insulin resistance.

Hyperhomocysteinemia causes various diseases including cardiovascular disease, osteoporotic fracture and dementia. Although there have been reports that hyperhomocysteinemia decreases physical performance, findings are inconsistent on the association of homocysteine, folate, vitamin B12 and physical performance. Considering that lower physical performance increases the risk of fall and fracture in the elderly, the effect of nutritional status on physical function must be clarified. This is a cross-sectional study conducted from April 2015 to November 2016. Eighty-six residents and users in five care facilities were evaluated for their blood homocysteine, folate and vitamin B12 concentrations and indices for physical performance; lower limb muscle strength, handgrip strength and gait speed. Analyses of physical performance were done in women only, considering the high proportion of women in the study population and the muscular gender difference. In the third tertile of plasma homocysteine concentration, handgrip strength was significantly lower than in the first tertile (p50.027). In the first tertile of serum folate concentration, handgrip strength was significantly lower than in the third tertile (p50.002). Although not statistically significant, lower limb muscle strength in the third tertile of folate was higher than in the first (p50.061) and second (p50.057) tertile. In the multiple regression analysis, however, only serum folate concentration was a significant contributor except for age. In subjects with their serum folate and vitamin B12 concentrations both exceeding the median, lower limb muscle strength was higher. Low serum folate concentration is a risk factor for lower physical performance independent of homocysteine in elderly women.

This study aimed to investigate risk factors for sarcopenia in community-dwelling older adults visiting regional medical institutions. We retrospectively analyzed medical records of 552 participants (mean age: 74.6 ± 6.7 years, males 31.3%) who underwent body composition evaluation between March 2017 and December 2018 at one of 24 medical institutions belonging to the Kadoma City Medical Association in Japan. We collected the participant’s characteristics and laboratory data. Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019. Sarcopenia, including severe sarcopenia, was detected in 22.3% of all participants, 17.3% of men, and 24.5% of women; rates increased with age. Multivariate logistic regression analysis revealed age (odds ratio [OR]: 2.12; 95% confidence interval [CI] 1.20–3.75), obesity (OR: 0.15; 95% CI 0.07–0.32), hypertension (OR: 0.44; 95% CI 0.25–0.76), certification of long term care (OR: 3.32; 95% CI 1.41–7.81), number of daily conversations (OR: 0.44; 95% CI 0.25–0.77), and malnutrition (OR: 2.42; 95% CI 1.04–5.60) as independent predictors of sarcopenia. Receiver operating characteristic curve analysis demonstrated that the cut-off for daily conversations defining sarcopenia was 4.8 persons. The prevalence of sarcopenia in this study was 22.3%. Besides traditional risk factors for sarcopenia, the number of daily conversations was an independent factor.