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.

Background: Adiponectin has been reported to be associated with lower skeletal muscle mass and skeletal strength and may be involved in skeletal muscle regulation along with myostatin. This study aims to evaluate the association between serum adiponectin and myostatin levels and identify independent factors using body composition and metabolic parameters in patients with obesity.Methods: Overall, 148 patients (age, 45.9 ± 14.3 years, body mass index, 37.2 ± 8.0 kg/m²) who initially visited the outpatient clinic of obesity between November 2013 and November 2019 were included. Body composition was measured using InBody 720 and dual energy X-ray absorptiometry. In addition, muscle strength, vascular function, and metabolic parameters were measured. Serum levels of adiponectin, leptin, myostatin, and irisin were measured from blood samples.Results: The serum adiponectin level was 2.9 μg/mL (1.7–4.1 μg/mL), and the serum myostatin level was 2398.4 pg/mL (1,777.1–2952.5 pg/mL). The stepwise regression analysis revealed less leg strength, homeostasis model assessment of insulin resistance, and C-reactive protein as an independent predictor of serum adiponectin levels based on the significance of the univariate analysis (R²= 0.190, P < 0.001). A high appendicular lean mass/body weight, reactive hyperemia index, and irisin were independent factors for serum myostatin levels (R²= 0.260, P < 0.001)Conclusion: The serum adiponectin level was associated with less muscle strength. Although serum myostatin was associated with a high appendicular lean mass, it is possible that myostatin was regulated by the percentage of body weight from appendicular lean mass.

Toe grip-related training requires individuals to actively exercise muscles that are not frequently used; therefore, it may improve not only toe grip strength but also cognitive function. The purpose of this study was to examine the effects of toe grip-related training on predictors of physical performance and cognitive function in nursing home residents. A total of 35 nursing home residents (35 left and 35 right feet; mean age, 82.1 ± 7.9 years) were included in this study. The participants were divided into two groups: a training group and a control group. The Mini-Mental State Examination (MMSE) was used to assess the cognitive function of the participants, and the Fall Risk Index (FRI) was used to evaluate the risk of falls. Toe grip-related physical function was also assessed. Baseline endpoints were evaluated and the effects of toe grip-related training were examined following a 12-week training intervention. The training group showed significant improvements in MMSE score, FRI score, toe grip strength, and the toe skill (TS) test; however, the control group did not show these changes. The training group showed significant increases in Δ MMSE, Δ toe grip strength, and Δ TS (right foot) than the control group. Stepwise regression analysis revealed that Δ toe grip strength is an independent factor of Δ MMSE. Toe grip training improves not only toe grip strength itself, but also cognitive function. Furthermore, change in toe grip strength was an independent factor of change in MMSE in those populations. UMIN, UMIN000027437 . Registered on 26 May 2017.

Circulating irisin levels gradually increased, and cardiometabolic risks gradually decreased with increasing cardiorespiratory fitness levels. The fitness levels required to increase irisin levels were moderate for young adults and lower than moderate for middle-aged and older adults. Moreover, circulating irisin levels are correlated with a reduction in cardiometabolic risk and an increase in cardiorespiratory fitness. These data suggest that circulating irisin levels are involved in the association between cardiorespiratory fitness and cardiometabolic risk.

While people with obesity have been found to chew fewer times and for shorter durations, few studies have quantitatively evaluated mastication among this group. This study examined the relationship between the mastication characteristics of people with obesity and the factors correlated with obesity. To this end, 46 people with obesity and 41 healthy participants placed an earphone-style light sensor in the aperture of their outer ear. We also examined the partial correlation between this, their body composition, and various biochemical markers by gender. A two-way analysis of variance (ANOVA) regarding the masticatory index, gender, and the presence/absence of obesity for all three food items revealed the main effects in the gender difference and the presence/absence of obesity. Additionally, the number of times the salad was chewed showed an interaction between the gender and the presence/absence of obesity. In the BMI-corrected partial correlation analysis of the chewing index and the glucose/lipid metabolism index, the chewing time and the number of chews of all the food items negatively correlated with hemoglobin A1c(HbA1c), fasting plasma glucose (FPG), immunoreactive insulin (IRI), and homeostasis model assessment of insulin resistance (HOMA-R) in the female obese group. These findings might be used in weight-loss interventions for men with obesity and treatments that target the metabolic function among women with obesity.