title: Associations between lower extremity muscle mass and metabolic parameters related to obesity in Japanese obese patients with type 2 diabetes.
abstract: Background. Age-related loss of muscle mass (sarcopenia) increases the incidence of obesity in the elderly by reducing physical activity. This sarcopenic obesity may become self-perpetuating, increasing the risks for metabolic syndrome, disability, and mortality. We investigated the associations of two sarcopenic indices, the ratio of lower extremity muscle mass to body weight (L/W ratio) and the ratio of lower extremity muscle mass to upper extremity muscle mass (L/U ratio), with metabolic parameters related to obesity in patients with type 2 diabetes and obesity. Methods. Of 148 inpatients with type 2 diabetes treated between October 2013 and April 2014, we recruited 26 with obesity but no physical disability. Daily physical activity was measured by a triaxial accelerometer during a period of hospitalization, and which was also evaluated by our previously reported non-exercise activity thermogenesis questionnaire. We measured body composition by bioelectrical impedance and investigated the correlations of L/W and L/U ratios with body weight, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), visceral fat area, subcutaneous fat area, serum lipid profile, and daily physical activity. Results. The L/W ratio was significantly and negatively correlated with BMI, WC, WHR, body fat mass, body fat percentage, subcutaneous fat area, and serum free fatty acid concentration, was positively correlated with daily physical activity: the locomotive non-exercise activity thermogenesis score, but was not correlated with visceral fat area. The L/U ratio was significantly and positively correlated with serum high-density lipoprotein cholesterol. Conclusions. High L/W and L/U ratios, indicative of relatively preserved lower extremity muscle mass, were predictive of improved metabolic parameters related to obesity. Preserved muscle fitness in obesity, especially of the lower extremities, may prevent sarcopenic obesity and lower associated risks for metabolic syndrome and early mortality.
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan ; General Internal Medicine, Community Healthcare Studies, Jichi Medical University Graduate School , Tochigi , Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Hamasaki
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Kawashima
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Adachi
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan.
authors.forename: Sumie
authors.initials: S
authors.lastname: Moriyama
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan.
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Katsuyama
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan.
authors.forename: Akahito
authors.initials: A
authors.lastname: Sako
authors.affiliation: Department of Internal Medicine, National Center for Global Health and Medicine Kohnodai Hospital , Chiba , Japan.
authors.forename: Hidekatsu
authors.initials: H
authors.lastname: Yanai
keywords: Muscle mass; Obesity; Resistance training; Sarcopenia; Type 2 diabetes