Appendicular Skeletal Muscle Mass and Insulin Resistance in an Elderly Korean Population: The Korean Social Life, Health and Aging Project-Health Examination Cohort

Abstract

BackgroundIncreasing evidence supports an association between age-related loss of muscle mass and insulin resistance. However, the association has not been fully investigated in the general population. Thus, we investigated the association between appendicular skeletal muscle mass (ASM) and insulin resistance in an elderly Korean population.MethodsThis cross-sectional study included 158 men (mean age, 71.8) and 241 women (mean age, 70.6) from the Korean Social Life, Health and Aging Project, which started in 2011. In this study, ASM was measured by bioelectrical impedance analysis and was analyzed in three forms: ASM (kg), ASM/height2 (kg/m2), and ASM/weight (%). The homeostasis model assessment of insulin resistance (HOMA-IR) was used as a measure of insulin resistance. The relationships between the ASM values and the HOMA-IR were investigated by multiple linear regression models.ResultsThe HOMA-IR was positively associated with ASM (β=0.43, P<0.0001) and ASM/height2 (β=0.36, P<0.0001) when adjusted for sex and age. However, after additional adjustment for body weight, HOMA-IR was inversely associated with ASM (β=-0.43, P<0.001) and ASM/height2 (β=-0.30, P=0.001). Adjustment for other potential confounders did not change these associations. Conversely, HOMA-IR was consistently and inversely associated with ASM/weight before and after adjustment for other potential confounders.ConclusionOur results support the idea that lower skeletal muscle mass is independently associated with insulin resistance in older adults. When evaluating sarcopenia or muscle-related conditions in older adults, their whole body sizes also need to be considered.

Frailty and sarcopenia as the basis for the phenotypic manifestation of chronic diseases in older adults

“…Moreover, a HOMA-IR value higher than 2.3 increased in 3-4 times the risk of developing low relative ASM in a 4.6-years follow-up (Alemán-Mateo et al, 2014). Similarly, HOMA-IR ≥2.5 was identified as an important risk factor for sarcopenia in men aged 65 years or older (Kim et al, 2014) while, after adjusting by body weight, HOMA-IR was inversely associated with ASM in older men and women (Lee et al, 2015b). In fact, supporting a causal effect of insulin resistance on sarcopenia in the elderly, induction of insulin resistance in old rats by sucrose feeding results in significant loss of lean body mass, increase in fat mass and reduced muscle protein synthesis (Gatineau et al, 2015).…”

Mediterranean diet, Dietary Approaches to Stop Hypertension (DASH) style diet, and metabolic health in U.S. adults

“…These findings suggest that other factors such as physical activity might be more important than diet in relation to metabolic abnormalities among older adults [36], which is supported by the fact that age-related changes in body composition, especially increase in visceral fat, may elevate the risk of cardiometabolic disease [37]. In our study, individuals in the older age group who reported getting recommended physical activity levels had higher odds of MHO and lower odds of MONW phenotype (Supplemental Table S7).…”

Low muscle mass and risk of type 2 diabetes in middle-aged and older adults: findings from the KoGES

“…At the limb level, lean body mass is synonymous with skeletal muscle mass, and the appendicular skeletal muscle mass (ASM) calculation was performed based on the sum of the lean body mass in all four limbs [20]. In our study, the muscle mass index (MMI) was derived by dividing ASM by weight in kg × 100, which is suggested to be a better predictor of insulin resistance and diabetes risk than ASM or height-adjusted ASM [11,13,[21][22][23].…”