Associations between adiponectin and leptin levels and skeletal muscle mass and myosteatosis in older adults: The Shimanami Health Promoting Program study

Abstract

Identifying plasma molecules associated with skeletal muscle properties can elucidate the pathophysiology of sarcopenia. Because adipocytokines are a promising candidate marker, the current study aimed to clarify the possible associations between adiponectin and leptin levels and mid-thigh muscle cross-sectional area and mean attenuation value, which are indices of muscle mass and fat deposition in muscle, respectively. The current study included 1440 older Japanese adults (mean age 69.3 years). Mid-thigh skeletal muscle cross-sectional area and mean attenuation value were evaluated through computed tomography scan. A low attenuation value showed a greater fat deposition in muscle. Circulating adiponectin and leptin levels were assessed using blood specimens collected during the baseline investigation. Plasma leptin level was inversely correlated with muscle cross-sectional area, but not with attenuation value. The association with cross-sectional area was independent of possible confounding factors including body size (Q1: reference; Q2: β = -0.032, P = 0.033; Q3: β = -0.064, P < 0.001; Q4: β = -0.111, P < 0.001). In contrast, adiponectin level was independently and inversely associated with attenuation value (Q1: reference; Q2: β = -0.044, P = 0.122; Q3: β = -0.080, P = 0.006; Q4: β = -0.159, P < 0.001), but not with cross-sectional area. These associations between adipocytokine levels and muscle properties were independent of abdominal fat area and insulin resistance. There were adiposity- and insulin resistance-independent associations between adipocytokines levels and skeletal muscle mass and fat deposition in muscle, suggesting an involvement of adipocytokines in muscle properties. Geriatr Gerontol Int 2023; 23: 444-449.