Relationships between trunk tissue distribution, metabolic risk factors and physical performance in young people—A pilot study

The present study examined the relationships between trunk tissue distribution, metabolic risk factors, and physical performance in young Japanese individuals using cross-sectional and longitudinal analyses. Thirty-six healthy Japanese men (n = 20, body mass index [BMI]: 20.8 ± 2.0 kg/m²) and women (n = 16, BMI: 19.6 ± 2.0 kg/m²) aged 20-26 years old visited our laboratory twice with an interval of 1 year. The thicknesses of skeletal muscle (MT), subcutaneous adipose tissue (SCAT), and the intra-abdominal cavity (IAT) were assessed by ultrasound imaging and adjusted by body mass^1/3 (BM^1/3). Blood properties related to hepatic function or metabolic syndrome, brachial-ankle pulse wave velocity, hand grip strength, two-step-length/height scores, and sit-and-reach test scores were also measured. As a result of the cross-sectional analysis, significant relationships were observed between SCAT/BM^1/3 and indices of glucose metabolism (HOMA-IR and QUICKI) in men (r = 0.513 and -0.583), and between IAT/BM^1/3 and fasting blood glucose in women (r = 0.524). Longitudinal analyses of women showed that changes (%) in IAT and MT/IAT correlated with % changes in the indices of hepatic function (AST) and glucose metabolism (HOMA-IR and HOMA-β) (r = -0.673 to 0.686). Significant correlations were also observed between MT/IAT and walking ability (two-step-length/height) in cross-sectional and longitudinal analyses of men (r = 0.463 and 0.525). In conclusion, the trunk tissue distribution could be used to detect the early symptoms of metabolic risks and declines in physical performance in young men and women.