Comparison between clinical significance of height-adjusted and weight-adjusted appendicular skeletal muscle mass

Background: This study aimed to compare relationships between height- or weight-adjusted appendicular skeletal muscle mass (ASM/Ht2 or ASM/Wt) and risk factors for cardiometabolic diseases or osteoporosis in Japanese men and women. Methods: Subjects were healthy Japanese men (n = 583) and women (n = 1218). The study population included a young group (310 men and 357 women; age, 18-40 years) and a middle-aged and elderly group (273 men and 861 women; age, = 41 years). ASM was measured by dual-energy X-ray absorptiometry. The reference values for class 1 and 2 sarcopenia in each sex were defined as values one and two standard deviations below the sex-specific means of the young group, respectively. Results: The reference values for class 1 and 2 sarcopenia defined by ASM/Ht(2) were 7.77 and 6.89 kg/m(2) in men and 6. 06 and 5.31 kg/m(2) in women, respectively. The reference values for ASM/Wt were 35.0 and 32.0% in men and 29.6 and 26.4% in women, respectively. In both men and women, ASM/Wt was negatively correlated with higher triglycerides (TG) and positively correlated with serum high-density lipoprotein cholesterol (HDL-C), but these associations were not found in height-adjusted ASM. In women, TG, systolic blood pressure, and diastolic blood pressure in sarcopenia defined by ASM/Wt were significantly higher than those in normal subjects, but these associations were not found in sarcopenia defined by ASM/Ht(2). Whole-body and regional bone mineral density in sarcopenia defined by ASM/Ht(2) were significantly lower than those in normal subjects, but these associations were not found in sarcopenia defined by ASM/Wt. Conclusions: Weight-adjusted definition was able to identify cardiometabolic risk factors such as TG and HDL-C while height-adjusted definition could identify factors for osteoporosis.