Body composition and its association with cardiometabolic risk factors in the elderly: a focus on sarcopenic obesity

Important changes in body composition with aging are a progressive loss of muscle mass and increase of fat mass. Despite their enormous clinical importance, body composition changes such as sarcopenic obesity in the elderly are under-recognized. This study aimed to examine the relationship of body composition with a wide variety of cardiometabolic risk factors among 2943 subjects (1250 men and 1693 women) aged 60 years or older from Korean National Health Examination and Nutrition Survey (KNHANES). Sarcopenia was defined as an appendicular skeletal muscle mass (ASM) divided by weight (%) of < 1 SD below the sex-specific mean for young adults. Obesity was defined as a body mass index (BMI) ≥ 25 kg/m(2). Body composition was categorized into four non-overlapping groups: the sarcopenic obese, sarcopenic nonobese, nonsarcopenic obese, and nonsarcopenic nonobese groups. A wide variety of cardiometabolic risk factors, including blood pressure (BP), glucose tolerance indices, lipid profiles, inflammatory markers, and vitamin D level, were compared according to body composition group. The prevalence of sarcopenic obesity was 18.4% in men and 25.8% in women. In both sexes, the prevalence of vitamin D deficiency and metabolic syndrome was highly prevalent in the sarcopenic obese group. Serum insulin level, homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride levels, and ferritin levels were the highest in the sarcopenic obese group in both men and women, whereas HDL-cholesterol and 25-hydroxyvitamin D (25(OH)D) levels were the lowest in the sarcopenic obese group. The sarcopenic obese group was more closely associated with insulin resistance, metabolic syndrome, and cardiovascular disease (CVD) risk factors than any other group in this elderly population.