Prevalence of sarcopenia and sarcopenic obesity in Korean adults: the Korean sarcopenic obesity study.

OBJECTIVES: To examine the prevalence of sarcopenia and sarcopenic obesity (SO) as defined by different indices, including appendicular skeletal muscle mass (ASM)/height(2), skeletal muscle mass index (SMI) and residuals for Korean adults, and to explore the association between SO and metabolic syndrome.

METHODS: Our study sample included 526 participants (328 women, 198 men) for whom complete data on body composition were collected using available dual X-ray absorptiometry. Modified National Cholesterol Education Program Adult Treatment Panel III criteria were used to identify the individuals with metabolic syndrome.

RESULTS: The prevalence of sarcopenia and SO is higher in older adults. Using two s.d. of ASM/height(2) below reference values from young, healthy adults as a definition of sarcopenia, the prevalence of sarcopenia and SO was 6.3% and 1.3% in older (> or =60 years) men and 4.1% and 0.8% in older women, respectively. The prevalence of sarcopenia using the residuals method was 15.4% in older men and 22.3% in older women. In addition, using two s.d. of SMI, the prevalence of sarcopenia and SO was 5.1% and 5.1%, respectively, in older men and 14.2% and 12.5%, respectively, in older women. Among women, SO subjects defined by the SMI had three times the risk of metabolic syndrome (odds ratios (OR)=3.24, 95% confidence interval (CI)=1.21-8.66) and non-sarcopenic obese subjects had approximately twice the risk of metabolic syndrome (OR=2.17, 95% CI=1.22-3.88) compared with normal subjects. Similar trends were observed in men.

CONCLUSION: The prevalence and cutoff values of sarcopenia and SO in the Korean population were evaluated using different methods. Among the different indices of sarcopenia and SO, SO only defined using the SMI was associated with the risk of metabolic syndrome. As the Korean population gets older and more obese, the problematics of SO need to be elucidated.