OBJECTIVE We investigated the prevalence of sarcopenic obesity (SO) and its relationship with metabolic syndrome in a community-based elderly cohort in Korea. RESEARCH DESIGN AND METHODS In this study, 287 men and 278 women aged 65 or older were recruited. Sarcopenia was defined as the appendicular skeletal muscle mass (ASM) divided by height squared (Ht²) (kg/m²) or by weight (Wt) (%) of <1 SD below the sex-specific mean for young adults. Obesity was defined as a visceral fat area ≥100 cm². RESULTS The prevalence of SO was 16.7% in men and 5.7% in women with sarcopenia defined by ASM/Ht²; however, it was 35.1% in men and 48.1% in women by ASM/Wt. Using ASM/Wt, the homeostasis model assessment of insulin resistance of subjects with SO was higher and they were at higher risk for metabolic syndrome (odds ratio [OR] 8.28 [95% CI 4.45–15.40]) than the obese (5.51 [2.81–10.80]) or sarcopenic group (2.64 [1.08–6.44]). CONCLUSIONS SO defined by ASM/Wt was more closely associated with metabolic syndrome than either sarcopenia or obesity alone.

The concept of sarcopenia has expanded recently to include muscle strength or physical performance. We investigated whether the Europe Working Group on Sarcopenia in Older People (EWGSOP) definition of sarcopenia predicts the risk of all-cause mortality in community-dwelling older adults. This study included 284 men and 272 women aged 65 and older. The outcome was all-cause mortality during the 6-year follow-up period. We defined sarcopenia based on the EWGSOP definitions of sarcopenia: height (ht)- or weight (wt)-adjusted appendicular skeletal muscle mass (ASM/ht² or ASM/wt) assessed by dual-energy x-ray absorptiometry, leg muscle strength, and short physical performance battery test score. During the 6-year follow-up, 40 men and 19 women died. The risk of death was 2.99 times and 3.22 times higher in men with sarcopenia identified by ASM/ht² and ASM/wt, respectively, compared with nonsarcopenic men. The hazard ratio for death was 5.37 for men with weak leg muscle strength. Men with a low short physical performance battery score had a 3.15 times higher risk of death compared with those with high short physical performance battery scores, even after adjusting for all covariates. The adjusted hazard ratios for EWGSOP-defined sarcopenia were 4.00 for ASM/ht² and 6.89 for ASM/wt in men. By contrast, sarcopenia defined by these criteria was not associated with a higher risk of death in women. Our data suggest that, in older men, EWGSOP-defined sarcopenia is related to higher mortality compared with nonsarcopenia regardless of the ASM/ht² or ASM/wt index. In older women, further studies with large sample sizes are needed to assess whether EWGSOP-defined sarcopenia increases the mortality risk.

Trabecular bone score (TBS) is a novel texture index that evaluates the pixel gray-level variations in lumbar spine dual-energy X-ray absorptiometry images and is related to bone microarchitecture independent of bone mineral density (BMD). We investigated lumbar spine TBS as an indicator for skeletal deterioration in diabetes. Cross-sectional data were collected from subjects participating in an ongoing prospective, community-based, cohort study from 2009 to 2010. We included 1229 men and 1529 postmenopausal women older than 50 years in the Ansung cohort. Biochemical parameters, lumbar spine TBS, and BMD from dual-energy X-ray absorptiometry images were measured. Lumbar spine TBS was lower in men with diabetes than in nondiabetic men (1.287 ± 0.005 vs 1.316 ± 0.003, P < .001), whereas lumbar spine BMD was higher in men with diabetes (1.135 ± 0.010 vs 1.088 ± 0.006 g/cm(2)). Lumbar spine TBS was lower in women with diabetes than in nondiabetic women only in an unadjusted model (1.333 ± 0.004 vs 1.353 ± 0.003). However, women younger than 65 years (n = 707) with diabetes had a lower TBS than those without diabetes, even after adjusted for covariates (P < .001). Diabetes was not associated with BMD at femur sites in both genders. TBS was negatively correlated with glycated hemoglobin, fasting plasma glucose, fasting insulin, and homeostasis model assessment for insulin resistance but not with homeostasis model assessment for β-cell function in both genders. The inverse association between lumbar spine TBS and insulin resistance may make it an indicator for determining skeletal deterioration in diabetic patients who have high BMD.

The Korean National Health Information Database (NHID) contains big data combining information obtained from the National Health Insurance Service and health examinations. Data are provided in the form of a cohort, and the NHID can be used to conduct longitudinal studies and research on rare diseases. Moreover, data on the cause and date of death are provided by Statistics Korea. Research and publications based on the NHID have increased explosively in the field of endocrine disorders. However, because the data were not collected for research purposes, studies using the NHID have limitations, particularly the need for the operational definition of diseases. In this review, we describe the characteristics of the Korean NHID, operational definitions of endocrine diseases used for research, and an overview of recent studies in endocrinology using the Korean NHID.