OBJECTIVE: We examined prevalence of sarcopenia in Korean patients with type 2 diabetes and compared body compositional parameters between subjects with and without type 2 diabetes. RESEARCH DESIGN AND METHODS: The Korean Sarcopenic Obesity Study (KSOS) included 810 subjects (414 patients with diabetes and 396 control subjects) who were examined using dual-energy X-ray absorptiometry. Prevalence of sarcopenia was defined using the skeletal muscle index (SMI). RESULTS: Prevalence in patients with diabetes and in the control group was 15.7 and 6.9%, respectively. In both men and women, SMI values were significantly decreased in patients with diabetes compared with subjects without diabetes. Furthermore, multiple logistic regression analysis showed that type 2 diabetes was independently associated with sarcopenia. CONCLUSIONS: Type 2 diabetes was associated with increased risk of sarcopenia. These characteristics may contribute to physical disability and metabolic disorders in older adults with diabetes.

Previous studies have shown that nonalcoholic fatty liver disease (NAFLD) and sarcopenia may share pathophysiological mechanisms, such as insulin resistance, inflammation, vitamin D deficiency, and decreased physical activity. However, their direct relationship has not been investigated. The association between NAFLD and sarcopenia was examined in 452 apparently healthy adults enrolled in the Korean Sarcopenic Obesity Study (KSOS), an ongoing prospective observational cohort study. The liver attenuation index (LAI), which was measured using abdominal computed tomography (CT), was used as a parameter for the diagnosis of NAFLD. Sarcopenia was defined using a skeletal muscle mass index (SMI) [SMI (%) = total skeletal muscle mass (kg) / weight (kg) × 100] that was measured by dual energy X-ray absorptiometry (DXA). After adjusting for age and sex, both SMI and LAI were negatively correlated with the homeostasis model assessment of insulin resistance (HOMA-IR) ( P < 0.001) and high sensitivity C-reactive protein (hsCRP) ( P < 0.001) as well as brachial-ankle pulse wave velocity (baPWV), an indicator of arterial stiffness. Furthermore, SMI and LAI had positive relationships with high-density lipoprotein (HDL)-cholesterol, but both had a negative relationship with triglyceride, alanine aminotransferase (ALT), and total body fat. In a multiple logistic regression analysis, the odds ratio for NAFLD risk was 5.16 (95% confidence interval [CI] = 1.63-16.33) in the lowest quartile of SMI compared to the highest after adjusting for potential confounding factors. Conclusion : Individuals with lower muscle mass exhibited increased risk of NAFLD. This result may provide a novel insight into the mechanism linking between sarcopenia and NAFLD. (Clinical trial no. NCT01594710.) (Hepatology 2014;59:1772–1778)

Chronotype is a trait determining individual circadian preference in behavioral and biological rhythm relative to external light-dark cycle. However, little is known about the relationship between chronotype and metabolic disorders. The aim of this study was to examine whether late chronotype is related to metabolic abnormalities and body composition in middle-aged adults, independent of sleep duration and lifestyle. A total of 1620 participants aged 47-59 years were recruited from the Korean Genome and Epidemiology Study. Chronotype was assessed by the Morningness-Eveningness Questionnaire. Associations of chronotype with diabetes, metabolic syndrome, sarcopenia, and visceral obesity were analyzed. All participants underwent the oral glucose tolerance test, and body composition was measured with dual energy x-ray absorptiometry. Visceral obesity was designated as visceral fat area, measured by abdominal computed tomography, of >100 cm(2). Chronotype was classified as morning in 29.6% of subjects, evening in 5.9%, neither morning nor evening in 64.5%. Evening type, when compared with morning type, was significantly associated with diabetes (odds ratio [OR], 1.73; 95% confidence interval [CI], 1.01-2.95), metabolic syndrome (OR, 1.74; 95% CI, 1.05-2.87), and sarcopenia (OR, 3.16; 95% CI, 1.36-7.33) after adjusting for confounding factors. Gender differences in the associations were evident. In men, evening type was associated with diabetes (OR, 2.98; 95% CI, 1.39-6.39) and sarcopenia (OR, 3.89; 95% CI, 1.33-11.33). Only metabolic syndrome was associated with evening type in women (OR, 2.22; 95% CI, 1.11-4.43). At the population level, evening chronotype was independently associated with diabetes, metabolic syndrome, and sarcopenia. These results support the importance of circadian rhythms in metabolic regulation.

Previous studies have shown that angiopoietin-like protein 8 (ANGPTL8), also called as betatrophin, acts together with ANGPTL3 to regulate lipid metabolism, glucose metabolism, and energy homeostasis. Moreover, ANGPTL8 promotes proliferation of pancreatic β-cells and induces insulin secretion. However, there are no previous longitudinal studies in humans. We analyzed the age- and sex-matched data of 240 normal weight and overweight Korean children from the Korean Metabolic disorders and Obesity Study in Elementary School children (K-MOSES), a prospective observational cohort study. At baseline, ANGPTL8 concentrations were positively associated with triglycerides (TG) (r = 0.168, P = 0.010), whereas ANGPTL3 levels were associated with fasting insulin (r = 0.248, P < 0.001) and the homeostasis model assessment of insulin resistance (HOMA-IR) (r = 0.197, P = 0.002). Although both ANGPTL8 and ANGPTL3 levels did not differ between children with normal weight and children with overweight, ANGPTL8 levels were increased in males compared to females (341.2 [267.4–436.5] vs. 270.2 [213.9–378.8] pg/ml, P = 0.001). In particular, there was no significant inter-relationship between circulating ANGPTL8 and ANGPTL3 concentrations in Korean boys and girls (r = −0.073, P = 0.265). Multivariate analysis showed that baseline ANGPTL8 concentrations were independently associated with future changes of serum TG levels in Korean children after adjusting for confounding factors after a 3 year follow-up period (r = −0.165, P = 0.016). This longitudinal study demonstrated for the first time that baseline ANGPTL8 levels were associated with baseline and future changes in TG levels in Korean children.