Hyun Joo Kang

Prevalence and Determinant Factors of Sarcopenia in Patients With Type 2 Diabetes The Korean Sarcopenic Obesity Study (KSOS)

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.

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)/height2, 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/height2 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 (⩾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 elucidate.

Relationships between sarcopenic obesity and insulin resistance, inflammation, and vitamin D status: the Korean Sarcopenic Obesity Study

It has been suggested that insulin resistance, low‐grade inflammation and vitamin D deficiency are associated with obesity and sarcopenia. However, their relationships with sarcopenic obesity (SO) are unclear. We evaluated the impact of homoeostasis model assessment of insulin resistance (HOMA‐IR), high‐sensitivity C‐reactive protein (hsCRP) and 25‐hydroxyvitamin D (25[OH]D) levels on SO in Korean adults.

Skeletal muscle mass to visceral fat area ratio is associated with metabolic syndrome and arterial stiffness: The Korean Sarcopenic Obesity Study (KSOS)

AIMS Sarcopenia measured as appendicular skeletal muscle mass (ASM), and central obesity measured as visceral fat area (VFA) may act synergistically to influence metabolic syndrome and atherosclerosis. However, several previous studies reported that metabolic risk is higher in non-sarcopenic obesity groups than in sarcopenic obesity groups because of the close relationship between muscle mass and body fat. We investigated the association of the ASM to VFA ratio, which we have termed the muscle-to-fat ratio (MFR), with metabolic syndrome and arterial stiffness. METHODS This study was performed in 526 apparently healthy adults enrolled in the Korean Sarcopenic Obesity Study, an ongoing prospective observational cohort study. ASM was evaluated with dual energy X-ray absorptiometry and VFA with computed tomography. Arterial stiffness was measured using brachial-ankle pulse wave velocity (baPWV). RESULTS MFR was significantly associated with waist circumference, blood pressure, lipid profiles, glucose and baPWV. By multiple logistic regression analysis, the odds ratio for metabolic syndrome was 5.43 (lowest versus highest tertile of MFR, 95% confidence interval, 2.56-13.34). Multiple stepwise regression analysis showed that MFR was an independent determinant of baPWV (R²=0.57). CONCLUSIONS MFR, a new index of sarcopenic obesity, showed an independent negative association with metabolic syndrome and arterial stiffness.

Body Size Phenotypes and Low Muscle Mass: The Korean Sarcopenic Obesity Study (KSOS)

CONTEXT Unique subsets of body size phenotypes seem to be more prone or more resistant to the development of obesity-associated metabolic disorders, although the underlying mechanism is not yet clearly understood. OBJECTIVES We investigated the prevalence and risk of low muscle mass in subjects who are classified as either metabolically healthy normal weight (MHNW), metabolically abnormal but normal weight (MANW), metabolically healthy obese (MHO), or metabolically abnormal obese (MAO). Subjects were classified based on body mass index and presence of metabolic syndrome. METHODS Thigh muscle cross-sectional area was evaluated using computed tomography as an index of muscle mass in 492 apparently healthy adults enrolled in the Korean Sarcopenic Obesity Study (KSOS), an ongoing prospective observational cohort study. Low muscle mass was defined as thigh muscle cross-sectional area divided by weight (percent) of <1 SD below the mean values of young adults in both sexes. RESULTS The prevalence rates of low muscle mass in MHNW, MANW, MHO, and MAO subjects were 6.2%, 17.8%, 23.2%, and 33.7%, respectively. In a multiple logistic regression analysis, men with the MANW phenotype showed a remarkably increased risk of low muscle mass (odds ratio = 11.30, 95% confidence interval, 1.73-73.28) compared with those with MHNW. Furthermore, in both men and women, MHO or MAO subjects had higher odds ratios of low muscle mass compared with MHNW subjects. CONCLUSIONS The present study suggests that low muscle mass may be associated with different metabolic consequences according to body size phenotype.

Impact of Visceral Fat on Skeletal Muscle Mass and Vice Versa in a Prospective Cohort Study: The Korean Sarcopenic Obesity Study (KSOS)

Objectives Sarcopenia and visceral obesity have been suggested to aggravate each other, resulting in a vicious cycle. However, evidence based on prospective study is very limited. Our purpose was to investigate whether visceral fat promotes a decrease in skeletal muscle mass and vice versa. Methods We observed changes in anthropometric and body composition data during a follow-up period of 27.6±2.8 months in 379 Korean men and women (mean age 51.9±14.6 years) from the Korean Sarcopenic Obesity Study (KSOS). Appendicular lean soft tissue (ALST) mass was calculated using dual-energy X-ray absorptiometry, and visceral fat area (VFA) was measured using computed tomography at baseline and follow-up examination. Results ALST mass significantly decreased, whereas trunk and total fat mass increased in both men and women despite no significant change in weight and body mass index. In particular, women with visceral obesity at baseline had a greater decrease in ALST mass than those without visceral obesity (P = 0.001). In multiple linear regression analysis, baseline VFA was an independent negative predictor of the changes in ALST after adjusting for confounding factors including age, gender, life style and body composition parameters, insulin resistance, high sensitivity C-reactive protein and vitamin D levels (P = 0.001), whereas the association between baseline ALST mass and changes in VFA was not statistically significant (P = 0.555). Conclusions This longitudinal study showed that visceral obesity was associated with future loss of skeletal muscle mass in Korean adults. These results may provide novel insight into sarcopenic obesity in an aging society.

Cutoff points of abdominal obesity indices in screening for non-alcoholic fatty liver disease in Asians.

Background/aims: Abdominal obesity is associated with metabolic syndrome and non‐alcoholic fatty liver disease (NAFLD). Although there have been many studies to determine the optimal cutoff points of waist circumference or visceral fat area in screening for metabolic syndrome, there have been no reports to establish adequate cutoff points of abdominal obesity indices in screening for NAFLD. Therefore, we examined the appropriate cutoff points of abdominal obesity indices associated with NAFLD in Korean men and women using receiver operating characteristic (ROC) curve analysis. Furthermore, we compared the usefulness of various abdominal obesity indices measured using computed tomography (CT), dual‐energy X‐ray absorptiometry (DXA) and anthropometric parameters for detecting NAFLD.

Comparisons of three different methods for defining sarcopenia: An aspect of cardiometabolic risk

Appraisal of muscle mass is important when considering the serious consequences of sarcopenia in an aging society. However, the associations between sarcopenia and its clinical outcomes might vary according to the method applied in its diagnosis. We compared the relationships between cardiometabolic risk parameters and sarcopenia defined according to three different diagnostic methods using dual-energy X-ray absorptiometry (DXA) and computed tomography (CT). Appendicular skeletal muscle mass (ASM) adjusted by height squared and BMI (ASM/height2 and ASM/BMI) measured using DXA and thigh muscle cross-sectional area (tmCSA) adjusted by weight (tmCSA/weight) measured using CT were used as indices of muscle mass. Sarcopenia was defined as two standard deviations below either the mean ASM/height2, ASM/BMI, or tmCSA/weight of a young reference group. ASM/BMI and tmCSA/weight showed a negative relationship with several components of metabolic syndrome and HOMA-IR, whereas ASM/height2 was positively associated with theses cardiometabolic risk factors. Logistic regression analyses demonstrated that ASM/BMI-defined sarcopenia was significantly associated with increased HOMA-IR (P = 0.01) and prevalence of visceral obesity (P = 0.03) and metabolic syndrome (P = 0.025), while ASM/height2- and tmCSA/weight-defined sarcopenia were not. ASM/BMI-defined sarcopenia exhibits a closer relationship with cardiometabolic risk factors than does ASM/height2- or tmCSA/weight-defined sarcopenia.

The association of low muscle mass with soluble receptor for advanced glycation end products (sRAGE): The Korean Sarcopenic Obesity Study (KSOS)

Advanced glycation end products (AGEs) are accumulated with aging in various tissues of humans. The soluble receptor for AGEs (sRAGE) exerts a protective role against the development of aging‐related chronic disorders by neutralizing the action of AGEs. We investigated the implication of sRAGE on low muscle mass in Asian men and women.