Yoon-Sok Chung

Prevalence of Sarcopenia and Sarcopenic Obesity in the Korean Population Based on the Fourth Korean National Health and Nutritional Examination Surveys

BACKGROUND Sarcopenia is an important factor of functional impairment related to aging. This study is conducted to investigate the prevalence of sarcopenia and sarcopenic obesity in Korean population. METHODS Representative Korean men (4,486) and women (5,999) aged 20 years or older were analyzed from the Fourth Korean National Health and Nutritional Examination Surveys. Sarcopenia was classified into Class I defined relative skeletal muscle mass loss within 1-2 SD of the gender-specific mean for healthy young adults and Class II below 2 SD. Relative skeletal muscle mass was represented by the appendicular skeletal muscle mass adjusted by height and body weight. Sarcopenic obesity was considered present in Class II sarcopenic participants whose waist circumference was more than or equal to 90 cm for men and more than or equal to 85 cm for women, respectively. RESULTS The prevalence of Class II sarcopenia in the Korean elderly population was 12.4% for men and 0.1% for women by height-adjusted definition and 9.7% for men and 11.8% for women by weight-adjusted definition. The prevalence of sarcopenic obesity was 7.6% for men and 9.1% for women by weight-adjusted definition but nearly zero for men and women by height-adjusted definition. The prevalence of sarcopenia increased with age for men but for women only when applied with weight-adjusted definition. CONCLUSIONS The prevalence of sarcopenia and sarcopenic obesity differs by gender and definition criteria. The height-adjusted definition may tend to underestimate the prevalence of sarcopenia and sarcopenic obesity, especially in women.

Glucocorticoid induces apoptosis of osteoblast cells through the activation of glycogen synthase kinase 3β

Glucocorticoids (GCs), which play an important role in the normal regulation of bone remodeling, are widely used as anti-inflammatory and chemotherapeutic agents. However, continued exposure to GCs results in osteoporosis, which is partially due to apoptosis of osteoblasts and osteocytes. To understand the mechanism of how GCs induce cell death in osteoblasts, we examined apoptotic effects of dexamethasone (Dex), GC, on MC3T3-E1 osteoblast cells. Results revealed that Dex-induced apoptosis was inhibited by a GC receptor antagonist, mifepristone, and a general caspase inhibitor, Z-VAD-fmk, indicating that Dex induces apoptosis of MC3T3-E1 cells through the pathways involved in GC receptor and caspase. Glycogen synthase kinase 3β (GSK3β) is known to participate in apoptosis signaling in MC3T3-E1 cells. Dex activated both GSK3β and p38-mitogen-activated protein kinase (MAPK). The inhibition of GSK3β by inhibitor (LiCl) or small interference RNA (siRNA) decreased apoptosis. In contrast, the inhibition of p38-MAPK by inhibitor (SB203580) or siRNA did not decrease, but increase apoptosis. These results suggest that Dex-mediated apoptosis of osteoblasts is facilitated by GSK3β, but prevented by p38-MAPK.

Association of physical activity with sarcopenia and sarcopenic obesity in community-dwelling older adults: the Fourth Korea National Health and Nutrition Examination Survey

OBJECTIVE this study examined the association of physical activity with sarcopenia and sarcopenic obesity among the community-dwelling Korean elderly. METHODS subjects consisted of 2,264 aged 65 years or older in the 2008-09 Korea National Health and Nutrition Examination Survey. Sarcopenia was defined as 2 SD below the mean of the appendicular skeletal muscle/weight for healthy young adults. Obesity was defined as waist circumference ≥ 90 cm for men and ≥ 85 cm for women. Levels of physical activity were classified using the metabolic equivalent task method. RESULTS the prevalence of sarcopenia was 12.1% in men and 11.9% in women. Among those with sarcopenia, obesity was prevalent in 68.3% of men and 65.0% of women. Adjusting for all covariates, compared with those with low physical activity, men who engaged in moderate and high activity were 38% and 74%, respectively, less likely to have sarcopenia (Ptrend < 0.001). In women, the relationship between physical activity and sarcopenia was not significant. For sarcopenic obesity, men participating in moderate [odds ratio (OR) = 0.47; 95% confidence interval (CI) 0.26-0.87] and high (OR = 0.27; 95% CI: 0.12-0.60) physical activity, compared with low activity, had significantly lower risk (Ptrend = 0.001). In women, high physical activity was associated with a lower risk of sarcopenic obesity (OR = 0.43; 95% CI: 0.22-0.86). CONCLUSION physical activity is associated with a reduced risk of sarcopenia and sarcopenic obesity in older Korean adults. There were gender differences in the relationship, with stronger associations observed in men than in women.

The prevalence of osteoporosis in Korean adults aged 50 years or older and the higher diagnosis rates in women who were beneficiaries of a national screening program: the Korea National Health and Nutrition Examination Survey 2008-2009.

For the prevention of osteoporotic fracture, adequate screening and treatment are important. However, there are few published data on diagnosis and treatment rates of osteoporosis in Asia. We used data from the fourth Korea National Health and Nutrition Examination Survey 2008–2009 to estimate the nationwide prevalence, physician diagnosis rate, and treatment rate of osteoporosis in adults aged 50 years and older. The bone mineral density (BMD) measurements of central skeletal sites (lumbar spine, femoral neck, and total hip) were obtained using dual‐energy X‐ray absorptiometry (DXA) (Discovery‐W; Hologic Inc., Waltham, MA, USA). Diagnosis of osteopenia or osteoporosis was defined by the World Health Organization (WHO) T‐score criteria. The prevalence of osteoporosis in adults aged 50 years or older was 35.5% in women and 7.5% in men. The prevalence of osteoporosis in Korea was similar to other East Asian countries but higher than that in Caucasians. Lumbar spine bone density T‐scores tended to be lower than those of the femoral neck or hip. The estimated diagnosis rate was 26.2% (women 29.9%, men 5.8%) and the treatment rate was 12.8% (women 14.4%, men 4.0%). The physician diagnosis rate was significantly higher in females aged 66 to 68 years who were the beneficiaries of the national screening program than that in females of other ages (43.6% versus 28.1%, p < 0.05). The national screening program for osteoporosis may have contributed to an increased diagnosis rate in older Korean women. However, it was evident that treatment following a diagnosis of osteoporosis was still inadequate.

Effects of Secreted Frizzled-Related Protein 3 on Osteoblasts In Vitro

To examine if sFRP3s act as decoy receptors for Wnt, we examined the effects of recombinant sFRP3 on mouse osteoblast proliferation and differentiation. We found that sFRP3 unexpectedly increased osteoblast differentiation, suggesting it may act through other mechanisms besides acting as a decoy receptor for Wnts.

The Relationship between Diabetes Mellitus and Health-Related Quality of Life in Korean Adults: The Fourth Korea National Health and Nutrition Examination Survey (2007-2009)

Background Diabetes is a major health problem in Korea. However, interest in the quality of life in patients with diabetes is low. We examined the effects of diabetes on health-related quality of life (HRQoL) and compared it with HRQoL in the general Korean population using the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV) (2007-2009). Methods Using KNHANES IV data, we compared EuroQol (EQ)-5D and EQ-visual analogue scale (VAS) scores after adjusting for sociodemographic and psychosocial factors as well as for comorbidities (hypertension, heart disease, stroke, arthritis, and chronic renal disease). Logistic regressions were used to explore determinants for the lowest quintile HRQoL scales in the diabetes group. Results The mean age of the 14,441 enrolled subjects (6,129 men and 8,312 women) was 52.5±14.5 years. The mean EQ-5D and EQ-VAS scores were significantly lower in the diabetes group (EQ-5D. 0.87; EQ-VAS, 71.94) than in the non-diabetes group (EQ-5D, 0.94; EQ-VAS, 77.40) (P<0.001). Self-reported depressive symptom had a significant effect on lowering the EQ-VAS (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1 to 2.6) in the diabetes group. Stress level had a significant effect in lowering both the EQ-5D (OR, 2.0; 95% CI, 1.3 to 2.9) and the EQ-VAS (OR, 1.9; 95% CI, 1.3 to 2.9). HbA1c, diabetes duration, and treatment modalities had no significant effect on lowering HRQoL. Conclusion Diabetes was clearly associated with impaired HRQoL compared with the non-diabetic population regardless of comorbidities. Therapeutic approaches should focus much more on the subjective perception of health in patients with diabetes.

The Prevalence of the Metabolic Syndrome in Korean Adults: Comparison of WHO and NCEP Criteria

The aims of this study were to compare the prevalence of the metabolic syndrome according to the WHO and NCEP ATP III criteria in Korean adults, and to compare the prevalence of the metabolic syndrome with the results in previous Korean studies. The study comprised 1,230 subjects (627 men, 603 women) aged 30-79 years (mean 52.4±10.3 years) who underwent medical check-up from April to June, 2001 in the Korea Association of Health (KAH). The prevalence of the metabolic syndrome according to the modified WHO criteria was 21.8% of men and 19.4% of women. However, the prevalence was increased 1.6 times (34.2%) in men and 2.0 times (38.7%) in women using the modified NCEP criteria. The prevalence of the metabolic syndrome has varied widely according to differences in the criteria. Thus, further studies are necessary to define the appropriate criteria of the metabolic syndrome for Korean adults.

Multiple Brown Tumors in Parathyroid Carcinoma Mimicking Metastatic Bone Disease

An unusual case of multiple brown tumors due to parathyroid carcinoma is reported. The patient presented with lower leg pain. Plain radiographs demonstrated multiple lytic lesions of the lower legs and a Tc-99m MDP bone scan depicted multiple areas of increased uptake suggesting skeletal metastases. Tc-99m sestamibi tumor scintigraphy showed multiple sites of tumor uptake in bones and a large area of increased uptake with a cystic component in the right lower pole of the thyroid gland. An open biopsy from the right tibial lesion revealed a brown tumor. A large parathyroid carcinoma with a necrotic cyst was removed. After parathyroidectomy and right thyroid lobectomy, the patient became free of bone pain and serum PTH levels normalized. A 9-month follow-up Tc-99m MDP bone scan demonstrated less intense uptake in the pelvis, tibia, and fibulae. Nine-month follow-up tumor imaging with Tc-99m MIBI revealed disappearance of the preoperative uptake of multiple brown tumor.

Age-and region-dependent changes in three-dimensional microstructural properties of proximal femoral trabeculae

SummaryThis study investigated regional variations in the 3D microstructure of trabecular bone in human proximal femur, with respect to aging. The results demonstrate that age-related changes in trabecular microstructure significantly varied from different sub-regions of the proximal femur.IntroductionWe hypothesize that the age-related changes in trabecular bone microstructure appear to be varied from specific anatomic sub-regions of the proximal femur followed by non-uniform bone loss. The purpose of this study was therefore to explore regional variations in the 3D microstructure of trabecular bone in human proximal femur, with respect to aging.MethodsA total of 162 trabecular bone cores from six regions of 27 femora of male cadaver donors were scanned using micro-computed tomography (micro-CT). The following microstructural parameters were calculated: bone volume fraction (BV/TV), trabecular number (Tb.N), thickness (Tb.Th) and separation (Tb.Sp), structure model index (SMI), and degree of anisotropy (DOA).ResultsAge-related changes in trabecular microstructure varied from different regions of the proximal femur. There was a significant decrease in bone volume fraction and an almost identical decrease in trabecular thickness associated with aging at any region. Regional analysis demonstrated a significant difference in BV/TV, Tb.Th, Tb.Sp, Tb.N and DOA between superior and inferior neck, as well as a significant difference in BV/TV, Tb.Sp, Tb.N, SMI and DOA between superior and inferior trochanter.ConclusionsAge-related changes in bone loss and trabecular microstructure within the male proximal femur are not uniform in this cadaveric population.

Association of vegetables and fruits consumption with sarcopenia in older adults: the Fourth Korea National Health and Nutrition Examination Survey

BACKGROUND several studies have found nutrients, including antioxidants, to be associated with sarcopenia. However, whether specific foods, such as vegetables and fruits, are associated with sarcopenia has not been studied. OBJECTIVE to examine the association of the frequency of vegetables and fruits consumption with sarcopenia in older people. METHODS this study used cross-sectional data from the Fourth Korea National Health and Nutrition Examination Survey in 2008-09. Subjects were community-dwelling 823 men and 1,089 women aged ≥65 years. Frequency of food group consumption was obtained by using the food frequency questionnaire. Body composition was measured with the dual-energy X-ray absorptiometry and sarcopenia was defined as appendicular lean mass adjusted for height and fat mass. Logistic regression was used to assess the association of the frequency of food group consumption with sarcopenia, controlling for sociodemographics and health-related variables. RESULTS dietary intake of vegetables, fruits and both vegetables and fruits was associated with a significantly reduced risk of sarcopenia after controlling for covariates in men (P = 0.026 for trend, P = 0.012 for trend, P = 0.003 for trend, respectively). Men in the highest quintile, compared with those in the lowest quintile, of vegetables [odds ratio (OR) = 0.48; 95% confidence interval (CI): 0.24-0.95], fruits (OR = 0.30; 95% CI: 0.13-0.70) and vegetables and fruits consumption (OR = 0.32; 95% CI: 0.16-0.67) demonstrated a lower risk of sarcopenia. In women, high consumption of fruits demonstrated a lower risk of sarcopenia (OR = 0.39; 95% CI: 0.18-0.83). CONCLUSION frequent vegetables and fruits consumption was inversely associated with sarcopenia in older adults.