Purpose: Muscles play an important role in energy metabolism. Several studies have investigated the association between muscle mass and metabolic syndrome (MetS), reporting conflicting results. However, studies concerning the association between muscle strength and MetS are limited. We aimed to investigate the association between relative handgrip strength (HGS) and MetS in Korean adults. Participants and methods: We analyzed data from 5,014 Korean adults aged ≥20 years (2,472 men and 2,542 women) who participated in the Korea National Health and Nutrition Examination Survey (KNHANES) VI (2014–2015). Results: The increasing quartiles of relative HGS (defined as the sum of both hands’ HGS divided by body mass index) were inversely associated with the risk of MetS in both men and women (OR, 0.37; 95% CI, 0.30–0.45, vs OR, 0.19; 95% CI, 0.14–0.27, respectively) after multivariable adjustment for age, region of residence, smoking status, heavy alcohol consumption, regular exercise, family income, and education level. On multivariable logistic regression analyses, participants with the highest relative HGS had a significant decrease in relative risk of MetS, compared with those with the lowest relative HGS. The multivariable-adjusted ORs (with 95% CIs) for MetS in quartiles 1, 2, 3, and 4 were 1.00, 0.72 (0.55–0.94), 0.34 (0.26–0.46), and 0.22 (0.15–0.32) in men and 1.00, 0.50 (0.36–0.68), 0.26 (0.17–0.40), and 0.16 (0.09–0.27) in women, respectively. Conclusion: Relative HGS showed a highly significant inverse association with the risk of MetS in Korean adults, and it can be a novel biomarker for assessing the risk of MetS.

Purpose: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and it is the hepatic manifestation of metabolic syndrome (MetS). We aimed to estimate the prevalence of NAFLD defined by the fatty liver index (FLI), in order to investigate the association between FLI and metabolic disorders and to determine the cutoff value of FLI to screen for MetS. Subjects and methods: This study utilized a national representative sample of Korean adults (the Korean National Health and Nutrition Examination Surveys) which was conducted in 2010–2011. A total of 10,107 adults aged 19 years or older were selected. NAFLD was diagnosed on the basis of an increased FLI (≥60) after the exclusion of alcohol or viral liver disease. Results: NAFLD was identified in 1,134 subjects (age-standardized prevalence, 10.0%). When subjects were categorized into three groups by FLI (<20, 20–59, and ≥60), the higher FLI group showed a higher prevalence of hypertension (49.7% vs 14.4%), diabetes mellitus (DM; 20.4% vs 3.8%), and MetS (74.9% vs 7.4%). FLI was positively associated with age, body mass index, blood pressure, hemoglobin A1c, and homeostasis model assessment of insulin resistance (P for trend <0.001). In the multivariate analysis, the higher FLI group had a significantly higher risk for hypertension (OR =2.92, 95% CI =2.18–3.90, P<0.001), DM (OR =4.38, 95% CI =2.96–6.49, P<0.001), and MetS (OR =24.85, 95% CI =17.33–35.64, P<0.001). However, no increase was observed for cardiovascular disease after adjustment of other risk factors. The cutoff value of the FLI estimated to predict the presence of MetS was 20 (area under the curve 0.849, sensitivity 0.828, and negative predictive value 91.9%). Conclusion: NAFLD prevalence using FLI is significantly higher in subjects with metabolic disorder including MetS. FLI might be a useful screening tool to detect subjects who may require early management of MetS and who have a high cardiovascular risk.

Vascular calcification refers to the deposition of calcium phosphate in cardiovascular tissues, including arteries and myocardium. Vascular calcification is frequently associated with cardiovascular disease. Recently, bone morphgenetic protein-7 (BMP-7) has been proposed to play an inhibitory role in vascular calcification, but its inhibitory effect has not been fully elucidated. We therefore tested the hypothesis that BMP-7 inhibits vascular calcification by using two conditions, high levels of vitamin D and phosphate, each of which could enhance vascular calcification. C57BL/6 mice were treated for 3 days with high vitamin D (500,000 IU/kg/day) in the presence or absence of recombinant human BMP-7 (rhBMP-7). Expression levels of osteopontin and osteocalcin, markers of the osteoblastic phenotype, were assessed by immunohistochemical staining or Western blotting analysis. Vitamin D increased calcium staining in thoracic aortas and hearts and the expression levels of osteopontin and osteocalcin in mice. Importantly, pretreatment for 7 days and subsequent treatment for 3 days with rhBMP-7 (10 μg/kg/day) abolished the vitamin D-mediated increases in the above parameters. In addition, human aortic smooth muscle cells (HASMCs) were cultured with high β-glycerophosphate, a phosphate donor, for 2 weeks in the presence or absence of rhBMP-7. High β-glycerophosphate increased expression levels of osteopontin and osteocalcin as well as calcium staining in HASMCs, but these changes were attenuated by treatment with BMP-7. Thus, BMP-7 inhibits vascular calcification associated with high levels of vitamin D or phosphate. We propose that BMP-7 treatment may be helpful in reducing the risks of cardiovascular disease related to vascular calcification.

Background: The present study investigated the role of synergistic interaction between hyperuricemia and abdominal obesity as a risk factor for the components of metabolic syndrome.Methods: We performed a cross-sectional study using the data of 16,094 individuals from the seventh Korean National Health and Nutrition Examination Survey (2016 to 2018). The adjusted odds ratios of metabolic syndrome and its components were analyzed by multivariate logistic regression analysis. The presence of synergistic interaction between hyperuricemia and abdominal obesity was evaluated by calculating the additive scales—the relative excess risk due to interaction, attributable proportion due to interaction, and synergy index (SI).Results: There was a synergistic interaction between hyperuricemia and abdominal obesity in hypertriglyceridemia (men: SI, 1.39; 95% confidence interval [CI], 1.01 to 1.98; women: SI, 1.61; 95% CI, 1.02 to 2.69), and low high-density lipoprotein cholesterol (HDL-C) (men: SI, 2.03; 95% CI, 1.41 to 2.91; women: SI, 1.70; 95% CI, 1.05 to 2.95). There was no significant synergistic interaction between hyperuricemia and abdominal obesity for the risk of high blood pressure (men: SI, 1.22; 95% CI, 0.85 to 1.77; women: SI, 1.53; 95% CI, 0.79 to 2.97), and hyperglycemia (men: SI, 1.03; 95% CI, 0.72 to 1.47; women: SI, 1.39; 95% CI, 0.75 to 2.57).Conclusion: Hyperuricemia and abdominal obesity synergistically increased the risk of hypertriglyceridemia and low HDL-C in both sexes.

Objective: This study investigated the association between relative hand grip strength (HGS) and glycemic status, such as impaired fasting glucose (IFG) and diabetes, using data from the Korea National Health and Nutrition Examination Survey (KNHANES). Methods: We performed a cross-sectional study using the data from the KNHANES of 27,894 individuals from 2014 to 2019. Relative HGS was defined as the absolute HGS divided by body mass index and divided into quartiles in men and women. Odds ratios (OR) for diabetes and IFG were calculated using multivariate logistic regression analysis. All analyses were stratified by sex, and subgroup analysis was age-stratified. Results: The lowest relative HGS quartile had a significant increase in the risk for diabetes (men: OR 2.72, 95% confidence interval [CI] 2.12–3.50; women: OR 3.38, 95% CI 2.70–4.24) and IFG (men: OR 1.35, 95% CI 1.15–1.59; women: OR 1.60, 95% CI 1.40–1.84). The ORs for diabetes and IFG according to the decreasing quartiles of relative HGS gradually increased in both sexes (P for trend <0.001). ORs and 95% CI of the lowest relative HGS quartile for diabetes were higher in the younger age group than that of the older age group (men: 4.47 and 2.80–7.14 for young adults; 2.41 and 1.37–4.25 for older adults; women: 5.91 and 3.06–9.38 for young adults; 1.47 and 0.92–2.33 for older adults). ORs and 95% CI for IFG was similar with the trend of ORs for diabetes (men: 1.80 and 1.43–2.26 for young adults; 1.17 and 0.75–1.84 for older adults; women: 2.20 and 1.77–2.72 for young adults; 1.33 and 0.86–2.07 for older adults). Conclusion: Lower relative HGS was associated with a higher risk of not only diabetes but also IFG in both sexes. These trends were stronger in younger adults than in older adults.