Independent and Synergistic Associations of Aerobic Physical Activity and Resistance Exercise with Nonalcoholic Fatty Liver Disease.

Background/Aims: This study aimed to examine the independent and synergistic association of aerobic physical activity and resistance exercise with nonalcoholic fatty liver disease (NAFLD) using a nationwide representative database. Methods: This was a cross-sectional study using data from the Korea National Health and Nutritional Examination Survey between 2007 and 2010. Multiple logistic regression models were used to examine the independent and synergistic (additive interaction) associations of aerobic physical activity and resistance exercise with NAFLD after adjusting for multiple covariates. Results: The prevalence of NAFLD was 26.2% for men and 17.6% for women. In the fully adjusted multiple logistic regression model to examine the independent association of aerobic physical activity or resistance exercise with NAFLD, the odds ratios for NAFLD were significantly decreased in both men (p=0.03) and women (p<0.01) who had highly active aerobic physical activity. Regarding the frequency of resistance exercise, the odds ratio for NAFLD was decreased in men who did resistance exercise ≥5 days per week (p=0.04), but not in women (p=0.19). However, when investigating the synergistic associations of aerobic physical activity and resistance exercise, the odds ratios for NAFLD significantly decreased when the frequency of both exercises increased together in both men (p for interaction <0.01) and women (p for interaction<0.01). Conclusions: Combining aerobic physical activity and resistance exercise had a synergistic preventive association for NAFLD in Korean men and women.

Components of metabolic syndrome and their relation to the risk of incident cerebral infarction.

Metabolic syndrome (MetS) consists of 5 metabolic components, which are recognized as risk factors for cerebral infarction. The present study was to evaluate the relative influence of individual metabolic component on incident cerebral infarction. Using a data of 209,339 Koreans registered in National Health Information Corporation, we evaluated the risk for incident cerebral infarction according to the number of metabolic component and each metabolic component for 4.37 years' follow-up. Cox proportional hazards model was used to calculate hazard ratios (HRs) for cerebral infarction and their confidence interval (CI). The more metabolic components accompanied the worse metabolic profile, leading increased incidence of cerebral infarction. The risk of cerebral infarction increased proportionally to the number of present metabolic components (number 0: reference, number 1: 1.78 [1.42-2.23], number 2: 2.20 [1.76-2.74], number 3: 2.61 [2.09-3.25] and number 4-5: 3.18 [2.54-3.98]). Compared to subjects without metabolic component, the impact of each component on cerebral infarction was relatively higher in elevated fasting glucose (1.56 [1.14-2.13]) and elevated BP (2.13 [1.66-2.73]), indicating no statistical significance in low HDL-cholesterol (1.53 [0.96-2.44]), high triglyceride (1.24 [0.84-1.84]) and abdominal obesity (1.05 [0.63-1.73]). Proportional relationship was found between the number of metabolic component and risk of cerebral infarction. Out of metabolic components, fasting glucose and BP are more powerful predictor for cerebral infarction.

Fasting glucose level and the risk of incident osteoporosis in the Koreans.

PURPOSE/INTRODUCTION: Conflicting results have been published regarding the effect of abnormal glucose metabolism on osteoporosis (AGM). Fasting glucose is a reliable indicator for abnormal glucose metabolism. Therefore, the aim of present study is to identify the association of fasting glucose level with the risk of incident osteoporosis. METHODS: In a cohort of 59,936 men and 36,690 women (mean age of 63.9 ± 7.1 years) registered in national health insurance database, we assessed the risk of incident osteoporosis according to the quartile levels of baseline fasting glucose (quartile 1: <88 mg/dL, quartile 2: 88-96 mg/dL, quartile 3: 97-107 mg/dL and quartile 4: ≥108 mg/dL) and glycemic status categorized into normal, impaired fasting glucose (IFG) and diabetes mellitus (DM). Multivariate Cox-proportional hazard model was used in calculating adjusted hazard ratios (HRs) and 95% confidence interval (CI) for incident osteoporosis (adjusted HRs [95% CI]). RESULTS: Compared with first quartile (reference), the risk of osteoporosis significantly decreased above the fourth quartile in men (second quartile: 1.04 [0.91-1.18], third quartile: 0.88 (0.76-1.00) and fourth quartile: 0.80 [0.70-0.92]) and above third quartile in women (second quartile: 0.95 [0.90-1.01], third quartile: 0.91 [0.86-0.97] and fourth quartile: 0.82 [0.77-0.88]). The risk of osteoporosis was less associated with IFG (men: 0.84 [0.76-0.94] and women: 0.93 [0.89-0.98]) and DM (men: 0.77 [0.65-0.91] and women: 0.75 [0.69-0.81]) than normal glucose group in both men and women. CONCLUSION: Our results suggest that elevated fasting glucose potentially associated with the decreased risk of osteoporosis. MINI-ABSTRACT: This retrospective study investigated the association between fasting glucose level and incidence of osteoporosis. Our findings indicate that elevated fasting glucose is significantly associated with the decreased risk of osteoporosis.

Reduced Glomerular Filtration Rate and Risk of Stroke: A Nationwide Cohort Study in South Korea.

AIMS: Although chronic kidney disease is recognized as an independent risk factor for cerebrovascular disease, its association with hemorrhagic and ischemic stroke remains controversial. METHODS: We conducted a retrospective cohort study using the National Health Insurance Service-National Sample Cohort, which is representative of the Korean population. A total of 195,772 Koreans who were not diagnosed with stroke before 2009 were included in this study from 2009 to 2013. The eGFR was divided into six categories (≥ 90, 75-89, 60-74, 45-59, 30-44, ＜30 mL/min/1.73 m2). The Kaplan-Meier plot was illustrated to compare the incidence of stroke. Cox proportional hazard model was used to estimate the hazard ratio (HR) of eGFR for risk of ischemic and hemorrhagic stroke by sex. RESULTS: During an average of 4.36 years of follow-up period, 2,236 and 668 people were diagnosed with newly ischemic and hemorrhagic stroke, respectively. Age-adjusted incidence rate for ischemic stroke among people with eGFR ＜45 mL/min/1.73 m2 was higher than those with eGFR ≥ 90 mL/min/1.73 m2, whereas that for hemorrhagic stroke among people with eGFR ≥ 90 mL/min/1.73 m2 was higher than those with eGFR ＜45 mL/min/1.73 m2. After adjusting for multiple covariates, the adjusted HR for ischemic stroke increased with decreasing eGFR in men (p for trend ＜0.001), but not in women (p for trend=0.48). On the other hand, there was no significant relationship between eGFR and risk of hemorrhagic stroke in both men and women. CONCLUSIONS: Reduced glomerular filtration rate less than 45 mL/min/1.73 m2 was associated with an increased risk of ischemic stroke, especially in men.

Visceral adiposity index and longitudinal risk of incident metabolic syndrome: Korean genome and epidemiology study (KoGES).

Available data is insufficient to identify the influence of visceral adiposity assessed by visceral adiposity index (VAI) on incident MetS. This study was to evaluate the association of VAI with incident MetS. In a cohort of Korean genome epidemiology study, 5,807 free of MetS were followed-up for 10 years. They were subdivided into 3 tertile groups according to VAI score. Cox proportional hazard model was used to evaluate the hazard ratios (HRs) and 95% confidential interval (CI) [adjusted HRs (95% CI)] for MetS according to VAI tertiles. Subgroup analyses were conducted for VAI and waist circumference (WC). Receiver operating characteristic (ROC) and area under curve (AUC) analyses were conducted to compare the discriminative ability for Mets among indices. The risk for MetS increased proportionally to VAI tertiles in all participants, which was similarly observed in both men and women. Subgroup analysis indicated that group with high VAI and low WC had the increased risk for MetS (all participants: 2.76 [2.48-3.07], men: 2.77 [2.40-3.19] and women: 2.55 [2.16-3.00]), compared with groups with low VAI and low WC. Group with low VAI and high WC generally had the higher adjusted HRs for MetS than group with the high VAI and low WC. In AUC analyses, WC had the highest discriminative ability for Mets. In conclusion, elevated VAI was significantly associated with the increased long-term risk of MetS. VAI is a useful supplementary to classic anthropometric indices in screening high risk group of MetS.

The Risk for Incident Ischemic Heart Disease According to Estimated Glomerular Filtration Rate in A Korean Population.

AIM: Chronic kidney disease, evaluated by the estimated glomerular filtration rate (eGFR), is an established risk factor for cardiovascular disease. However, the association between renal function stratified by the eGFR and the risk of incident ischemic heart disease (IHD) in a community-based Asian population is still inconclusive. STUDY DESIGN: Retrospective longitudinal observational study. METHOD: In data from 206,919 Korean patients registered in the National Health Insurance Corporation (NHIC), we analyzed the risk of incident IHD according to the quartiles (Q) of eGFR (ml/min/1.73 m2) (Q1 ＜71.07, Q2: 71.07-83.16, Q3: 83.17-95.49, Q4 ＞95.50). The identification of IHD was based on the International Classification of Diseases (ICD) for IHD (ICD code: I20-I25) registered in the NHIC. The Cox proportional hazards model was used to calculate the adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for IHD according to quartile groups of eGFR levels. RESULTS: Q1 had the more unfavorable baseline metabolic conditions than the other quartile groups. Considering Q4 as the reference, the unadjusted HRs (95% CIs) for IHD increased significantly in the order of Q3 (1.42 [1.29-1.56]), Q2 (1.51 [1.38-1.67]), and Q1 (2.11 [1.93-2.30]), and fully adjusted HRs (95% CIs) increased significantly from Q2 (1.15 [1.04-1.27]) to Q1 (1.31 [1.18-1.44]). CONCLUSION: The risk of IHD increased significantly from individuals with an eGFR ≤ 83.16. Mildly decreased renal function is a potential risk factor for IHD.

Body fat percentage, obesity, and their relation to the incidental risk of hypertension.

Studies have indicated that increased body fat is associated with cardiovascular risk factors including hypertension. However, there is only limited information about the influence of body fat percentage (BF%) on incident hypertension. In a cohort of Korean genome epidemiology study (KoGES), 4864 non-hypertensive participants were divided into 5 quintile groups, and followed-up for 10 years to monitor incident hypertension. Cox proportional hazard model was used to evaluate the hazard ratio (HRs) and 95% confidence interval (CI) for hypertension (adjusted HRs [95% CI]) according to BF% quintile groups. Subgroup analysis was conducted by low or high level of BF% (cutoff: 22.5% in men and 32.5% in women) and low or high level of body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR). In adjusted model, compared with BF% quintile 1, the risk of incident hypertension significantly increased over BF% quintile 3 (BF% ≥19.9%) in men (quintile 3:1.42 [1.10-1.85], quintile 4:1.58 [1.22-2.05], quintile 5:1.82 [1.40-2.36]), and quintile 4 (BF% ≥32.5%) in women (quintile 4:1.48 [1.12-1.94], quintile 5:1.56 [1.20-2.04]). Subgroup analysis showed that individuals with high BF% were significantly associated with the increased risk of hypertension even in individuals with low BMI, WC, and WHR. The risk of hypertension increased proportionally to BF% over the specific level of BF% in Koreans. Even in non-obese individuals, increase in BF% was significantly associated with the increased risk of hypertension.

Levels of Systolic and Diastolic Blood Pressure and Their Relation to Incident Metabolic Syndrome.

BACKGROUND: Elevated blood pressure (BP) is a component of the metabolic syndrome (MetS), and one third of individuals with hypertension simultaneously have MetS. However, the evidence is still unclear regarding the predictive ability of BP for incident MetS. METHODS: In total, 5,809 Koreans without baseline MetS were grouped by baseline systolic (SBP) and diastolic BP (DBP) and monitored for 10 years to identify incident MetS. A Cox proportional hazards model was used to evaluate the HR and 95% CI for MetS according to SBP and DBP. Subgroup analysis was conducted in the normotensive population based on a new guideline of the American College of Cardiology and the American Heart Association. RESULTS: High-BP groups tended to have worse metabolic profiles than the lowest-BP group in both SBP and DBP categories. In all of the participants, elevated SBP and DBP levels were significantly associated with the increased HR for MetS, even after adjusting for covariates. Subgroup analysis for normotensive participants indicated that the HR for MetS increased proportionally to both SBP (<110 mm Hg: reference, 110-119 mm Hg: HR = 1.60 [95% CI 1.40-1.84], and 120-129 mm Hg: HR = 2.12 [95% CI 1.82-2.48]) and DBP levels (<70 mm Hg: reference, 71-74 mm Hg: HR = 1.31 [95% CI 1.09-1.58], and 75-79 mm Hg: HR = 1.51 [95% CI 1.25-1.81]). CONCLUSION: The risk of incident MetS increased proportionally to baseline SBP and DBP, and this was identically observed even in normotensive participants.

The association between metabolic syndrome and peanuts, pine nuts, almonds consumption: The Ansan and Ansung Study.

BACKGROUND: Previous studies reported an inverted relationship between nut consumption and the incidence of metabolic syndrome (MetS). The present study investigated the incidental risk for MetS according to peanut, almond, and fine nut consumption in the Korean population. METHODS: In a community-based Korean cohort, 5306 Korean adults were divided into four groups according to their peanut, almond, and fine nut intake (<1/month, 1/month-0.5/week, 0.5-1/week, and ≥1/week, in which one serving = 15 g) and were followed-up for 10 years. A Cox proportional hazard model was used to evaluate the hazard ratios (HRs) with confidence intervals (CI) for MetS in each study group. Age subgroup (≥50 or <50 years) analysis was also conducted. RESULTS: The age and multivariable-adjusted HRs with 95% CIs for MetS showed a significant inverse dose-response relationship between peanut, almond, and fine nut intake and the incidence of MetS in men and women (multivariable-adjusted HRs [95% CI] in men; 0.91 [0.76-1.09] in 1/month-0.5/week, 1.03 [0.80-1.31] in 0.5-1/week, 0.72 [0.56-0.93] in ≥1/week and in women; 0.81 [0.65-1.003] in 1/month-0.5/week, 0.76 [0.54-1.07] in 0.5-1/week, 0.57 [0.41-0.79] ≥1/week)). Subgroup analysis showed a significant difference in middle-aged men (≥1/week) and old-aged women (≥0.5/week). CONCLUSION: The results of the present study suggested that peanut, almond, and fine nut intake (≥15 g/week) may be inversely related to incidence risk of MetS in the Korean general population. Additionally, the association between nut consumption and MetS incidence risk may differ in sex and age subgroups.

Association of fasting glucose and glycated hemoglobin with the long-term risk of incident metabolic syndrome: Korean Genome and Epidemiology Study (KoGES).

AIMS: Previous studies have proposed potential benefit of glycated hemoglobin (HbA1c) supplementary to fasting glucose in detecting metabolic syndrome (MetS). This study was to investigate an association of incident MetS with levels of HbA1c and fasting glucose. METHODS: In a cohort of Korean Genome and Epidemiology Study, 5515 non-diabetic adults were grouped by the levels of baseline fasting glucose and HbA1c, and followed-up for 10 years. Using multivariate Cox proportional hazards assumption, hazards ratios (HRs) and 95% confidence interval (CI) for incident MetS (adjusted HRs [95% CI]) were calculated according to baseline fasting glucose and HbA1c. In individuals with normal fasting glucose, subgroup analysis was conducted to evaluate an association of HbA1c levels with MetS. RESULTS: The risk for MetS significantly increased proportionally to fasting glucose ≥ 80 mg/dL and HbA1c ≥ 5.5%, compared with fating glucose < 80 mg/dL and HbA1c < 5.3%, respectively. In subgroups of normal fasting glucose, HbA1c ≥ 5.7% had the increased risk of MetS in fasting glucose < 80 mg/dL (5.7-5.9%: 1.41 [1.07-1.86] and 6.0-6.4%: 2.20 [1.40-2.92]), and HbA1c ≥ 5.5% had the increased risk of MetS in fasting glucose of 80-99 mg/dL (5.5-5.6%: 1.33 [1.08-1.64], 5.7-5.9%: 1.57 (1.27-1.93), and 6.0-6.4%: 2.37 [1.87-3.00]). CONCLUSIONS: Both elevated fasting glucose and HbA1c were significantly associated with the increased risk of MetS even within normal range. HbA1c is effective in identifying high-risk group for MetS in individuals with normal fasting glucose.

Very high high-density lipoprotein cholesterol is associated with increased all-cause mortality in South Koreans.

BACKGROUND AND AIMS: Our study aimed to investigate the association between high-density lipoprotein cholesterol (HDL-C) and all-cause and cause-specific mortality in Korean adults. METHODS: A total of 365,457 participants aged ≥40 years were selected from the Korean National Health Insurance Service-National Sample Cohort from 2009 to 2015. HDL-C level was categorized into <1.0, 1.0-1.19, 1.2-1.39, 1.4-1.59, 1.6-1.79 (reference), 1.8-1.99, 2.0-2.19 and ≥ 2.20 mmol/L. Cox proportional hazard models were used to examine the association between HDL-C level and mortality risk. RESULTS: In a median 3.5-year follow-up period, 9,350 participants (2.6%) died. Men with HDL-C level of 1.6-1.79 mmol/L and women with HDL-C level of 1.4-1.59 mmol/L had the lowest age-standardized mortality rates for all-cause death. However, for cardiovascular death, men with HDL-C level ≥2.20 mmol/L and women with HDL-C level of 1.8-1.99 mmol/L showed the lowest mortality rate. After adjusting for multiple covariates, the hazard ratios for all-cause and cancer deaths showed a U-shaped relationship with HDL-C level for both sexes. However, there were heterogenetic associations between HDL-C level and mortality risk of subtypes of cardiovascular disease by sex. For other causes of death except for cardiovascular and cancer death, elevated mortality risk was mainly due to external causes (ICD-10 code, S00-T98). CONCLUSIONS: In South Korea, very high HDL-C level was associated with increased risk of all-cause death. However, the increased all-cause mortality risk in people with very high HDL-C level was partly due to mortality risk from external causes.

Serum ferritin level is associated with liver steatosis and fibrosis in Korean general population.

BACKGROUND: Elevation of serum ferritin levels is frequently observed in non-alcoholic fatty liver disease (NAFLD) patients. Our study aims to examine the association between serum ferritin levels and NAFLD in Korean population. METHODS AND RESULTS: A total of 25,597 participants were selected from Korean National Health and Nutritional Examination Surveys 2007-2012. The NAFLD liver fat score (NLFS) was used to define NAFLD. Elevation of ALT levels was defined as ALT level > 40 IU/L for male and ALT level > 31 IU/L for female. Multiple logistic regression was used to examine the association of serum ferritin levels and NAFLD by sex. After adjusting for multiple covariates, the ORs (95% CI) of the elevated ALT levels were 1.56 (95% CI: 1.17-2.07), 1.84 (95% CI: 1.39-2.45), and 4.08 (95% CI: 3.08-5.40) for the second, third and fourth serum ferritin quartiles in male (p for trend < 0.01), 1.67 (95% CI: 1.24-2.23), 2.23 (95% CI: 1.68-2.96), and 5.72 (95% CI: 4.32-7.60) for the second, third and fourth serum ferritin quartiles in female (p for trend < 0.01). Serum ferritin levels were also significantly associated with NAFLD and liver fibrosis both in male and female. CONCLUSIONS: Elevation of serum ferritin level is significantly associated with NAFLD and blood ALT elevation in Korean general population.

1-Hour and 2-Hour Postload Glucose Level on Oral Glucose Tolerance Test and the Risk of Incident Metabolic Syndrome.

Background: Metabolic syndrome (MetS) increases the cardiometabolic risk even in nondiabetic patients. Previous studies have demonstrated that 1-hour postload glucose (PG) and 2-hour PG based on oral glucose tolerance test (OGTT) predicted cardiometabolic risk. However, it is still unclear whether and to what extent postload glucose is associated with the risk of MetS. Methods: A total of 5389 nondiabetic Koreans were dichotomized into normoglycemic (NG) groups and abnormal glycemic groups based on OGTT, including elevated 1-hour PG (155 to 199 mg/dL) and impaired glucose tolerance (IGT) (2-hour PG 140 to 199 mg/dL), and followed up for 10 years. Cox proportional hazard model was used to evaluate hazard ratios (HRs) with 95% CIs for incident MetS. Subgroups were determined by high or normal 1-hour PG (cutoff: 155 mg/dL) and 2-hour PG (cutoff: 140 mg/dL). Results: Compared with NG, the risk of MetS increased proportionally to the level of 1-hour PG and 2-hour PG, independently of the number of baseline metabolic components. Even within people with normoglycemia, elevated PG above specific levels (1-hour PG ≥115 mg/dL and 2-hour PG ≥100 mg/dL) was significantly associated with the increased risk of MetS. In subgroup analysis, adjusted HR for MetS was higher in the group with high 1-hour PG and normal 2-hour PG [1.53 (95% CI, 1.35 to 1.74)] than in the group with normal 1-hour PG and high 2-hour PG [1.32 (95% CI, 1.02 to 1.70)]. Conclusion: Elevated 1-hour PG and 2-hour PG significantly are associated with greater risk for MetS, and 1-hour PG was superior to 2-hour PG in predicting MetS.

Changing trends in suicide rates in South Korea from 1993 to 2016: a descriptive study.

OBJECTIVES: The South Korean government has recently implemented policies to prevent suicide. However, there were few studies examining the recent changing trends in suicide rates. This study aims to examine the changing trends in suicide rates by time and age group. DESIGN: A descriptive study using nationwide mortality rates. SETTING: Data on the nationwide cause of death from 1993 to 2016 were obtained from Statistics Korea. PARTICIPANTS: People living in South Korea. INTERVENTIONS: Implementation of national suicide prevention policies (first: year 2004, second: year 2009). PRIMARY OUTCOME MEASURES: Suicide was defined as 'X60-X84' code according to the ICD-10 code. Age-standardised suicide rates were estimated, and a Joinpoint regression model was applied to describe the trends in suicide rate. RESULTS: From 2010 to 2016, the suicide rates in South Korea have been decreasing by 5.5% (95% CI -10.3% to -0.5%) annually. In terms of sex, the suicide rate for men had increased by 5.0% (95% CI 3.6% to 6.4%) annually from 1993 to 2010. However, there has been no statistically significant change from 2010 to 2016. For women, the suicide rate had increased by 7.5% (95% CI 6.3% to 8.7%) annually from 1993 to 2009, but since 2009, the suicide rate has been significantly decreasing by 6.1% (95% CI -9.1% to -3.0%) annually until 2016. In terms of the age group, the suicide rates among women of almost all age groups have been decreasing since 2010; however, the suicide rates of men aged between 30 and 49 years showed continuously increasing trends. CONCLUSION: Our results showed that there were differences in the changing trends in suicide rate by sex and age groups. Our finding suggests that there was a possible relationship between implementation of second national suicide prevention policies and a decline in suicide rate.

Long-Term Risk of Hypertension in Normoglycemia and Prediabetes, and Their Relation to the Change of Glycemic State.

BACKGROUND: Although increasing evidence has suggested the significant association between dysglycemia and hypertension, this association is less well described in prediabetes. Additionally, it is unclear how risk of hypertension varies according to the change of glycemic state. METHODS: Five thousand four hundred thirteen nondiabetic Koreans were dichotomized into normoglycemia (NG) and prediabetes group and followed-up for 10 years. Cox proportional hazard model was used to evaluate hazard ratios (HRs) with 95% confidence interval (CI) [adjusted HRs (95% CI)] for the development of hypertension. Subgroup analysis was conducted in subdivided glycated hemoglobin (HbA1c) with <5.7%, 5.7-5.9%, and 6.0-6.4% and 2 hour post-load glucose (2 hr-PG) with <140, 140-169, and 170-199 mg/dl. The glycemic states are NG, prediabetes, and diabetes mellitus (DM), which are used in evaluating the change of glycemic state during follow-up in baseline NG (NG → NG, NG → prediabetes, and NG → DM) and baseline prediabetes (prediabetes → prediabetes and prediabetes → DM). RESULTS: Compared with NG, prediabetes was not significantly associated with the risk of hypertension [1.11 (0.997-1.23)]. HbA1c ≥5.7% [1.13 (1.02-1.26)] and 2 hr-PG ≥140 mg/dl [1.15 (1.004-1.31)] were marginally associated with the risk of hypertension. In subgroup analysis, only 2 hr-PG of 170-199 mg/dl showed the significantly increased risk of hypertension [1.37 (1.09-1.73)]. Compared with the maintaining glycemic state, the progression of glycemic state had the significantly increased risk of hypertension [NG → prediabetes; 1.41 (1.19-1.67), NG→DM; 1.77 (1.36-2.30), and prediabetes → DM; 1.32 (1.13-1.55)]. CONCLUSION: The progression of glycemic state was a strong determinant on the development of hypertension.

The relationship of depression with the level of blood pressure in population-based Kangbuk Samsung Health Study.

There has been increasing evidence about psychosomatic relationship between mood disorder and blood pressure (BP). However, the degree to which BP categories are associated with depression has been less well described. Thus, this study was to investigate the association of depression with BP categories. A total of 90,643 men and 68,933 women were enrolled in this study. They were stratified into four groups (normal, prehypertension, newly diagnosed hypertension, and recognized hypertension) according to the BP levels and the history of hypertension. Center for Epidemiological Studies-Depression was used to evaluate the depressive symptom, and the degree of depression was evaluated by the cutoff of Center for Epidemiological Studies-Depression (mild: 16-20, moderate: 21-24, severe: ≥25). The multivariate logistic regression was used in calculating odds ratios for depression according to the four BP categories, with adjustment for multiple confounding factors. Subgroup analysis was conducted by gender and age. The adjusted odds ratios for depression tended to decrease from normal to newly diagnosed hypertension, but significantly increased in recognized hypertension (normal: reference, prehypertension: 0.85 [0.80-0.91], newly diagnosed hypertension: 0.75 [0.65-0.86], recognized hypertension: 1.11 [1.03-1.20]). Subgroup analysis also indicated the similar pattern of relationship, which was more prominent in male and middle-aged subgroup than any other subgroups. Depression was inversely associated with elevated BP. However, recognized hypertension had the increased likelihood of depression in male and young age group. These findings suggest that the association between depression and BP may be moderated by the chronicity of hypertension in men and young individuals.

Longitudinally evaluated the relationship between body fat percentage and the risk for type 2 diabetes mellitus: Korean Genome and Epidemiology Study (KoGES).

BACKGROUND: Body fat plays the significant role in maintaining glucose homeostasis. However, it is not fully identified how body fat percentage (BF%) has an impact on the development of type 2 diabetes mellitus (T2DM). Thus, this study was to evaluate the incidental risk for T2DM according to BF% level. METHODS: In a community-based Korean cohort, 5972 Korean adults were divided into quintile groups by BF% and followed up for 10 years to monitor the development of T2DM. Cox proportional hazard model was used to evaluate the hazard ratios (HRs) for T2DM according to BF% quintile. Additionally, subgroup analysis was conducted by low and high level of BF% (cut-off: 25 in men and 35 in women) and body mass index (BMI). RESULTS: In adjusted model, compared to the BF% quintile 1 group, the risk for T2DM significantly increased over BF% of 22.8% in men and 32.9% in women (≥quintile 4). The level of BF% related to the increased risk for T2DM was lower in non-obese men (22.8%) than obese men (28.4%). In subgroup analysis, men with low BMI (<25) and high BF% (≥25) had the highest risk for T2DM than other subgroups (HRs: 1.83 (1.33-2.52)). However, this association did not show the statistical significance in women (HRs: 1.63 (0.98-2.72)). CONCLUSION: The incidental risk for T2DM significantly increased over the specific level of BF%, which was lower in non-obese population than obese population. Gender difference was suggested in the incidental relationship between BF% and T2DM.

The risk of type 2 diabetes mellitus according to the categories of body mass index: the Korean Genome and Epidemiology Study (KoGES).

AIMS: Obesity is an established risk factor for type 2 diabetes mellitus (T2DM). However, there is limited information on the pattern of relationship between the risk for T2DM and body mass index (BMI) categories including underweight and overweight. Thus, this study was to evaluate the risk of T2DM according to BMI categories defined by Asian-specific cutoff of BMI. METHODS: 7660 non-diabetic Koreans were grouped into five BMI categories (underweight, normal, overweight, obese and severe obese) defined by Asian-specific cutoff of BMI and followed up for 10 years to monitor the development of T2DM. With a reference of normal BMI group, Cox proportional hazards assumption was used to calculate hazard ratios (HRs) and their 95% confidence intervals for T2DM in five groups. Subgroup analysis was conducted by gender and age (40-59 years and 60-69 years). RESULTS: Baseline mean value of metabolic factors like fasting glucose, HOMA-IR, total cholesterol and the proportion of impaired fasting glucose increased proportionally to the level of BMI categories. Underweight group had the higher proportion of impaired glucose tolerance than normal and overweight group. In all subgroups, underweight, overweight, obese and severe obese group had the higher HRs for T2DM than normal group, but statistical significance was only found in overweight, obese and severe obese group. CONCLUSIONS: The risk of T2DM tends to increase proportionally to the level of BMI categories from overweight to severe obese group. Further studies should be considered to identify the incidental relationship between underweight and T2DM.

The influence of prehypertension, hypertension, and glycated hemoglobin on the development of type 2 diabetes mellitus in prediabetes: the Korean Genome and Epidemiology Study (KoGES).

BACKGROUND: It has been reported that elevated blood pressure (BP) was significantly associated with the increased risk for type 2 diabetes mellitus (T2DM). However, there is still limited information about the influence of BP on the risk for T2DM across the level of glycated hemoglobin (HbA1c). METHOD: In a cohort of the Korean Genome and Epidemiology Study (KoGES), 2830 non-diabetic Korean adults with prediabetes defined by HbA1c level of 5.7-6.4% were followed-up for 10 years. Multivariate cox proportional hazards assumption was used to assess the risk for T2DM according to the baseline BP categories (normal, prehypertension and hypertension) and HbA1c level (low: 5.7-5.9% and high: 6.0-6.4%). RESULTS: The risk for T2DM significantly increased proportionally to BP categories (adjusted HR; reference in normal BP, 1.32 [1.10-1.59] in prehypertension and 1.61 [1.35-1.92] in hypertension). Subgroup analysis indicated that individuals with high HbA1c had the higher risk for T2DM than individuals with low HbA1c regardless of BP. Additionally, combined presence of hypertension and high HbA1c had the highest risk for T2DM (adjusted HR: 3.82 [3.00-4.87]). In each systolic and diastolic BP level, the risk for T2DM significantly increased from systolic BP ≥ 130 mmHg (adjusted HRs: 1.39 ([1.15-1.71]) and diastolic BP ≥ 80 mmHg (adjusted HRs: 1.30 ([1.07-1.58]). CONCLUSION: BP and HbA1c may be useful tools in identifying individuals with prediabetes more potentially predisposed to T2DM. Prospective studies should be considered to examine whether controlling BP actually lowers the risk for T2DM.

Consuming Green Tea at Least Twice Each Day Is Associated with Reduced Odds of Chronic Obstructive Lung Disease in Middle-Aged and Older Korean Adults.

Background: The frequent consumption of green tea has been shown to have antioxidant and anti-inflammatory effects and to reduce the risk of lung cancer and type 2 diabetes. However, few studies have investigated the relation between green tea consumption and the risk of chronic obstructive lung disease (COPD). Objective: This study aimed to examine the association between green tea intake and COPD with the use of a nationwide representative database. Methods: This study was designed as a cross-sectional survey with the use of data from the Korean National Health and Nutritional Examination Survey collected between 2008 and 2015. Of these participants, 13,570 participants aged ≥40 y were included in the study population. COPD was defined as forced expiratory volume in 1 s (FEV1) divided by forced vital capacity (FVC) <0.70. Multiple linear and logistic regression models were used to examine the association between the frequency of green tea intake and risk of COPD after adjusting for age, sex, body mass index, smoking status, alcohol consumption, physical activity, and socioeconomic status. Results: The incidence of COPD decreased from 14.1% to 5.9% with increased frequency of green tea intake from never to ≥2 times/d (P < 0.001). In the fully adjusted multiple linear regression model, the frequency of green tea intake showed a linear dose-response relation with FEV1/FVC (P-trend = 0.031). In the multiple logistic regression model, the OR for COPD among people who consumed green tea ≥2 times/d was 0.62 (95% CI: 0.40, 0.97), compared with those who never drank green tea, after adjusting for all covariates. Conclusion: This study suggests that the consumption of green tea ≥2 times/d is associated with a reduced risk of COPD in Korean populations.