Ju Mi Lee

Association Between Serum Uric Acid Level and Metabolic Syndrome

Objectives Serum uric acid levels have been reported to be associated with a variety of cardiovascular conditions. However, the direct association between uric acid levels and metabolic syndrome remains controversial. Thus, we evaluated the association of serum uric acid levels and metabolic syndrome in a community-based cohort study in Korea. Methods We performed cross-sectional analysis of baseline data of 889 males and 1491 females (aged 38 to 87) who participated in baseline examinations of the Korean Genome and Epidemiology Study: Kanghwa study. Blood samples were collected after at least an 8 hour fast. Uric acid quartiles were defined as follows: <4.8, 4.8-<5.6, 5.6-<6.5, ≥6.5 mg/dL in males; and <3.8, 3.8-<4.3, 4.3-<5.1, ≥5.1 mg/dL in females. Metabolic syndrome was defined by the National Cholesterol Education Program Adult Treatment Panel III Criteria with adjusted waist circumference cutoffs (90 cm for males; 80 cm for females). The association between serum uric acid quartiles and metabolic syndrome was assessed using multivariate logistic regression. Results The odds ratio for having metabolic syndrome in the highest versus lowest quartiles of serum uric acid levels was 2.67 (95% confidence interval [CI], 1.60 to 4.46) in males and 2.14 (95% CI, 1.50 to 3.05) in females after adjusting for age, smoking, alcohol intake, body mass index, total cholesterol, HbA1c, albumin, γ-glutamyltransferase, blood urea nitrogen, and log C-reactive protein. The number of metabolic abnormalities also increased gradually with increasing serum uric acid levels (adjusted p for trend < 0.001 in both sexes). Conclusions Higher serum uric acid levels are positively associated with the presence of metabolic syndrome in Korean males and females.

The Korean urban rural elderly cohort study: study design and protocol

BackgroundKorea is one of the fastest aging countries and is expected to become a super-aged society within 12xa0years. The Korean Urban Rural Elderly (KURE) study was developed to evaluate the epidemiological characteristics and establish the prevention and management of major disorders of the elderly in Korea.Methods/DesignThe KURE study is a community-based prospective cohort study on health, aging, and common geriatric disorders of Korean elderly persons aged at least 65xa0years. To construct a cohort reflecting both urban and rural areas, we selected 2 representative communities in the country. To establish multidisciplinary approaches to geriatric health, this study was performed by researchers in the divisions of geriatrics, preventive medicine, endocrinology, and sociology. The baseline examinations began in 2012; the study will follow more than 4,000 elderly Koreans over 10xa0years. The first and second follow-up health examinations will be performed every 4xa0years. Every 2xa0years after each health examination, inter-assessment interview will be conducted to improve participant retention.DiscussionThe KURE study will provide longitudinal epidemiologic data on health, aging, and common geriatric disorders of the elderly in Korea. This is a comprehensive, multidisciplinary study of the elderly with respect to biological, physical, socio-economic, and environmental factors. The results of this study will contribute to improve public health and welfare policies for the aging society in Korea.

The Association Between Serum Albumin Levels and Metabolic Syndrome in a Rural Population of Korea

Objectives A positive association between serum albumin levels and metabolic syndrome has been reported in observation studies, but it has not been established in the Korean population. The purpose of this study was to evaluate the association between serum albumin levels and the presence of metabolic syndrome among a sample of apparently healthy Korean adults. Methods This cross-sectional study analyzed data of 3189 community-dwelling people (1189 men and 2000 women) who were aged 40 to 87 years and were living in a rural area in Korea. Serum albumin levels were classified into quartile groups for each sex. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III guidelines with an adjusted waist circumference cut-off value (≥90 cm for men and ≥85 cm for women). An independent association between serum albumin levels and metabolic syndrome was assessed by multiple logistic regression analysis. Results Higher serum albumin levels were associated with increased prevalence of metabolic syndrome. The odds ratio (95% confidence interval) of the prevalence of metabolic syndrome for the highest versus the lowest serum albumin quartiles was 2.81 (1.91 to 4.14) in men and 1.96 (1.52 to 2.52) in women, after adjusting for age, smoking status, alcohol consumption, and physical activity. When each metabolic abnormality was analyzed separately, higher serum albumin levels were significantly associated with hypertriglyceridemia and hyperglycemia in both sexes, and with abdominal obesity in men. Conclusions These results suggest that higher serum albumin levels are positively associated with an increased risk of metabolic syndrome in Korean adults.

Association between C reactive protein level and depressive symptoms in an elderly Korean population: Korean Social Life, Health and Aging Project

Objective The relationship between inflammatory markers and depressive symptoms has been reported inconsistently. Moreover, there were only a few studies conducted in an Asian population. The purpose of this study was to examine the association between C reactive protein (CRP) and depressive symptoms in an elderly Korean population. Design, setting and participants This study used data from the Korean Social Life, Health and Aging Project Health Examination Cohort, which started in 2011. Among participants aged 60 or over recruited from a rural community, 569 (224 men and 345 women) without a history of stroke, angina pectoris, myocardial infarction or CRP≥20u2005mg/L were employed for cross-sectional analyses. As a marker of systemic inflammation, CRP was measured. Depressive symptoms were measured with the Center for Epidemiologic Studies Depression (CES-D) scale. Multiple linear regression analysis was used to investigate the relationship between CRP and depressive symptoms. Results In men, CRP levels had significant associations with depressive symptoms before (β=0.420, p=0.010) and after (β=0.336, p=0.025) adjusting for age, body mass index, systolic blood pressure, number of comorbidities, smoking status, alcohol intake, marital status, education and sleep duration. However, in women, the association between CRP and depressive symptoms was not significant before (p=0.250) and after (p=0.256) adjustment. Conclusions Our findings suggest that elevated CRP levels are independently associated with the presence of depressive symptoms in elderly Korean men.

Serum uric acid concentration and metabolic syndrome among elderly Koreans: The Korean Urban Rural Elderly (KURE) study

BACKGROUNDnEpidemiologic studies have demonstrated that elevated serum uric acid concentration is an independent risk factor for metabolic syndrome. However, few studies have focused on elderly populations. Thus, we investigated the association of serum uric acid concentration with metabolic syndrome in community-dwelling elderly Koreans.nnnMETHODSnThis cross-sectional analysis included 2940 participants (986 men and 1954 women) aged 65 years or older who participated in a baseline health assessment for the Korean Urban Rural Elderly cohort study from 2012 to 2014. Serum uric acid concentration was analyzed using both continuous and dichotomous variables. Hyperuricemia was defined as a uric acid concentration ≥7.0 mg/dL in men and ≥6.0 mg/dL in women. Metabolic syndrome was defined according to the 2009 harmonizing definition. Multiple logistic regression models were used to investigate independent association between serum uric acid and metabolic syndrome, after adjusting for age, body mass index, LDL cholesterol, glycated hemoglobin, blood urea nitrogen, estimated glomerular filtration rate health behaviors, and medications.nnnRESULTSnPrevalence of metabolic syndrome and its components increased significantly according to uric acid concentration in both sexes. The adjusted odds ratios for having metabolic syndrome per 1.0mg/dL higher uric acid concentration were 1.16 (95% CI: 1.03-1.31) in men and 1.27 (95% CI: 1.13-1.42) in women. Hyperuricemia was also associated with metabolic syndrome, with adjusted odds ratios of 1.71 (95% CI: 1.11-2.63) in men and 1.55 (95% CI: 1.05-2.29) in women.nnnCONCLUSIONSnElevated serum uric acid concentration was independently associated with an increased prevalence of metabolic syndrome in community-dwelling elderly Koreans.

Urban-Rural Differences Explain the Association between Serum 25-Hydroxyvitamin D Level and Insulin Resistance in Korea

An increasing number of studies report associations between low serum 25-hydroxyvitamin D [25(OH)D] level and insulin resistance; however, whether low vitamin D levels directly contribute to increased insulin resistance is unclear. We investigated the impact of residential area on the association between 25(OH)D and insulin resistance in elderly Koreans. Using data from the Korean Urban Rural Elderly study, we conducted cross-sectional analyses in 1628 participants (505 men and 1123 women). Serum 25(OH)D was analyzed as both continuous and categorized variables. Homeostasis model assessment for insulin resistance (HOMA-IR) was calculated using fasting blood glucose and insulin levels. In men, 25(OH)D level was inversely associated with HOMA-IR (standardized β = −0.133, p < 0.001) after adjustment for age, body mass index, waist circumference, smoking, alcohol intake, exercise, and study year. However, we noted significant urban-rural differences in 25(OH)D level (43.4 versus 65.6 nmol/L; p < 0.001) and HOMA-IR (1.2 versus 0.8 mmol·pmol/L2; p < 0.001). When we additionally adjusted for residential area, the association between 25(OH)D and HOMA-IR was attenuated (standardized β = −0.063, p = 0.115). In women, the association between 25(OH)D and HOMA-IR was not significant before or after adjustment for residential area. Environmental or lifestyle differences in urban and rural areas may largely explain the inverse association between serum 25(OH)D and insulin resistance.

Associations of cortisol/testosterone and cortisol/sex hormone-binding globulin ratios with atherosclerosis in middle-age women

Background and aims The cortisol/testosterone (C/T) ratio has been hypothesized to be a better predictor of atherosclerosis than cortisol alone. No study has assessed whether the C/T and C/sex hormone-binding globulin (SHBG) ratios are associated with atherosclerosis in a U.S. population sample. Methods This substudy included 367 women who had both cortisol from year 15 and testosterone and SHBG at year 16 of the Coronary Artery Risk Development in Young Adults study, an ongoing observational cohort in the United States. Of these, intima-media thickness (IMT) was available at follow-up year 20 in 339 (n = 332 with measurement at carotid bulb), and 303 were free of prevalent coronary artery calcium (CAC) at year 15. Area under the curve (AUC) of salivary cortisol was available in 302 individuals. Ratios of AUCs of cortisol to total testosterone, free testosterone, and SHBG were categorized into tertiles. Associations with CAC and IMT were assessed by regression models adjusted for age, race, body mass index, systolic blood pressure, menopause, oral contraceptive use, diabetes, alcohol, and smoking. Results Only the highest tertile of the AUC/free testosterone ratio was positively associated with carotid bulb IMT (β = 0.088, P = 0.006). This tertile was also positively associated with new onset CAC between year 15 and 25 (OR 3.45, 95% CI 1.18–10.06). Tertiles of cortisol or testosterone alone were not associated with new onset CAC. Conclusion AUC/Free testosterone ratio may be more associated with atherosclerosis in women than either indicator alone. The ratio may serve as a suitable biomarker of cortisol-linked stress.

Association between changes in systolic blood pressure and incident diabetes in a community-based cohort study in Korea

An association between hypertension and diabetes has been reported; however, the temporal relationship of blood pressure changes and incident diabetes has not been fully investigated in the general population. We examined whether increasing blood pressure is associated with the risk of developing diabetes among community-dwelling Korean adults. This study included 2225 participants (859 men and 1366 women) aged 27–87 years from the Korean Genome Epidemiology Study. The participants were free of diabetes and cardiovascular disease at baseline. Incident diabetes was defined as fasting blood glucose⩾126u2009mgu2009dl−1 or hemoglobin a1c ⩾6.5% (48u2009mmolu2009mol−1) at follow-up examination and/or a physician’s diagnosis of diabetes during the follow-up period. The effects of the baseline level and change in blood pressure on the risk of incident diabetes were assessed by multivariate logistic regression analysis. During the mean follow-up of 2.6 years, new-onset diabetes was observed in 5.0% (43/859) of the men and 3.4% (47/1366) of the women. In the multivariate model, the baseline systolic blood pressure was not significantly associated with incident diabetes (adjusted odds ratio 0.93 per 10u2009mmHg, P=0.747). However, an increase in systolic blood pressure during the follow-up period was independently associated with incident diabetes (adjusted odds ratio 5.53 per 5u2009mmHg per year, P=0.002) after adjusting for the baseline blood pressure and other potential confounders. Increasing blood pressure, but not a high baseline blood pressure, was independently associated with the risk of diabetes in Korean adults.

Cross-sectional and longitudinal association between hemoglobin concentration and hypertension: A population-based cohort study

Abstract We investigated the cross-sectional and longitudinal associations between hemoglobin concentration and hypertension in a Korean population. Between 2006 and 2013, we examined 4899 participants with mean age of 56.6 years (range 35–88 years) from a rural community. We excluded 298 participants with a history of myocardial infarction or stroke and 264 participants with very low hemoglobin levels (men: <13.3u200ag/dL; women: <11.6u200ag/dL). Finally, we performed a cross-sectional analysis on 1629 men and 2708 women. Longitudinal associations were evaluated in 654 men and 1099 women, after excluding 2584 people with hypertension at baseline and those who did not participate in follow-up examinations. Hypertension was defined as systolic blood pressure ≥140u200amm Hg, diastolic blood pressure ≥90u200amm Hg, or use of antihypertensive treatment. The mean hemoglobin level was significantly higher in people with hypertension than in those without hypertension (P = 0.002 for men, P = 0.006 for women). On cross-sectional analysis, the odds ratio (95% confidence interval) for hypertension per 1 standard deviation increase in hemoglobin concentration (1.2u200ag/dL) was 1.11 (1.05–1.18) before adjustment and 1.20 (1.09–1.32) after adjusting for age, sex, body mass index, kidney markers, lifestyle factors, and comorbidities. On longitudinal analysis, the relative risk (95% confidence interval) for incident hypertension per 1 standard deviation increase in hemoglobin concentration was 1.09 (0.96–1.23) before adjustment and 0.91 (0.78–1.08) after adjusting for age, sex, body mass index, lifestyle factors, baseline blood pressure, baseline comorbidities, and baseline kidney markers. This study suggests that hemoglobin per se does not cause hypertension development.

Association between Mean Corpuscular Hemoglobin Concentration and Future Depressive Symptoms in Women

Insufficient hemoglobin and depression share several symptoms and often occur in the same patients. Here, we sought to clarify their relationship by investigating two indices of oxygenation at the tissue level: mean corpuscular hemoglobin concentration (MCHC) and hemoglobin level. We hypothesized that MCHC would be more informative than hemoglobin levels. This prospective, longitudinal, community-based study included 337 participants (108 men and 229 women; age range, 38-87 years) who received evaluations of MCHC, hemoglobin levels and depressive symptom scores (DSS) during baseline and follow-up examinations, which were performed in 2008-2011 and 2010-2012, respectively. MCHC and hemoglobin levels were measured as part of complete blood counts, while DSS was evaluated using the Beck Depression Inventory. Associations were analyzed using linear regression. We found a statistically significant association between baseline MCHC and follow-up DSS (β = -0.69, p = 0.026), which remained statistically significant after controlling for potential confounders (β = -0.71, p = 0.011). Further, when we analyzed the relationship separately for men and women, we observed that it remained stable for women before (β = -1.00, p = 0.014) and after (β = -1.09, p = 0.003) adjusting for confounders. The stable association indicates that MCHC may be superior to hemoglobin level as a prognostic factor for future depressive symptoms in women. MCHC is easy to measure and low MCHC is usually treatable. Therefore, screening and intervention efforts could be targeted at women with low MCHC, who appear to have elevated risks of developing depressive symptoms.