Jong-Koo Kim

Relationship between white blood cell count and nonalcoholic fatty liver disease

BACKGROUND Higher levels of white blood cell (WBC) count are known to be associated with metabolic syndrome and insulin resistance. Nonalcoholic fatty liver disease (NAFLD) is also considered a hepatic manifestation of insulin resistance. AIMS The present study aimed to determine the relation between WBC count and the presence of NAFLD based on abdominal sonographic findings. METHODS A cross-sectional study with 3681 healthy subjects (2066 men, 1615 women) undergoing medical check-up was conducted. The odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD were calculated using multivariate logistic regression analyses across WBC quartiles. RESULTS A graded independent relationship between higher levels of WBC count and the prevalence risk of NAFLD was observed. After adjusting for age, smoking status, regular exercise, body mass index (BMI), blood pressure, fasting plasma glucose, triglyceride, and HDL-cholesterol, the ORs (95% CIs) for NAFLD according to WBC quartiles were 1.00, 1.48 (1.10-1.98), 1.59 (1.18-2.14), and 1.84 (1.35-2.51) for men and 1.00, 1.15 (0.67-1.96), 1.88 (1.13-3.11), and 2.74 (1.68-4.46) for women. CONCLUSIONS WBC count was found to be independently associated with the presence of NAFLD regardless of classical cardiovascular risk factors and other components of metabolic syndrome.

Effects of Coenzyme Q10 on Arterial Stiffness, Metabolic Parameters, and Fatigue in Obese Subjects: A Double-Blind Randomized Controlled Study

This study investigated the effects of coenzyme Q(10) supplementation on metabolic parameters, inflammatory markers, arterial stiffness, and fatigue in obese subjects. We performed a randomized, double-blind, placebo-controlled, single-center study on 51 obese subjects with a body mass index (BMI) of ≥25 kg/m(2). Subjects were randomized into either a coenzyme Q(10) (200 mg/day) group (n = 26, BMI = 27.9 ± 2.3 kg/m(2), age = 42.7 ± 11.3 years) or a placebo group (n = 25, BMI = 26.8 ± 2.8 kg/m(2), age = 41.3 ± 11.2 years) for a 12-week study. We collected anthropometric measurements, blood for laboratory testing, brachial-ankle pulse wave velocity (baPWV) as an indicator of arterial stiffness, and responses to a fatigue severity scale (FSS) questionnaire at the initial (0 week) and final (12 weeks) visits. A total of 36 subjects successfully completed the study protocol. Serum coenzyme Q(10) levels increased significantly from 0.65 ± 0.27 μg/mL to 1.20 ± 0.38 μg/mL in the coenzyme Q(10) group (P < .001). Oral administration of coenzyme Q(10) did not significantly affect lipid profiles, oxidative and inflammatory markers [including lipoprotein (a), oxidized low-density lipoprotein level, C-reactive protein, and white blood cell count], or baPWV. The mean FSS score decreased significantly from 40.1 to 33.1 in the coenzyme Q(10) group (P = .017), but no significant change was seen in the placebo group (P = .464). However, the extents of the change in mean FSS score between the placebo and coenzyme Q(10) groups were not significantly different (P = .287). In conclusion, we found no evidence that coenzyme Q(10) affects fatigue index, arterial stiffness, metabolic parameters, or inflammatory markers.

Elevated white blood cell count is associated with arterial stiffness

BACKGROUND AND AIMS White blood cell (WBC) count, a usual marker of systemic inflammation, is known to be associated with atherosclerotic cardiovascular disease. The aim of the present study was to determine the association of WBC count with arterial stiffness measured by brachial-ankle pulse wave velocity (baPWV). METHODS AND RESULTS We examined the association between WBC count and baPWV in 788 Korean adults (375 men, 413 women) in a health examination program. The odds ratios for a high baPWV were calculated using multivariate logistic regression analysis after adjusting for confounding variables across WBC count quartiles (Q1: <or=5190, Q2: 5200-6080, Q3: 6090-7310, and Q4: >or=7320 cells/mm(3)). A high baPWV was defined as more than 1440 cm/s (>75th percentile). Age-adjusted baPWV mean values gradually increased with WBC quartiles (Q1=1294, Q2=1322, Q3=1347, and Q4=1367 cm/s). The odds ratios (95% CI) for a high baPWV in each WBC count quartile were 1.00, 1.34 (0.61-3.00), 2.20 (0.96-5.06), and 2.69 (1.15-6.47) after adjusting for age, sex, cigarette smoking, alcohol intake, regular exercise, body mass index (BMI), mean arterial blood pressure, fasting plasma glucose, triglyceride, HDL-cholesterol, gamma-glutamyltransferase (GGT), and uric acid. CONCLUSION These findings indicate that elevated WBC count is associated with arterial stiffness. Accordingly, early detection of an elevated WBC count is important for arterial function and the assessment of cardiovascular risk.

The ratio of serum leptin to adiponectin provides adjunctive information to the risk of metabolic syndrome beyond the homeostasis model assessment insulin resistance: The Korean Genomic Rural Cohort Study

BACKGROUND Leptin and adiponectin are adipokines, shown to have opposing functions for fat metabolism and development of metabolic syndrome. We determined if the ratio of serum leptin to adiponectin (L/A ratio) adjunctively contributes to the risk of metabolic syndrome beyond the homeostasis model assessment of insulin resistance (HOMA-IR). METHODS This study included 1532 men and 1856 women, aged 40-70 y assessed in the Korean Genomic Rural Cohort Study from 2005 to 2008. The serum concentrations of adiponectin and leptin were measured by radioimmunoassay. Area under the receiver operating characteristic curve (AUROC) analyses were used to describe the ability of L/A ratio and HOMA-IR to differentiate between subjects with and without metabolic syndrome. RESULTS There were no significant differences in the ability of L/A ratio and HOMA-IR to predict metabolic syndrome (AUROC of L/A ratio vs. HOMA-IR, 0.771 vs. 0.774, p=0.8006 for men; 0.677 vs. 0.691, p=0.3088 for women). There was a significant adjunctive contribution by the L/A ratio, beyond that of HOMA-IR, to the risk of metabolic syndrome in men (p<0.0001 with 0.028 increased AUROC) and women (p=0.025 with 0.017 increased AUROC). CONCLUSIONS The L/A ratio provides significant adjunctive information to the risk of metabolic syndrome beyond HOMA-IR alone. The L/A ratio could be a good surrogate marker to assess metabolic syndrome.

Inverse Association Between Total Bilirubin and Metabolic Syndrome in Rural Korean Women

UNLABELLED Abstract Background: Chronic inflammation and oxidative stress are associated with the development of metabolic syndrome (MetS). Bilirubin is an antioxidant and has a protective effect against cardiovascular disease (CVD). The purpose of this study was to examine the association between total bilirubin levels and the prevalence of MetS in rural Korean women. METHODS This cross-sectional study included 5,266 women (>40 years) enrolled in the Korean Genomic Rural Cohort (KGRC). MetS was defined using the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) guidelines. Total bilirubin levels were categorized into quartiles. RESULTS Subjects in the upper quartiles of total bilirubin were younger and had lower waist circumferences, systolic blood pressure, and triglyceride levels and higher high-density lipoprotein cholesterol (HDL-C) concentrations. The overall prevalence of MetS was 39.0%. When the participants were categorized into quartiles by total bilirubin level, the prevalence of MetS according to increasing total bilirubin quartiles was 47.9%, 41.2%, 34.3%, and 32.7%, respectively. By comparison to the lowest quartile of total bilirubin (<0.61 mg/dL), the odds ratio (OR) (95% confidence interval [CI]) for MetS in the highest quartile of total bilirubin (≥0.94 mg/dL) was 0.63 (0.52-0.77) after adjusting for menopausal status, C-reactive protein (CRP) levels, insulin resistance, and other covariates. CONCLUSIONS Total bilirubin level appears to be inversely associated with the prevalence of MetS in rural Korean women >40 years of age in the KGRC, even after adjusting for risk factors of MetS, including body mass index (BMI), menopausal status, CRP levels, and homeostasis model assessment of insulin resistance (HOMA-IR).

Association of serum gamma-glutamyltransferase with C-reactive protein levels and white blood cell count in Korean adults.

Abstract Background: Elevated γ-glutamyltransferase (GGT) has emerged as an independent predictor of cardiovascular disease (CVD) which is increasingly viewed as an inflammatory disease. Thus, the mechanism underlying the link between elevated GGT and CVD may be inflammation. Methods: We examined the relationship between GGT and C-reactive protein (CRP) levels and white blood cell (WBC) count in 4562 Korean adults (2104 men, 2458 women). The odds ratio (OR) and 95% confidence interval (CI) for high CRP and WBC count (≥75th percentile) for both men and women were calculated across each quartile of serum GGT. Results: Results for the OR (95% CI) for high CRP levels by GGT quartiles were 1.00, 1.67 (1.21–2.29), 2.10 (1.51–2.93) and 2.51 (1.81–3.60) in men, and 1.00, 1.05 (0.65–1.68), 1.45 (0.79–2.02) and 2.16 (1.37–3.41) in women after adjustment for age, smoking status, alcohol intake, exercise, body mass index, blood pressure, fasting plasma glucose, triglyceride, high-density lipoprotein-cholesterol, and uric acid. Similarly, positive associations between serum GGT and WBC count were also observed. Conclusions: The present study demonstrates a positive correlation between GGT and two markers of inflammation, serum CRP and WBC count. Our findings suggest that serum GGT may be a surrogate inflammatory marker and a useful additional measure in assessing cardiovascular risk. Clin Chem Lab Med 2008;46:1410–5.

Association between the Ratio of Triglycerides to High-Density Lipoprotein Cholesterol and Chronic Kidney Disease in Korean Adults: The 2005 Korean National Health and Nutrition Examination Survey

Background: The ratio of triglycerides (TG, mg/dl) to high-density lipoprotein cholesterol (HDL-C, mg/dl) is a reliable indicator of insulin resistance and atherosclerotic diseases. The purpose of this study was to examine the association between TG/HDL-C and chronic kidney disease (CKD) in a nationally representative sample of Korean adults. Methods: This cross-sectional study included 5,503 subjects (≧19 years of age) who participated in the 2005 Korean National Health and Nutrition Examination Survey. CKD was defined as an estimated glomerular filtration rate (eGFR) below 60 ml/min/1.73 m2 as calculated by the abbreviated formula from the Modification of Diet in Renal Disease study. Results: The overall prevalence of CKD in our sample was 9.0%. eGFR was negatively correlated with logarithm-transformed TG/HDL-C in Pearson’s correlation. The prevalence of CKD in increasing TG/HDL-C quintiles was 4.4, 6.6, 9.5, 11.9, and 12.8%. In comparison with the lowest quintile of TG/HDL-C (<1.38), the odds ratio (95% confidence interval) for CKD in the highest quintile of TG/HDL-C (≧4.50) was 2.15 (1.38–3.37), after adjustment for multiple covariates (p value for trend = 0.036). Conclusions: TG/HDL-C was independently associated with increased prevalence of CKD in a sample of Korean adults.

Gender difference and determinants of C-reactive protein level in Korean adults

Abstract Background: C-reactive protein (CRP) has emerged as an important predictor for cardiovascular disease (CVD). To facilitate clinical and public health interventions, CRP thresholds have been defined as follows: low-risk (<1.0 mg/L), average-risk (1.0–3.0 mg/L), and high-risk (>3.0 mg/L). However, these cut-off thresholds are based on distributions in Western populations, and do not distinguish between men and women. Methods: We examined CRP distribution, gender difference, and determinants of CRP concentrations ranging from 0.02 mg/L to 10.0 mg/L, in 4923 Korean adults (2248 men; 2675 women) who received health checkups at Gangnam Severance Hospital from March 2006 to May 2007. Results: The distribution of CRP was highly skewed toward lower concentrations. CRP was higher in men than women, and the cut-off thresholds for the high-risk tertile of CRP concentrations corresponded to 1.01 mg/L in men and 0.62 mg/L in women, based on the current study population. Age, male gender, cigarette smoking, physical activity, body mass index, total cholesterol, high density lipoprotein cholesterol, γ-glutamyltransferase, and uric acid were independently associated with CRP concentrations. Conclusions: CRP distribution and gender difference in Korean adults were found to be different from previous Western studies, although similar risk factors influence CRP concentrations. Our results suggest that ethnicity and gender specific cut-off thresholds for CRP concentrations should be taken into consideration in CVD risk assessment. Clin Chem Lab Med 2009;47:863–9.

Independent association of TG/HDL-C with urinary albumin excretion in normotensive subjects in a rural Korean population.

BACKGROUND The ratio of triglycerides (TG, mg/dl) to high-density lipoprotein cholesterol (HDL-C, mg/dl) is a reliable indicator of insulin resistance and atherosclerotic diseases in some ethnic groups. This study is performed to examine the association between TG/HDL-C and albuminuria. METHODS This cross-sectional study included 9094 adult subjects (4091 men, 5003 women) who were enrolled in the Korean Genomic Rural Cohort (KGRC) and aged 40 years or more. Albuminuria was defined as a urine albumin/creatinine ratio ≥ 30 mg/g. Participants were categorized into TG/HDL-C quartile. RESULTS Compared to the lowest TG/HDL-C quartile (<1.94 in men, <1.71 in women), the odds ratios (ORs) for albuminuria in participants who were categorized in the highest TG/HDL-C quartile (≥ 4.98 in men, ≥ 4.20 in women) were 1.30 (95% CI: 0.97-1.75) and 1.36 (1.03-1.79) in men and women, respectively, when adjusted for blood pressure and other covariates. In normotensive men and women, the ORs for albuminuria in the highest TG/HDL-C quartile were 1.58 (1.04-2.39) and 1.68 (1.15-2.45), respectively, even after fully adjusted. In contrast, TG/HDL-C was not associated with albuminuria in hypertensive subjects. CONCLUSIONS TG/HDL-C was independently associated with increased prevalence of albuminuria in normotensive rural Korean subjects aged 40 years or more in KGRC.

The clustering patterns of metabolic risk factors and its association with sub-clinical atherosclerosis in Korean population

Background and aims: Metabolic syndrome (MetS) is considered to be an insulin-resistance syndrome, but recent evidence suggests that MetS has multiple physiological origins which may be related to atherosclerosis. This study investigated clustering patterns of metabolic risk factors and its association with sub-clinical atherosclerosis. Subjects and methods: This study used factor analysis of 11 metabolic factors in 1374 individuals to define clustering patterns and determine their association with carotid intima-media thickness (CIMT). Eleven metabolic factors were used: body mass index (BMI), waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), fasting blood insulin (FBI), serum triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), homeostasis model assessment-insulin resistance (HOMA-IR), high-sensitivity C-reactive protein (hsCRP) and adiponectin. Two regression analyses were done, the first using individual metabolic variables and the second using each factor from the factor analysis to evaluate their relationships with CIMT. Results: Four clustering patterns, insulin-resistance factor (FBG, FBI, HOMA-IR), obesity-inflammatory factor (BMI, WC, hsCRP), blood pressure factor (SBP, DBP) and lipid metabolic factor (HDL-C, TG, adiponectin) were categorized. In a multivariate regression model after adjustment for age, sex, low-density lipoprotein cholesterol and smoking history (pack year), insulin resistance factor (B = 11.09, p = 0.026), obesity-inflammatory factor (B = 18.50, p < 0.001), blood pressure factor (B = 12.84, p = 0.010) and lipid metabolic factor (B = − 11.55, p = 0.023) were found to be significantly associated with CIMT. Conclusion: In conclusion, metabolic risk factors have four distinct clustering patterns that are independently associated with sub-clinical atherosclerosis.