Jin-Ha Yoon

Different prognostic significance of high on-treatment platelet reactivity as assessed by the VerifyNow P2Y12 assay after coronary stenting in patients with and without acute myocardial infarction.

OBJECTIVES This study compared the prognostic role of high on-treatment platelet reactivity (HTPR) in predicting thrombotic events in a Korean population undergoing percutaneous coronary intervention (PCI) in the acute myocardial infarction (AMI) and non-AMI setting. BACKGROUND The prognostic significance and optimal cutoff of HTPR might differ according to a given clinical condition, such as AMI and ethnicity. METHODS On-treatment platelet reactivity was measured with a VerifyNow P2Y12 assay (Accumetrics, San Diego, California) in 1,226 patients (824 men; age 65 ± 10 years), including 413 AMI cases, 12 to 24 h after PCI between March 2008 and March 2010. The prevalence of cardiovascular (CV) events defined as a composite of death from CV causes, nonfatal myocardial infarction, or stent thrombosis at 1-year follow-up were compared according to HTPR between patients with and without AMI. RESULTS The optimal cutoff for HTPR was 272 IU of the P2Y(12) reaction unit (PRU) (area under the curve: 0.708; 95% confidence interval [CI]: 0.607 to 0.809, p = 0.03), which was the upper-tertile threshold. Among AMI patients, 1-year CV events occurred more frequently in patients with versus without HTPR (n = 14 [8.8%] vs. n = 1 [0.4%], p < 0.001), whereas there was no difference in the composite endpoint on the basis of HTPR in patients without AMI (n = 7 [2.8%] vs. n = 8 [1.4%], p = 0.193). CONCLUSIONS Increased residual platelet reactivity is related to post-discharge CV events in subjects with AMI, whereas the prognostic significance of HTPR seems to be attenuated in patients with stable coronary disease after PCI.

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.

Preliminary report: A serious link between adiponectin levels and metabolic syndrome in a Korean nondiabetic population

This large-scale cross-sectional investigation highlights the relationships between adiponectin levels and a number of metabolic syndrome components in a nondiabetic Korean population (N = 6634). In a multivariate logistic regression model, after adjustment for age, homeostasis model assessment of insulin resistance, body mass index, smoking history, C-reactive protein, and low-density lipoprotein cholesterol, adiponectin levels were inversely related with metabolic syndrome in men and women (P < .05). Adiponectin level was found to be a significant contributor to metabolic syndrome. Our findings suggest that adiponectin is an important biomarker even in a nondiabetic population at high risk of metabolic syndrome.

Urine Albumin Creatinine Ratio is Associated with Carotid Atherosclerosis in a Community Based Cohort: Atherosclerosis Risk of Rural Area in Korean General Population Study

Background Albuminuria is a surrogate marker of endothelial dysfunction and a predictor of cardiovascular events. Data are limited with regard to the relationship between albuminuria and subclinical atherosclerosis in a community-based cohort. We determined the association between albuminuria measured by the urine albumin creatinine ratio (UACR) and carotid intima media thickness (CIMT) in a Korean rural population. Methods We enrolled 1,369 healthy subjects older than 40 years (857 males and 518 females) with normal renal function and measured the CIMT. We excluded subjects with overt proteinuria (> 300 mg/day) or with treatment of diabetes mellitus, hypertension, dyslipidemia, and any cardiovascular disease. The subjects were stratified into the quartile value of the UACR (lowest quartile: UACR < 4.8 and highest quartile: UACR > 17.7). And we evaluate the relationship between UACR and CIMT by linear regression and logistic regression analysis. Results Increasing quartile of the UACR had a stepwise increase in body mass index, blood pressure, cholesterol profile [low density lipoprotein (LDL)-cholesterol and triglyceride], glucose, homeostratic model assessment of insulin resistance (HOMA-IR), and C-reactive protein (all p values < 0.001). Maximal CIMT from the 1st to the 4th quartile values of the UACR were 0.74 ± 0.17, 0.77 ± 0.18, 0.78 ± 0.18, and 0.82 ± 0.21 mm, respectively (p < 0.001). In a multivariate regression model adjusted for age, sex, systolic blood pressure, triglyceride, LDL-cholesterol, fasting blood sugar, waist circumference, adiponectin, HOMA-IR, high sensitive C-reactive protein, smoking, UACR showed a significant association with maximal CIMT (B = 0.014, R2 = 0.145, p = 0.002). Conclusion Albuminuria measured by the UACR was significantly associated with both CIMT and traditional risk factors of atherosclerosis except for smoking in healthy Koreans.

Adverse health outcomes in residents exposed to cement dust

This study investigated the adverse health outcomes and urinary heavy metal levels in residents exposed to cement dust, compared to those who were not exposed. A total of 374 residents (276 for the exposed group and 98 for the unexposed group) were surveyed. Participant demographics, health-related behaviors (smoking and drinking), medical history, and clinical symptoms were collected using a self-administered questionnaire. Urinary metal levels were determined using an Atomic Absorption Spectrometer (AAS). Clinical adverse health outcomes such as asthma, rhinitis, and dermatitis were found to be more common in the group exposed to cement dust than in the unexposed group. Urinary levels of chromium and mercury were found to be significantly higher in the exposed group compared to the unexposed group. A limitation of this study is that we did not measure air pollution and heavy metals in local soils and plants and the cement dust could not be concluded as the unique origin of those metals because of other sources of those metals. Although these limitation are, these results suggest that exposure to cement dust may lead to chronic symptoms and disease.

The association between serum adiponectin and carotid intima media thickness in community based cohort in Korea: The ARIRANG study

Growing body of evidence suggests an association between circulating adiponectin and the development of atherosclerosis. However most of these studies have been performed with healthy subjects with relatively small sample size or patients with preexisting cardiovascular diseases. The results obtained are inconstant for an independent association between adiponectin and subclinical atherosclerosis. We aimed to evaluate the association between circulating adiponectin and carotid intima media thickness (CIMT) in a large sample of individuals from the community. We performed a non-diabetic community based cohort study conducted on a healthy Korean adults (age>40 years) population. The serum adiponectin concentrations were measured by a radioimmunoassay. The mean adiponectin level was significantly lower in subjects with high CIMT defined by >0.9 mm than those with low CIMT (9.18 vs. 10.44 g/mL, P=0.03). The adiponectin level was correlated negatively with waist circumference (r=−0.27), body mass index (r=−0.21), systolic blood pressure (r=−0.11), diastolic blood pressure (r=−0.10), triglyceride (r=−0.30), LDL-cholesterol (r=−0.02), glucose (r=−0.16), insulin (r=−0.17), homeostasis assessment-insulin resistance (r=−0.23) and C-reactive protein (r=−0.11), and correlated positively with HDL cholesterol (r=0.30) (all P<0.05). Adiponectin was significantly associated with CIMT independently of age, sex, and all metabolic risk factors (R2=0.14, P=0.04). In conclusion, serum adiponectin levels are independently associated with CIMT as a surrogate of subclinical atherosclerosis in a non-diabetic community based cohort.