Su-Yeon Choi

The Relation Between Non-Alcoholic Fatty Liver Disease and the Risk of Coronary Heart Disease in Koreans

OBJECTIVES:Non-alcoholic fatty liver disease (NAFLD) is known to be related to factors that predict the development of coronary heart disease (CHD), such as dyslipidemia, central obesity, and metabolic syndrome (MS). The aim of this study was to determine whether individuals with NAFLD have an elevated risk of CHD, as estimated using the Framingham risk score (FRS).METHODS:A total of 21,130 individuals who underwent a voluntary general health examination were recruited. NAFLD was diagnosed among these individuals on the basis of typical sonographic findings and a level of alcohol consumption of <20 g/day. Of the 21,130 individuals, 3,780 were excluded because they had known causes of liver disease (1,690 were alcoholics, 975 had hepatitis B virus, 242 had hepatitis C virus, 91 had other hepatitis history, and 593 were taking medication known to produce fatty liver) or a history of heart disease (189).RESULTS:NAFLD was diagnosed in 5,769 of the 17,350 individuals (33.3%). The 11,581 normal individuals constituted the control group. The 5,769 individuals with NAFLD were split into two groups on the basis of ultrasonographic findings, that is, into a mild NAFLD group (n=3,278) and a moderate–severe NAFLD group (n=2,491). Individuals with NAFLD had an elevated risk of CHD, as estimated using FRS. Multivariable regression analysis, adjusted for confounding factors, showed a strong association between a higher FRS and NAFLD.CONCLUSIONS:Individuals with ultrasonographically detected NAFLD have an elevated 10-year risk of developing CHD as estimated using FRS. Furthermore, NAFLD was found to be independently related to the risk of developing CHD, regardless of classical risk factors and other components of MS.

Comparison between sitagliptin as add-on therapy to insulin and insulin dose-increase therapy in uncontrolled Korean type 2 diabetes: CSI study

Aim: Individuals requiring insulin therapy for type 2 diabetes often require escalation of their regimen to achieve glycaemic control. Optimal management strategies for uncontrolled type 2 diabetes would improve glycaemic control without hypoglycaemia and weight gain. This study compared the efficacy and tolerability of adding sitagliptin, an oral dipeptidyl peptidase‐4 inhibitor, and an up to 20% increase in insulin dose in patients with uncontrolled type 2 diabetes on insulin therapy.

General and abdominal obesity and abdominal visceral fat accumulation associated with coronary artery calcification in Korean men

OBJECTIVE It is unclear whether visceral adipose tissue (VAT) is responsible for an increased risk of coronary artery calcification (CAC). We evaluated the associations between body mass index (BMI), waist circumference (WC) and abdominal VAT area with the CAC in healthy Korean men. METHODS This is a cross-sectional study of 1336 Korean men free of cardiovascular disease who underwent CAC score (CACS) by multislice computed tomography (CT) and abdominal CT as part of a routine medical examination. VAT area was measured at the level of the umbilicus using CT. RESULTS Mean BMI, WC, total adipose tissue and VAT area were higher in subjects with moderate-to-severe CAC (CACS>100) compared to subjects with CACS ≤ 100. The subjects in the fourth quartile of VAT had significantly higher CACS and the greater prevalence of CAC presence and moderate-to-severe CAC than those in the first to third quartiles. The highest quartiles of BMI, WC and VAT area were significantly associated with moderate-to-severe CAC in the age- and CVD risk factor-adjusted model (OR [95% CI]=1.56 [1.11-2.19], 1.56 [1.12-2.18] and 1.42 [1.01-1.98] with p<0.05 for all, respectively). CONCLUSION The higher levels of general and central measure of obesity and the amount of abdominal visceral fat were related to moderate-to-severe CAC in asymptomatic Korean men with relatively low risk.

Nonalcoholic fatty liver disease as a risk factor of cardiovascular disease; Relation of non-alcoholic fatty liver disease to carotid atherosclerosis

BACKGROUND/AIMS Non-alcoholic fatty liver disease (NAFLD) is closely associated with abdominal obesity, dyslipidemia, hypertension, and Type 2 diabetes, which are all features of the metabolic syndrome. The aim of the present study was to elucidate whether NAFLD is associated with carotid atherosclerosis. METHODS The study population comprised 659 subjects without hepatitis B and C infections and who did not consume alcohol. Fatty infiltrations of liver were detected by abdominal ultrasonography, and intima-media thickness (IMT) and plaque prevalence were estimated by carotid ultrasonography. RESULTS The mean values of systolic and diastolic pressures, body mass index (BMI), aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase, uric acid, total cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol, fasting glucose, fasting insulin, homeostasis model of assessment (HOMA) index, hemoglobin A1c, and plasminogen activator inhibitor-1 differed significantly between patients with NAFLD (n=314) and normal controls (n=345). The carotid IMT was 0.817+/-0.212 (mean+/-SD) mm in patients with NAFLD and 0.757+/-0.198 mm in normal controls (p<0.001). The prevalence of carotid plaques was higher in patients with NAFLD (26.4%) than in normal controls (15.9%) (p<0.001). This association persisted significantly after adjusting for age, sex, BMI, HOMA index and individual factors of metabolic syndrome by multiple logistic regression analysis. CONCLUSIONS Patients with NAFLD are at a high risk of carotid atherosclerosis regardless of metabolic syndrome and classical cardiovascular risk factors. Therefore, the detection of NAFLD should alert to the existence of an increased cardiovascular risk. Moreover, NAFLD might be an independent risk factor for cardiovascular disease.

Feature extraction algorithm based on adaptive wavelet packet for surface defect classification

This paper proposes a feature extraction method to effectively handle the textural characteristics in images with defects in cold rolled strips. An adaptive wavelet packet scheme is developed to produce the optimum number of features automatically through subband coding gain. Also four classical entropy features in the images with defects are used as local features in the spatial domain. A neural network is used to classify the defects from these features. Experiments with real image data show good training and generalization performances of the proposed method.

Long-Term Exercise Training Attenuates Age-Related Diastolic Dysfunction: Association of Myocardial Collagen Cross-Linking

The incidence of diastolic heart failure increases dramatically with age. We investigated the impact of long-term exercise training on age-related diastolic dysfunction. Old (25-month-old) male Fischer 344 rats were studied after 12 weeks of treadmill exercise training or sedentary cage life (N=7, in each group). We determined cardiac performance using a pressure-volume conductance catheter and magnetic resonance imaging. Collagen volume fraction (CVF) and myocardial collagen solubility by pepsin as an index of advanced glycation end products (AGEs) cross-linked collagen were measured. The maximal slope of systolic pressure increment (+dP/dt) and the slope of end-systolic pressure-volume relation were higher, and end diastolic volume (EDV), ΔEDV (the percentage of the EDV increment-to-baseline EDV) and the slope of end-diastolic pressure-volume relation were lower in training group. The maximal slope of diastolic pressure decrement (-dP/dt) and time constant of LV pressure decay (τ) had no difference. AGEs cross-linked collagen, not CVF was reduced by exercise training. Long-term exercise training appears to attenuate age-related deterioration in cardiac systolic function and myocardial stiffness and could be reduce in pathologic AGEs cross-linked collagen in myocardium.

Restoration of left ventricular synchronous contraction after acute myocardial infarction by stem cell therapy: new insights into the therapeutic implication of stem cell therapy for acute myocardial infarction.

Objective: To evaluate the effects of stem cell therapy on restoration of the left ventricular (LV) synchronous contraction in patients with acute myocardial infarction (AMI). Methods: 40 patients with AMI who underwent successful coronary revascularisation were randomly allocated to the cell infusion or the control group. Evaluations were performed with echocardiographic tissue synchronisation imaging to determine LV dyssynchrony and with cardiac magnetic resonance imaging to estimate LV ejection fraction (LVEF) at baseline and at 6 months. To quantify the severity of systolic LV dyssynchrony, the standard deviations of time to peak systolic velocity of the 12 LV segments (Ts-SD) were calculated. Results: At 6 months, greater improvements of Ts-SD (ΔTs-SD: −45.0 (40.2) vs 5.0 (39.9) ms, p<0.001) and LVEF (ΔLVEF: 6.8% (9.1%) vs −0.2% (6.9%), p = 0.015) relative to the corresponding baseline values were observed in the cell infusion group than in the control group. By multivariate analysis, ΔTs-SD and baseline LVEF emerged as the independent determinants of LVEF improvement and cell infusion, and baseline Ts-SD as the determinant of ΔTs-SD improvement. Maximal exercise capacity measured by symptom-limited treadmill testing correlated well with Ts-SD but not with LVEF at 6 months of follow-up. Conclusion: Stem cell therapy had a favourable effect on the restoration of LV synchronous contraction in patients with AMI.

Cardio-ankle vascular index reflects coronary atherosclerosis in patients with abnormal glucose metabolism: Assessment with 256 slice multi-detector computed tomography

OBJECTIVE The association between arterial stiffness, as measured by the cardio-ankle vascular index (CAVI), and coronary atherosclerosis, using coronary artery computed tomography (CT), was investigated in the asymptomatic general population, with special interest in subjects with abnormal glucose metabolism. PATIENTS AND METHODS A total of 158 normoglycemic subjects and 373 subjects with abnormal glucose metabolism were evaluated. CAVI was assessed in relation with coronary artery calcium score (CACS) and degree of stenosis detected by CT. RESULTS The association of CAVI with other clinical parameters was evaluated in patients with abnormal glucose metabolism. CAVI was higher, and CACS and the degree of coronary artery stenosis were both greater compared to the normal group. CAVI showed a significant correlation with CACS and the degree of stenosis (r=0.167, p=0.001; r=0.182, p<0.001, respectively). The cut-off level of CAVI from receiver operating characteristic (ROC) curve was ≥ 8.0 for predicting ≥ 50% coronary artery stenosis (area under the curve 0.713, sensitivity 69%, and specificity 61%). CAVI ≥ 8.0 was independently associated with significant coronary artery stenosis, even after adjusting for age, sex, and presence of hypertension and hypercholesterolemia (odds ratio 3.143, 95% confidence interval 1.004-9.842, p=0.049). CONCLUSION CAVI is an independent parameter which reflects coronary atherosclerosis in patients with abnormal glucose metabolism. CAVI can be a useful tool not only to assess arterial stiffness, but also to evaluate the risk for subclinical coronary atherosclerosis in asymptomatic patients.

Visceral obesity is associated with microalbuminuria in nondiabetic Asians

Microalbuminuria is an indicator of renal disease and is known to be related to obesity. The aim of this study is to investigate the association between the cross-sectional area of visceral adipose tissue (VAT) and the prevalence of microalbuminuria. We conducted a cross-sectional study of 1154 subjects who underwent routine checkups, including computed tomography (CT) scans of abdominal adipose tissue. We used the lowest tertile as a reference of abdominal fat. The highest tertile of VAT was related to the highest prevalence of microalbuminuria (odds ratio (OR): 1.96; 95% CI: 1.12–3.43). Subcutaneous adipose tissue (SAT) was not associated with microalbuminuria. In men, the highest tertile for VAT was associated with the highest prevalence of microalbuminuria (OR: 2.74; 95% CI: 1.44–5.22). In women, VAT or SAT was not associated with microalbuminuria. In nondiabetic subjects, the highest tertile for VAT was associated with the highest prevalence of microalbuminuria (OR: 2.23; 95% CI: 1.15–4.32). Among subjects without metabolic syndrome or with body mass index <25 kg m−2, the highest tertile for VAT was associated with microalbuminuria in age- and sex-adjusted model, respectively (OR: 1.62; 95% CI: 1.01–2.31; OR: 2.21; 95% CI: 1.05–4.65). The analysis of the association of VAT and insulin resistance (IR) indicated that a higher VAT was associated with a higher IR (highest tertile for VAT—OR: 2.91; 95% CI: 1.70–4.96). In conclusion, the highest VAT of the current study was significantly correlated with the highest prevalence of microalbuminuria, even in traditionally low-risk subjects without diabetes, and this association is potentially related with a higher IR.

Incremental Benefit of Coronary Artery Calcium Score Above Traditional Risk Factors for All-Cause Mortality in Asymptomatic Korean Adults

BACKGROUND Coronary artery calcium score (CACS) is a well-recognized marker for subclinical coronary atherosclerosis, particularly in asymptomatic populations. To date, however, the added prognostic benefit of CACS compared with traditional risk factors in an Asian population remains unknown. This study therefore investigated the benefit of CACS over traditional risk factors for all-cause mortality in a large multicenter registry of asymptomatic Korean adults. METHODSANDRESULTS A total of 34,386 individuals were retrospectively enrolled to participate in a general health examination. The Framingham 10-year risk score (FRS) was calculated according to the traditional risk stratification algorithm and CACS was calculated in log(CACS+1) for continuous data and categorized as 0, 1-100, 101-400 and >400. During a median follow-up of 4.9 years (IQR, 3.0-7.1), there were 303 all-cause deaths (0.9%). Following adjustment, CACS was independently associated with all-cause death (hazard ratio, 1.10; 95% confidence interval (CI): 1.05-1.17; P<0.001). Notably, CACS added further prognostic value above and beyond FRS (likelihood ratio, χ(2)=75.42, P<0.001; continuous net reclassification improvement=0.40, 95% CI: 0.29-0.51, P≤0.001; improving C-statistic from 0.64, 95% CI: 0.61-0.67 to 0.68, 95% CI: 0.64-0.71; ∆C=0.04, 95% CI: 0.01-0.06, P=0.002). CONCLUSIONS In an asymptomatic Korean population, CACS improved prediction of all-cause mortality over and above that of a conventional risk tool.