[show abstract][hide abstract] ABSTRACT: There are limited data regarding the role of coronary computed tomographic angiography (CCTA) in asymptomatic patients with type 2 diabetes mellitus. We analyzed 557 asymptomatic type 2 diabetic patients who underwent CCTA. Cardiac event was defined as a composite of cardiac death, nonfatal myocardial infarction, acute coronary syndrome requiring hospitalization, or late revascularization. Atherosclerotic plaques were observed in 395 patients (70.9%), and 170 patients (30.5%) showed significant coronary artery disease (CAD) on CCTA. Ninety-two patients (16.5%) were associated with a significant stenosis in the left main or proximal left anterior descending artery. During the follow-up period (33.7 ± 7.8 months), although an excellent prognosis was observed in patients without significant CAD on CCTA, those with significant CAD showed more cardiac events (7.1% vs 0.5%) and lower 3-year event-free survival rates (99.2 ± 0.6% vs 90.9 ± 2.6%, p <0.001). Furthermore, in group with significant CAD, patients with significant CAD in the left main or proximal left anterior descending artery had more cardiac events (10.9% vs 2.6%) and lower 3-year event-free survival rates (97.4 ± 1.8% vs 86.1 ± 4.2%, p = 0.049). On multivariate analysis, family history of premature CAD, previous history of stroke, higher UK Prospective Diabetes Study 10-year risk scores, neuropathy, and retinopathy were independent clinical predictors of having significant CAD and left main or proximal left anterior descending artery significant CAD on CCTA. In conclusion, about 1/3 of asymptomatic type 2 diabetic patients had significant CAD on CCTA with a subsequent high risk for cardiac events. These findings suggest that CCTA may have a potential role in identifying patients with high cardiovascular risks in asymptomatic type 2 diabetes.
The American journal of cardiology 03/2014; 113(5):765-71. · 3.58 Impact Factor
[show abstract][hide abstract] ABSTRACT: Vaspin is an adipocytokine that was recently identified in the visceral adipose tissue of diabetic rats and has anti-diabetic and anti-atherogenic effects. We hypothesized that vaspin prevents inflammatory cytokine-induced nuclear factor-kappa B (NF-kappaB) activation by activating AMP-activated protein kinase (AMPK) in vascular endothelial cells.
We examined the effects of vaspin on NF-kappaB activation and the expression of the NF-kappaB-mediated genes intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, and monocyte chemoattractant protein-1 (MCP-1). Human aortic endothelial cells (HAECS) were used. Tumor necrosis factor alpha (TNFalpha) was used as a representative proinflammatory cytokine.
Treatment with vaspin significantly increased the phosphorylation of AMPK and acetyl-CoA carboxylase, the down-stream target of AMPK. Furthermore, treatment with vaspin significantly decreased TNFalpha-induced activation of NF-kappaB, as well as the expression of the adhesion molecules ICAM-1, VCAM-1, E-selectin, and MCP-1. These effects were abolished following transfection of AMPKalpha1-specific small interfering RNA. In an adhesion assay using THP-1 cells, vaspin reduced TNFalpha-induced adhesion of monocytes to HAECS in an AMPK-dependent manner.
Vaspin might attenuate the cytokine-induced expression of adhesion molecule genes by inhibiting NF-kappaB following AMPK activation.
[show abstract][hide abstract] ABSTRACT: Recently the Korea Diabetes Association participated in the ‘Cambodia-Korea Twinning Project’ to help Cambodia establish its own modernized diabetes center and to raise awareness of the seriousness of diabetes. Here we report the status of diabetes in an urban area of Cambodia as obtained through this project.
[show abstract][hide abstract] ABSTRACT: Aims
Increased sugar consumption may adversely affect glycemic control in patients with diabetes. Although patients with diabetes are generally thought to prefer sweet tastes, few data are available on the sucrose preference in these individuals. The aim of the present study was to evaluate sucrose preference in patients with type 2 diabetes in comparison with subjects without diabetes.
Sucrose preference was assessed in 200 subjects (100 type 2 diabetes patients and 100 age-, sex- and body mass index (BMI)-matched control subjects). Sucrose preference was evaluated together with sucrose perception (i.e., sucrose sensitivity). Clinical and biochemical factors affecting sucrose taste were also analyzed.
Participants with type 2 diabetes preferred lower sucrose concentrations compared with control subjects (p = 0.001), although they had a less sensitive palate for sucrose compared with subjects without diabetes (p = 0.012). Individual sucrose preference demonstrated a negative relationship with sensitivity to sucrose in control subjects. Notably, this relationship between sucrose preference and sensitivity was completely absent in participants with type 2 diabetes. Male patients with diabetes demonstrated a higher sucrose preference compared with female patients. There were no significant correlations between sucrose preference and glycemic control, duration of diabetes, or anti-diabetic medications.
Participants with type 2 diabetes demonstrate a lower preference for sweet tastes than control subjects despite their decreased perception of sucrose. Reduced sucrose preference is not associated with better glycemic control in individuals with diabetes.
[show abstract][hide abstract] ABSTRACT: Aims/IntroductionInsulin has been associated with the risk of colorectal cancer (CRC). However, few studies have evaluated the association between insulin and colorectal adenoma. We investigated the relationship between fasting serum insulin levels or homeostasis model assessment of insulin resistance (HOMA-IR) and colorectal adenoma. Materials and Methods
We retrospectively enrolled 15,427 participants who underwent both fasting serum insulin measurement and colonoscopy for a routine health examination at Asan Medical Center from January 2007 to December 2008. Participants with a history of any cancer, previous colectomy or polypectomy, those taking antidiabetic medications, and inflammatory bowel disease, non-specific colitis, non-adenomatous polyps only or CRC on colonoscopic findings were excluded. Finally, 3,606 participants with histologically confirmed colorectal adenoma and 6,019 controls with no abnormal findings on colonoscopy were included. Participants were categorized into quartiles (Q) based on fasting serum insulin levels and HOMA-IR. ResultsFasting serum insulin and HOMA-IR were significantly higher in participants with colorectal adenomas compared with controls. Multivariate regression analysis adjusting for age, sex, smoking habits, drinking habits and family history of CRC showed that participants with higher quartiles of fasting serum insulin levels (odd ratio [OR] 1.17 for 2nd Q, 1.19 for 3rd Q, and 1.42 for 4th Q, P < 0.05) or HOMA-IR (OR 1.18 for 2nd Q and 1.45 for 4th Q, P < 0.05) showed significantly increased ORs of colorectal adenoma compared with the lowest quartiles. Conclusions
These findings showed that increased serum insulin levels and insulin resistance were significantly associated with the presence of colorectal adenoma.
[show abstract][hide abstract] ABSTRACT: Bilirubin, a natural product of heme catabolism by heme oxygenase, one of key antioxidant enzymes, has been recognized as a substance with potent antioxidant and cytoprotective properties. Several studies have shown a significant negative relationship between serum bilirubin levels and the risk of metabolic disorders, including type 2 diabetes. However, longitudinal studies investigating the association of elevated serum bilirubin levels and type 2 diabetes are lacking. In the present study, we aimed to investigate the longitudinal effects of baseline serum bilirubin concentrations on the development of type 2 diabetes in healthy Korean men.
This 4year retrospective longitudinal observational study was conducted at the Asan Medical Center, Seoul, Republic of Korea. The study population consisted of 5960 men without type 2 diabetes who underwent routine health examinations in 2007 (baseline) and 2011 (follow-up). Baseline serum bilirubin concentrations were determined by the vanadate oxidation method.
During a 4year period, 409 incident cases of diabetes (6.9 %) were identified. Incident type 2 diabetes decreased across the baseline bilirubin quartile categories (P for trend <0.001). In multivariable-adjusted model, the relative risk (RR) for the development of type 2 diabetes was significantly lower in the highest (i.e., 1.30-2.00mg/dl) than in the lowest bilirubin quartile category (i.e., ≤0.90mg/dl), even after adjustment for confounding variables (RR=0.69, 95% confidence interval 0.48-0.99, P for trend=0.041).
The results indicate that serum total bilirubin level may provide additional information for predicting future development of type 2 diabetes in healthy subjects.
Metabolism: clinical and experimental 10/2013; · 3.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: Despite the noninvasiveness and accuracy of multidetector computed tomography (MDCT), its use as a routine screening tool for occult coronary atherosclerosis is unclear. We investigated whether the ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1), an indicator of the balance between atherogenic and atheroprotective cholesterol transport could predict occult coronary atherosclerosis detected by MDCT. We collected the data of 1,401 subjects (877 men and 524 women) who participated in a routine health screening examination of Asan Medical Center. Significant coronary artery stenosis defined as > 50% stenosis was detected in 114 subjects (8.1%). An increase in apoB/A1 quartiles was associated with increased percentages of subjects with significant coronary stenosis and noncalcified plaques (NCAP). After adjustment for confounding variables, each 0.1 increase in serum apoB/A1 was significantly associated with increased odds ratios (ORs) for coronary stenosis and NCAP of 1.23 and 1.18, respectively. The optimal apoB/A1 ratio cut off value for MDCT detection of significant coronary stenosis was 0.58, which had a sensitivity of 70.2% and a specificity of 48.2% (area under the curve, 0.61; 95% CI, 0.58-0.63, P < 0.001). Our results indicate that apoB/A1 ratio is a good indicator of occult coronary atherosclerosis detected by coronary MDCT.
Journal of Korean medical science 05/2013; 28(5):709-16. · 0.84 Impact Factor
[show abstract][hide abstract] ABSTRACT: OBJECTIVE: Increasing evidence suggests that osteocalcin (OC), one of the osteoblast-specific proteins, has been associated with atherosclerosis, but results are conflicting. The aim of this study was to elucidate the independent effect of uncarboxylated osteocalcin (ucOC), an active form of osteocalcin which has been suggested to have an insulin sensitizing effect, on vascular endothelial cells. MATERIALS AND METHODS: We used human aortic endothelial cells and treated them with ucOC. Linoleic acid (LA) was used as a representative free fatty acid. Apoptosis was evaluated using various methods including a terminal deoxyribonucleotide transferase-mediated deoxyuridine triphosphate nick-end labeling analysis kit and Western blotting for cleaved caspase 3, cleaved poly (ADP-ribose) polymerase and Bcl-xL. The phosphorylations of Akt and endothelial nitric oxide synthase (eNOS) as well as the level of NO were measured to confirm the effect of ucOC on insulin signaling pathway. RESULTS: Pretreatment of ucOC (30ng/ml) prevented LA-induced apoptosis in insulin-stimulated endothelial cells; effects were abolished by pretreatment with the phosphatidylinositol 3-kinase (PI3-kinase) inhibitor, wortmannin. Treatment of ucOC (ranged from 0.3 to 30ng/ml) significantly increased the phosphorylation of Akt and eNOS and nitric oxide secretion from endothelial cells in a PI3-kinase dependent manner. CONCLUSIONS: Our study is the first to demonstrate the independent effect of ucOC on vascular endothelial cells. Our results further suggest that ucOC could have beneficial effects on atherosclerosis.
Metabolism: clinical and experimental 04/2013; · 3.10 Impact Factor
[show abstract][hide abstract] ABSTRACT: Regulating the entry of secretory and membrane proteins into the ER is shown to be an important physiological process, in terms of controlling quantity, localization and therefore function of target proteins. However, few small molecule modulators are available to pharmacologically regulate translocation of a specific protein. Here, we identified a small molecule that specifically inhibits pathogenic PrP biosynthesis using a highly sensitive and reproducible assay based on the fluorogenic substrate reporter PrP. This molecule specifically destabilized the signal peptide of PrP, leading to cotranslational rerouting of a significant amount of nascent PrP to proteasome-dependent degradation pathway in the cytosol. This study suggests that regulating differential translocation efficiency attributable to sequence diversity in signal peptides of disease-causing secretory and membrane proteins using cell-permeable small molecules may be a potential therapeutic approach for diseases associated with impaired protein biogenesis.
Experimental Cell Research 04/2013; · 3.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although clusterin (CLU) was originally identified as a secreted glycoprotein that plays cytoprotective role, several intracellular CLU variants have been recently identified in the diverse pathological conditions. The mechanistic basis of these variants is now believed to be alternative splicing and retrotranslocation. Here, we uncovered, an unglycosylated and signal sequence-unprocessed, CLU variant in the cytosol. This variant proved to be a product that cotranslationally rerouted to the cytosol during translocation. Cytosolic CLU was prone to aggregation at peri-nuclear region of cells and induced cell death. Signal sequence is shown to be an important determinant for cytosolic CLU generation and aggregation. These results provide not only a new mechanistic insight into the cytosolic CLU generation but also an idea for therapeutic mislocalization of CLU as a strategy for cancer treatment.
Experimental Cell Research 02/2013; · 3.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: Elevated ferritin concentration has been implicated in the etiology of type 2 diabetes. Accumulating evidence, mostly from studies conducted on western populations, has demonstrated a strong association between the elevated ferritin concentrations and incident type 2 diabetes. In Asian populations, however, the longitudinal studies investigating the association of elevated serum ferritin levels and type 2 diabetes are lacking. In present study, we aimed to determine whether elevated serum ferritin levels are related to the incident type 2 diabetes in healthy Korean men.
This 4 year longitudinal observational study was conducted at the Asan Medical Center, Seoul, Republic of Korea. The study population consisted of 2,029 men without type 2 diabetes who underwent routine health examination in 2007 (baseline) and 2011 (follow-up). Baseline serum ferritin concentrations were measured by chemiluminescent two-site sandwich immunoassay. In multiple-adjusted model, the relative risk (RR) for incident type 2 diabetes was significantly higher in highest compared with the lowest ferritin quartile category, even after adjusting for confounding variables including homeostasis model assessment of insulin resistance (RR = 2.17, 95% confidence interval 1.27-3.72, P for trend = 0.013).
These results demonstrated that elevated level of serum ferritin at baseline was associated with incident type 2 diabetes in an Asian population.
PLoS ONE 01/2013; 8(9):e75250. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Clusterin is a stress-responsive and highly glycosylated secretory protein that plays cytoprotective role in most body fluids. In addition to extracellular clusterin, several intracellular clusterin variants that are rather cytotoxic have been recently uncovered under diverse pathological conditions. Although these variants revealed heterogeneity in their glycan modification, its significance in many diseases remains to be validated. Here, we found that clusterin is differentially metabolized by two well-characterized ER stress inducers. Thapsigargin induced retrotranslocation and rapid degradation of clusterin from the endoplasmic reticulum, whereas tunicamycin failed to degrade but rather retained clusterin in the endoplasmic reticulum. Important sorting determinant for these processes proved to be N-glycan moieties that are required for the prevention of terminal misfolding and aggregation of clusterin in the endoplasmic reticulum. This study provides a mechanistic insight into the generation of noble cytotoxic variant of intracellular clusterin and an idea about molecular pathogenesis of diseases associated with chronic endoplasmic reticulum stress, such as neurodegeneration.
The international journal of biochemistry & cell biology 11/2012; · 4.89 Impact Factor
[show abstract][hide abstract] ABSTRACT: Abstract Background: Increased oxidative stress contributes to the development of arterial stiffness. Arterial stiffness, as measured by brachial-ankle pulse wave velocity (baPWV), has been known to be correlated with oxidative stress. Serum ceruloplasmin (CP), a copper-carrying protein, may indicate the overall level of oxidative stress in the body. The present study investigated whether serum CP levels are associated with baPWV in Korean men with type 2 diabetes mellitus (DM). Subjects and Methods: Serum CP levels and conventional risk factors were measured in 760 Korean men with type 2 DM. Arterial stiffness was assessed by baPWV obtained with an automatic device (model VP-1000; Colin, Komaki, Japan). Results: Correlation analysis indicated a significant positive association between serum CP and baPWV (r=0.109, P=0.003). Age-adjusted baPWV increased gradually according to serum CP quartiles (Q1, 1,500.3±18.4 cm/s; Q2, 1,511.6±17.8 cm/s; Q3, 1,551.8±17.9 cm/s; Q4, 1,622.1±17.8 cm/s; P for trend<0.001). Multivariate linear regression analysis showed that serum CP was independently associated with baPWV in various models. Conclusions: A positive relationship was identified between CP and baPWV in adult male subjects with type 2 DM, which was independent of conventional cardiovascular risk factors. Further studies are needed to confirm whether CP contributes to the pathogenesis of increased arterial stiffness in subjects with type 2 DM.
[show abstract][hide abstract] ABSTRACT: Abstract Background: This study investigated the incidence of β-cell dysfunction and the clinical and biochemical factors affecting that in patients with type 2 diabetes having more than 3 years of follow-up. Subjects and Methods: β-Cell dysfunction was assessed by measuring changes in the fasting serum C-peptide concentrations. Patients were classified into two groups: cases showing a decreased (Group D) or an unchanged or increased (Group I) C-peptide concentration from the baseline. Results: Of the 504 patients included in this study, 259 (51%) showed decreased C-peptide concentrations, of whom 20% showed a decrease of ≥50%. Most patients, however, had a final C-peptide concentration of ≥1 ng/mL, with only 18 (4%) individuals having a level <0.6 ng/mL. Patients in Group D had a longer duration of diabetes, higher initial hemoglobin A1c concentration, and longer treatment durations with sulfonylurea and insulin compared with Group I. After adjusting for diabetes duration and C-peptide follow-up period, the duration of sulfonylurea treatment was found to be the only factor independently associated with decreases in the C-peptide concentration. Conclusions: Although β-cell function deteriorates over time in patients with type 2 diabetes, these cases mainly have fasting serum C-peptide concentrations of ≥1 ng/mL. A longer treatment duration with sulfonylurea is associated with a more rapid decline in the C-peptide concentration.
[show abstract][hide abstract] ABSTRACT: Abstract Background: Although obesity and metabolic syndrome have been associated with the risk of type 2 diabetes mellitus (T2DM), it is unclear whether obese or overweight people without metabolic syndrome are at increased risk for T2DM. Methods: Clinical and laboratory data were assessed in 8,748 subjects without diabetes (5,707 men, 3,041 women; age 20-79 years) who underwent voluntary medical check-ups at a 5-year interval. The subjects were categorized by body mass index (BMI) and metabolic syndrome status at baseline, and the incidence of diabetes over 5 years was assessed. Results: Of the 8,748 subjects, 308 (3.5%) developed T2DM over 5 years. Compared with normal weight (BMI <25.0 kg/m(2)) individuals without metabolic syndrome, the adjusted odds ratios (ORs) were 1.61 (1.13-2.29) and 4.93 (1.90-12.79) for overweight (BMI 25.0-29.9 kg/m(2)) and obese (BMI ≥30.0 kg/m(2)) individuals without metabolic syndrome, respectively, and 6.94 (5.08-9.47) and 10.61 (5.59-20.14) for overweight and obese individuals with metabolic syndrome, respectively. Using the lower BMI cutoff points for Asian populations, compared with subjects with BMI <23 kg/m(2) without metabolic syndrome, the adjusted ORs for subjects with BMI 23-27.4 kg/m(2) and BMI ≥27.5 kg/m(2) without metabolic syndrome were 2.64 (1.74-4.00) and 4.31 (2.36-7.86), respectively, and 10.11 (6.53-15.67) and 16.69 (10.40-26.77), respectively, for those with metabolic syndrome. Conclusions: Overweight/obesity and metabolic syndrome both are significant risk factors for development of T2DM in Koreans, and overweight or obesity without metabolic syndrome should not be considered a harmless condition. The lower BMI cutoffs for Asian populations can be useful in predicting risk of T2DM in Koreans.
Metabolic syndrome and related disorders 05/2012; 10(5):321-5.
[show abstract][hide abstract] ABSTRACT: Fibroblast growth factor 21 (FGF21) was originally identified as a paroxysm proliferator activated receptor-α target gene product and is a hormone involved in metabolic regulation. The purpose of this study was to investigate the diurnal variation of serum FGF21 concentration in obese and non-obese healthy volunteers.
Blood samples were collected from five non-obese (body mass index [BMI] ≤23 kg/m(2)) and five obese (BMI ≥25 kg/m(2)) healthy young men every 30 to 60 minutes over 24 hours. Serum FGF21 concentrations were determined by radioimmunoassay. Anthropometric parameters, glucose, free fatty acid, insulin, leptin, and cortisol concentrations were also measured.
The serum FGF21 concentrations displayed various individual oscillation patterns. The oscillation frequency ranged between 6 and 12 times per day. The average duration of oscillation was 2.52 hours (range, 1.9 to 3.0 hours). The peaks and troughs of FGF21 oscillation showed no circadian rhythm. However, the oscillation frequency had a diurnal variation and was lower during the light-off period than during the light-on period (2.4 vs. 7.3 times, P<0.001). There was no difference in the total frequency or duration of oscillations between non-obese and obese subjects, but obese individuals had increased numbers of larger oscillations (amplitude ≥0.19 ng/mL).
Various oscillation patterns in serum FGF21 concentration were observed, and reduced oscillation frequencies were seen during sleep. The oscillation patterns of serum FGF21 concentration suggest that FGF21 may be secreted into systemic circulation in a pulsatile manner. Obesity appeared to affect the amplitude of oscillations of serum FGF21.
[show abstract][hide abstract] ABSTRACT: Objective The ratio of apolipoprotein B (apoB) to apolipoprotein A1 (apoA1) has been reported to be associated with the metabolic syndrome (MetS). However, the optimal cut-off value of apoB/A1 ratio for detecting subjects with MetS has remained undetermined. In the present study, we aimed to investigate whether apoB/A1 ratio can be an indicator of MetS and to determine the optimal cut-off value of apoB/A1 ratio in detecting subjects with MetS in a Korean population. Design This cross-sectional study was conducted at the Asan Medical Center, Seoul, Republic of Korea. Subjects and measurements We collected the data of 10 940 subjects who participated in a routine health screening examination regarding conventional risk factors and serum levels of apoB and apoA1. Results The odds for MetS were significantly higher in the highest compared with the lowest apoB/A1 ratio quartiles, after adjustment for confounding variables, in both men [odds ratio (OR) = 4·07, 95% CI = 3·42-4·84] and women (OR = 8·41, 95% CI = 5·85-12·08). The optimal apoB/A1 ratio cut-off value for the detection of MetS was 0·65, which had a sensitivity of 63·5% and a specificity of 61·3% (area under the curve = 0·67, 95% CI = 0·66-0·68, P < 0·001) in men and 0·62, which had a sensitivity of 67·9% and a specificity of 61·9% (area under the curve = 0·70, 95% CI = 0·69-0·71, P < 0·001) in women. Conclusions These results suggest that apoB/A1 ratio is independently associated with MetS and that an apoB/A1 ratio >0·65 in men and 0·62 in women is a marker of MetS independent from conventional risk factors.
[show abstract][hide abstract] ABSTRACT: Vaspin is an adipocytokine recently identified in the visceral adipose tissue of diabetic rats and having anti-diabetic effects. We have recently shown that vaspin has anti-atherogenic effect through Akt-mediated inhibition of endothelial cell apoptosis. Decreased activity of endothelial nitric oxide synthase (eNOS) plays an important role in the pathogenesis of atherosclerosis. Asymmetric dimethylarginine (ADMA) is a well-known endogenous competitive inhibitor of eNOS and risk factor of cardiovascular diseases. The aim of this study was to examine whether vaspin might protect against atherosclerosis through its beneficial effects on the ADMA-eNOS system. Treatment of vaspin significantly increased NO secretion from endothelial cells and isolated aorta from Sprague-Dawley (SD) rats. Furthermore, treatment of vaspin prevented fatty acid-induced decrease in endothelium-dependent vasorelaxation in isolated aorta of SD rat. For the mechanism of vaspin-induced NO biosynthesis, vaspin activated the STAT3 signaling pathway and stimulated eNOS phosphorylation (Ser 1177), a marker of eNOS activation, through STAT3-dependent mechanism. Furthermore, vaspin treatment increased the expression of dimethylarginine dimethylaminohydrolase (DDAH) II, the responsible enzyme for the degradation of ADMA, leading to a reduction in ADMA levels. Vaspin-induced increase in DDAH II gene expression was through STAT3-mediated stimulation of DDAH II promoter activity. These results suggest that vaspin increases eNOS activity by reducing ADMA level through STAT3-mediated regulation of DDAH II expression. Our findings provide a novel molecular mechanism of antiatherogenic actions of vaspin.
PLoS ONE 01/2012; 7(12):e52346. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: Objective The aim of this study was to determine whether the absence of coronary artery calcium (CAC) can safely exclude obstructive coronary artery disease (CAD) in asymptomatic patients with type 2 diabetes. Methods We enrolled 478 consecutive asymptomatic patients with type 2 diabetes who visited the diabetes clinic of the Asan Medical Center between October 1, 2009 and December 31, 2010. All patients underwent 64-slice dual-source computed tomography (DSCT) for CAC scoring as well as computed tomography angiography (CTA). Patients with at least one significant coronary stenosis with >50% luminal narrowing were classified as having obstructive CAD. The findings were confirmed using conventional coronary angiography (CAG). Results Among the 478 patients, 157 (33%) had a CAC score of 0 (CAC=0). Of these, 17 (11%) had obstructive CAD confirmed on CAG. The presence of CAC had a negative predictive value for obstructive CAD on CAG of 89% and a sensitivity of 88%, a specificity of 42% and a positive predictive value of 38%. A multivariate logistic regression analysis showed that current smoking habits were significantly associated with the presence of obstructive CAD in patients with CAC=0 after adjusting for traditional cardiovascular risk factors (odds ratio 4.87, 95% confidence interval 1.65-14.42, p=0.004). Conclusion Our findings suggest that CAC=0 on 64-slice DSCT cannot safely exclude obstructive CAD on CAG in asymptomatic patients with type 2 diabetes, particularly in current smokers. CTA should be combined with CAC scoring in screening for CAD in asymptomatic patients with type 2 diabetes.
Internal Medicine 01/2012; 51(21):3017-23. · 0.97 Impact Factor