Abstract

BACKGROUND
Many of the maturity-onset type 2 diabetic patients with hypertension and dyslipidemia in Korea are not associated with obesity. However, these patients are at risk for developing macrovascular complications such as atherosclerosis due to hyperinsulinemia, insulin resistance and abdominal obesity. The aims of this study were to compare the clinical and biochemical differences between the type 2 diabetic patients that are with and without abdominal obesity, and we also wished to investigate the degree of insulin resistance and atherosclerosis in these patients. METHODS: Among 530 type 2 diabetes mellitus (DM) patients, the percentages of under-weight (UW), normal-weight (NW), over-weight (OW) and obese (OB) (BMI <20, 20-25, 25-29.9 and > or =30, respectively) subjects were 8.9%, 62.1%, 25.1% and 3.9%, respectively. To evaluate the severity of their atherosclerosis, the coronary artery calcification (CAC) score was measured by electron beam computed tomography, and the intima-media thickness (IMT) of the common carotid artery and the ankle-brachial pressure index (ABPI) were also measured. The Insulin sensitivity index (ISI) was measured by the plasma glucose disappearance rate (kitt: %/min). RESULTS: 1. There were no differences in age, duration of DM and the HbA1c levels according to BMI for both the men and women, but the waist-hip ratio (WHR) and systolic blood pressure (SBP) were significantly different among each group. Serum triglyceride (TG), HDL-cholesterol (HDL-C), free fatty acid (FFA), fibrinogen, and fasting c-peptide levels, {excluding total cholesterol (TC)}, were also significantly different. The ISI, which is a marker for insulin resistance, as well correlated with the patients' BMI. Subjects having an with ISI above 2.5%/min were considered as having insulin resistance, and 28%, 60%, 68% and 75% of patients in the UW, NW, OW and OB groups, respectively, demonstrated insulin resistance. The visceral fat area/subcutaneous fat area ratio and visceral fat area/thigh muscle area ratio also increased with BMI. 2. The median values of the WHR were 0.95 for the men and 0.91 for the women. There were no significant differences for age, BMI, duration of DM and HbA1c between patients with and without abdominal obesity, but the SBP, TG, HDL-C, FFA, fibrinogen and ISI were significantly different between those two groups. 3. For the OW group as well as the NW group, the carotid IMT, ABPI and CAC scores were significantly different between the patients with and without abdominal obesity. However, there were no differences between the NW group and the OW group. CONCLUSION: In conclusion, those patients with abdominal obesity, regardless of their BMIs, have a higher prevalence for atherosclerosis, dyslipidemia, and hypertension, compared to those patients without abdominal obesity. Therefore, it is important to screen for atherosclerosis and to manage it accordingly, for the patients with insulin resistance or abdominal obesity in order to decrease their risk of developing atherosclerotic events.

• Keywords: Abdominal obesity;Insulin resistance;Type 2 diabetes;Atherosclerosis;