BACKGROUND
Korean type 2 diabetic patients who are frequently non-obese, may be genetically different from Western type 2 diabetics who are frequently obese. Therefore, the diabetic complications of type 2 diabetes mellitus in Korea may be also different from those of Western countries. Until now, most studies reported in Korea did not analyse the microvascular complications of type 2 diabetes mellitus according to obesity, and also the criteria in the diagnosis of microvascular complications were different in each study. We investigated the microvascular complications and its relationship with obesity, in type 2 diabetic patients visiting an outpatient clinic. METHODS: The study subjects were type 2 diabetic patients visiting an outpatient clinic of Ajou University Hospital. We selected patients participating in a 75 g oral glucose tolerance test, retrospectively. Type 2 diabetes was diagnosed according to the WHO/NDDG classification of diabetes. Biochemical studies including lipid profile, plasma insulin and C-peptide levels were done. Anthropometric measurements were performed. Based on BMI (kg/m2), the patients were divided into the following groups: the lean group, whan the BMI was less than 20kg/m2; the ideal body weight (IBW) group, if the BMI was between 20 kg/m and 25 kg/m in women and 20kg/m and 27 kg/m in men; and the obese group, when the BMI was>25 kg/m in women and >27 kg/m2 in men. RESULTS: 1. Neuropathy (45.2%) was the most frequent among the microvascular complications, and the frequency of retinopathy was 15.1%, and that of nephropathy was 4.9k. Within 5 years of diabetes duration, the frequency of neuropathy, retinopathy, and nephropathy was 43.2%, 11.8%, and 2,9%, respectively. 2. Glycosylated hemoglobin (HbA1c) and fasting blood glucose levels were not different among the three groups. Beta cell function{delta(insulin 30min insulin Omin)/delta(glucose 30min - glucose Omin)} was the highest in the obese group, However, beta cell function(delta/delta G) divided by the basal insulin level, considered insulin resistance, was not different among the three groups. 3. Within 5 years of diabetes duration, retinopathy tended to be the most frequent in the lean group, whereas neuropathy tended to be the most frequent in the obese group, and body mass index influenced the retinopathy and neuropathy, statistically significantly. CONCLUSION: Diabetic neuropathy was the most frequent among microvascular complications of type 2 diabetes mellitus in our study subjects. At the time of presentation within 5 years of diabetes duration, the lean group of type 2 diabetics had a tendency of the more frequent retinopathy, the obese group had a tendency of the more frequent neuropathy. These results suggest that type 2 diabetes mellitus in Korea is also not a singie disease entity, as in Western countries and is a heterogenous group of disorders with a diversity of microvascular complications. However, the more studies about this will be required.