The correlation of microalbuminuria and glomerular filtration rate in normotensive patients with type 2 diabetes mellitus / 대한내과학회지

ABSTRACT

BACKGROUND: Diabetic nephropathy is one of the major causes of end-stage renal disease. Microalbuminuria predicts not only progressive renal disease, but also increased cardiovascular morbidity and mortality. But, the relationship between urinary albumin excretion rate (UAER) and glomerular filtration rate (GFR) remains an unresolved issue. In order to investigate the early renal function abnormalities, UAER and GFR were assessed and their relationship was examined in normotensive patients with type 2 diabetes mellitus (DM). METHODS: Between January 1997 and June 2001, in a cross sectional study of 112 normotensive patients with type 2 DM not showing overt proteinuria and thirty healthy subjects served as control group. According to UAER, type 2 DM patients were divided into normoalbuminuria group and microalbuminuria group. The GFR was measured using 99mTc-DTPA renal scan. Clinical values in type 2 DM patients and control subjects were compared using one-way analysis of variance (ANOVA) with Scheffe's F test. In type 2 DM patients, Univariate Chi-square analysis was used to evaluate the prevalence of diabetic retinopathy and the differences in anti-diabetic treatment. Pearson correlation coefficients were used to demonstrate a strength of an association between UAER and other variables including GFR. RESULTS: Three groups were well matched with regard to gender, age and body mass index. There were no significant differences in disease duration and anti-diabetic treatment in type 2 DM patients. The GFR in microalbuminuric patients was significantly higher than in normoalbuminuric patients (124.0 17.6 vs 102.9+/-15.5 mL/min/1.73 m2, p<0.05). The prevalence of diabetic retinopathy in microalbuminuric patients was significantly higher than in normoalbuminuric patients (53.8% vs 24.7%, p<0.05). Only there was significant positive correlation between log UAER and GFR (r=0.303, p<0.05). CONCLUSION: As in type 1 DM patients, there was a significant relationship between UAER and GFR in normotensive type 2 DM patients without overt proteinuria.