Microalbuminuria in non-insulin dependent diabetes mellitus

Non-insulin-dependent diabetes mellitus (NIDDM) is the commonest form of diabetes. The aim of this study was to evaluate the nature and prevalence of microalbuminuria (MAU) in NIDDM. One hundred and twenty-eight NIDDM patients participated in this study on the prevalence of microalbuminuria and albumin excretion rate (AER). An attempt was made to correlate them to the clinical profile, glycemic control and to diabetic complications. Eighteen patients had MAU with 14.1% prevalence (males--17.5% v/s females--10.8%; NS). Prevalence of MAU was higher in the third and fourth decades of age (28.6%) with a decrease in the fifth decade (12.5%). Prevalence of MAU also increased progressively with duration of diabetes--13 to 14% (< 10 yrs) to 25% (> 10 yrs). High AER in obese patients (13.4 +/- 5.5 v/s 7.9 +/- 1.4 micrograms/min) supports an association of obesity with albuminuria. The prevalence of MAU in patients with borderline and overt hypertension was not statistically different from that in normotensive NIDDM patients. However, NIDDM with borderline hypertension showed high AER 16.2 +/- 5.6 micrograms/min compared to 7.8 +/- 1.3 micrograms/min in normotensives. Prevalence to MAU and AER increased progressively with the deterioration of glycemic control--from 3.3% in well controlled to 18.9% in fairly controlled (P < 0.5) and 31% in poor controlled patients (P < 0.01). Also AER increased significantly from 3.9 +/- 0.8 to 12.3 +/- 4.1 and 18.4 +/- 4.6 micrograms/min, in patients with well to fairly and poorly controlled glycemia respectively. The prevalence of MAU and AER did not correlate with glycated hemoglobin (GHb) levels. The prevalences of peripheral neuropathy (PN) (42.6% v/s 55.6%) were similar in normo- and microalbuminuric patients. Patients with PN had high AER 11.9 +/- 2.7 micrograms/min. Diabetic retinopathy (DR) was equally prevalent in normo- and microalbuminuric NIDDM patients of (20.4% v/s 22.2), and AER was not significantly higher (12.1 +/- 4.3 micrograms/min) in NIDDM with retinopathy. High prevalences of cardiovascular disease (CVD) in MAU-NIDDM (22.2%; NS) was observed compared to normoalbuminuric (9.3%) patients. Also AER was significantly high in NIDDM associated with CVD (21.9 +/- 10.9 micrograms/min; P < 0.025). It can be concluded that, MAU is more prevalent in third and fourth decades and with longer duration of diabetes. Poor glycemic control was identified as a risk factor as in IDDM for development of MAU. MAU was a marker of generalised vascular dysfunction.