Effect of antihypertensive combinations on arterial pressure,albuminuria, and glycemic control in patients with type II diabetic nephropathy: a randomized study

Type II diabetic patients with albuminuria are at high risk for cardiovascular complications; the intense antihypertensive treatment required often involves using drug combinations. The aim of the present study was to compare the effect of two different, renin-angiotensin blocking combinations, on blood pressure (BP), albuminuria and glycemic control. Its design was prospective, randomised, controlled, of parallel branches, and performed in one Endocrinology Department, in Spain. 77 type-II diabetic patients, with stable albuminuria (30-1,000 mg/day) were included. After a pre-inclusion time of 2 weeks, patients were randomised to verapamil SR/trandolapril 180/2 (VT) or losartan/hydrochlorothiazide (LH) 20/12.5 mg/day. Duration of treatment was 1 year. The evaluated parameters were changes in blood pressure, urinary albumin excretion for 24 hours, glycated hemoglobin and plasmatic urea. Overall BP significantly decreased from 161.6 +/- 18.7/83.6 +/- 10.2 mmHg to 137.2 +/- 15.7/70.9 +/- 8.3 mmHg (p < 0.0005). Values, by treatment, were: For VT, 164.3 +/- 18.5/87.2 +/- 10.7 mmHg at baseline and 135.0 +/- 15.1/71.3 +/- 8.4 mmHg at conclusion. For LH, 158.8 +/- 17.4/80.1 +/- 8.4 mmHg at baseline and 139.3 +/- 16.1/70.5 +/- 8.2 mmHg at conclusion. Albuminuria significantly decreased from 308.2 +/- 544.7 mg/day to 198.0 +/- 285.3 mg/day. Both parameters showed no significant difference between treatments. Glycated hemoglobin decreased from 7.59 +/- 1.3% to 7.14 +/- 1.2% in the VT group, and from 7.96 +/- 1.29% to 7.84 +/- 1.62% in the LH group (ANOVA, p = 0.022). Changes adjusted from baseline values showed a trend to the difference between both treatments (p = 0.092). Plasmatic urea increased from 39.8 +/- 12.7 to 40.5 +/- 11.1 mg/dL in the TV group and from 43.4 +/- 12.0 mg/dL to 52.4 +/- 19.4 mg/dL in the LH group (ANOVA, p = 0.028). In conclusion, both treatments reduce blood pressure and albuminuria in a similar way in type II diabetic patients. The verapamil/trandolapril combination contributes to a better carbohydrate metabolism than losartan/hydroclorothiazide.