Losartan Reduces Blood Pressure and Albuminuria in Hypertensive Type 2 Diabetics

The angiotensin II receptor blocker (ARB) losartan reduces blood pressure and urinary albumin excretion in hypertensive patients with type 2 diabetes.

In the same study, the long-acting dihydropyridine calcium channel blocker amlodipine was effective only in reducing blood pressure.

Dr. Gen Yasuda from Yokohama City University School of Medicine, Japan stated that, "The renoprotective action of ARBs is important independent of their antihypertensive effects."

Dr. Yasuda and colleagues compared the effects of losartan and amlodipine in a 12-week study of 87 patients with hypertension and type 2 diabetes.

Losartan significantly decreased office and ambulatory blood pressure, lowering daytime pressure more than nighttime pressure, the authors report. Amlodipine resulted in a similar decrease in blood pressures, but daytime and nocturnal pressures declined to the same degree.

Twenty-four-hour urinary albumin excretion significantly decreased from 810 mg/day to 570 mg/day with losartan treatment (p < 0.001), the report indicates. In contrast, 24-hour urinary albumin excretion remained stable at 790 mg/day throughout treatment with amlodipine.

Neither treatment had a significant effect on the diurnal sympathetic and parasympathetic nervous rhythm, as measured by spectral analysis of heart rate variability.

"These findings suggest that 24-hour blood pressure regulation alone is not enough to improve overt nephropathy," the researchers conclude, "and additional beneficial effects of losartan on intraglomerular mechanism are crucial for an antiproteinuric effect."

Dr. Yasuda added that he would expect angiotensin-converting enzyme (ACE) inhibitors to have benefits similar to those seen with losartan.
Diabetes Care 2005;28:1862-1868.