Issue 154 Item 1 Long-Term Enalapril Slows Disease Damage In Diabetics

Enalapril treatment resulted in an absolute risk reduction of 22.4 percentage points for the development of clinical albuminuria over five years. Long-term treatment with enalapril, an angiotensin-converting enzyme inhibitor, may reduce or delay the progression of structural glomerular damage in microalbuminuric diabetics who do not have marked hypertension.

Endocrinologists at Aligarh Muslim University, India, drew this conclusion as the result of a 5-year, double-blind, placebo-controlled study investigating what effect enalapril had on renal function and histology in type 1 diabetics with microalbuminuria.

Seventy three type 1 diabetics whose blood pressure was less than <140/90 mm Hg and who had persistent albuminuria (albumin excretion rate 20-200 micrograms/min) and normal renal function were randomly assigned to receive either enalapril or placebo. A percutaneous renal biopsy was successfully performed in 69 patients. After 5 years, this was repeated in 59 patients. Patients’ mean glomerular volume, mesangial volume and glomerular basement membrane thickness were all measured. Before treatment, the active drug and placebo groups had similar clinical characteristics, blood pressure, HbA1c, albumin excretion rate, glomerular filtration rate, serum creatinine and renal structural damage. Blood pressure was well controlled in both groups. Albuminuria fell significantly in the 37 patients given enalapril, with only 3 patients (8.1%) progressing to clinical albuminuria (albumin excretion rate exceeding 300 mg. per 24 hours). That compared with 11 of the 36 patients (30.5%) given placebo. Enalapril treatment resulted in an absolute risk reduction of 22.4 percentage points for the development of clinical albuminuria over five years. After 5 years of treatment, glomerular basement membrane thickness showed a consistent, though not statistically significant, rise in the placebo group but remained stable in enalapril recipients. At the end of the study, the specialists observed a significant rise in mean glomerular volume and mesangial volume among patients given placebo. Diabetes Research and Clinical Practice 2003;60:2:131-138