DREAMing of diabetes prevention. Part I

NEJM 10/12 – ACE-Inhibitors are pretty much standard of care in diabetics for prevention of nephropathy. But some evidence suggests that angiotensin blockade may have direct beneficial effects on glucose tolerance. An editorial in the latest New England by Ingelfinger and Solomon explains the evidence that led to a trial of ramipril for the prevention of diabetes mellitus. Take note of their mention of potential confounding by the often overlooked fact that thiazide diuretics and B-blockers may promote diabetes – and the ACEIs were often compared to these drugs.
The study by the DREAM trial investigators involved subjects with impaired fasting glucose or impaired glucose tolerance. Subjects were given ramipril or placebo and followed for three years. Unfortunately, it didnt appear to work too well. The incidence of diabetes was similar in both ACEI treatment and placebo groups. However, treatment group patients did show a significantly better response in an oral glucose tolerance test. The trial seems to show that there may well be an effect of RAS blockade on glucose homeostasis, but not enough for primary prevention of diabetes.