Patients given two modern blood pressure drugs -- a calcium channel blocker and an ACE inhibitor -- are one-third less likely to develop diabetes than those on older pills, according to British researchers.

A new analysis of 19,000-person hypertensive study halted in November 2004 because the newer drugs proved so much better in reducing strokes and heart attacks showed that 8 percent given newer medicines developed diabetes after five years compared to 11.4 percent of those on older drugs.

The trial compared two older drugs, a beta blocker and a diuretic, with Norvasc (amlodipine), a calcium channel blocker, and Aceon (perindopril), an ace inhibitor.

Professor Peter Sever of Imperial College in London, co-chairman of the study, said he believes the reason the newer drugs are better at preventing diabetes largely lies in the way beta-blockers restrict blood flow to muscles, making it more difficult for the body to metabolize glucose.

He added that calcium channel blockers and ACE inhibitors probably also help by dilating blood vessels.