Lipoprotein oxidation, dyslipidemia, and hypertension are important underlying causes of accelerated atherosclerosis in patients with diabetes mellitus. The potential of antihypertensive medications to reduce lipid oxidation is, therefore, an important determinant in the choice of agents for patients with diabetes mellitus. The aim of this study was to compare the lowering effect of a new dihydropyridine calcium antagonist, lercanidipine, with that of the first angiotensin‐receptor blocker, losartan, on low‐density lipoprotein (LDL) oxidation.

Forty patients in metabolically stable condition who had type 2 diabetes mellitus with hypertension were studied in this single‐blind, randomized, prospective crossover study, comprising 2 treatment periods of 16 weeks each, separated by a 4‐week washout period. LDL oxidation was evaluated by dialdehyde analysis by means of the thiobarbituric acid‐reactive substances assay with and without cupric sulfate, as well as determination of conjugated dienes in the LDL lipid extract.

Lercanidipine and losartan both significantly reduced the propensity of the serum to oxidize LDL (P = .001). With one method of estimation (conjugated dienes), the effect of lercanidipine was superior to that of losartan (P = .04). Losartan lowered urinary albumin excretion but lercanidipine did not.

Both lercanidipine and losartan attenuate LDL oxidation in patients with type 2 diabetes mellitus and hypertension. This observation may offer insight into the mechanisms of the therapeutic effects of these agents in patients with diabetes mellitus.

Clinical Pharmacology & Therapeutics (2002) 72, 302–307; doi: 10.1067/mcp.2002.127110