Antihypertensive treatment and homocysteine concentrations

Thiazides and angiotensin-converting enzyme (ACE) inhibitors are first-choice drugs for lowering elevated blood pressure and hence risk of cardiovascular disease. Homocysteine (tHcy) is another and independent cardiovascular risk factor and has been reported to be elevated in patients on antihypertensive therapy. As these studies reported only associations, a preliminary, randomized, prospective treatment study was performed in 40 hypertensive patients. We investigated the major determinants of tHcy concentrations after treatment with hydrochlorothiazide (HCT) or captopril: vitamins B6, B12, folic acid, and creatinine and cystatin C as parameters of renal function. A total of 21 Patients were treated with HCT and 19 with captopril, for, respectively, 31 and 29 days. HCT, but not captopril, raised tHcy by 16% (P =.003) and also creatinine and cystatin C (P =.025 and P =.004, respectively). This tHcy increase may offset the desired cardioprotection conferred by lowering the blood pressure.