Metabolic issues in the Antihypertensive and Lipid-Lowering Heart Attack Trial Study.

Based on the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack (ALLHAT) Trial, the Seventh Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC-7) states that "thiazide-type diuretics should be used as initial therapy for most patients with hypertension." In the ALLHAT study, although there was no difference in the primary outcome for fatal heart attack and nonfatal myocardial infarction between all treatment groups, the manuscript endorses thiazide-type diuretics as first choice, based on their cardioprotective effects and low cost. It is well known that thiazide-type diuretics cause hypokalemia, glucose intolerance, and diabetes, although the ALLHAT study showed a significant 43% to 65% higher risk of new-onset diabetes with chlorthalidone compared with amlodipine (30%) and lisinopril (18%). The investigators justified the fact that the greater incidence of diabetes did not translate into more cardiovascular events. Such a conclusion ignores that the morbidity and mortality from diabetes manifests over decades and not the mere 2- to 6-year time frame examined in the ALLHAT study. It would appear that the strong endorsement of thiazide-type diuretics as first-line therapy by the JNC-7 will lead to a higher incidence of diabetes in these patients.