Hyperlipidemia in hypertension: causes and prevention.

Hyperlipidemia is prevalent in hypertension, but the cause of this association is unknown. Treatment of hypertension with thiazide diuretics accentuates the hyperlipidemia, perhaps by causing potassium or sodium depletion. To assess the role of hypokalemia in thiazide hyperlipidemia, I measured lipid concentrations while using a spironolactone-thiazide regimen to prevent potassium wastage during the treatment of hypertension. Blood pressure decreased substantially, but hyperlipidemia occurred despite the maintenance of normal serum potassium. To test a role of sodium balance, I measured lipid levels during periods of sodium feeding and placebo therapy. Cholesterol levels decreased during sodium administration. Carrying this information to therapy, I participated in a multicenter comparison of enalapril and indapamide therapy in resistant hypertension. Both regimens caused minor metabolic effects, but indapamide provided superior antihypertensive potency. This evidence suggests that sodium feeding improves lipid metabolism, but sodium diuresis enhances an antihypertensive effect. Low-dose therapy combining a diuretic, such as indapamide, with a nondiuretic agent promises to improve metabolic tolerance and maximize hypertension control. This strategy optimally lowers overall cardiovascular risk.