The effects of thiazide diuretics upon plasma lipoproteins

In a double-blind, placebo-controlled, crossover study in 16 hypertensives, 4 weeks of 50 mg hydrochlorothiazide twice daily, caused significant elevations in total plasma cholesterol, high density lipoprotein (HDL)-cholesterol, low density lipoprotein (LDL)-cholesterol, very low density lipoprotein (VLDL)-cholesterol and triglycerides. Significant elevations in fasting plasma glucose and in plasma insulin were observed, but no correlation between individual lipid elevations and either glucose or insulin elevations was apparent. The metabolic effects developed within 2 weeks, and dissipated within 4 weeks. Changes induced within 4 weeks of treatment with hydrochlorothiazide were unaltered at 6 months. Hydrochlorothiazide induces elevation of all lipoprotein cholesterol fractions and VLDL-triglyceride. However, as the important ratio between LDL- and HDL-cholesterol is unchanged, coronary risk may be unchanged.