Effects of natural estrogen/gestagen and thiazide on coronary risk factors in normal postmenopausal women. A 2-year double-blind placebo study.

A 2-year double-blind trial designed for studying the separate and combined effects of bendroflumethiazide (BFTZ) and cyclical administration of 17 beta-estradiol + estriol/norethisterone (E/N) on coronary risk factors and bone mineral loss (reported elsewhere) was undertaken. Serum lipids, fasting blood glucose, body weight and blood pressure were measured every 3 months in 97 normal women in their early menopause. All participants received a supplement of 500 mg calcium and were randomized to one of the following treatment groups: 1) placebo (P) + P (n = 33); 2) P + E/N (n=21); 3) BFTZ + E/N (n=22); and 4) BFTZ + P (n=21). As compared with placebo BFTZ raised serum cholesterol by 6.0% (p less than 0.01), decreased systolic and diastolic blood pressures (p less than 0.01) and reduced body weight (p less than 0.001). E/N decreased serum cholesterol by 9.8% (p less than 0.001) and diastolic blood pressure to the same extent as BFTZ (p less than 0.01), but left systolic blood pressure unchanged. Neither BFTZ nor E/N affected serum triglycerides or blood glucose significantly. During their combined use E/N easily overcame the hypercholesterolemic action of BFTZ, as serum cholesterol remained 6.5% and 12.5% below the mean values of the placebo and BFTZ group, respectively (p less than 0.001). The tendency of both BFTZ and E/N to raise serum triglycerides was added to cause a significant increase of 6.5% (p less than 0.01). No other additive effects were observed. In conclusion, the thiazide increased one (serum cholesterol) and decreased another (blood pressure) of the important coronary risk factors, whereas cyclical estrogen/-gestagen reduced both risk factors, also when given in combination with thiazide.