Does the hormonal situation modify lipid effects by lifestyle factors in middle-aged women? Results from a population-based study of Swedish women: the women's health in the Lund area study.

The aim of the study was to outline whether the influence by lifestyle factors on serum lipids was modified by the hormonal situation in middle-aged women. Six thousand nine hundred eight women, aged 50 to 59 years, participated in a health assessment program, including a serum lipid profile evaluation. The women were grouped according to their hormonal status into premenopausal (PM) (n = 492), postmenopausal without hormone therapy (HT) (PM0) (n = 3600), and postmenopausal with HT (PMT) (n = 2816). From the PMT group, we analyzed oral (n = 901) and transdermal HT (n = 351) regimens, containing norethisterone acetate and 17beta-estradiol. Serum lipids and lipoproteins were determined by conventional methods. Lifestyle factors included smoking and physical activity at leisure time and at work. Multivariate linear regression analysis controlling for age, education, and dietary habits showed that current smoking was positively associated with triglycerides in the PM, PM0, PMT, and oral HT groups. In the PM0, PMT, and oral HT groups, current smoking was positively associated with total cholesterol and low-density lipoprotein and negatively associated with high-density lipoprotein (HDL). Low physical activity at leisure time was positively associated with triglycerides in the PM and PMT groups and negatively associated with HDL in the PM0 and PMT groups. High physical activity at work was positively associated with triglycerides in the PMT group and with total cholesterol in the PM0 group, but negatively associated with HDL in the PMT and transdermal groups. Body mass index was positively associated with triglycerides and negatively with HDL in all the groups regardless of the hormonal situation. The serum lipid profile as influenced by lifestyle factors was modified by the hormonal situation. Compared with the postmenopausal women without HT use, the use of HT contributes to fewer "negative" effects by lifestyle factors on serum lipids.