Objective: Many observational studies suggest hormone therapy protects against coronary heart disease in contrast to findings from large randomised clinical trials and an observational Danish study. A potential bias in the observational literature concerning the cardiovascular risk and benefits associated with use of hormone therapy is the so-called 'healthy user' phenomenon, i.e. self-selection to HT use is associated with healthier cardiovascular risk profile. This study investigates whether a random sample of Danish women using HT was characterised by a favourable cardiovascular risk profile prior to menopause.
Methods: A sample of 621 women born in 1936 living in Copenhagen County was included in a prospective population-based study initiated in 1976 with follow-ups in 1981, 1987 and 1996. Investigations comprised questionnaires and physical examinations.
Results: At 51 and 60 years, respectively, one-third and one-half had ever used HT. At 40 years women who subsequently use HT had lower body mass index, lower self-rated health and lower fasting glucose, but no differences according to blood pressure, cholesterol, triglyceride, physical activity, smoking habits or alcohol consumption.
Conclusion: In a cohort of Danish women from the general population ever users of HT could not be characterised as unambiguous 'healthy users'.