This study aims to assess whether the timing of menopausal hormone therapy initiation in relation to onset of menopause and hormone therapy duration is associated with myocardial infarction risk.
This study was based on the Stockholm Heart Epidemiology Program, a population-based case-control study including 347 postmenopausal women who had experienced a nonfatal myocardial infarction and 499 female control individuals matched for age and residential area. Odds ratios (with 95% CIs) for myocardial infarction were calculated using logistic regression.
Early initiation of hormone therapy (within 10 y of onset of menopause or before age 60 y), compared with never use, was associated with an odds ratio of 0.87 (95% CI, 0.58-1.30) after adjustments for lifestyle factors, body mass index, and socioeconomic status. For late initiation of hormone therapy, the corresponding odds ratio was 0.97 (95% CI, 0.53-1.76). For hormone therapy duration of 5 years or more, compared with never use, the adjusted odds ratio was 0.64 (95% CI, 0.35-1.18). For hormone therapy duration of less than 5 years, the odds ratio was 0.97 (95% CI, 0.63-1.48).
Neither the timing of hormone therapy initiation nor the duration of therapy is significantly associated with myocardial infarction risk.
From the 1Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; 2Division of Cardiovascular Medicine, Department of Clinical Sciences, Danderyd Hospital, Karolinska Institutet, Stockholm, Sweden; 3Department of Clinical Sciences, Intervention, and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden; 4Department of Cardiology, Karolinska University Hospital, Stockholm, Sweden; and 5Department of Public Health and Caring Sciences, Uppsala University, Uppsala, Sweden.
Received June 20, 2014; revised and accepted August 27, 2014.
The funders had no role in study design, data collection and analysis, the decision to publish the manuscript, or the preparation of the manuscript.
Funding/support: The current study was supported by grants from the Stockholm County Council, the Swedish Council for Work Life Research, the Swedish Council for Social Research, the Swedish Heart and Lung Foundation, the Cardiovascular Program at Karolinska Hospital/Karolinska Institutet, Support for Strategic Epidemiological Research at Karolinska Institutet, and Junior Faculty Support at Institute of Environmental Medicine (to K.L.).
Financial disclosure/conflicts of interest: None reported.
Address correspondence to: Germán D. Carrasquilla, MD, Unit of Cardiovascular Epidemiology, Institute of Environmental Medicine, Karolinska Institutet, Nobels väg 13, Box 210, Stockholm 171 77, Sweden. E-mail: firstname.lastname@example.org