The use of hormone therapy (HT) up to 5 years after onset of menopause is associated with a lower risk for ischemic and hemorrhagic stroke compared with late HT initiation or no HT use, according to findings from an observational study reported in PLoS Medicine.
A total of 88,914 postmenopausal women with no prior cardiovascular disease who reported HT use in 5 population-based Swedish cohort studies were included in the assessment. The investigators identified incident ischemic stroke and hemorrhagic stroke events at a median follow-up of 14.3 years.
During the follow-up period, 6371 first-time strokes, of which 1080 were hemorrhagic, were identified. Compared with no HT use, initiation of HT therapy <5 years after the onset of menopause was associated with a longer stroke-free duration (fifth percentile difference [PD], 1.00 years; 95% CI, 0.42-1.57); however, no differences were observed with regard to time until hemorrhagic stroke (first PD, 1.52 years; 95% CI, -0.32 to 3.37).
Late vs no initiation of single conjugated equine estrogen HT was associated with a higher risk for stroke (fifth PD, -4.41 years; 95% CI, -7.14 to -1.68) and hemorrhagic stroke (first PD, -9.51 years; 95% CI, -12.77 to -6.24) during follow-up. Additionally, late initiation of combined HT vs no HT was associated with shorter hemorrhagic stroke-free duration (first PD, -1.97 years; 95% CI, -3.81 to -0.13).
The authors state that women who used HT during the time of the study were likely quite health conscious and of higher socioeconomic status; therefore, the study is limited in that it may not provide a direct 1:1 comparison against those who never initiated HT. In addition, uncontrolled confounding was possible in this analysis because of its observational design.
Based on the findings, the investigators of this trial suggest that the “results should not influence current practice that recommends against the use of HT for cardiovascular disease prevention.”
Carrasquilla GD, Frumento P, Berglund A, et al. Postmenopausal hormone therapy and risk of stroke: a pooled analysis of data from population-based cohort studies. PLoS Med. 2017;14(11):e1002445.