Hormone replacement therapy and myocardial infarction and stroke in postmenopausal Korean women

This study aimed to investigate the association of hormone replacement therapy (HRT) use, type, duration and age of commencement with myocardial infarction (MI) and stroke in postmenopausal Korean women.

This nested case-control study used data from the National Health Insurance Service database to analyze 2017 data from women aged ≥50 years and diagnosed with natural menopause between 2004 and 2007. Among 356,160 eligible women, 36,446 used HRT for ≥1 year and 319,714 did not (controls). These two groups were matched 1:1 for statistical analysis. Type and duration were categorized into three categories.

Women who started estrogen-progestogen therapy (EPT) or estrogen therapy (ET) in their 50s, or EPT or tibolone in their ≥60s exhibited a lower stroke risk than controls. MI risk was lower among women who used tibolone - regardless of duration - or EPT or ET for 1-3 years than among controls. Stroke risk was lower with tibolone use for ≥5 years or with EPT or ET use for 1-3 years or ≥5 years than non-users.

Our study may support the beneficial effect of HRT by showing that Korean postmenopausal women who used HRT at a relatively younger and healthier age had a relative benefit for MI and stroke.