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On March 20, 2023, we reported on a study published in BMC Medicine that examined the association between menstrual cycle characteristics and long-term risk of cardiometabolic outcomes.
Researchers tapped data from The Health Improvement Network, a UK-based database of anonymized electronic health records (ERH) contributed by 787 general practices. Data collected were provided by patients as part of routine primary care between 1995 and 2021. Eligible participants were aged 18 to 40 years.
The investigators examined 2 exposures related to menstrual history—regularity and frequency of menstrual cycles and created 2 study cohorts: The first comprised women with irregular or no menstrual cycle (exposed group) and matched controls from the general population with no history of irregular menstrual cycles. The second group included women with a pattern of infrequent or frequent menstrual cycles (exposed group) and matched controls with no such history. The research team compared rates of cardiometabolic outcomes between exposed and control groups.
The specified primary outcome was incident diagnosis of CVD, a composite of ischemic heart disease (IHD), heart failure (HF), or cerebrovascular disease (stroke or transient ischemic attack [TIA]). For secondary outcomes, the researchers identified each of the CV conditions alone as well as hypertension and type 2 diabetes (T2D).
The full cohort numbered 704 743 participants including 215 378 with a history of irregular menstrual cycles and 36 947 with a history of frequent or infrequent cycles. Median age of women in both groups was approximately 27 years. During 26 years of follow-up, a total of 20 605 cardiometabolic events occurred among the full 704 743-participant cohort.
In adjusted models, when compared to women with regular menstrual cycles, the adjusted hazard ratio (aHR) (95% CI) for women with irregular menstrual cycles for composite CVD was 1.08 (95% CI 1.00–1.19). For the individual CV conditions, aHR were: IHD 1.18 (1.01–1.37), cerebrovascular disease 1.04 (0.92–1.17), HF 1.30 (1.02–1.65), hypertension 1.07 (1.03–1.11), and T2D 1.37 (1.29–1.45).
The aHR comparing frequent or infrequent menstrual cycles to menstrual cycles of normal frequency for compositive CVD was 1.24 (1.02–1.52). For secondary outcomes, aHR were IHD 1.13 (0.81–1.57), cerebrovascular disease 1.43 (1.10–1.87), HF 0.99 (0.57–1.75), hypertension 1.31 (1.21–1.43), and T2D 1.74 (1.52–1.98).
Note from authors
"History of irregular menstrual cycles or frequent or infrequent menstrual cycles is associated with increased risk of cardiometabolic outcomes in later-life. Research is needed to unravel the pathophysiological links behind changes in menstrual cycle and adverse cardiometabolic health. Incorporating reproductive history including menstrual cycle characteristics as part of routine medical evaluation may help identify potential candidates for periodic assessment of cardiometabolic health."