Association of age at menarche, reproductive lifespan and age at menopause with the risk of atrial fibrillation: The HUNT study

Background Age at menarche, reproductive lifespan, and age at menopause are associated with several cardiovascular diseases, but their relationship with atrial fibrillation (AF) is uncertain. Methods We linked information on all women who participated in the third survey of the population-based, longitudinal HUNT study in Norway with medical records from all local hospitals. A total of 14,632 women aged 60 or more were followed for validated incident AF. We retrieved age at menarche and age at menopause from the HUNT questionnaires. Reproductive lifespan was defined as the difference between age at menarche and age at menopause. We used Cox proportional hazards regression models to assess associations between AF and age at menarche, reproductive lifespan, and age at menopause. Results During a median follow-up of 8.17 years (136,494 person-years), 1217 (8.3 %) participants developed AF. In multivariable-adjusted analyses, we observed no associations between early or late age at menarche and AF (hazard ratios (HRs): <12 years: 0.85 [95 % confidence interval (CI), 0.65–1.12]; ≥16 years: 0.99 [95 % CI, 0.80–1.24] compared to those who attained menarche at 13–14 years). The HR for a reproductive lifespan shorter than 30 years was 0.91 [95 % CI, 0.72–1.15] compared to 34–37 years. Likewise, there was no clear association between premature or early age at menopause and AF (HRs: <40 years: 1.21 [95 % CI, 0.83–1.75]; 40–44 years: 0.97 [95 % CI, 0.77–1.22] compared to 50–54 years). Conclusions In this population of women aged 60 years and over, the risk of AF was not associated with age at menarche, reproductive lifespan, or age at menopause.