Background: As rheumatoid arthritis (RA) occurs more often in women than in men, it has been suggested that reproductive hormones may play an important role in the pathogenesis.
Methods: Between 1991 and 1996, 30 447 subjects (18 326 women) were included in a community-based health survey. Information on female hormonal changes and stress-related factors was obtained using a self-administered questionnaire. This population was linked to four different local and national RA registers. The medical records for patients with a diagnosis of RA were subjected to a structured review and all women with incident RA according to the 1987 American College of Rheumatology criteria after inclusion in the health survey were included in a nested case-control study. Matched controls (1:4) were selected from the health survey population.
Results: Early age at menopause (≤45 years) was associated with the subsequent development of RA (OR 2.42, 95% CI 1.32 to 4.45). The effect of early menopause remained significant after adjusting for smoking, level of education and length of breastfeeding (OR 1.92, 95% CI 1.02 to 3.64)
Conclusion: RA was predicted by an early age at menopause. This implicates an influence of hormonal changes during the fertile period on the development of RA in postmenopausal women.