A RECENT study has suggested that those who begin menarche later than the age of 14 years, and experience menopause earlier than age 45, have a higher risk of developing rheumatoid arthritis (RA). The study, carried out using data from the UK Biobank, also identified other hormonal and reproductive factors which affect the risk of developing RA, including hysterectomy and oophorectomy.
The data analysed were taken from 223,526 female patients (mean age: 56.2 years). Of these, 1.5% received an initial diagnosis of RA during a 12.39-year median follow-up period. The research group utilised restricted cubic spline in order to examine the associations between risk for RA and reproductive factors. Cox proportional hazard regressions were used to estimate hazard ratios for RA.
They found that early (<12 years) and late (>14 years) menarche were associated with the occurrence of RA (hazard ratio [HR]: 1.19; 95% confidence interval [CI]: 1.07–1.32; and HR: 1.09; 95% CI: 0.98–1.21, respectively). RA risk was also greater amongst postmenopausal females (HR: 1.19; 95% CI: 1.21–1.36), as well as those who had experienced fewer than 33 reproductive years (HR: 1.39; 95% CI: 1.21–1.59). Menopause occurring at <45 years of age demonstrated greater risk for RA (HR: 1.46; 95% CI: 1.27–1.67), compared to between 50–51 years of age.
Risk was also heightened amongst those who had undergone hysterectomy (HR: 1.4; 95% CI: 1.25–1.56), oophorectomy (HR: 1.21; 95% CI: 1.08–1.35), and exogenous hormone replacement therapy (HR: 1.46; 95% CI: 1.35–1.57). History of pregnancy had no statistically significant effect on development risk, contrary to previous research. However, giving birth to four or more children was associated with higher risk (HR: 1.18; 95% CI: 1.04–1.34).
Lead study author Ling-Qiong Jiang, Anhui Medical University, Hefei, China, commented: “While there is a wealth of literature linking hormonal and reproductive factors to an increased risk of RA, female-specific hormonal and reproductive factors and the gender differences in RA present a burgeoning research path that, to our understanding, has not been entirely explored.”
The research team recommend that when females are being diagnosed with RA, and their conditions managed, “hormonal and reproductive aspects should be carefully evaluated.” They hope that further studies will investigate the involvement of female hormones within RA’s pathophysiology.
