To describe the association of reproductive and hormonal factors with the presence and severity of hand osteoarthritis (OA) in Tasmanian women.
Cross-sectional study of 348 women from 76 families. A structured questionnaire collected information regarding reproductive history and the use of estrogen containing medications. Hand OA was assessed by two observers using the Altman atlas for joint space narrowing and osteophytes at distal interphalangeal (DIP) and carpometacarpal (CMC) joints, as well as Heberden's nodes (HN) based on hand photography.
The prevalence of hand OA was high in this sample at 65-70%. Parity, increasing age at menopause and years of menstruation were associated with both symptomatic hand OA and a more severe DIP score (but not presence of radiographic disease) while both current and ever use of hormone replacement therapy (HRT) were significantly associated with increased prevalence of HN and severity of HN and DIP OA (all P<0.05). HRT usage less than 5 years was associated with increased severity of both DIP disease and HN. No factors were associated with CMC disease apart from ever breast-feeding which was protective (OR 0.37, 95% CI 0.18-0.79).
These results require confirmation in clinical trials or carefully controlled longitudinal studies but suggest that estrogen exposure around the time of disease onset (either endogenous or exogenous) may have a "priming" effect on the severity of DIP OA while breast-feeding in earlier life may be protective for CMC OA.