Reproductive risk factors associated with an increased risk for total knee replacement (TKR) in women with severe knee osteoarthritis (OA) include higher parity, earlier age at menarche, and use of oral contraceptives, according to study results published in Osteoarthritis Cartilage.
Researchers analyzed data from the Singapore Chinese Health Study, which included 35,298 women aged 45 to 74 years. These data were linked to records from a nationwide hospital discharge database and 1645 cases of TKR for severe knee OA were identified. The team conducted interviews to collect clinical information on parity, height and weight, lifestyle parameters, use of hormonal therapies, and age at menopause and menarche.
After statistical analysis, the researchers found that higher parity was associated with an increased TKR risk in a progressive manner (P <.001). Compared with women who had never given birth, those with ≥5 children had the highest risk (hazard ratio, 2.01; 95% CI, 1.50-2.70). In addition, the team reported that use of oral contraceptives and an earlier age of menarche were also associated with an increased TKR risk (P ≤.002).
One key limitation of the study was the lack of specificity in data collection.
“A major strength of our study is that the cohort participants were relatively lean, and the variation in [body mass index] among the different reproductive factors was fairly small,” the researchers wrote.
“These findings implicate the important role of reproductive and hormonal factors in pathogenesis of knee OA,” they concluded.
Leung YY, Talaei M, Ang LW, Yuan JM, Koh WP. Reproductive factors and risk of total knee replacement due to severe knee osteoarthritis in women, the Singapore Chinese Health Study [published online March 19, 2019]. Osteoarthritis Cartilage. doi:10.1016/j.joca.2019.03.002