SAT0479 Associations between Endogenous Sex Hormones and MRI Structural Changes in Patients with Symptomatic Knee Osteoarthritis

BackgroundIncreased prevalence of knee osteoarthritis (OA) among postmenopausal women suggests involvement of endogenous hormones in pathogenesis. However, the effects of endogenous sex hormones on knee OA structures remain uncertain.ObjectivesTo describe the longitudinal associations between serum levels of estrogen, progesterone and testosterone and knee structural changes using magnetic resonance imaging (MRI) in both males and females with symptomatic knee OA.MethodsWe examined 200 participants (mean age 63.0 ± 7.3 years) from a clinical trial of vitamin D supplement for symptomatic knee OA. Serum levels of estradiol, progesterone, testosterone and sex hormone binding globulin (SHBG) were analyzed at baseline and 24 months later. Magnetic resonance imaging (MRI) scans of the knees were obtained at both baseline and follow-up for the measurement of cartilage volume, cartilage defects, bone marrow lesions (BMLs) and effusion-synovitis volume. Knee pain was assessed using a 100mm visual analogue scale (VAS). Longitudinal data were analyzed using linear mixed-effects model.Results107 males and 93 females were included in this study. For females, after adjustment for age, body mass index, and treatment allocation, progesterone was associated with cartilage volume (β =0.12 per quartile, p=0.01). Estradiol levels were associated with lower grades of BMLs (β = -0.45 per quartile, p=0.03), while estradiol (β = -1.26 per quartile, p=0.05), progesterone (β = -1.60 per quartile, p