Total serum testosterone and WOMAC pain and function among older men and women with severe knee OA

OBJECTIVES: We investigated if serum total testosterone (T)-level is associated with knee pain and function in men and women with severe knee osteoarthritis (OA). METHODS: We enrolled 272 adults ≥60 years (70.4±4.4 years, 53% women) who underwent unilateral total knee replacement (TKR) due to severe knee OA. Serum T-levels and WOMAC pain and function of the operated and contra-lateral knee were measured at 6-8 weeks after surgery. At the non-operated knee, 56% participants had radiographic knee OA with a Kellgren-Lawrence grade ≥2. Cross-sectional analyses were performed by gender and BMI subgroups using multivariable regression adjusted for age, physical activity and BMI. RESULTS: At the operated knee, higher T-levels were associated with less WOMAC pain in men (B = -0.62; P = 0.046) and women (B = -3.79; P = 0.02), and less WOMAC disability scores in women (B = -3.62; P = 0.02) and obese men (B = -1.99; P = 0.02). At the non-operated knee, T-levels were not associated with WOMAC pain in men or women, but higher T-levels were associated with less disability in women (B = -0.95; P = 0.02). T-levels were inconsistently associated with pain and disability in BMI subgroups among men. Only among obese women, T-levels were inversely associated with radiographic knee OA (OR = 0.10; P = 0.003). CONCLUSIONS: Higher total T-levels were associated with less pain in the operated knee in men and women undergoing TKR and less disability in women. At the non-operated knee, higher T-levels were inconsistently associated with less pain and disability.