Associations between testosterone and knee and hand osteoarthritis among males and females from the general population.

PURPOSE: The aim of this study was to examine the relationship between testosterone levels (total and free) and the prevalence, incidence and progression of radiographic osteoarthritis (OA) and chronic pain outcomes in the knee and hand joints.

METHODS

This study is embedded in the Rotterdam Study cohort, a population-based prospective study with participants aged 45 and older. The association between testosterone levels and OA was tested in more than 8600 individuals, using generalized linear models and generalized estimating equations models, adjusting for age, body mass index (BMI), lifestyle factors and co-morbidities.

RESULTS

Higher total testosterone (Relative Risk [RR] 0.84, 95% Confidence Interval [CI] 0.69-1.00) and higher free testosterone (RR 0.85, 95% CI 0.70-1.00) were significantly associated with a lower prevalence of radiographic knee OA in females, but not significant in males. Higher free testosterone was significantly associated with lower incidence of chronic knee pain (CKP) in females (RR 0.85, 95% CI 0.71-0.98), but not in males. In contrast, higher free testosterone (RR 1.07, 95% CI 1.02-1.11) and total testosterone (RR 1.08, 95% CI 1.03-1.13) were significantly associated with higher severity of hand OA in males, but not in females. These associations were independent of BMI, other lifestyle factors, co-morbidities and years since menopause.

CONCLUSIONS

Our findings suggest a protective effect of free testosterone for CKP only in females. Future replication of our findings is needed in prospective cohort studies.