Association between serum uric acid levels and bone mineral density in patients with osteoporosis: a cross-sectional study

BackgroundThe results of studies exploring the association between serum uric acid (SUA) and bone mineral density (BMD) have been controversial and inconsistent. We thus sought to explore whether SUA levels were independently associated with BMD in patients with osteoporosis (OP).MethodsThis cross-sectional analysis was conducted using prospectively obtained data from the Affiliated Kunshan Hospital of Jiangsu University database pertaining to 1,249 OP patients that were hospitalized from January 2015 - March 2022. BMD was the outcome variable for this study, while baseline SUA levels were the exposure variable. Analyses were adjusted for a range of covariates including age, gender, body mass index (BMI) and a range of other baseline laboratory and clinical findings.ResultsSUA levels and BMD were independently positively associated with one another in OP patients. Following adjustment for age, gender, BMI, blood urae nitrogen (BUN), and 25(OH)D levels, a 0.0286 g/cm(2) (beta, 0.0286; 95% confidence interval [CI], 0.0193-0.0378, P < 0.000001) increase in BMD was observed per 100 mu mol/L rise in SUA levels. A non-linear association between SUA and BMD was also observed for patients with a BMI < 24 kg/m(2), with a SUA level inflection point at 296 mu mol/L in the adjusted smoothed curve.ConclusionsThese analyses revealed SUA levels to be independently positively associated with BMD in OP patients, with an additional non-linear relationship between these two variables being evident for individuals of normal or low body weight. This suggests that SUA levels may exert a protective effect on BMD at concentrations below 296 mu mol/L in normal- and low-weight OP patients, whereas SUA levels above this concentration were unrelated to BMD.