Association between Bone Mineral Density and Serum Uric Acid in the Elderly Chinese: Observational and Mendelian Randomization Analyses

Abstract

AbstractSummaryAs an endogenous antioxidant, serum uric acid (SUA) can promote the proliferation and differentiation of osteoblasts and prevent osteoporosis. We found the higher SUA levels may associate with lower risk of osteoporosis (OP) in postmenopausal women.MethodsA community-based cross-sectional study was designed on the basis of 2156 postmenopausal women and elderly men (≥50 years old) from Kunming and Jinshan, China. the bone mineral density (BMD) was measured using dual-energy X-ray absorptiometry (DXA).ResultsA total of 1755 participants were recruited. In observational study, a linear association between SUA and BMD existed only in postmenopausal women, and the association was still significant after other confounding factors were adjusted (P<0.05). The binary logistic regression analysis proved that the odds ratio(OR) for OP in SUA quartile 4 was the lowest (Model 1:OR=0.521<1, 95% confidence intervals (CI), 0.358~0.757,P= 0.01). Restricted cubic spline (RCS) concluded no nonlinear relationship of SUA with BMD in both women and men (P>0.05). Moreover, the Mendelian randomization (MR)analysis showed no causal effect of SUA on BMD at different skeletal sites (IVW causal effect -0.02, 95%CI-0.08 to 0.04,P= 0.55, and MR- -Egger causal effect -0.03, 95%CI-0.13 to 0.06,P=0.50).ConclusionsOur study concluded a positive linear relationship between SUA and BMD only in the postmenopausal women, and a higher SUA level could predict a higher BMD and a lower risk of OP. However, we found no casual effect of SUA on BMD.