Relationship of Bone Status with Serum Uric Acid and Bilirubin in Men with Type 2 Diabetes: A Cross-Sectional Study

BACKGROUND: Accumulating evidence has shown that serum uric acid and bilirubin are associated with some chronic diseases, owing to their antioxidant capacity, but the previous research produced discrepant results regarding the relation between uric acid, as well as bilirubin, and bone health. This study was designed to assess the relationship of serum uric acid and total bilirubin with bone mineral density and bone turnover markers in men with type 2 diabetes. MATERIAL/METHODS: In total, 631 male patients with type 2 diabetes were included. Data of patients’ medical history, biochemical index, bone mineral density of the lumbar vertebra, femoral neck, and total hip, and bone turnover markers including osteocalcin (OC), amino-terminal propeptide of type I procollagen (PINP), type I collagen carboxy-terminal peptide (CTX), and parathyroid hormone were collected and retrospectively analyzed. RESULTS: Both serum uric acid and total bilirubin were positively related to bone mineral density of the lumbar vertebra (β=0.179, p<0.001; β=0.095, p=0.030), femoral neck (β=0.133, p=0.002; β=0.089, p=0.029), and total hip (β=0.142, p=0.001; β=0.087, p=0.032), respectively. Serum uric acid concentration was negatively related to bone turnover markers (OC: r=−0.148, p=0.037; PINP: r=−0.139, p=0005; CTX: r=−0.200, p=0.005). Each unit increase of serum uric acid and total bilirubin was associated with a 0.4% and 5.6% lower risk of osteoporosis or osteopenia (OR=0.996, 95% CI=0.994–0.998; OR=0.944, 95% CI=0.899–0.992), respectively. The risk of osteoporosis and osteopenia in patients with low-tertile concentrations of serum uric acid and total bilirubin was increased (OR=3.486, 95% CI=1.535–7.913). CONCLUSIONS: In men with type 2 diabetes, serum uric acid level and total bilirubin were significantly associated with bone mineral density and were protective factors against osteoporosis and osteopenia.