Fat-Bone Relationship in Chronic Kidney Disease-Mineral Bone Disorders: Adiponectin Is Associated with Skeletal Events among Hemodialysis Patients

Background: The risk of skeletal events is rising in parallel with the burden of chronic kidney disease and mineral bone disorder (CKD-MBD), whilst the role of the fat-bone axis in CKD-MBD remains elusive. Adiponectin derived from adipocytes has emerged as a valid biomarker of low bone mineral density and increased marrow adiposity. We aimed to explore the association between adiponectin and bone fracture (BF) risks in patients with maintenance hemodialysis (MHD). Methods: Serum concentrations of adiponectin and bio-clinical data were determined at study entry. The Cox proportional hazard regression analyses were used to assess unadjusted and adjusted hazard ratios (aHRs) of adiponectin and various clinical predictors for BF risks. The predictive accuracy of adiponectin for BF events was evaluated by receiver operating characteristic (ROC) curve analysis. Results: Age and serum concentrations of adiponectin, phosphate, and intact parathyroid hormone were significantly associated with higher risks of BF. With respect to the risk of BF events, the cumulative event-free survival curves differed significantly between the high and low concentration groups of adiponectin (p = 0.02). In multivariable analysis, higher adiponectin levels were associated with an incremental risk of BF (adjusted hazard ratios (aHRs): 1.08 (95% confidence interval (CI): 1.01-1.15, p < 0.05). The ROC analysis of adiponectin cutoff point concentration (18.15 ug/mL) for prediction of BF showed 0.66 (95% CI = 0.49 to 0.84). Conclusion: Adiponectin was associated with an incremental risk of BF that could serve as a potential predictor of BF in MHD patients. In the high-risk population with hyperphosphatemia, an elevated adiponectin level could alert clinicians to the urgent need to correct mineral dysregulation and undertake further bone survey.