Osteocalcin and Risks of Incident Diabetes and Diabetic Kidney Disease: A 4.6-Year Prospective Cohort Study

OBJECTIVE We aimed to examine the relationship between osteocalcin (OC) and the risk of incident diabetes and the risk of incident diabetic kidney disease (DKD). RESEARCH DESIGN AND METHODS We followed 5,396 participants without diabetes (nondiabetes subcohort) and 1,174 participants with diabetes and normal kidney function (diabetes subcohort) at baseline. Logistic regression and modified Poisson regression models were used to estimate the relative risk (RR) of baseline OC levels with incident diabetes and DKD. RESULTS During a mean 4.6-year follow-up period, 296 cases of incident diabetes and 184 cases of incident DKD were identified. In the nondiabetes subcohort, higher OC levels were linearly associated with a decreased risk of diabetes (RR for 1-unit increase of loge-transformed OC 0.51 [95% CI 0.35–0.76]; RR for highest vs. lowest quartile 0.65 [95% CI 0.44–0.95]; P for trend < 0.05). In the diabetes subcohort, OC levels were linearly inversely associated with incident DKD (RR for 1-unit increase of loge-transformed OC 0.49 [95% CI 0.33–0.74]; RR for highest vs. lowest quartile 0.56 [95% CI 0.38–0.83]; P for trend < 0.05), even independent of baseline estimated glomerular filtration rate and urinary albumin-to-creatinine ratio. No significant interactions between OC and various subgroups on incident diabetes or DKD were observed. CONCLUSIONS Lower OC levels were associated with an increased risk of incident diabetes and DKD.