Low serum creatinine and risk of diabetes: The Japan Epidemiology Collaboration on Occupational Health Study

AIMS/INTRODUCTION: We examined a prospective association between serum creatinine levels and diabetes. MATERIALS AND METHODS: The present study included 31,343 male workers without diabetes, and aged between 20 and 64 years at baseline. We calculated the cumulative average of their serum creatinine over the study period. We defined diabetes as either glycated hemoglobin levels ≥6.5%, random glucose levels ≥200 mg/dL, fasting glucose levels ≥126 mg/dL or receiving antidiabetic treatment. Cox proportional hazards regression analysis was carried out to estimate the hazard ratio (HR) and 95% confidence interval (CI). RESULTS: With a median observation of 7.7 years, 2,509 participants developed diabetes. After adjusting for age, smoking, body mass index, hypertension and dyslipidemia, lower cumulative average serum creatinine levels were related to a greater diabetes risk: HRs were 1.56 (95% CI 1.35–1.82), 1.22 (1.09–1.35) and 1.06 (0.96–1.17) for the participants with serum creatinine <0.70, 0.70–0.79 and 0.80–0.89 mg/dL, respectively, compared with those with 0.90–1.20 mg/dL (P for trend <0.001). The serum creatinine‐diabetes association was more pronounced among older adults (serum creatinine <0.70 vs 0.90–1.20 mg/dL, HR 1.66, 95% CI 1.37–2.00) than younger adults (HR 1.32, 95% CI 1.02–1.71; P for interaction by age group = 0.001). CONCLUSIONS: Low serum creatinine is associated with an increased risk of diabetes. Screening serum creatinine levels can be used to identify those who are at high risk of diabetes.