Association between creatinine-to-body weight ratio and incident prediabetes in Chinese adults: a large-scale retrospective cohort study

Background and objective While the creatinine-to-body weight ratio (Cre/BW) has emerged as a promising biomarker for muscle mass assessment, its relationship with prediabetes remains unclear. This study aimed to investigate the association between Cre/BW ratio and incident prediabetes in Chinese adults. Methods We conducted a large-scale retrospective cohort study involving 173,476 participants from health check-up programs across 11 Chinese cities. Cox proportional hazards models were employed to evaluate the association between baseline Cre/BW ratio and incident prediabetes. To address potential non-linear relationships, we applied Cox proportional hazards regression with cubic spline functions and smooth curve fitting, using a recursive algorithm to calculate inflection points. Multiple imputation was used for missing data, and comprehensive sensitivity analyses were performed to assess result robustness. Results During a median follow-up of 3.0 years, 18,506 participants (10.67%) developed prediabetes. A lower Cre/BW ratio was associated with an increased risk of prediabetes (adjusted HR = 0.869, 95%CI: 0.806-0.973). Exploratory threshold effect analysis suggested a potential inflection point at 0.96(95% CI 0.90-1.01)μmol/L/kg, below which the association might be stronger (HR = 0.407, 95%CI: 0.328-0.506). The association remained stable in sensitivity analyses excluding participants with smoking history, drinking history, or family history of diabetes. Subgroup analyses revealed more pronounced associations among individuals aged 30–40 years (HR = 0.614, 95%CI: 0.532-0.708), females (HR = 0.726, 95%CI: 0.640-0.824), and those with normal blood pressure (systolic blood pressure <140 mmHg, HR = 0.816, 95%CI: 0.752-0.886). Conclusion A lower Cre/BW ratio is associated with an increased risk of prediabetes in Chinese adults. Exploratory threshold effect analysis suggested a potential inflection point at 0.96(95% CI 0.90-1.01) μmol/L/kg. These findings suggest that the Cre/BW ratio could serve as a simple, cost-effective tool for prediabetes risk stratification in clinical practice.