Changes in creatinine-to-cystatin C ratio over 4 years, risk of diabetes, and cardiometabolic control: The China Health and Retirement Longitudinal Study.

Background Creatinine-to-cystatin C ratio has attracted substantial interest as a measure to reflect health well-being, but no studies have assessed whether its longitudinal changes are associated with risk of diabetes. We aimed to examine their association, along with the exploration of the relationship of such changes with cardiometabolic control in middle-aged and older adults. Methods We included a total of 3278 participants aged ≥45 years who provided measurements of creatinine and cystatin C at baseline and 4 years later from the China Health and Retirement Longitudinal Study. Diabetes was diagnosed based on glucose, hemoglobin A1c (HbA1c), medical history, or use of antidiabetic mediations. Odds ratio (OR) and 95% confidence interval (CI) were obtained using logistic regression analyses. Results After 4-year follow-up, 272 participants developed diabetes. Larger increases in creatinine-to-cystatin C ratio were associated with lower risk of diabetes. The multivariable-adjusted OR for diabetes per 1 SD increase in creatinine-to-cystatin C ratio was 0.84 (95% CI 0.72-0.98). Compared with participants showing decreases in creatinine-to-cystatin C ratio but increases in body mass index (BMI), those experiencing increases in creatinine-to-cystatin C ratio and decreases in BMI had the largest risk reduction (multivariable-adjusted OR 0.52). Changes in creatinine-to-cystatin C ratio showed inverse correlation with blood pressure, HbA1c, lipids, and C-reactive protein at the 4-year follow-up. Moreover, they also correlated inversely with changes in HbA1c and C-reactive protein (all P ≤ 0.004). Conclusions Increases in creatinine-to-cystatin C ratio led to reduced risk of diabetes and may benefit cardiometabolic control.