The Difference Between Cystatin C- and Creatinine-Based Estimated Glomerular Filtration Rate and Risk of Diabetic Microvascular Complications among Adults with Diabetes: A Population-Based Cohort Study

The impact of the difference between cystatin C- and creatinine-based estimated glomerular filtration rate (eGFRdiff) on diabetic microvascular complications (DMCs) remains unknown. We aimed to investigate the associations of eGFRdiff with overall DMCs and subtypes including diabetic retinopathy (DR), diabetic kidney disease (DKD), and diabetic neuropathy (DN).Research Design and Methods This prospective cohort study included 25,825 participants with diabetes free of DMCs at baseline (2006 to 2010) from the UK Biobank. eGFRdiff was calculated using both absolute difference (eGFRabdiff) and the ratio (eGFRrediff) between cystatin C- and creatinine-based calculations. Incidence of DMCs was ascertained using electronic health records. Cox proportional hazards regression models were used to evaluate the associations of eGFRdiff with overall DMCs and subtypes. ResultsDuring a median follow-up of 13.6 years, 5,753 participants developed DMCs, including 2,752 cases of DR, 3,203 DKD, and 1,149 DN. Each standard-deviation decrease of eGFRabdiff was associated with a 28% higher risk of overall DMCs, 14% higher risk of DR, 56% higher risk of DKD, and 29% higher risk of DN. For each 10-percent decrease in eGFRrediff, the corresponding hazard ratios (95% confidence intervals) were 1.16 (1.14, 1.18) for overall DMCs, 1.08 (1.05, 1.11) for DR, 1.29 (1.26, 1.33) for DKD, and 1.17 (1.12, 1.22) for DN respectively. The magnitude of associations was not materially altered in all sensitivity analyses.ConclusionsLarge eGFRdiff was independently associated with risk of DMCs and its subtypes. Our findings suggested monitoring eGFRdiff among diabetes population have potentially beneficial for identification of high-risk patients.