Heterogeneity in the association between prediabetes categories and reduction on glomerular filtration rate in a 5-year follow-up

Prediabetes and not just diabetes can cause kidney damage. This study assess the association of prediabetes with development of impaired renal function (IRF). We used data from PREDAPS prospective study a cohort of 1072 subjects with prediabetes and another cohort of 772 subjects without prediabetes were follow-up from 2012 to 2017. Prediabetes was defined according to American Association of Diabetes criteria. IRF was defined as having a glomerular filtration rate < 60 mL/min/1.73 m². Incidence rates of IRF in both cohorts and in different categories of prediabetes, based on impaired glycosylated hemoglobin (HbA1c) and/or fasting plasma glucose (FPG), were calculated. Hazard ratios (HR) for the association of the prediabetes with IRF, adjusting for potential confounders, were estimated by Cox regression models. Incidence rates of IRF per 100 person-years were 1.72 (95% confidence interval [CI]: 1.34-2.21) and 1.79 (95%CI: 1.45-2.20) for those without and with prediabetes, respectively .The HR of IRF in subjects with prediabetes with respect to subjects without prediabetes was 0.76 (95% CI: 0. 54-1.07). Corresponding HRs for type of prediabetes was 0.68 (95%CI: 0.40-1.15) for those with both altered parameters, 0.68 (95%CI: 00.40-1.15) for those with only impaired HbA1c and 1.12 (95%CI: 0.68-1.85) for those with only impaired FPG. The present study reflects an overall trend towards a slightly decreased risk of IRF onset associated to prediabetes except for individuals with only isolated impaired FPG. Further studies are warranted to fully assess the renal progression of each group.