Prediabetes is associated with glomerular hyperfiltration in a European Mediterranean cohort study.

Background: Glomerular hyperfiltration is well recognized as an early renal alteration in subjects with diabetes mellitus. However, what is not well-known is whether hyperfiltration also occurs in the early stages of hyperglycaemia, for instance in prediabetes. Identifying subjects with glomerular hyperfiltration from among those with prediabetes might be helpful to implement preventive and therapeutic strategies. This study aimed to investigate the association of prediabetes with glomerular hyperfiltration and its associated variables.

Methods: A representative sample of 9238 people aged ≥ 30 years and whose entire clinical and laboratory data were available, were included in this study. Hyperfiltration was defined as an estimated glomerular filtration rate (eGFR) above the age- and gender-specific 95th percentile. The eGFR was assessed using the Chronic Kidney Disease Epidemiology Collaboration equation.

Results: After adjustment for age, gender, body mass index, systolic blood pressure and diastolic blood pressure, cholesterol, log (triglycerides), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, serum uric acid, smoking status, hypertension, and use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, fasting plasma glucose (FPG) was found to be independently positively associated with eGFR. The hazard ratios (95% confidence interval) for hyperfiltration were 1.61 (1.28-2.03) and 2.30 (1.89-2.79) for prediabetes and diabetes, respectively, when compared with participants with normoglycemia.

Conclusion: Prediabetes was associated with glomerular hyperfiltration. Longitudinal studies are needed to investigate whether hyperfiltration in prediabetes is associated with a later decline in eGFR.