Impaired fasting glucose is associated with lower glomerular filtration rate decline among men but not women –a large cohort study from Israel

Objectives: Early stages of diabetes are associated with an increased glomerular filtration rate (GFR). Little is known, however, about the change in GFR among patients with impaired fasting glucose (IFG). We aimed to evaluate the yearly decline rate of GFR among IFG patients. Methods: A retrospective analysis of a large cohort of subjects attending a medical screening center in Israel. Patients with diabetes mellitus and patients with decreased estimated GFR (eGFR) were excluded. We divided the cohort into 2 subgroups; Healthy controls and impaired fasting control subjects. For each group, we calculated the average yearly estimated GFR decline (ΔeGFR). The results were adjusted for age, BMI, hypertension and smoking status. Results: 8176 subjects met the inclusion criteria. The median follow up time was 4.8 years (range 2.0 to 13.4). For the whole cohort (men and women), yearly ΔeGFR was −0.68 among healthy controls, and − 0.47 among IFG patients (p =.003). Among men, average yearly ΔeGFR in healthy controls and IFG patients was −0.7 and − 0.4, respectively (p =.0002). All results remained significant after adjusting for age, BMI, hypertension, smoking status and level of HDL and triglycerides. In contrast, among IFG women there was no significant difference in ΔeGFR in comparison with healthy women. Conclusions: Impaired fasting glucose is associated with a decreased rate of GFR reduction compared with healthy subjects. This effect is gender dependent - observed in men but not in women. A mechanism of glomerular hyperfiltration might be involved.