High levels of fasting glucose and glycosylated hemoglobin values are associated with hyperfiltration in a Spanish prediabetes cohort. The PREDAPS Study

Aim This study aimed to investigate whether different levels of fasting plasma glucose (FPG) and hemoglobin Al c (HbA1 c) in prediabetes are associated with hyperfiltration. Methods A prospective cohort of 2,022 individuals aged 30-74 years took part in the PREDAPS Study. One cohort of 1,184 participants with prediabetes and another cohort of 838 participants with normal FPG and normal HbA1 c were followed for 5 years. Hyperfiltration was defined as an estimated glomerular filtration rate (eGFR) above the age- and gender-specific 95th percentile for healthy control participants, while hypofiltration was defined as an eGFR below the 5th percentile. The prevalence of hyperfiltration was compared for different levels of prediabetes: level 1 of prediabetes: FPG <100 mg/dL plus HbAl c 5.7-6.0% or FPG 100-109 mg/dL plus HbAl c < 5.7%; level 2 of prediabetes: FPG <100 mg/dL plus HbAl c 6.1-6.4% or FPG 100-109 mg/dL plus HbAl c 5.7-6.0% or FPG 110-125 mg/dL plus HbAl c <5.7% and level 3 of prediabetes: FPG 100-109 mg/dL plus HbAl c 6.1-6.4% or FPG 110-125 mg/dL plus HbAl c 5.7-6.4%. Results The participants with hyperfiltration were significantly younger, had a higher percentage of active smokers, and lower levels of hemoglobin and less use of ACEIs or ARBs. Only level 3 prediabetes based on FPG 100-109 mg/dL plus HbA1c 6.1-6.4% or FPG 110-125 mg/dL plus HbA1c 5.7-6.4% had a significantly higher odds ratio (OR) of hyperfiltration (OR 1.69 (1.05-2.74); P < 0.001) compared with no prediabetes (FPG < 100 mg/dL and HbA1c < 5.7%) after adjustment for different factors. The odds ratios for different levels of HbA1c alone in prediabetes increased progressively, but not significantly. Conclusions Level 3 of prediabetes based on FPG 100-109 mg/dL plus HbA1c 6.1-6.4% or FPG 110-125 mg/dL plus HbA1c 5.7-6.4% had a significantly higher OR of hyperfiltration compared with participants without prediabetes.