Prediabetes defined by the International Expert Committee as a risk for development of glomerular hyperfiltration

To clarify if prediabetes defined by the International Expert Committee (Prediabetes_IEC) and/or the American Diabetes Society (Prediabetes_ADA) is a risk for incident glomerular hyperfiltration (GH).

24,524 health examinees without diabetes, chronic kidney disease (CKD), GH and antihypertensive treatment at baseline, and repeated examinations at least twice during a mean of 5.3 years were retrospectively analysed. Diabetes was defined as fasting plasma glucose (FPG) ≥ 7.0 mmol/L and/or HbA_1c ≥ 47 mmol/mol, CKD by estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m² and/or dipstick-positive proteinuria, and GH by upper 95th eGFR in the Japanese adults. Prediabetes_IEC was diagnosed by “HbA_1c 42–46 mmol/mol and/or FPG 6.1–6.9 mmol/L”, Prediabetes_ADA by “HbA_1c 39–46 mmol/mol and/or FPG 5.6–6.9 mmol/L”, Prediabetes_ADA−IEC for the condition met the ADA but not the IEC prediabetes definition, and the ADA-normal glucose regulation (NGR_ADA) by both HbA_1c and FPG lower than Prediabetes_ADA. Risk of Prediabetes_IEC and Prediabetes_ADA for incident GH was examined by multivariate Cox proportional hazards model with seven covariates and probability of incident GH was calculated on the basis of it.

Prediabetes_IEC was a significant risk for incident GH [adjusted HR 1.91, 95% CI 1.32–2.71] but Prediabetes_ADA was not [adjusted HR 1.22, 95% CI 0.93–1.61]. The mean (SD) probability of incident GH was 2.3 (4.5)%, 1.0 (2.3)% and 1.0 (2.4)% for Prediabetes_IEC, Prediabetes_ADA−IEC and NGR_ADA, respectively: the former was significantly larger than the latter two which were not significantly different from each other.

Prediabetes_IEC was an independent risk for incident GH.