Fasting blood glucose, but not 2-h postload blood glucose or HbA1c, is associated with mild decline in estimated glomerular filtration rate in healthy Chinese.

backgroundThe association of blood glucose [including fasting blood glucose (FBG), 2-h postload blood glucose, and glycated hemoglobin (HbA1c)] with the risk of a mild decline in the estimated glomerular filtration rate (eGFR) in healthy subjects was unclear. The aim of the study was to investigate this association in middle-aged and elderly healthy Chinese.

methodsThe study included 1,112 healthy Chinese who were ≥40 years old, and all the subjects were divided into two groups based on FBG value of 5.6 mmol/L. A mildly reduced eGFR was defined as 60-90 mL/min/1.73 m2. Multiple linear or logistic regression analysis was used to estimate the association of blood glucose with eGFR and the risk of a mildly reduced eGFR, respectively. A generalized additive model was used to explore a possible nonlinear relationship between FBG and eGFR.

resultsFBG was significantly associated with decreased eGFR and increased risk of a mildly reduced eGFR independent of age, gender, body mass index, waist circumference, systolic blood pressure (BP), diastolic BP, triglyceride, high-density lipoprotein cholesterol, fasting insulin, smoking, and drinking. Additionally, FBG and eGFR showed a nonlinear association (P<0.001). Interestingly, the group with FBG≥5.6 mmol/L significantly increased the risk of a mildly reduced eGFR (OR 2.06, P=0.001) after multivariable adjustment.

conclusionsFBG is closely associated with decreased eGFR and increased risk of a mildly reduced eGFR. The ADA criteria using FBG=5.6 mmol/L instead of 6.1 mmol/L as cutoff point to define prediabetes are more suitable for the prevention of diabetes and related kidney disease.