Prediabetes a Risk Factor for Hyperfiltration and Albuminuria

Prediabetes is independently associated with glomerular hyperfiltration and an increased albumin-creatinine ratio (ACR) at medium-term follow-up, reports a study in The New England Journal of Medicine.

The study included a general population sample of 1261 white, middle-aged adults from the Renal Iohexol Clearance Survey in Tromsø 6 (RENIS-T6) and the RENIS Follow-Up Study. All subjects underwent measurement of glomerular filtration rate (GFR) by iohexol clearance. The presence of prediabetes was assessed from fasting glucose and hemoglobin A1c levels, according to criteria of the American Diabetes Association (ADA) and the International Expert Committee of 2009 (IEC).

Patients were followed up for a median of 5.6 years. Prediabetes was assessed as a risk factor for change in measured GFR; hyperfiltration, defined as GFR over the 90th percentile adjusted for age, sex, weight, and height; and high-normal ACR of greater than 10 mg/g at follow-up.

Prediabetes was present in 595 individuals based on ADA criteria and 169 based on IEC criteria. In multivariable analyses, both definitions of prediabetes were associated with a higher measured GFR at follow-up and with a lower annual rate of decline in GFR. Based on the IEC definition, odds ratios were 1.95 for hyperfiltration and 1.83 for high-normal ACR. The associations remained significant after adjustment for blood pressure and other baseline cardiovascular risk factors, as well as for changes in antihypertensive medication during follow-up.

Prediabetes is cross-sectionally associated with chronic kidney disease—however, it is unclear whether prediabetes predicts CKD in people who do not develop diabetes. The new study, using measured rather than estimated GFR, suggests an independent role of prediabetes in the development of glomerular hyperfiltration and albuminuria. If the results are confirmed by further studies, early treatment for prediabetes might help to lower the burden of CKD in diabetes [Melson T, et al. Prediabetes and risk of glomerular hyperfiltration and albuminuria in the general nondiabetic population: a prospective cohort study [Am J Kidney Dis 2015 Dec 16. pii: S0272-6386(15)01389-X. doi: 10.1053/j.ajkd.2015.10.025].