A synergistic effect of variability in estimated glomerular filtration rate with chronic kidney disease on all-cause mortality prediction in patients with type 2 diabetes: a retrospective cohort study

Cardiovasc Diabetol. 2021 Oct 18;20(1):209. doi: 10.1186/s12933-021-01399-z.

Abstract

Background: The combination of diabetes mellitus (DM) and chronic kidney disease (CKD) is associated with a high risk of mortality. Annual assessment of the estimated glomerular filtration rate (eGFR) is recommended for patients with DM. We investigated the effect of variability in annual eGFR values on all-cause mortality in patients with type 2 DM.

Methods: In this retrospective cohort study, we enrolled patients with eGFR data between 01 Aug 2017 and 31 July 2018. We defined the index eGFR as the first available eGFR value within the enrollment year and collected additional annual eGFR data from the previous three years. A total of 3592 patients with type 2 DM were enrolled, including 959 patients with CKD (index eGFR < 60 mL/min/1.73 m2) and 2633 patients without CKD. We assessed eGFR variability by using the standard deviation (SD) of the three annual eGFR and index eGFR values. We divided patients into subgroups according to the median SD of their annual eGFR (7.62 mL/min/1.73 m2). The primary endpoint was all-cause mortality after the index eGFR was assessed.

Results: During a median follow-up of 19 months (interquartile range: 18‒20 months), 127 (3.5%) deaths occurred among all 3592 enrolled patients. The highest mortality risk was observed in the high SD with CKD group, with a hazard ratio (HR) of 2.382 [95% confidence interval (CI) 1.346‒4.215] in comparison to the low SD without CKD group after adjusting for the associated factors. In patients without CKD, a high SD was an independent risk factor for mortality (HR = 2.105, 95% CI 1.256‒3.528). According to the C-index, the mortality prediction ability was better for the index eGFR + SD model than for the index eGFR alone model (0.671 vs. 0.629, P < 0.001).

Conclusion: There was a synergistic effect of eGFR variability with single-measured eGFR for the prediction of mortality in patients with type 2 DM. The SD of the annual eGFR values was also an independent predictor of mortality in patients with an eGFR > 60 mL/min/1.73 m2.

Keywords: Annual; Chronic kidney disease; Estimated glomerular filtration; Mortality; Standard deviation; Type 2 diabetes; Variability.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers / blood
  • Cause of Death
  • Diabetes Mellitus, Type 2 / blood
  • Diabetes Mellitus, Type 2 / diagnosis
  • Diabetes Mellitus, Type 2 / mortality*
  • Female
  • Glomerular Filtration Rate
  • Glycated Hemoglobin / metabolism
  • Humans
  • Kidney / physiopathology*
  • Lipids / blood
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Prognosis
  • Renal Insufficiency, Chronic / diagnosis
  • Renal Insufficiency, Chronic / mortality*
  • Renal Insufficiency, Chronic / physiopathology
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors

Substances

  • Biomarkers
  • Glycated Hemoglobin A
  • Lipids
  • hemoglobin A1c protein, human