Introduction:
Diabetes is the leading cause of end-stage kidney disease. We investigated the association between glycaemic status defined categorically or using HbA1c as a continuous variable, with decline in renal function over time in inpatients admitted to Austin Health.
Methods:
In this prospective, observational cohort study, all patients ≥54 years admitted 2013-2016 had an HbA1c measurement as part of the Diabetes Discovery Initiative. Only patients with two or more admissions were included in the current analysis. Baseline clinical and biochemical characteristics were obtained. To define the degree of renal function change, patients were classified into three groups based on the Acute Kidney Injury Network (AKIN) classification which utilises changes in the serum creatinine and estimated glomerular filtration rate (eGFR) over time. Results were analysed using robust and negative binomial regression.
Results:
Following exclusion of episodes with missing data or single admissions (n=22,162), 9300 admissions were identified. 25%, 39% and 36% of the inpatients had diabetes, pre-diabetes and no diabetes respectively. 41% of patients experienced some degree of kidney injury (AKIN1-3). After correcting for age, Charlson comorbidity index (excluding diabetes and age), haemoglobin and number of days between first and last admission, presence of diabetes, categorically and using HbA1c level as a continuous variable were significantly associated with decline in renal function defined as higher creatinine and lower eGFR ratio between first and last admission (p<0.001).
Conclusion:
Presence of diabetes, defined categorically and with higher HbA1c levels was associated with higher risk of long term decline in renal function. While glycaemic control is an important factor associated with renal function decline, interventional studies aimed to prevent further decline in renal function over time are required in inpatients with diabetes.