Definitions
The date of hospital admission was accepted as the first day. Patients using antihypertensive drugs were accepted as hypertensive, while those using antidiabetic drugs were accepted as diabetic.
The estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula [14]. Decreased eGFR was defined as < 60 mL/min/1.73 m2.
AKI on admission or during hospital stay was defined according to Kidney Disease: Improving Global Outcomes (KDIGO) criteria as follows: stage 1, as an increase in SCr level by 0.3 mg/dL within 48 hours or 1.5 to 1.9 times increase in SCr from baseline within 7 days; stage 2, as 2 to 2.9 times increase in SCr within 7 days; stage 3, as 3 or more times increase in SCr within 7 days or initiation of renal replacement therapy (RRT) [15]. Patients were stratified according to the highest AKI stage attained during their hospital stay. Available baseline value for each patient was taken as the mean outpatient value 7-365 days prior to admission [16]. If baseline value of SCr was not available, the lowest value during hospitalisation was taken [15]. We did not use the urine output criteria to define AKI as the documentation of urine output in the electronic health record was unavailable.
Renal glycosuria was defined in a person if blood glucose level rises higher than 170–200 mg/dL who doesn’t have diabetes or if blood glucose level rises higher than 200–250 mg/dL who has type 2 diabetes mellitus and the filtered glucose load exceeds the capacity for tubular glucose reabsorption [17]
Proteinuria was defined as the presence of ⩾1+ on dipstick urinalysis. Trace proteinuria was considered as negative. Microscopic hematuria was accepted as the presence of three or more erythrocytes per high-power field. Pyuria was also accepted as the presence of five or more leukocytes per high-power field.
The follow-up period started from the date of hospitalization and ended the day of discharge or in-hospital mortality.