Long-term renal outcomes of episodic urinary tract infection in diabetic patients

Urinary tract infection (UTI) exists in 9%-20% of female and 3%-11% of male patients with diabetes. Diabetic patients experience increased risk of bacteremia, hospitalization, and mortality; however, few studies report long-term renal outcomes of episodic UTI in diabetic patients with chronic kidney disease (CKD).

We investigated 225 diabetic patients admitted with UTI from 2001 to 2011. Based on the glomerular filtration rate (GFR) on admission, we divided the patients into early- (GFR ≥30 ml/min; n=131) and late-stage (stages 4 and 5, GFR <30 ml/min; n=94) CKD groups. We compared admission risk factors, post-UTI GFR decline and its long term trend between these groups.

Poor glycemic control contributed to admission with UTI in the early- and late-stage CKD patients (glycosylated hemoglobin: (9.7±2.8% versus 8.6±2.6%). Early-stage CKD patients exhibited higher urinary glucose. Besides, acute kidney injury (AKI) occurred on admission in late-stage CKD patients (mean eGFR 14.2 ml/min). However, if the infection was cured, almost all diabetic patients reverted to their GFR trends 6 months later.

Late-stage CKD diabetic patients with UTI are at increased risk of superimposed AKI. Almost all patients gradually reverted to their GFR trend later after infection was cured. Early recognition of complicating AKI factors and aggressive treatment of symptomatic UTI instead of antibiotic prophylaxis for asymptomatic bacteriuria are suggested.