Albumin excretion rate is not affected by asymptomatic urinary tract infection: a prospective study

The aim of the study was to evaluate whether asymptomatic urinary tract infection (UTI) significantly influences the level of albumin excretion rate (AER) in diabetic patients.

We screened prospectively for UTI and AER in 765 type 2 diabetic subjects. AER was determined before and after antimicrobial therapy in those patients in whom an asymptomatic UTI was diagnosed (n = 59). To interpret the clinical significance of AER changes, the coefficient of biological variation (CVb) of the AER (CVb-AER) was assessed in a control group of type 2 diabetic patients without UTI (n = 56).

AER did not change after antimicrobial treatment either in the whole group of patients with UTI (pre: 13.8 microg/min [0.1-195] vs. post: 8.5 microg/min [0.1-185]; P = 0.1) or in those patients in whom the infection was eradicated (pre: 11.7 microg/min [0.1-195] vs. post: 7.1 microg/min [0.1-185]; NS). The CVb-AER was 64% in the control group and was inversely correlated with AER (r = -0.44; P = 0.001). The decrease of AER after antimicrobial therapy (55%) did not exceed the biological variation of AER (64%). Finally, UTI did not significantly influence the classification of diabetic patients as normo- or microalbuminuric.

Asymptomatic UTI does not increase AER in type 2 diabetic patients. Therefore, our results suggest that testing for UTI is not necessary when AER is measured in diabetic patients.