Background: The long-term consequences of asymptomatic bacteriuria (ASB) on renal function in women with diabetes mellitus (DM) are unknown.
Methods: A prospective study was performed among women with type 1 or type 2 DM. Women with ASB (diagnosis based on findings from 1 urine culture specimen) were compared with women without ASB for differences in renal function development and incidence of hypertension.
Results: A total of 644 women were included in the study (296 with type 1 DM and 348 with type 2 DM; mean [SD] age, 51  years) and followed up for a mean (SD) duration of 6.1 (1.9) years. The prevalence of ASB was 17%. In women with DM and ASB, the creatinine clearance decreased from 87 mL/min (1.45 mL/s) at baseline to 76 mL/min (1.27 mL/s) at study end point; in women with DM without ASB the creatinine clearance decreased from 97 to 88 mL/min (from 1.62 to 1.47 mL/s). In the multivariate analyses, adjusted for age, length of follow- up, duration of DM, and microalbuminuria at baseline, no association was found between ASB and the relative or the absolute decrease in creatinine clearance; the same results were shown also when women with DM type 1 and women with DM type 2 were analyzed separately. Women with ASB developed hypertension more often than women without ASB (54% vs 37%; P=. 045), but there was no significant association in the multivariate analysis ( odds ratio, 1.5; 95% confidence interval, 0.7-3.6).
Conclusion: Women with DM (type 1 or type 2) with ASB do not have an increased risk for a faster decline in renal function or the development of hypertension after 6 years of follow-up.