Incidence of urinary tract infection in patients with type 2 diabetes. Experience from adverse event reporting in clinical trials.

PURPOSE

Diabetes mellitus has long been widely considered to be associated with an increased risk of urinary tract infection (UTI), but information on incidence rates are scarce and risk factor data have been conflicting. The aim was to estimate UTI incidence and evaluate potential risk factors for UTI in patients with type 2 diabetes included in recent clinical trials.

METHODS

Type 2 diabetes patients from 10 AstraZeneca phase III diabetes clinical trials (n=6016, mean 57.4 years, 50.7% female) conducted during 2004-2007 were included. Patients free of UTI at baseline were followed for up to 6 months after inclusion in the trials. UTI was considered present if any term sorting under the MedDRA high-level term "UTIs" was recorded as an adverse event.

RESULTS

In all, 142 patients had an adverse event for UTI, corresponding to an incidence of 59.5/1000 person-years for all patients (91.5/1000 in women, 28.2/1000 in men) and a cumulative incidence of 2% during 6 months. Female gender was associated with an increased incidence [relative risk (RR) 3.4; 95% confidence interval (CI) 2.3-5.1] and also higher age (RR 2.5 [95% CI 1.4-4.8] for ages ≥ 70 years vs. 40-49 years). No increased incidence was associated with body mass index (25-29, 30+ vs. <25 kg/m(2) ), HbA1c (<8% vs. >8%), race (Black, Oriental vs. Caucasian) or drug treatment (study drug, comparator vs. placebo). A history of immune system disorder conveyed a twofold higher risk for UTI.

CONCLUSION

UTI is common among female patients with type 2 diabetes and older patients of both genders.