CHICAGO—New data demonstrate that patients with type 2 diabetes are more likely to experience a urinary tract infection (UTI) and repeat UTI than patients without the disease, according to a report at the 73rd Scientific Sessions of the American Diabetes Association.

Kristy Iglay, MPH, Global Health Outcomes Research Fellow at Merck & Company in Whitehouse Station, N.J., and colleagues examined the association between type 2 diabetes and UTI using information drawn from a large healthcare claims database. The database is representative of the national commercially insured population and those who have both Medicare coverage and supplemental employer-sponsored coverage and captures the full continuum of care in multiple settings, including physician office visits, hospital stays, and outpatient pharmacy claims.

The analysis included patients aged 18 years or older with a diagnosis of type 2 diabetes in 2010 who were matched to patients without type 2 diabetes for age at the index date, gender, index date, urban/rural location, and geographic region.

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Results for 89,790 matched pairs from the prevalence cohort showed that 7.6% of all patients had been diagnosed with a UTI over a one-year follow-up period. The prevalence of UTI was 9.4% in patients with type 2 diabetes versus 5.7% in those without type 2 diabetes.

Although a UTI was more likely in women than men, the likelihood of a UTI was higher in diabetics than nondiabetics for both sexes. Specifically, 14% of diabetic women had a UTI versus 9.1% of nondiabetic women, and 5% of diabetic men had a UTI versus 2.4% of nondiabetic men.

For each age group, a larger percentage of type 2 diabetics experienced a UTI than those without type 2 diabetes during follow-up, and this relationship remained consistent even after stratification by gender.

Recurrent UTI was also more likely with type 2 diabetes (1.6% versus 0.6%) during follow up.

Iglay cited several potential study limitations.For example, because measurements of glycemic control were not available, it was not possible to evaluate their impact on UTI risk.

Additionally, type 2 diabetics may see their physicians more regularly than the general population and thus may be more likely to have their UTI detected. Iglay pointed out, however, that her team controlled for baseline physician visits in the logistic regression model and the relationship between UTI occurrence and diabetes status remained intact.  Baseline physician visits were correlated with post-index physician visits.

Without confirmation by laboratory testing, it is possible that the analysis included both false-positive and false-negative results.

Furthermore, given that some patients may have asymptomatic UTIs, the use of International Classification of Diseases (ICD)-9 codes for UTI assessment may have led to underreporting, she said.

Finally, the type of type 2 diabetes treatment, pregnancy, history of urinary tract abnormalities, certain lifestyle factors, and co-morbid conditions may have contributed to the development of a UTI and therefore bias the results.

Senior author Kimberly G. Brodovicz, DrPH, Diabetes Epidemiology Lead at Merck & Company, explained that while it has not been clearly established why UTIs are more common in diabetics than nondiabetics, several theories have been proposed.  “For example, diabetic neuropathy could lead to bladder dysfunction,” she said. “Also, more glucose in the urine could allow bacteria to reproduce more easily. Another possibility is that patients with type 2 diabetes could have an impaired immune response.