Public Release: 

Why some diabetics are at greater risk for UTIs

American Society for Microbiology

NEW ORLEANS - May 25, 2004 -- Researchers at Midwestern University may have solved the mystery as to why some diabetics are at greater risk for getting urinary tract infections (UTI). They report their findings at the 104th General Meeting of the American Society for Microbiology.

"Patients with type-2 diabetes and females with gestational diabetes are at higher risk for acquiring urinary tract infections as compared to non-diabetic patients and even individuals with type-1 diabetes. Although all these groups have high levels of glucose [in the blood] that can spill into the urine, type-2 diabetics and pregnant women with gestational diabetes can also have high levels of insulin which can also spill into the urine," says Karolina Klosowka, a researcher on the study.

Klosowka and her colleagues investigated the effects of insulin on Escherichia coli, a bacterium that commonly causes UTIs. An essential part of E. coli's ability to cause UTIs is its ability to adhere in the bladder. The researchers found that insulin along with glucose in concentrations similar to what are found in the urine of type-2 and gestational diabetics increases E. coli's adherence. This enhanced binding may begin to explain why these types of diabetics have a greater risk for UTIs. They also found that insulin affected the cell surface of the bacteria in ways that may provide some protection against antibiotics.

"Based on our observations, it appears that insulin with glucose affects the growth and some of the surface characteristic of E. coli that correlate with its ability to cause urinary tract infections," says Klosowka. "These findings bring a new perspective in helping to understand why patients with type-2 diabetes and females with gestational diabetes have a higher incidence of urinary tract infections."


This release is a summary of a presentation from the 104th General Meeting of the American Society for Microbiology, May 23-27, 2004, in New Orleans, Louisiana. Additional information on these and other presentations at the 104th ASM General Meeting can be found online at or by contacting Jim Sliwa ( in the ASM Office of Communications. The phone number for the General Meeting Press Room is 504-670-4240 and will be active from 12:00 noon CDT, May 23 until 12:00 noon CDT, May 27.

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