Age, antibiotics factors for infected diabetic foot ulcers

Prolonged courses of antibiotics can raise the risk of infection.
Prolonged courses of antibiotics can raise the risk of infection.

Older diabetes patients who receive prolonged courses of antibiotics are at the highest risk of having infected diabetic foot ulcers, a new study shows.

Researchers at Qazvin University of Medical Sciences in Iran studied 500 patients with diabetes mellitus over two years. During primary examinations, 61 patients were found to have diabetic foot ulcers, 51 of them infected ulcers.

The majority of patients found to have infected ulcers were males. Researchers also found that patients who were older, had diabetes for longer and had larger ulcers were more prone to developing infection.

“Diabetes mellitus leads to impaired immunologic defense. In addition, older age may create immunosuppressive conditions,” wrote lead researcher Simin Samani, M.D. “This combination may lead to an increased risk for infected [diabetic foot ulcers].” 

Samples of the ulcers' secretions pinpointed 69 pathogenic microorganisms, which are the primary cause of infected diabetic foot ulcers. These microorganisms also can be to blame for weak responses to antibiotic treatments, researchers noted.

Patients who received extended or inappropriate courses of antibiotics, or those who had long hospital stays, surgeries or other chronic wounds, also were at higher risk for developing infected ulcers.

Results of the study appear in the November issue of Wounds