Evaluation of serum interleukin-6 level in diabetic patients with urinary tract infections

Urinary tract infections (UTIs) are common in type 2 diabetic patients, who have higher risks of mortality and bacteremia. Interleukin-6 (IL-6) plays a dual role: protective at normal levels, but proinflammatory in chronic inflammation. This study aimed to identify the main UTI-causing bacteria in diabetic and non-diabetic individuals, evaluate antibiotic resistance, and assess serum IL-6 levels in both groups. This was a comparative cross-sectional study included 140 patients aged 18-70 years, of both sexes, with and without type 2 diabetes. Patients were divided into four groups, each of 35 patients. Group A (controlled diabetic UTI cases, HbA1c ≤ 7%), Group B (uncontrolled diabetic UTI cases, HbA1c > 7%), Group C (non-diabetic UTI cases, HbA1c < 5.7%), and a normal control group. Urine samples were analyzed by culture, bacterial count, organism identification, and antibiotic sensitivity. Serum IL-6 was measured using an enzyme-linked immunosorbent assay (ELISA. Group B had the highest mean serum IL-6 level (29.60 ± 10.23), followed by Group A (26.42 ± 9.56), while the control group showed the lowest (15.50 ± 5.42). Candida albicans was more frequent in Group B (14.29%). Gram-negative bacilli predominated in all groups, especially Group A (91.43%). Escherichia coli was the most common bacterial isolate (~50%). Group B had the highest bacterial count (57.89 ± 23.72). Group C showed the highest antibiotic sensitivity, notably to meropenem (91.4%), polymyxin B (82.9%), and amikacin (80.0%). Group B exhibited the highest resistance rates to cefotaxime (79.5%), norfloxacin (61.5%), azithromycin (59%), and cotrimoxazole (56%). In conclusion, diabetic patients, especially those with uncontrolled diabetes, showed higher bacterial loads, more mixed and fungal infections, increased antibiotic resistance, and elevated serum IL-6 levels compared to non-diabetic individuals.