Cytokine secretion is impaired in women with diabetes mellitus

BACKGROUND: As women with diabetes mellitus (DM) have an increased prevalence of asymptomatic bacteriuria (ASB) and it is known that a correlation exists between the increased prevalence of genitourinary tract infection and impaired cytokine production in women infected with Human Immunodeficiency Virus (HIV), we studied urinary cytokine excretion in diabetic women and compared it with that of nondiabetic controls. MATERIALS AND METHODS: To evaluate the cytokine secretion capacity of women with DM, both whole blood and isolated monocytes of women with and without DM were stimulated in vitro with lipopolysaccharide (LPS). RESULTS: Lower urinary interleukin-8 (IL-8) and interleukin-6 (IL-6) concentrations (P = 0.1 and P < 0.001, respectively) were found in diabetic women than in nondiabetic controls. A lower urinary leukocyte cell count correlated with lower urinary IL-8 and IL-6 concentrations (P < 0.05). Lower tumour necrosis factor-alpha (TNF-alpha) and IL-6, but comparable interleukin-10 (IL-10) concentrations were found in whole blood (P < 0.04) and isolated monocytes (P = 0.03) of women with DM type 1 compared to women without DM. CONCLUSIONS: Diabetic women with ASB have lower urinary IL-6 concentrations than nondiabetic bacteriuric controls. In addition, monocytes of women with DM type 1 secrete lower pro-inflammatory cytokines after stimulation with LPS than monocytes of women without DM. This is not due to an inhibitory effect of the anti-inflammatory cytokine IL-10. This can have important consequences for both host defense, endothelial cell functioning and atherogenesis.