BACKGROUND
The major causes of death in diabetic patients are atherosclerosis-related diseases. Infection with Chlamydia pneumoniae(C. pneumoniae) has been reported to play a pathogenic role in atherosclerosis. However, data relating to C. pneumoniae exposure are rare in type 2 diabetes that are more susceptible to infection. The aim of this study was to see whether C. pneumoniae seropositivity was associated with carotid atherosclerosis in type 2 diabetic patients. METHODS: The subjects of this study were 135 type 2 diabetic patients. Serum samples from the subjects were assayed for risk factors, including lipid profiles, HbA1c, fibrinogen and CRP. Serum titers of antibodies to C. pneumoniae(IgG, IgM) were measured using microimmunofluorescence(MIF). tests Carotid ultrasound examination was used to measure the intima-media thickness(IMT), plaques and the presence of stenosis in each segment of both carotid arteries. RESULTS: C. pneumoniae seropositivity was detected in 17.8%(n=24), but without any difference between the sexes, in the 135 type 2 diabetic patients. The CRP level was increased in the seropositive group(P=0.041). The presence of carotid stenosis and IMT were significantly from a associated with C. pneumoniae seropositivity from a univariate analysis(IMTmean: IgG(+), 0.93mm vs. IgG(-), 0.85mm, P = 0.038, IMTmax: IgG(+), 1.29mm vs. IgG(-), 1.17mm, P = 0.025, stenosis: IgG (+), 25% vs. IgG(-) 7.2%, P = 0.020). No association was found for the plaque count or score. After controlling for cardiovascular risk factors, including age, sex, hypertension, cholesterol, and CRP, the association of C. pneumonia seropositivity with the IMTmean or carotid stenosis remained significant(IMTmean: P = 0.027, stenosis: P = 0.026). CONCLUSIONS: Serologic evidence of C. pneumoniae infection was detected in 17.8% randomly-assigned type 2 diabetic patients. C. pneumoniae seropositivity may be a risk factor for carotid atherosclerosis in type 2 diabetic patients.