Arterial intima-media thickness in 13-year-old adolescents and previous antichlamydial antimicrobial use: a retrospective follow-up study.

Background: Children with persistent Chlamydia pneumoniae infection may be at increased risk for atherosclerosis. The impact of antimicrobial therapy for primary prevention of atherosclerotic cardiovascular disease is unsolved.
Objective: The purpose of this study was to determine whether treatment with antimicrobial agents effective against C pneumoniae during childhood, regardless of indication, has a favorable influence on the arterial wall-thickness in children by the time they reach adolescence.
Subjects and Methods: The association of macrolide, tetracycline, quinolone, and rifamycin use (number of exposure events) between ages 5 and 13 years with carotid and aortic intima-media thickness at age 13 years was investigated among 508 healthy children. Information about the use of medications was obtained from the Finnish prescription register. Arterial intima-media thickness was measured with a high-resolution ultrasound.
Results: Mean aortic intima-media thickness showed a significant direct association with the number of antichlamydial antimicrobial exposure events also after controlling for established atherosclerotic risk factors. Elevated C-reactive protein level had an additional effect on aortic intima-media thickness in a multivariable model. Carotid intima-media thickness was not associated with the number of preceding antichlamydial treatments.
Conclusions: Recurrent antichlamydial treatments in childhood have no favorable influence on early vascular changes but are associated with increased intima-media thickness in the abdominal aorta. These findings suggest that the use of antimicrobial agents does not offer protection against the potential atherogenicity of repeated infectious insults.