Determinants of lumbar artery occlusion among patients with sciatica: a three-year follow-up with magnetic resonance angiography.

We showed previously that chronic Chlamydia pneumoniae infection increases the risk of lumbar artery occlusion. We did not evaluate, however, the effect of other risk factors for cardiovascular diseases in combination with this chronic infection. The purpose of this study was to investigate the combined effect of chronic C. pneumoniae infection and other known determinants of artery occlusion in a population of sciatica patients. Two-dimensional time-of-flight magnetic resonance angiography (MRA) was used to evaluate lumbar arteries at baseline and three years. The arteries on both sides (L1-L4) were evaluated visually and scored as normal, narrowed or occluded. Logistic regression analysis was performed separately for baseline total arterial stenosis and each L1-L4 segmental artery pair, and for incident new stenosis during the follow-up period. The determinants analyzed included age, body mass index (BMI, kg/m(2)), education, gender, and smoking, in addition to presence of chronic C. pneumoniae infection. MRA was obtained at baseline for 147 patients and at 3 years for 134 patients. Sixty-four (47.8%) of 134 patients had new arterial stenosis. Total incidence of new arterial stenosis was distributed quite evenly between the individual segmental levels, varying from 12.7 to 18.6%. BMI was the only predictor of new arterial stenosis (odds ratio (OR) 1.13). A reasonable logistic model could be established only for baseline L4 and total arterial scores. At L4, education was a protective factor (OR 0.07), whereas age (OR for the oldest age group 6.7) and BMI (OR 1.17) were associated with increased risk of occlusion. For total arterial score, chronic C. pneumoniae infection was an independent determinant of arterial occlusion, increasing the risk to almost eightfold. Additionally, BMI (OR 1.16), and age (for the oldest age group OR 11.4) were significant determinants for stenosis. Smoking was not statistically significant. As chronic C. pneumoniae infection was an independent determinant of lumbar artery occlusion, treatments of this chronic infection may have an impact on lumbar diseases. The importance of BMI for new arterial stenosis suggests that weight reduction may also have a beneficial effect in lumbar artery disease.