Aims: Both clinical and epidemiologic studies have shown an association between atherosclerotic changes in the aorta or lumbar arteries and lumbar disc degeneration. However, the association between atherosclerosis and sciatica is unknown. The aim of this study was to investigate the association between carotid intima-media thickness (IMT) and clinically defined sciatica in a representative population sample.

Methods: The target population consisted of people aged 45–74 years who had participated in a nationwide Finnish population study during 2000–2001 and lived within 200 kilometres from the six study clinics. Of the 1867 eligible subjects, 1386 (74%) were included in the study. High-resolution B-mode ultrasound imaging was used to measure IMT. Local or radiating low back pain (LBP) was determined by a standard interview and clinical signs of sciatica by physician’s clinical examination.

Results: Carotid IMT was associated with continuous radiating LBP and with a positive unilateral clinical sign of sciatica. The associations were seen only in men; after adjustment for potential confounders, each standard deviation (0.23 mm) increment in carotid IMT showed an odds ratio of 1.6 (95% confidence interval 1.1–2.3) for continuous radiating LBP and 1.7 (95% confidence interval 1.3–2.1) for a positive unilateral clinical sign of sciatica. This latter association was observed in subjects with and in those without exposure to physical work load factors. Carotid IMT was not associated with local LBP.

Conclusions: Sciatica may be a manifestation of atherosclerosis, or both conditions may share common risk factors.