ApoB/apoA-I ratio is related to femoral artery plaques in 64-year-old women also in cases with low LDL cholesterol.

INTRODUCTION: The apolipoproteinB (apoB)/apolipoproteinA-I (apoA-I) ratio mirrors the number of pro-atherogenic and anti-atherogenic lipoprotein particles. This ratio may carry more information on risk for atherosclerosis than LDL in cohorts with impaired glucose tolerance. The aim was to examine the association between the apoB/apoA-I ratio and ultrasound-assessed atherosclerosis in the carotid and femoral arteries in women with varying degrees of glucose tolerance.

METHODS: Plaque occurrence, and intima-media thickness in the carotid and femoral arteries were examined by B-mode ultrasound in a random sample of 64-year-old women (n=646) living in Gothenburg, Sweden, representing different degrees of glucose intolerance (diabetes (n=234), impaired (n=212) and normal glucose tolerance (n=200)). Traditional risk factors and serum concentrations of apolipoproteins were analysed.

RESULTS: For subjects in the lowest LDL tertile, the risk of having a plaque in the femoral artery was three times greater for subjects in the highest apoB/apoA-I tertile compared to subjects in the lowest tertile (OR: 3.0, 95% CI: 1.2-7.5). A clear increase in the occurrence of femoral plaque was observed already at a cut-off value of 0.63 (OR: 1.8, 95% CI: 1.2-2.6). ApoB/apoA-I was also related to femoral plaque occurrence in women with low HbA1c. ApoB/A-I ratio was associated with carotid and femoral IMT but not carotid plaques.

CONCLUSION: The apoB/apoA-I ratio improved the identification of cases with femoral artery atherosclerosis in a cohort of women with varying degrees of glucose tolerance. Such cases could also be identified in women with normal LDL and HbA1c levels. The results indicate that an apoB/apoA-I ratio above 0.63 should be used as a marker of increased risk.