Early vascular damage in primary hypoalphalipoproteinemia

Abstract

The relationship between hypoalphalipoproteinemia (hypoalpha), a metabolic disorder characterized by reduced high-density lipoprotein (HDL) cholesterol levels, and atherosclerotic disease is not completely understood. We investigated arterial functional and structural changes in 19 subjects with hypoalpha (HDL cholesterol < or = 0.7 mmol/L for men and < or = 0.8 mmol/L for women; 13 men; 47 +/- 7 years) and in 21 healthy control subjects (11 men; 46 +/- 13 years). Brachial-artery flow-mediated vasodilation (FMV) and intima-media thickness (IMT) of the carotid and femoral arteries were determined in all subjects. FMV was significantly lower in hypoalpha than in controls (5.6% +/- 4.3% v 8.2% +/- 2.7%; P <.05). IMT was greater in hypoalpha than in controls at both the internal carotid (0.83 +/- 0.1 mm v 0.69 +/- 0.1 mm) and superficial femoral level (0.83 +/- 0.2 mm v 0.68 +/- 0.1 mm; both P <.05). FMV had a positive correlation with HDL cholesterol (r =.42, P =.06) and a negative one with triglycerides (r = -0.38, P =.01). An inverse relationship was found between HDL cholesterol and internal carotid and superficial femoral IMT (r = -0.64 and r = -0.60, respectively; P <.01 for both) and a positive one between triglycerides and internal carotid and superficial femoral IMT (r =.53 and r =.47, P <.05). In a multivariate regression analysis, brachial FMV was predicted by HDL cholesterol and brachial diameter (beta =.42 and -0.43, respectively; both P <.05). HDL cholesterol was the only significant predictor of internal carotid and superficial femoral IMT (beta = -0.45 and -0.49, respectively; both P <.05). In conclusion, subjects with primary hypoalpha, without overt cardiovascular disease, are characterized by an impaired endothelial function and by an increase in large-artery IMT.