Increased carotid artery intima-media thickness in subjects with primary hypoalphalipoproteinemia
Damiano Baldassarre1, Mauro Amato, Linda Pustina
1Center E. Grossi Paoletti, Department of Pharmacological Sciences, University of Milan, Italy.
Insights
Low high-density lipoprotein cholesterol (HDL-C) is linked to increased atherosclerosis. This study found significantly greater carotid intima-media thickness in individuals with low HDL-C, but not in those with high HDL-C.
Area of Science:
- Cardiovascular Science
- Lipid Metabolism
- Vascular Biology
Background:
- Plasma high-density lipoprotein cholesterol (HDL-C) concentration shows an inverse correlation with atherosclerotic vascular events.
- Understanding the relationship between HDL-C levels at the extremes of normal distribution and early atherosclerosis is crucial for cardiovascular risk assessment.
Purpose of the Study:
- To evaluate pre-intrusive atherosclerosis in subjects with very low (hypoalphalipoproteinemia, HypoALP) or high (hyperalphalipoproteinemia, HyperALP) plasma HDL-C levels.
- To compare carotid intima-media thickness (IMT) in these groups with control subjects and a large cohort of hyperlipidemic patients.
Main Methods:
- Comparison of 55 HypoALP and 55 HyperALP subjects with 55 age-, sex-, and cholesterol-matched controls.
- Measurement of average and maximal intima-media thickness (Avg-IMT and Max-IMT) across 48 carotid segments per subject.
- Analysis of a large cohort (n=559) of hyperlipidemic subjects stratified by HDL-C quintiles.
Main Results:
- Avg-IMT and Max-IMT were approximately 40% greater in HypoALP subjects compared to controls (P=0.004 and P=0.025, respectively).
- IMT values in HyperALP subjects were comparable to those of control subjects.
- In hyperlipidemic patients, significantly greater Avg-IMT and Max-IMT were observed in the lowest HDL-C quintile (<42 mg/dL) compared to other quintiles.
Conclusions:
- Low HDL-C levels are associated with significant pre-intrusive atherosclerosis, indicated by increased carotid IMT.
- Above-average HDL-C levels do not appear to confer additional protection against arterial wall thickening in this context.
- These findings highlight the detrimental impact of low HDL-C on early atherosclerotic development.
Abstract:
The plasma concentration of high-density lipoprotein cholesterol (HDL-C) is inversely correlated with the incidence of atherosclerotic vascular events. In the present study, we evaluated pre-intrusive atherosclerosis in subjects with plasma HDL-C at the extremities of normal distribution. Fifty-five subjects with primary hypoalphalipoproteinemia (HypoALP) or hyperalphalipoproteinemia (HyperALP) were compared with fifty-five control subjects with average HDL-C levels, matched for sex, age, and plasma cholesterol. The average and maximal intima-media thicknesses (Avg-IMT and Max-IMT) of 48 carotid segments for each subject were approximately 40% greater in HypoALP than in control subjects (0.94 +/- 0.06 versus 0.69 +/- 0.04 mm, P=0.004, and 1.86 +/- 0.16 versus 1.35 +/- 0.10 mm, P=0.025, respectively). The IMT values in HyperALP subjects (Avg-IMT, 0.71 +/- 0.04 and Max-IMT, 1.38 +/- 0.14 mm) were the same as in controls. In a large cohort of hyperlipidemic subjects (n=559), significantly greater Avg-IMT and Max-IMT were found in subjects belonging to the first HDL-C quintile (<42 mg/dL) than in all the others. The measurement of carotid IMT in cases with HypoALP and HyperALP, and in a large series of hyperlipidemic patients, thus indicates that a low HDL-C is associated with significant pre-intrusive atherosclerosis, whereas a HDL-C level above average values does not lead to a further reduction of arterial wall thickening.
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