Low HDL cholesterol concentration is associated with increased intima-media thickness independent of arterial stiffness in healthy subjects from families with low HDL cholesterol.

BACKGROUND

Low high-density lipoprotein cholesterol (HDL-C) is associated with increased risk for developing coronary artery disease. Cardiovascular disease is characterized by increased intima-media thickness (IMT) and arterial stiffness, but the effect of low HDL on these measurements has not been reported.

MATERIALS AND METHODS

We studied 18 apparently healthy subjects from families with low HDL-C and 18 control subjects, which were pair-matched to maximize statistical power. Intima-media thickness was assessed using ultrasound examination of the carotid arteries. Arterial stiffness was measured using applanation tonometry on the radial artery and pulse-wave analysis to obtain central aortic pulse-pressure waveform, from which the augmentation index, a measure of global large artery stiffness, was calculated.

RESULTS

Low HDL subjects (age 41 +/- 3 years, BMI 26.6 +/- 1.0 kg m(-2) had significantly lower HDL-C than the control subjects (age 41 +/- 3 years, BMI 26.5 +/- 1.0 kg m-2; 1.00 +/- 0.05 vs. 1.49 +/- 0.09 mmol L-1, low HDL vs. control subjects, P < 0.0001). Subjects with low HDL-C had significantly thicker mean IMTs than the control subjects (0.77 +/- 0.03 vs. 0.70 +/- 0.02 mm, low HDL vs. control subjects, P < 0.01). The maximal (0.99 +/- 0.04 vs. 0.89 +/- 0.03 mm, P < 0.01), far wall (0.76 +/- 0.04 vs. 0.69 +/- 0.02 mm, P < 0.05) and carotid bulb (1.11 +/- 0.06 vs. 0.97 +/- 0.04 mm) IMTs were also significantly increased, whereas the mean common carotid and the internal artery IMT were not. The age-related increase in mean IMT was more pronounced in the low HDL subjects than the control subjects (P < 0.01 for difference between elevations of age vs. IMT slopes). There were no differences in central pressure augmentation, the augmentation index, peripheral or central blood pressures between the groups.

CONCLUSIONS

A low HDL-C concentration is associated with thickening of carotid IMT independent of other risk factors in healthy affected members of low HDL families.