Background: High-density lipoprotein (HDL) could enhance inflammation in atherogenesis when inflammatory response is present, and the activity of paraoxonase and antioxidant in HDL in the elderly is significantly decreased. There might be a different role for high-density lipoprotein cholesterol (HDL-C) between different age groups in patients with coronary heart disease (CHD).
Methods: For this study, 225 inpatients with CHD (coronary atherosclerosis stenosis >/= 50% on >/= 1 major coronary arteries by coronary angiography), and 80 without CHD; 120 resting unstable angina patients, and 68 with stable angina were consecutively recruited. Risk factors were analyzed for CHD and resting unstable angina.
Results: High-density lipoprotein cholesterol in resting unstable angina was higher than that in stable angina (1.24 +/- 1.05 versus 1.05 +/- 0.29 mmol/L, p = 0.032). After adjustment for age, sex, physical inactivity, hypertension, diabetes, C-reactive protein, triglycerides, total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) the adjusted odds ratio (OR) (95% CI) of resting unstable angina was 10.19 (2.18-47.6, p = 0.003) for HDL-C. Risk factors were further investigated in different age groups. Adjusted OR of CHD associated with HDL-C in < 55-year-old group was 0.09 (0.01-0.66, p = 0.018), in >/= 55-year-old group it was 0.55 (0.08-3.82, p > 0.05). Adjusted OR of resting unstable angina associated with high HDL-C was 19.24 (2.86-129.4, p = 0.002) in patients aged >/= 55 years.
Conclusions: Elevated HDL-C might be an independent risk factor for resting unstable angina, even though HDL-C could play a much more important role in protection against coronary stenosis in younger or middle-aged persons.