Objective: To evaluate the prediction value of blood lipid levels on the newly-identified carotid plaque in middle-aged and elderly Chinese population.
Methods: All study subjects were recruited from two cohorts from 2002 to 2007 [the People's Republic of China/United States of America collaborative study (USA-PRC study) and the Chinese multi-provincial cohort study (CMCS)]. The baseline examination including cardiovascular disease risk factors and B-mode ultrasound of carotid artery was performed in 2002 and the second examination was made in September to October, 2007. The relationship between baseline lipids and carotid plaque incidence was analyzed in a total of 2000 subjects aged 47 to 79 years (mean 63 years).
Results: (1) During these 5 years, the prevalence of carotid plaque increased from 30.3% to 62.2% and from 21.5% to 51.5% for men and women, respectively. The newly-identified carotid plaque incidence was 41.8% for men and 34.1% for women. (2) The incidence of artery plaque significantly increased in both sexes in proportion to increase of baseline total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C), and total to high-density cholesterol ratio (TC/HDL-C) levels (P < 0.05 or P < 0.01). (3) Cross-stratification analysis of LDL-C, triglyceride (TG) and HDL-C for carotid plaque incidence indicated the existence of conjoint effects between LDL-C and HDL-C, LDL and TG, as well as between TG and HDL-C, on the increased incidence of carotid plaque. (4) Multi-factorial analysis showed that higher LDL-C, non-HDL-C and TC/HDL-C were independent risk factors for development of new carotid plaque [OR = 1.44 (95%CI = 1.07 - 1.94), OR = 1.45 (95% CI = 1.08 - 1.96), OR = 1.59(95% CI = 1.14 - 2.23) in men;OR = 1.47 (95% CI = 1.13 - 1.92), OR = 1.35 (95% CI = 1.04 - 1.75), OR = 1.64 (95% CI = 1.20 - 2.23) in women].
Conclusions: The prevalence of carotid plaque increased rapidly in this cohort between 2002 and 2007. Elevated LDL-C, non-HDL-C and TC/HDL-C levels were independent predictors of newly developed carotid plaque.