Objective To provide the changing prevalence of carotid plaque in a Chinese elderly population from 2002 to 2007 and accordingly evaluate the predictive effect of baseline lipid levels of interest on the newly-identified carotid plaque.

Methods All study subjects were recruited from two cohorts, viz. 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 was taken in 2002 including CVD risk factors and B-mode ultrasound of carotid artery and the second examination was carried out in 2007. The carotid plaque was measured in a total of 2000 subjects aged 47–79 years (mean 63 year).

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 reached 41.8% for men and 34.1% for women. 2. With the increase of baseline total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglyceride (TG, except for men), non-high-density lipoprotein cholesterol (non-HDL-C), and total to high-density cholesterol ratio (TC/HDL-C) levels, the artery plaque incidence significantly increased in both sexes (p<0.05). 3. Cross-stratification analysis of LDL-C, 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 elevated carotid plaque. For example, at the normal levels of LDL-C and HDL-C, the plaque incidence was 23.3%, whereas the abnormal levels of these two lipids yielded an exceedingly high incidence of 49.0%. 4. In multifactorial analysis, higher LDL-C, non-HDL-C and TC/HDL-C was recognised as an independent factors of carotid plaque incidence (RR=1.44, 95% CI 1.07 to 1.94; RR=1.45, 95% CI 1.08 to 1.96; RR=1.59, 95% CI 1.14 to 2.23 in men; RR=1.47, 95% CI 1.13 to 1.92; RR=1.35, 95% CI 1.04 to 1.75; RR=1.64, 95% CI 1.20 to 2.23 in women).

Conclusions The prevalence of carotid plaque increased rapidly in a Chinese elderly population. Elevated LDL-C, non-HDL-C and TC/HDL-C levels serve as predictor of carotid plaque incidence.