Abstract
BACKGROUND: Massive evidence supports that increase of lipids bring more risk of atherosclerosis. However, it is not clear if lipids measured a long time ago bear more risk than the current measurement. HYPOTHESIS: Lipids measured currently is more associated with carotid atherosclerosis than lipids measured long time ago. METHODS: A cohort of 1195 participants age 35 to 64 years was examined in both 1993-1994 and 2002 for serum lipids, and in 2002 for carotid intima-media thickness (CIMT) with B mode ultrasound. The associations of lipids at baseline and at reexamination with CIMT were analyzed and compared using multiple linear regressions. RESULTS: All lipid variables, except for high-density lipoprotein cholesterol (HDL-C) both at baseline and reexamination, were significantly associated with age-adjusted CIMT in both males and females (all P(trend) <0.01). The age-adjusted mean of CIMT in all of the population was 0.696 mm in those having low low-density lipoprotein cholesterol (LDL-C) at both examinations, 0.719 mm in those having high LDL-C only at baseline, 0.706 mm in those having high LDL-C only at reexamination, and 0.727 mm in those having high LDL-C at both examinations. Further analysis showed that lipids measured at baseline remained significant, whereas lipids at reexamination became not significant in all models, except those for HDL-C and total cholesterol (TC)/HDL-C, which allow the lipids at different times to compete in association with CIMT. CONCLUSIONS: Both the current measurement of lipids (TC, LDL-C, non-HDL-C, TC/HDL-C, and LDL-C/HDL-C) and the measurement from 9 years ago are significantly associated with CIMT, but the measurement from 9 years ago had an even stronger association.