Effects of systolic blood pressure and low density lipoprotein on carotid plaques

Abstract

To explore the different effects of systolic blood pressure (SBP) and low density lipoprotein on carotid plaques (LDL-C). A total of 101 510 serving and retired workers of a company who participated in the health examination in 2006-2009, 5852 participants were selected as study subjects by stratified random sampling according to the age and sex ratio. These subjects took their health examination in 2010-2011 including the carotid ultrasound. Finally, 5361 eligible participants with complete data were included in the analysis. The detection and weighted rates of carotid plaques were calculated for four groups: normal SBP and LDL-C group (3524 subjects), normal SBP and high LDL-C group (356 subjects), elevated SBP and normal LDL-C group (1308 subjects) and elevated SBP and high LDL-C group (173 subjects). The effects of different baseline SBP and LDL-C on detection rates of the carotid artery plaques were analyzed by logistic regression. The detection rate of carotid plaques in normal SBP and LDL-C group, normal SBP and high LDL-C group, elevated SBP and normal LDL-C group, elevated SBP and high LDL-C group was 33.7% (1186/3524), 41.3% (147/356), 64.8% (847/1308), 68.8% (119/173) (χ(2) = 425.75, P < 0.05) and the weighted detection rate was 36.0%, 42.0%, 64.5% and 68.3% respectively. For men, the detection rate was 44.2% (877/1985), 51.1% (97/190), 70.6% (657/930), 71.3% (82/115) (χ(2) = 194.02, P < 0.05) and the weighted detection rate was 31.2%, 36.1%, 49.8% and 50.3% respectively. For women, the detection rate was 20.1% (309/1539), 30.1% (50/166), 50.3% (190/378), 63.8% (37/58) (χ(2) = 180.17, P < 0.05) and the weighted detection rate was 30.9%, 46.3%, 70.3%, and 88.1% respectively. After adjusted for other risk factors, the OR (95%CI) value was 1.37 (1.05 - 1.78), 2.05 (1.74 - 2.43) and 2.12 (1.45 - 3.12) for normal SBP and high LDL-C group, elevated SBP and normal LDL-C group and elevated SBP and high LDL-C group respectively compared with normal SBP and LDL-C group. Elevated SBP and high LDL-C were risk factors of the carotid artery plaques. Compared with high LDL-C, elevated SBP may add a higher risk for carotid plaques.