Correlation between Apolipoprotein B-to-Apolipoprotein A1 Ratio and Total-to-HDL-Cholesterol Ratio in a Healthy Population: Should Castelli Index be Updated?

Abstract

SUMMARY The total cholesterol/HDL cholesterol ratio (TC/HDL-Cr) was proposed as a marker of coronary risk about 25 years ago by Dr. William Castelli and the suggested target was 0.43; and propose an updated CI target. Material and Methods Apolipoprotein levels were measured by immnuno-phelometry in samples obtained from blood donors. Models of simple linear regression were made to analyze the relationship between the ApoB/ApoA and TC/HDL ratios. A ROC analysis was carried out to evaluate the accuracy of the CI to distinguish between subjects with ApoB / ApoAr ≤0.43 and > 0.43. Subjects with hypertension, vascular disease, diabetes or treated with lipid-lowering drugs were excluded. Results A total of 283 subjects were included, 64% men, 31% smokers. General characteristics (mean ± SD): age 41.8 ± 14 years, BMI 26.2 ± 4, TC 199.5 ± 48 mg / dl, HDL 49 ± 13 mg / dl, CI 4.31 ± 1.3, ApoB 95.2 ± 28 mg / dl, ApoA 157.4 ± 32 mg / dl, ApoB / ApoAr 0.62 ± 0.21. In the overall population, the correlation between ApoB / ApoAr and the CI was 0.90 and the ApoB / ApoAr of 0.43 corresponded to an CI of 3.22. The area under the ROC curve of the CI to distinguish between subjects with ApoB/ApoAr  0.43 and > 0.43 was 0.936 (CI 95% 0.897- 0.975) and OPC was 3.238. Background