Can cord blood lipid and lipoprotein levels inform LDL targets?

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Current ESC dyslipidemia guidelines recommend lowering LDL targets to 1.4mmol/L (55mg/dL) for very high risk individuals. Lipid levels of newborns may provide insights into physiologic levels at the time of birth. There is limited data on cord blood lipids/lipoprotein levels in Asian populations. This study aims to describe cord blood lipid levels in a multi-ethnic Asian population. Methods We analyzed 563 (F = 275) anonymized residual cord serum samples for the measurement of cholesterol, triglycerides, dLDL and HDL on the Cobas c702 autoanalyzer and cLDL after exclusion of outliers (Tukey). Following tests for Gaussian distribution (Shapiro-Wilk) all data were log transformed. Gender differences were assessed by Mann-Whitney U test. dLDL was compared with cLDL (Passing-Bablok regression, Wilcoxon’s test, Bland-Altman plot). Statistical calculations were performed using MedCalc v20 (MedCalc software, Ostend, Belgium). Results There was no gender difference for cord cholesterol (p = 0.1781) and cLDL (p = 0.6186) and their values were: cholesterol (range:0.78-3.09mmol/L; mean:1.486; reference interval:0.92-2.42) and cLDL (range:0.19-1.85mmol/L; mean:0.60 ; reference interval:0.27-1.21). dLDL was higher in females (p = 0.0388) (range:0.17-1.84mmol/L; median:0.54; IQR:0.37,0.71; reference interval:0.22-1.26; 99th percentile 1.42) compared to males (range:0.16-1.19mmol/L; median:0.49; IQR:0.36,0.62; reference interval:0.21-0.98; 99th percentile 1.13). Cord dLDL values were significantly lower (p < 0.001) than cLDL; the difference (Bland-Altman) between dLDL and cLDL ranged from -0.2062-0.0141 mmol/L (mean -0.0960). Passing-Bablok regression analysis showed cLDL = 1.0465dLDL + 0.0695 with a correlation coefficient (Spearman) of 0.963 (p < 0.0001). Female triglycerides were lower (p < 0.0001) [range:0.11-0.82mmol/L; median:0.24; IQR:0.19,0.31; reference interval:0.11-0.64] than males [range:0.11-0.85mmol/L; median:0.28; IQR:0.21,0.38; reference interval:0.13-0.66]. HDL was higher in females [range:0.40-1.62mmol/L; median:0.75; IQR:0.62,0.93; reference interval:0.44-1.34] than males [range:0.33-1.29mmol/L; median:0.69; IQR:0.58,0.86; reference interval:0.43-1.16] (p = 0.005). Conclusion Contemporary cord blood lipid/lipoprotein values have been derived for our local multi-ethnic Asian population. Directly measured LDL, shows ESC guideline LDL targets are not lower than cord dLDL levels at the 99th percentile. However cLDL overestimates cord dLDL in this cohort of subjects.