Surrogate lipid markers for small dense low-density lipoprotein particles in overweight youth

Abstract

Objectives: To determine if the ratio of triglycerides to high-density lipoprotein cholesterol (TG/HDL) and non-HDL cholesterol concentration could identify youth with small dense low-density lipoprotein (LDL).

Study design: One hundred forty-one (75 black and 66 white) overweight adolescents (9 to <18 years) had a fasting measurement of plasma lipids and LDL particle concentrations and size. Receiver operating characteristic curves were used to indicate the ability of different TG/HDL ratios and non-HDL cholesterol concentrations to identify overweight youth with atherogenic LDL concentration and size.

Results: Youth with a TG/HDL ratio of ≥3 vs <3 had higher concentrations of small dense LDL (1279.5 ± 60.1 vs 841.8 ± 24.2 nmol/L, P < .001) and smaller LDL particle size (20.3 ± 0.1 vs 21.2 ± 0.1 nm, P < .001). In receiver operating characteristic analyses a TG/HDL cut-point of 3 best predicted LDL concentration in white youth, and 2.5 in black youth. Non-HDL cholesterol cut-point of 120 mg/dL and 145 mg/dL predicted LDL particle concentration in white and in black youth, respectively. TG/HDL ratio with body mass index or waist circumference explained 71% and 79% of the variance, respectively, in total small LDL.

Conclusions: TG/HDL ratio and non-HDL cholesterol can identify overweight youth with atherogenic LDL particles. These easily obtained clinical lipid markers, in combination with body mass index and waist circumference, could be cost effective, in observational or interventional studies, for screening and follow-up of youth at heightened risk for atherogenic LDL.

Figure 1

ROC curves for total, total small, medium small, and very small LDL particle concentrations and LDL particle size A, at a TG/HDL ratio and B, cut-point of 3 in all overweight and white overweight youth, and C, cut-point of 2.5 in black overweight youth. AUC, area under the curve.

Figure 2

ROC curves for total, total small, medium small, and very small LDL particle concentrations, and LDL particle size, at a non-HDL cholesterol cut-point of A, 120 mg/dL for overweight white youth and B, 145 mg/dL for overweight black youth.

Figure 3

Concentrations of A, total, B, large, C, medium small, and D, very small LDL, and E, LDL particle size in black and white youth with a TG/HDL ratio <3 and ≥3. Differences compared using 2-way ANOVA. NS, not significant.