LAUSR

OBJECTIVE A high triglyceride (TG) to high-density lipoprotein cholesterol (HDL) ratio (TG/HDL) predicts atherosclerosis and cardiovascular events. This study examined whether a proatherogenic distribution of plasma lipoprotein subclasses is associated with a high TG/HDL ratio in youths with obesity. METHODS Lipoprotein particle concentration and size were measured by proton nuclear magnetic resonance in a multiethnic cohort of 592 adolescents with overweight/obesity (age 13 ± 3 years, 58% females, BMI z score 2.1 ± 0.8) who were phenotyped with a 3-hour oral glucose tolerance test and abdominal magnetic resonance imaging. RESULTS The highest TG/HDL quartile showed a higher particle concentration of very low-density lipoprotein (VLDL; +178%, p < 0.0001), intermediate-density lipoprotein (+338%, p < 0.0001), and low-density lipoprotein (LDL; +42%, p < 0.0001), compared with the lowest quartile. The prevalence of large VLDL, very small LDL, and small HDL progressively increased across TG/HDL quartiles. The TG/HDL ratio correlated positively with the average particle size of VLDL (r = 0.37, p < 0.0001) and negatively with particle size of both LDL (r = -0.51, p < 0.0001) and HDL (r = -0.69, p < 0.0001). These associations were independent of sex, age, race/ethnicity, body mass, fasting plasma glucose, and insulin sensitivity. CONCLUSIONS In youths with obesity, an elevated TG/HDL ratio is associated with high concentrations of proatherogenic lipoprotein subclasses. This phenotype may explain the increased cardiovascular risk associated with a high TG/HDL ratio.