Insulin resistance tied to atherogenic lipoprotein/lipid, cIMT in obese youths

Insulin resistance in young people with obesity is positively associated with an atherogenic lipoprotein/lipid profile and carotid intima-media thickness (cIMT), regardless of their glucose tolerance status, suggests a study.

In addition, insulin resistance in abnormal glucose tolerant (AGT) youths appears to contribute to a shift to smaller high-density lipoprotein particles (HDL-P) relative to those with normoglycaemia and obesity.

Of the 155 youths included in this observational cohort study, 44 were obese insulin sensitive (OIS; fasting insulin ≤20 µM/mL, body mass index [BMI] ≥95th percentile), 35 obese insulin resistant (OIR; fasting insulin >20 µM/mL, BMI ≥95th percentile), 34 obese abnormal glucose tolerant (AGT; BMI ≥95th percentile), and 42 lean (BMI 5th-85th percentile).

The researchers used linear models, adjusted for age, race/ethnicity, biological sex, and Tanner stage, to compare lipids, lipoprotein particle size and concentration, insulin sensitivity (S_I an intravenous glucose test), and cIMT. After 2 years, they re-evaluated the lipid/lipoprotein profile and cIMT.

OIR and AGT had high triglycerides and low HDL-cholesterol but similar total cholesterol and low-density lipoprotein cholesterol (LDL-C) compared to OIS and lean. Among OIS, OIR, and AGT youths, lower insulin sensitivity correlated with atherogenic lipids (higher triglycerides, LDL-C, non‒HDL-C, and lower HDL-C) and lipoproteins (higher total LDL particles and small HDL-P, and lower large HDL-P).

Compared with OIR and OIS, AGT had a steeper decline in the association of insulin sensitivity with HDL-C and large HDL-P. On the other hand, cIMT was similar across groups and was inversely associated with insulin sensitivity, with no change after 2 years.

“Alterations in HDL-P metabolism may be early adverse manifestations of hyperglycaemia in youth with obesity,” the researchers said.