Abstract 10071: More Atherogenic High Density Lipoprotein Profile in Insulin Resistant Adolescents with Type 1 Diabetes
Type 1 Diabetes (T1D) is characterized by auto-immune destruction of the pancreatic beta cells. Adults with T1D (in contrast to T2D) have a less atherogenic fasting lipid profile (higher HDL-c; lower LDL-c and TG) than non-diabetics, but paradoxically have increased rates of cardiovascular disease (CVD). We previously reported, however, that insulin resistance (IR) was present in T1D and was associated with a more atherogenic lipoprotein cholesterol distribution particularly in T1D women. We hypothesized that lipoprotein subfraction cholesterol distribution may also differ in T1D adolescents, a time of heightened IR and poor glycemic control.
Fasting plasma samples of 43 subjects (age 15±2 yrs, 51% female, 70% T1D of 6±4 yrs duration) drawn prior to a hyperinsulinemic-euglycemic clamp, underwent fast protein liquid chromatography. Two Superose 6 columns (GE Healthcare) connected in series were used to fractionate the lipoproteins and the cholesterol distribution was evaluated. T1D and control youth were similar for age, Tanner stage, BMI, and activity level, but T1D youth had higher HbA1c and were more IR (glucose infusion rate 20±4 v 12±5, p<0.001).
Adolescents with T1D had more cholesterol distributed as LDL and less as HDL than controls (p<.05 for both, Figure). However, unlike adults with T1D there were no differences by sex nor were there sex differences within controls. Both males and females with T1D had less cholesterol in HDL fractions as compared to controls.
Adults with T1D have better fasting lipids but this is not seen in adolescents, in fact we found the opposite, i.e. a more atherogenic LDL-c and HDL-c distribution than age, sex, Tanner stage, and activity level similar non-diabetics. The heightened IR and worse glycemic control of youth are possible explanations. A better understanding about the transition from adolescence to adulthood and the impact of lipoprotein cholesterol distribution in adolescence on the increased burden of CVD in T1D is needed.
- © 2011 by American Heart Association, Inc.