Young women with T1D develop CHD without any apparent lipid related risk factor. To determine whether abnormalities in the five immunochemically defined apoB-containing lipoprotein subclasses might influence this risk, we have measured these subclasses in T1D subjects.ApoA- and B-containing lipoprotein subclasses were isolated immunochemically and quantitated in 37 young (mean age 31.8+/-12.7 years) otherwise healthy subjects (16 males; 21 females) with T1D (HbA1c=8.2+/-1.7%) treated conventionally with subcutaneous insulin.T1D women had significantly more cholesterol-rich Lp-B particles (T1D: 55.9+/-4.5 vs. control 46.8+/-11.1mg apoB/dL; p.01) which were over-represented in the apolipoprotein B particle pool (apoB/Lp-B: T1D: 1.49+/-.19 vs. control: 1.67+/-.22; p.01). HbA1c correlated with Lp-B (r=0.60; p.001) and the mass of apoB subclasses containing apoC-III (r=0.69; p.001).Women with T1D have a disturbance in the transport of Lp-B particles manifested by both an absolute and relative increase in their number that may result from portal hypoinsulinemia and reduced LDL B,E receptor activity. This pathway may enhance CHD risk in T1D women when of LDL and apoB levels are normal.
