Nuclear magnetic resonance-determined lipoprotein subclasses and carotid intima-media thickness in type 1 diabetes

- NMR-derived and conventional lipid profiles were correlated with carotid IMT in a DCCT/EDIC sub study (n=455).
- Lipids were measured at baseline and correlated with IMT about 19 years later.
- LDL subclasses (total IDL/LDL and large LDL) were positively associated with IMT in men.
- Conventional total and LDL-cholesterol levels were positively associated with IMT in men.
- No statistically significant associations were observed in women.

BackgroundDyslipidemia has been linked to vascular complications of Type 1 diabetes (T1DM). We investigated the prospective associations of nuclear magnetic resonance-determined lipoprotein subclass profiles (NMR-LSP) and conventional lipid profiles with carotid intima-media thickness (IMT) in T1DM.MethodsNMR-LSP and conventional lipids were measured in a subset of Diabetes Control and Complications Trial (DCCT) participants (n = 455) at study entry ('baseline', 1983-89), and were related to carotid IMT determined by ultrasonography during the observational follow-up of the DCCT, the Epidemiology of Diabetes Interventions and Complications (EDIC) study, at EDIC Year 12 (2004-2006). Associations were defined using multiple linear regression stratified by gender, and following adjustment for HbA1c, diabetes duration, body mass index, albuminuria, DCCT randomization group, smoking status, statin use, and ultrasound devices.ResultsIn men, significant positive associations were observed between some baseline NMR-subclasses of LDL (total IDL/LDL and large LDL) and common and/or internal carotid IMT, and between conventional total- and LDL-cholesterol and non-HDL-cholesterol and common carotid IMT, at EDIC Year 12; these persisted in adjusted analyses (p < 0.05). Large LDL particles and conventional triglycerides were positively associated with common carotid IMT changes over 12 years (p < 0.05). Inverse associations of mean HDL diameter and large HDL concentrations, and positive associations of small LDL with common and/or internal carotid IMT (all p < 0.05) were found, but did not persist in adjusted analyses. No significant associations were observed in women.ConclusionNMR-LSP-derived LDL particles, in addition to conventional lipid profiles, may help in identifying men with T1DM at highest risk for vascular disease.