Serum Apolipoproteins and Apolipopprotein-Defined Lipoprotein Subclasses: A Hypothesis-Generation Prospective Study of Cardiovascular Events in Type 1 Diabetes

Arpita Basu PhD, University of Nevada, Las Vegas
Ionut Bebu PhD, The George Washington University
Alicia J. Jenkins MD, University of Sidney
Julie A. Stoner PhD, University of Oklahoma Health Sciences Center
Ying Zhang MD; PhD, University of Oklahoma Health Sciences Center
Richard L. Klein PhD, Medical University of South Carolina
Maria F. Lopes-Virella MD; PhD, Medical University of South Carolina
W. Timothy Garvey MD, University of Alabama at Birmingham
Matthew J. Budoff MD, Los Angeles Biomedical Research Institute
Peter Alaupovic PhD, Oklahoma Medical Research Foundation
Timothy J. Lyons MD, Medical University of South Carolina

Abstract

Apolipoproteins and apolipoprotein-defined lipoprotein subclasses have been associated with dyslipidemia and cardiovascular disease (CVD). Our main objective was to define associations of serum apolipoproteins and ADLS with any CVD and major atherosclerotic cardiovascular events (MACE) in a prospective study of T1D. Serum apolipoproteins and ADLS (14 biomarkers in total) were measured in sera (obtained 1997-2000) from a subset (n=465) of the Epidemiology of Diabetes Interventions and Complications (EDIC) cohort. Prospective associations of any CVD (myocardial infarction, stroke, confirmed angina, silent MI, revascularization, or congestive heart failure) and MACE (fatal or nonfatal myocardial infarction or stroke), over 5942 and 6180 patient-years follow-up respectively, were investigated using Cox proportional hazards models, unadjusted and adjusted for risk factors. During 15 years follow-up, 50 any CVD and 24 MACE events occurred. Nominally significant positive univariate associations with any CVD were APOB, APOC3 and its sub-fractions [heparin precipitate (HP), heparin soluble (HS)], and ADLS-defined Lp-B. Nominally significant positive univariate associations with MACE were APOC3 and sub-fractions, and Lp-B:C; those with total APOC3 and APOC3-HS persisted in adjusted analyses. However, these associations did not reach significance after adjustment for multiple testing. There were no significant associations of APOA1, APOA2, APOE, or other ADLS with either any CVD or MACE. These hypothesis-generating data suggest that total serum APOC3 and APOC3 in HDL are potentially important predictive biomarkers for any CVD and MACE in T1D adults.