The coronary artery disease is associated with more than threefold-increased risk in diabetes mellitus. Lipoprotein(a) and apo(a), a specific protein of this lipoprotein are risk factors for atherosclerosis. However, the association of apo(a) size with the lipoprotein(a) levels in patients with type 1 diabetes mellitus still controversial.
Objective: We investigated the apo(a) polymorphism and its association with lipoprotein(a) levels in children with type 1 diabetes mellitus and their non diabetic first-degree relatives.
Methods: This cross-sectional study included 25 type 1 diabetic patients aged 1 to 17 years, one non-diabetic sibling of each patient and both parents. Glucose, lipids, lipoproteins, apoAI, apoB, lipoprotein(a) plasma concentration as well as apo(a) phenotypes were determined.
Results: Median plasma lipoprotein(a) concentrations were 8.3, 8.2, 4.2, and 9.3 mg/dL in type 1 diabetes mellitus, siblings, fathers and mothers respectively (p ns). The prevalence of plasma lipoprotein(a) excess (> 30 mg/dL) was not significantly higher in type 1 diabetes mellitus patients than in their non diabetic siblings, or in their parents. Lipoprotein(a) levels and apo(a) distribution were similar in all groups (p ns) and those of parents correlated directly with the lipoprotein(a) and phenotypes of their offspring.
Conclusions: Lipoprotein(a) levels and apo(a) size were similar in type 1 diabetes mellitus cases and their first degree relatives and the associations between them were similar too, suggesting that Lp(a) does not appear to explain increased risk of atherosclerosis in patients with this disease.