Abstract 11054: Lipoprotein(a) is Associated with Aortic Valve and Mitral Annular Calcification but not Thoracic Aortic Calcification in Type 2 Diabetics

Abstract

Background: Lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease, but its relationship to cardiovascular calcification remains unclear. We assessed whether Lp(a) was associated with aortic valve calcification (AVC), mitral annular calcification (MAC), and thoracic aortic calcification (TAC) in subjects with type 2 diabetes (T2DM).

Methods: Within the Penn Diabetes Heart Study, a cross-sectional study of T2DM subjects without coronary or renal disease, we quantified AVC, MAC and TAC Agatston scores in 1,659 subjects (63.4% male, 64.6% Caucasian). We used multivariable tobit regression to examine the association of Lp(a) with each calcification score (see Table 1 for variables adjusted for in model).

Results: AVC, MAC and TAC were present in 16.5%, 12.1%, and 54.1% of subjects, respectively. Table 1 shows multivariable tobit regression ratios (TRR) for Lp(a)’s associations by gender and race. For AVC there was a significant interaction by race (interaction p=0.02), wherein Lp(a) was associated with AVC in African-Americans but not in Caucasians (TRR for all African-Americans 1.90, p=0.001). With MAC, Lp(a) had a significant interaction by gender (interaction p<0.01), wherein Lp(a) was associated with MAC in women, but not in men (TRR for women 2.06, p<0.001). There were no significant associations between TAC and Lp(a). Likelihood ratio testing of models adding Lp(a) to a model of cardiovascular risk factors had similar results, with significant associations of Lp(a) with AVC in African-Americans (χ2 of 4.7 and 7.7 for women and men, respectively, p<0.05) and with MAC in women (χ2 of 8.7 and 10.6 for Caucasians and African-Americans, respectively, p<0.01).

Conclusion: In this sample of asymptomatic T2DM subjects, the association of Lp(a) with cardiovascular calcification varies by calcification site and by gender and race. Lp(a) has robust associations with AVC in African-Americans and with MAC in women, but lacks significant association with TAC.