Higher levels of hemoglobin A1c (HbA1c) are associated with increased cardiovascular disease risk among individuals without diabetes and may also be positively associated with coronary artery calcification (CAC). In a study conducted by Dr. April P. Carson, assistant professor in the department of epidemiology at the University of Alabama at Birmingham, the association of HbA1c with CAC progression in the Coronary Artery Risk Development in Young Adults (CARDIA) Study are investigated.
Dr. Carson and her fellow investigators included 2,076 participants with HbA1c and noncontrast computed tomography (CT) assessed at baseline (in 2005–2006), and CT repeated five years later (2010–2011). CAC progression was defined as (1) incident CAC (increase >0 Agatston units among those with no CAC at baseline); (2) any CAC progression (increase >10 Agatston units between examinations), and (3) advanced CAC progression (increase >100 Agatston units between examinations).
During the five-year follow-up period, 12.9 percent of participants without baseline CAC developed incident CAC; among all participants, 18.2 percent had any CAC progression and 5.4 percent had advanced CAC progression. Higher HbA1c was associated with incident CAC, and CAC progression, and advanced CAC progression after adjustment for sociodemographic factors. Additional adjustment for cardiovascular risk factors attenuated the associations of HbA1c with incident CAC and any CAC progression. In contrast, the association of HbA1c with advanced CAC progression persisted in multivariable adjusted models.
The researchers concluded that higher HbA1c was independently associated with advanced CAC progression among individuals without diabetes, while the associations with incident CAC and any CAC progression were accounted for by other established cardiovascular risk factors.
“Hemaglobin A1c and the Progression of Coronary Artery Calcification Among Adults Without Diabetes” was published in October in the journal Diabetes Care.