Microalbuminuria Increases CAC Risk
The finding comes from a substudy of the Multi-Ethnic Study of Atherosclerosis (MESA) in which Dr. DeFilippis examined data on subjects from four ethnic groups (white, black, Hispanic and Chinese) who were free of cardiovascular disease at baseline.
Using CT scans, Dr. DeFilippis assessed the progression and incidence of subclinical atherosclerosis among participants with and without CAC at baseline. He then analyzed the association between microalbuminuria—defined as a spot urinary albumin-to-creatinine ratio(UACR) of 30-300 mg/g—and incident CAC and CAC progression.
Of the 5,666 subjects in the study, 424 had microalbuminuria. Those with microalbuminuria were older; more likely to have hypertension, diabetes, or dyslipidemia; and had a lower calculated glomerular filtration rate than those without microalbuminuria. Sixty-two percent of subjects with microalbuminuria had CAC at baseline compared with 48% without microalbuminuria.
At a median follow-up of 2.4 years, microalbuminuria was associated with a 76% increased likelihood of developing new CAC after controlling for multiple traditional cardiovascular risk factors, said Dr. DeFilippis, a cardiology fellow at the Johns Hopkins Ciccarone Preventive Cardiology Center in Baltimore. When he examined microalbuminuria as a continuous variable, UACR remained a significant predictor of CAC development.
Among those with CAC at baseline, the risk of progression was on average 9 units higher in subjects who had microalbuminuria as compared with those who did not, after controlling for multiple traditional cardiovascular risk factors. “This relationship appears to persist over the four ethnic groups,” he said.
“Further study is needed to determine the degree to which microalbuminuria precedes and predicts progression of atherosclerosis and how this information can be used to reduce cardiovascular events,” Dr. DeFilippis said.