CAC More Effective for CVD, Mortality Prediction in Female vs Male Diabetics

Nathan Wong, MD

An analysis of data from a nationwide registry of adults with diabetes is revealing more about the clinical usefulness of coronary artery calcium (CAC) levels for predicting cardiovascular events and mortality.

Results of the analysis, which was performed by investigators at the University of California, Irvine (UCI) and Cedars-Sinai, found greater CAC levels more accurately predicted cardiovascular and total mortality in women than it did in men with diabetes.

“Our findings, showing significant levels of coronary calcium to predict mortality from cardiovascular causes more strongly in women than men with diabetes, might also help to explain the poorer prognosis for cardiovascular disease that has been observed for decades in women compared to men with diabetes,” said study lead investigator Nathan Wong, PhD, professor and director for UCI’s Heart Disease Prevention Program, in a statement.

While the value of CAC in treatment guidance for cardiovascular disease risk in patients with diabetes has been proven in multiple studies, relatively little is known about the sex-specific impact of CAC for predicting coronary heart disease in diabetics. With this in mind, Wong and colleagues designed the current to address unanswered questions surrounding this topic through an analysis of data from the CAC consortium.

Performed across 4 sites in the US from 2004-2014, the CAC consortium contained data from more than 65,000 patients aged 18 years and older. Of these, 4503 participants met the investigators’ inclusion criteria for diabetes, which included a physician diagnosis or self-report by the participant taking hypoglycemic therapy. The patient population had an age range of 21-93 years, 32.5% were women, and the mean follow-up time was 11.5 years. Of note, 61.2% of women and 80.4% of men had a CAC greater than 0.

In comparison, women included in the study were slightly older, had a lower BMI, and were less likely to be currently smoking. However, investigators noted women were also more likely to have a family history of coronary heart disease and hypertension.

Upon analysis, CAC scores were directly related to total, cardiovascular disease, and coronary heart disease-related mortality rates. Results also indicated women had higher total and cardiovascular mortality rate than men when CAC exceeded 100. Specifically, age- and risk factor-adjusted hazard ratios per log unit CAC were higher among women versus men for total (1.28 vs 1.18; P=.01) and cardiovascular disease mortality (1.47 vs 1.27; P=.04), but were similar for coronary heart disease mortality (1.53 vs 1.48; P=.03).

When assessing sex-specific cardiovascular disease-related mortality, patients with CAC scores between 101-400 were at a 3.67-times (1.30-10.38; P=.001) greater risk of mortality and patients with scores greater than 400 were associated with a 6.27-times (2.27-17.28; P=.0004) greater risk for women. In men, CAC scores between 101-400 were associated with a 1.63-times greater risk of cardiovascular disease-related mortality and scores greater than 400 were associated with a 3.48-times greater risk of cardiovascular disease-related mortality.

For all-cause mortality in women, scores of 101-400 and 400 or more were associated with 2.56-times (1.45-4.53) and 4.05-times (2.33-7.04) greater risk, respectively. For mortality in men, scores of 101-400 and 400 or more were associated with 1.88-times (1.15-3.09) and 2.66-times (0.29-24.30) greater risk, respectively (P for interaction=.01).

“Our findings suggest a call-to-action for even more aggressive risk factor management in a woman with diabetes found to have significant levels of coronary calcium to prevent future death from cardiovascular causes” added Wong.

This study, “Sex Differences in Coronary Artery Calcium and Mortality From Coronary Heart Disease, Cardiovascular Disease, and All Causes in Adults With Diabetes: The Coronary Calcium Consortium,” was published in Diabetes Care.