WEDNESDAY, July 27 (HealthDay News) -- Models that incorporate hemoglobin A1c (HbA1c) levels for patients with diabetes have improved predictive ability of cardiovascular disease (CVD) risk compared to classification of diabetes as a cardiovascular risk equivalent, according to a study published online July 25 in the Archives of Internal Medicine.
Nina P. Paynter, Ph.D., from the Brigham and Women's Hospital in Boston, and colleagues investigated the impact of including HbA1c levels in predicting the CVD risk for patients with diabetes, and compared the predictive ability with the currently recommended classification of diabetes as a cardiovascular risk equivalent. A total of 24,674 women (685 with diabetes) and 11,280 men (563 with diabetes) were followed-up for development of CVD. There were 125 CVD events in the group of women with diabetes, and 170 events in the group of men with diabetes. CVD risks were modelled separately for men and women using the standard CVD risk factors, with HbA1c levels included for the patients with diabetes.
The investigators found that, for women with diabetes, including HbA1c levels significantly improved the C statistic by 0.177 over the risk equivalence model and showed a significantly improved reclassification (net reclassification improvement [NRI] of 26.7 percent). For the men's group, the improvements were lower but still statistically significant with a C statistic change of 0.039 (NRI of 9.2 percent). Improved prediction over a dichotomous term for diabetes in women (NRI of 11.8 percent) was seen with inclusion of HbA1c levels, but this was not seen in men.
"We observed significant improvements in predictive ability of CVD risk using models incorporating HbA1c levels compared with classification of diabetes as a cardiovascular risk equivalent," the authors write.
One study author is listed as a coinventor on patents held by the Brigham and Women's Hospital, relating to use of inflammatory biomarkers in CVD, which are licensed to Siemens and AstraZeneca. Several authors disclosed financial relationships with the pharmaceutical and medical device industries, including F. Hoffmann-La Roche Ltd., which partially funded this study.