Hemoglobin Value Not Predictive of CVD Risk
For individuals without known CVD or diabetes, HbA1c provides little benefit.
Addition of information on hemoglobin A1c (HbA1c) to conventional cardiovascular risk factors provides little benefit in terms of cardiovascular disease (CVD) risk prediction, according to a study published in the Journal of the American Medical Association.
Emanuele Di Angelantonio, M.D., from the University of Cambridge in the United Kingdom, and colleagues investigated whether adding HbA1c values to conventional cardiovascular risk factors correlates with improvement in prediction of CVD risk. Individual-participant data from 73 prospective studies involving 294,998 participants without known CVD or diabetes mellitus at baseline were included.
During a median follow-up of 9.9 years, the researchers identified 20,840 incident fatal and nonfatal CVD outcomes. An approximately J-shaped association was found between HbA1c values and CVD risk after adjustment for several conventional cardiovascular risk factors.
After adjustment for total cholesterol and triglyceride concentrations or estimated glomerular filtration rate, the correlation between HbA1c values and CVD risk changed slightly, while after adjustment for high-density lipoprotein cholesterol and C-reactive protein, the association was attenuated somewhat.
A CVD risk prediction model including conventional cardiovascular risk factors alone had a C-index of 0.7434. The addition of HbA1c information correlated with a C-index change of 0.0018 and a 0.42 net reclassification improvement for the categories of predicted 10-year CVD risk.
"In a study of individuals without known CVD or diabetes, additional assessment of HbA1c values in the context of CVD risk assessment provided little incremental benefit for prediction of CVD risk," the authors write.
Several authors and/or their institutions disclosed financial ties to the pharmaceutical industry.