Background
The American Diabe
tes Associa
tion (ADA) recen
tly proposed
the use of hemoglobin A1c as a prac
tical and valid s
tra
tegy
to iden
tify high-risk people for whom delivery of an in
tensive lifes
tyle in
terven
tion
to preven
t type 2 diabe
tes is likely
to be cos
t effec
tive.
Purpose
To estimate composite risks of developing diabetes and cardiovascular disease (CVD) for adults with different hemoglobin A1c test results and to compare those risks with those of adults who met the 2003 ADA definition for prediabetes.
Methods
Cross-sectional data from the 2005–2006 National Health and Nutrition Examination Survey were analyzed in 2009. The method of Stern and colleagues was used to estimate the 7.5-year probability of type 2 diabetes, and the Framingham General CVD Risk Engine was used to estimate the 10-year probability of CVD for adults with different A1c results. Sample weights were used to account for sampling probability and to adjust for noncoverage and nonresponse.
Results
Among adults meeting the 2003 ADA definition for prediabetes, the probabilities for incident type 2 diabetes (over 7.5 years) and CVD (over 10 years) were 33.5 % and 10.7 % , respectively. Use of A1c alone, in the range of 5.5 % to <6.5 % , would identify a population with comparable risks for diabetes (32.4 % [SE=1.2 % ]) and CVD (11.4 % [SE=0.6 % ]). A slightly higher cutoff (≥5.7 % ) would identify adults with risks of 41.3 % (SE=1.5 % ) for diabetes and 13.3 % (SE=0.8 % ) for CVD—risks that are comparable to people enrolled in the Diabetes Prevention Program.
Conclusions
A1c-based testing in clinical settings should be considered as a means to identify greater numbers of adults at high risk of developing type 2 diabetes and CVD.