IMT measurement improves Framingham CVD risk prediction in diabetes
MedWire News: Intima-media thickness (IMT) of the carotid artery adds value to the Framingham Risk Score as a predictor for cardiovascular disease (CVD) in Type 2 diabetes patients, compared with using the risk score alone, report Japanese researchers.
"Although the Framingham Risk Score is considered a useful tool for quantitative assessment of the risk for CVD in the general population, the score does not have sufficient power to predict future onset of CVD in Type 2 diabetes patients," explain Tomoya Mita (Juntendo University, Tokyo) and colleagues.
As reported in the journal Diabetes Care, the team recruited 783 Type 2 diabetes patients without a history of CVD who had undergone measurements of carotid IMT and brachial-ankle pulse wave velocity (baPWV) between 2003 and 2005.
The researchers followed-up the patients for incidence of CVD for a period of 5.4 years and compared CVD prediction with IMT and baPWV using receiver operating characteristic (ROC) analysis.
Mita's team recorded 85 incidences of CVD, including CV death, nonfatal myocardial infarction, unstable angina, transient ischemic attack, and ischemic stroke, by the end of the study.
The areas under the receiver operating characteristic curve (AUC) for IMT and baPWV were similar, at 0.590 and 0.583, respectively (where 1.00 denotes perfect discrimination), while FRS was modestly higher, at 0.645.
After adjustment for conventional arterial CVD risk factors, Cox proportional hazard modeling identified IMT as a significant determinant of CVD.
The relative risk for CVD for each 1-standard deviation increase in IMT was 2.39, whereas baPWV was not independently associated with CVD risk.
Furthermore, analysis of Kaplan-Meir curves showed a combination of FRS and IMT, but not baPWV, improved the prediction of CVD in the study population, compared with FRS alone.
"Although the exact reason for the difference in their predictive power is not clear at present, IMT seems to have more power in predicting CVD than baPWV," write Mita and team.
"However, further studies of larger sample size are needed," they conclude.
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By Sally Robertson