Digital vasodilator function is related to multiple cardiovascular disease risk factors, particularly smoking, diabetes and obesity, which suggests the log PAT ratio may be a clinically useful measure of microvessel endothelial function, according to a Framingham Heart Study presented at the American Heart Association Scientific Sessions earlier this month in Orlando, Fla.
Naomi M. Hamburg, MD, and colleagues measured digital pulse amplitude in 1,957 Framingham third-generation cohort participants with a mean age of 40 years, 49 percent of which were women.
The measurement was taken using a fingertip peripheral arterial tonometry device, or Endo-PAT, manufactured by the Caesarea, Israel-based Itamar. The hyperemic response after 5-minute forearm cuff inflation was assessed as the log of the ratio of the post-deflation to baseline pulse amplitude in the hyperemic finger normalized to the contralateral finger, or log PAT ratio.
The researchers found that the relation of the log PAT ratio to cardiovascular risk factors was strongest in the 90 to 120 second interval following cuff deflation. Overall, men exhibited lower mean vasodilator response compared to women (log PAT ratio 0.58 vs. 0.81). In stepwise multivariable linear regression models, vascular risk factors inversely related to log PAT ratio were male sex, body mass index, total/HDL cholesterol, diabetes, smoking and lipid-lowering treatment.
Overweight and obese participants had lower mean log PAT ratio compared to normal weight participants.
The researchers concluded that there was an association between the Endo-PAT results and several risk factors.
The non-invasive Endo-PAT device, based on PAT technology, measures vaso-motion changes through a thimble-like probe placed over a person’s index finger, Itamar said.