Abstract 3721: Digital microvascular function is related to cardiovascular risk factors in the community: The Framingham Heart Study
Background: Abnormal endothelial function contributes to the pathogenesis of cardiovascular disease. Digital pulse amplitude augmentation following hyperemia is a novel measure of microvessel vasodilator function. We evaluated the relation of the digital pulse amplitude augmentation during hyperemia to cardiovascular risk factors in the Framingham Heart Study.
Methods: We measured digital pulse amplitude in Framingham Third Generation Cohort participants (n=1957, mean age 40±9 years, 49% women) using a fingertip peripheral arterial tonometry device (Endo-PAT; Itamar, Caesarea, Israel). 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 (log PAT ratio).
Results: The relation of the log PAT ratio to cardiovascular risk factors was strongest in the 90–120 second interval following cuff deflation (overall model R2=0.16). Men exhibited lower mean vasodilator response compared to women (log PAT ratio 0.58±0.34 vs. 0.81±0.36). 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 (all p-values <0.01). Overweight and obese participants had lower mean log PAT ratio compared to normal weight participants(0.66±0.01 and 0.61±0.01 vs. 0.77±0.01).
Conclusions: In a community-based sample, digital vasodilator function was related to multiple cardiovascular disease risk factors, particularly smoking, diabetes and obesity. Our findings suggest that the log PAT ratio may be a clinically useful measure of microvessel endothelial function.