Physical Activity is Associated with Attenuated Carotid Blood Pressure Response to Mental Stress

Background: Blood pressure (BP) reactivity in response to mental stress increases with age and contributes to vascular damage manifesting as increased carotid intima-media thickness (IMT). This increases risk for cardiovascular (CV) events. Participation in regular physical activity (PA) may lead to a favorable CV response to stress.

Purpose: To examine inter-relations between PA, carotid IMT and carotid BP reactivity in response to mental stress.

Methods:Healthy young and middle aged adults (n=21, mean age 40±12, BMI≤30 kg/m2) completed a 4-minute color-word interference mental stress task. Carotid IMT was determined at rest, using ultrasonography. Applanation tonometry was performed on the carotid artery and used to determine carotid systolic (S)BP. Brachial SBP and diastolic (D)BP were measured using a standard oscillometric cuff. BP reactivity was determined as the difference between BP during mental stress minus resting BP. PA level was assessed over 3 days as total counts using accelerometry (ActiGraph GT3X).

Results: Carotid IMT and carotid SBP reactivity, but not brachial BP reactivity, were significantly associated with age (see Table 1). Higher carotid SBP reactivity, but not brachial BP reactivity, was associated with lower PA counts and higher carotid IMT. Carotid IMT was not significantly associated with PA counts. Signifi cance: **p < 0.01, *p < 0.05.

Conclusion: Carotid BP response to mental stress was associated with greater carotid IMT and older age; similar associations were not detected when examining brachial BP reactivity. Individuals with higher levels of PA have a blunted carotid SBP response to mental stress.

Supported by Dairy Research Institute Grant 1154 and NIH Grant R01ES023252