INVERSE RELATIONSHIP OF URINARY CYCLIC CMP TO BLOOD-PRESSURE REACTIVITY IN THE CARDIA STUDY - VASODILATORY REGULATION OF SYMPATHETIC VASOCONSTRICTION

Objective: To determine whether urinary cyclic GMP (cGMP), which media tes the actions of the vasodilators nitric oxide and atrial natriureti c factor, is inversely related to blood pressure (BP) reactivity. In p revious work, we found that urinary cGMP was inversely related to dias tolic BP, but cGMP levels were higher among individuals presumed to ha ve increased adrenergic activity, increased reactivity, and increased risk of hypertension (blacks, individuals with a family history of hyp ertension). Method: We measured 24-hour urinary cGMP levels in a subst udy of 529 individuals in the Coronary Artery Risk Development in Youn g Adults (CARDIA) study; the sample was 23 to 35 years of age and appr oximately balanced for race (black/white) and gender. BP reactivity to stressors (video game, star-tracing, cold presser) was tested 3 years earlier. Baseline BP was included as a covariate in all analyses. Res ults: Diastolic BP reactivity to cold presser was inversely related to cGMP excretion (p < .05); the relationship was strongest among black women with a family history of hypertension (partial r = -.33, p < .01 ). Systolic BP reactivity to star-tracing was also inversely related t o cGMP (p < .01); the relationship for both star-tracing and video gam e stressors was strongest among black men (partial r values = -.25 and -.24, respectively; p values < .01). Conclusions: The results indicat e that vasodilatory activity may impact the BP response to stress thro ugh modulation of adrenergic activation, particularly among blacks.