A population-based study of plasma cyclic guanosine monophosphate:: relations to age, atrial natriuretic factor and angiotensin-converting enzyme activity

In order to study the relations between plasma cyclic guanosine monophosphate (cGMP) and anthropometric variables, plasma atrial natriuretic factor (ANP) and serum angiotensin-converting enzyme activity (ACE), a population study with random selection of 217 subjects (49% men) 18-69 years old was performed. Venous blood was drawn at 08.00 h and ambulatory blood pressure (ABP) recording was then performed. There was no gender-difference in cGMP levels (men 2.2 +/- 1.1 nmol L-1 women 2.2 +/- 1.1 nmol L-1). A weak negative correlation was seen between cGMP and systolic ABP in both genders 20-44 years of age (r= -0.3, p=0.05 for both), but this correlation did not persist in multivariate analysis with correction for ANP, age and ACE. In women, cGMP correlated positively with ANP (r = 0.27, p = 0.005) independently of ANP, ACE, ABP and age. ACE correlated negatively with cGMP in men (all; r = -0.22, p = 0.03, 45 - 69 years of age r= -0.49, p = 0.0002) and this correlation was independent of ANP, ACE, ABP and age. ACE catalyses the breakdown of bradykinin, which stimulates the release of NO. As the second messenger of NO is cGMP, the negative correlation between ACE and cGMP in men might be a reflection of reduced production of NO. Our results also suggest that there are gender differences in the stimuli for basal cGMP production.