The ACE I/D polymorphism is associated with resting ACE activity such that DD>ID>II. The D allele is strongly associated with increased exercise-induced left ventricular hypertrophy (LVH) and cardiovascular risk.
Objective: Examine the relation between ACE genotype, exercise, circulating ACE and angiotensin II.
Ethical approval was obtained and 17 (9DD, 8II) healthy, male (22.9+/-1.9 years, 178.6+/-2.8cm, 71.9+/-2.2kg) Caucasian subjects performed 20 min exercise (70% VO2 max) with venous samples at rest, immediately after and 40 min post exercise. ACE was assayed by a fluorometric method using Z-Phe-His-Leu as substrate. Angiotensin II samples were drawn into chilled tubes containing a renin inhibitor, with plasma shock frozen in liquid nitrogen before RIA. Paired t-tests examined the whole-group change in ACE and angiotensin II, with ANOVA for genotype differences. All figures: mean+/-sem, ACE activity (nmolHis/Leu/ml/min), angiotensin II (pg/ml plasma).
Baseline ACE activity was significantly different (p<0.001) between the II (24.9+/-1.8) and DD subjects (45.5+/-2). The whole-group increase in ACE with exercise (5.7+/-0.7) was significant (p<0.001), with the difference in ACE between II (29.9+/-2.1 and 27.2+/-2.1) and DD (51.83+/-3 and 48.6+/-2.3) subjects persisting (p<0.001 for both immediate and 40 min post-exercise ACE respectively). Baseline angiotensin II was no different between genotypes (2.8+/-1.2 and 2.6+/-1.5, DD and II respectively, p=0.9). Angiotensin II levels rose significantly (27.6+/-2.7, p<0.001), but were no different between genotypes immediately post-exercise (25.6+/-2.9 and 33.9+/-5.3 for DD and II respectively, p=0.2). However, there was a significant difference 40 min post-exercise (increased 19.2+/-4.6 and 6.2+/-1.6 for DD and II respectively, p=0.03).
This is the first report that DD subjects demonstrate a greater rise in Angiotensin II at 40 min post-exercise than II subjects. This may reflect increased levels of circulating ACE persisting after exercise. The hypertrophic and vasoconstricting action of angiotensin II may thus facilitate the increased LVH in DD subjects with exercise.
08 - 11 Apr 2002
British Endocrine Societies