Objective:

To analyze the impact of I/D polymorphism of the angiotensin-converting enzyme gene on the responses of 24 h blood pressure, heart rate variability and nitric oxide after moderate aerobic exercise session.

Method:

Twenty seven hypertensive elderly were genotyped for the I/D polymorphism of the angiotensin-converting enzyme gene (D/D: n = 9; I/D: n = 9; I/I: n = 9) and performed a bout of aerobic exercise at 90% of anaerobic threshold. Measurements of mean blood pressure, heart rate variability and nitric oxide were performed before and during 24 h post-aerobic exercise session.

Results:

The D/D genotype showed impaired mean arterial pressure responses (elevation) in the nocturnal sleep (10:30 pm to 06:30 am) post-aerobic exercise when compared to rest (D/D = −4.2 ± 8.1 mmHg; p > 0.05, I/D = −9.2 ± 9.1 mmHg; p < 0.05 and I/I = −7.0 ± 6.9 mmHg; p < 0.05). Besides, in day time of 06:30 am to 10:30 am (next day) higher values of mean arterial pressure responses occur between D/D = 4.7 ± 4.6 mmHg vs. I/D = −2.0 ± 13.0 mmHg; p < 0.05. The carriers of the D allele, in addition to not release nitric oxide significantly post-aerobic exercise session (p > 0.05), showed reduced elevation of nitric oxide between genotypes immediately after aerobic exercise (D/D = 12.8 ± 135.3 μM and I/D = −8.7 ± 69.0 μM vs. I/I = 132.9 ± 188.7 μM; p < 0.05). Reduced elevation of heart rate variability post-aerobic exercise session occurred when compared to rest (D/D = 1 h: −0.08 ± 0.09 s; p < 0.05 and 24 h: −0.08 ± 0.11 s; p < 0.05).

Conclusion:

Elderly hypertensive individuals carrying the D/D genotype of the angiotensin converting enzyme gene showed impaired responses of blood pressure post-aerobic exercise, especially during sleep, and reduced heart rate variability during the 24 h post-aerobic exercise. Besides, to angiotensin converting enzyme genotypes with the presence of D allele (D/D and I/D) was impaired release of nitric oxide post-aerobic exercise session.