Ethnic differences in vascular responses to aerobic exercise.

Unlabelled: Indigenous populations currently experience greater rates of cardiovascular disease. Although ethnic differences in cardiovascular responses to exercise have previously been identified, these responses among indigenous populations are unknown.

Purpose: This investigation aimed to evaluate the vascular responses to aerobic exercise of Canadian indigenous and European adults.

Methods: Twelve age- and sex-matched indigenous and European adults completed a cycle ergometer maximal aerobic power test and submaximal 30 min of 60% maximal aerobic capacity on two separate days. Blood pressure, pulse wave velocity, baroreceptor sensitivity, arterial compliance, vascular resistance, and intima-media thickness were directly measured before and after aerobic exercises.

Results: Vascular responses to exercise were generally similar between indigenous and European adults including decreases in baroreceptor sensitivity and vascular resistance after maximal exercise. No changes in intima-media thickness, pulse wave velocity, and arterial compliance were observed after exercise in either group. However, after submaximal exercise, only European adults demonstrated reductions in baroreceptor sensitivity (spectral: 9.2 ± 4.3 to 11.5 ± 6.7 ms·mm Hg, P = 0.41, vs 15.8 ± 8.3 m·s to 8.9 ± 5.7 ms·mm Hg, P = 0.02; sequence: 14.6 ± 5.4 to 16.5 ± 11.0 ms·mm Hg, P = 0.48, vs 26.2 ± 10.5 m·s to 15.4 ± 9.4 ms·mm Hg, P = 0.02). Similarly, decreases in blood pressure after exercise were observed only among European adults.

Conclusions: Indigenous adults demonstrated vascular responses similar to those demonstrated by European adults, although blood pressure was only observed to decrease among European adults after maximal and submaximal exercise, and baroreceptor sensitivity, after submaximal exercise.