Open AccessSouth Asians Have Elevated Postexercise Blood Pressure and Myocardial Oxygen Consumption Compared to Europeans Despite Equivalent Resting Pressure
Author(s) -
Chaturvedi Nish,
Bathula Rajaram,
Shore Angela C.,
Panerai Ronney,
Potter John,
Kooner Jaspal,
Chambers John,
Hughes Alun D.
Publication year - 2012
Publication title -
journal of the american heart association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.494
H-Index - 85
ISSN - 2047-9980
DOI - 10.1161/jaha.111.000281
Subject(s) - medicine , cardiology , blood pressure , heart rate , confidence interval , population , hemodynamics , vo2 max , stroke volume , rate pressure product , environmental health
Background Stroke mortality rate is higher in South Asians than in Europeans, despite equivalent or lower resting blood pressure (BP). Elevated recovery BP after exercise predicts stroke, independently of resting values. We hypothesized that South Asians would have adverse postexercise hemodynamics and sought explanations for this. Methods and Results A population‐based sample of 147 European and 145 South Asian middle‐aged men and women performed the Dundee 3‐minute step test. Cardiovascular risk factors were measured. BP, heart rate, and rate–pressure product, a measure of myocardial oxygen consumption, were compared. With 90% power and 5% significance, we could detect a difference of 0.38 of a standard deviation in any outcome measure. Resting systolic BP was similar in South Asians (144 mm Hg) and Europeans (142 mm Hg) ( P =0.2), as was exercise BP ( P =0.4). However, recovery systolic BP at 3 minutes after exercise was higher in South Asians by 4.3 mm Hg (95% confidence interval [CI], 0.2 to 8.3 mm Hg; P =0.04). This effect persisted when adjusted for exercise BP and work effort (5.4 mm Hg [95% CI, 2.2 to 8.7 mm Hg; P =0.001]). Adjustment for baroreflex insensitivity and greater aortic stiffness in South Asians contributes greatly to attenuating this ethnic difference (1.9 mm Hg [95% CI, −0.9 to 4.6 mm Hg; P =0.4]). Similarly, rate–pressure product recovery after exercise was impaired in South Asians by 735 mm Hg/min (95% CI, 137 to 1334 mm Hg/min; P =0.02); again, adjustment for baroreflex insensitivity and aortic stiffness attenuated this difference (261 mm Hg/min [95% CI, −39 to 561 mm Hg/min; P =0.3]). Conclusion Postexercise recovery of BP and rate–pressure product is impaired in South Asians compared to Europeans even though resting and exercise BP are similar. This is associated with the autonomic dysfunction and aortic stiffness in South Asians. ( J Am Heart Assoc . 2012;1:e000281 doi : 10.1161/JAHA.111.000281 .)