National Heart and Lung Institute, Imperial College Academic Health Sciences Centre, London, UK.
J Am Heart Assoc. 2012 Oct;1(5):e000281. doi: 10.1161/JAHA.111.000281. Epub 2012 Oct 25.
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.
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]).
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.
南亚人的中风死亡率高于欧洲人，尽管他们的静息血压（BP）相等或更低。运动后恢复的 BP 升高可预测中风，独立于静息值。我们假设南亚人会有不良的运动后血液动力学，并寻求对此的解释。
一项基于人群的研究，纳入了 147 名欧洲和 145 名南亚中年男女，进行了邓迪 3 分钟台阶测试。测量了心血管危险因素。比较了 BP、心率和心率-血压乘积，这是衡量心肌耗氧量的指标。在 90%的功率和 5%的显著性水平下，我们可以检测到任何结果测量的 0.38 个标准差的差异。南亚人的静息收缩压（144mmHg）与欧洲人相似（142mmHg）（P=0.2），运动时的血压也相似（P=0.4）。然而，运动后 3 分钟时，南亚人的收缩压恢复较高，高出 4.3mmHg（95%置信区间[CI]，0.2 至 8.3mmHg；P=0.04）。当调整运动时的血压和工作量时，这种影响仍然存在（5.4mmHg[95%CI，2.2 至 8.7mmHg；P=0.001]）。在南亚人中，对压力反射不敏感和更大的主动脉僵硬的调整大大减弱了这种种族差异（1.9mmHg[95%CI，-0.9 至 4.6mmHg；P=0.4]）。同样，运动后心率-血压乘积的恢复在南亚人中受损了 735mmHg/min（95%CI，137 至 1334mmHg/min；P=0.02）；同样，对压力反射不敏感和主动脉僵硬的调整减弱了这种差异（261mmHg/min[95%CI，-39 至 561mmHg/min；P=0.3]）。
与欧洲人相比，南亚人运动后 BP 和心率-血压乘积的恢复受损，尽管他们的静息和运动时的血压相似。这与南亚人的自主神经功能障碍和主动脉僵硬有关。
