Kavey R E, Kveselis D A, Gaum W E
Division of Pediatric Cardiology, State University of New York Health Science Center, Syracuse, NY 13210, USA.
Am Heart J. 1997 Feb;133(2):162-8. doi: 10.1016/s0002-8703(97)70204-7.
Arterial vascular responses are characteristically altered with hypercholesterolemia: conduit vessels manifest increased stiffness, and conduit and resistance vessels demonstrate impaired endothelium-dependent dilation and augmented vasoconstriction to neurohumoral stimulation. These changes should be reflected in an exaggerated blood pressure increase in response to exercise. To evaluate this hypothesis, we compared the blood pressure response to treadmill exercise in children with hypercholesterolemia and children with normal lipid levels. In a preliminary retrospective study, 15 hypercholesterolemic boys 10 to 18 years old underwent treadmill exercise testing, and their blood pressure results were compared with those of 32 normolipidemic children in the same age group who had undergone treadmill exercise electively in the same time period. In the second phase, 10 hypercholesterolemic boys and 10 normolipidemic age-matched boys were evaluated prospectively according to the same protocol. Treadmill exercise involved a modified Bruce protocol with heart rate and blood pressure measured before exercise, immediately after exercise, and throughout recovery. Office blood pressures were normal in all children, with no significant difference between groups. With treadmill exercise, all subjects achieved >95% of predicted maximum heart rate and endurance times, maximum oxygen consumption, and maximum respiratory ratio did not differ between groups. Results of the retrospective and prospective groups were similar and were therefore combined. Children with increased low-density lipoprotein (LDL) cholesterol had significantly higher systolic and diastolic blood pressures immediately before treadmill exercise (systolic 120 +/- 13 mm Hg vs 113 +/- 13 mm Hg, p < 0.03; diastolic 68 +/- 8 mm Hg vs 63 +/- 9 mm Hg, p < 0.01). After exercise, blood pressures were again significantly higher in the subjects with high LDL cholesterol (systolic 182 +/- 20 mm Hg vs 160 +/- 23 mm Hg, p < 0.0003; diastolic 77 +/- 12 mm Hg vs 72 +/- 9 mm Hg, p < 0.03). At the end of recovery, systolic blood pressures remained significantly higher in subjects with high LDL cholesterol (120 +/- 9 mm Hg vs 112 +/- 12 mm Hg, p < 0.005). In this study, children with severely increased LDL cholesterol had an exaggerated blood pressure response to exercise when compared with normolipidemic control subjects. The study findings suggest that control of arterial vascular tone may already be altered in children with hypercholesterolemia.
输送血管表现出硬度增加，输送血管和阻力血管显示出内皮依赖性舒张功能受损，对神经体液刺激的血管收缩增强。这些变化应反映在运动时血压过度升高上。为了评估这一假设，我们比较了高胆固醇血症儿童和血脂水平正常儿童对跑步机运动的血压反应。在一项初步回顾性研究中，15名10至18岁的高胆固醇血症男孩接受了跑步机运动测试，并将他们的血压结果与同期自愿接受跑步机运动的32名同年龄组血脂正常儿童的结果进行比较。在第二阶段，根据相同方案对10名高胆固醇血症男孩和10名年龄匹配的血脂正常男孩进行前瞻性评估。跑步机运动采用改良的布鲁斯方案，在运动前、运动后立即以及整个恢复过程中测量心率和血压。所有儿童的诊室血压均正常，两组之间无显著差异。进行跑步机运动时，所有受试者的心率均达到预测最大心率的>95%，耐力时间、最大耗氧量和最大呼吸比在两组之间无差异。回顾性和前瞻性组的结果相似，因此合并分析。低密度脂蛋白（LDL）胆固醇升高的儿童在跑步机运动前收缩压和舒张压显著更高（收缩压120±13 mmHg对113±13 mmHg，p<0.03；舒张压68±8 mmHg对63±9 mmHg，p<0.01）。运动后，LDL胆固醇高的受试者血压再次显著更高（收缩压182±20 mmHg对160±23 mmHg，p<0.0003；舒张压77±12 mmHg对72±9 mmHg，p<0.03）。恢复结束时，LDL胆固醇高的受试者收缩压仍显著更高（120±9 mmHg对112±12 mmHg，p<0.005）。在本研究中，与血脂正常的对照受试者相比，LDL胆固醇严重升高的儿童对运动的血压反应过度。研究结果表明，高胆固醇血症儿童动脉血管张力的控制可能已经改变。
