Background: Aerobic capacity is impaired in end-stage renal disease (ESRD), reducing quality of life and longevity. Whilst determinants of maximal exercise intolerance are well defined, little is known of limitation during submaximal exercise. By comparing ESRD and healthy controls, the aim of this study was to characterise mechanisms of exercise intolerance in ESRD by assessing cardiopulmonary physiology at rest and during exercise. Methods: Resting spirometry and echocardiography were performed in 20 ESRD participants and 20 healthy age and gender matched controls. Exercise tolerance was assessed with ventilatory gas exchange and central hemodynamics during a maximal cardiopulmonary exercise test (CPEX) and 30 minutes of submaximal constant load exercise (CLEX). Results: Left ventricular mass (292 ± 102 vs. 185 ± 83 g; p = 0.01) and filling pressure (E/e': 6.48 ± 3.57 vs. 12.09 ± 6.50 m/s; p = 0.02) were higher in ESRD; forced vital capacity (3.44 ± 1 vs. 4.29 ± 0.95 L/min; p = 0.03) and peak VO₂ (13.3 ± 2.7 vs. 24.6 ± 7.3 ml.kg^-1.min^-1; p < 0.001) were lower. During CLEX, the relative increase in (a-v) O₂ difference (13 ± 18 vs. 74 ± 18%) and heart rate (32 ± 18 vs. 75 ± 29%) were less in ESRD despite exercise being performed at a higher percentage of maximum VE (48 ± 3 vs 39 ± 3%) and HR (82 ± 2 vs. 64 ± 2%). Conclusion: Ventilatory and chronotropic incompetence contribute to exercise intolerance in ESRD. Both are potential targets for medical and lifestyle interventions.

中文翻译：

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终末期肾病增量和恒定负荷运动期间的通气和变时功能不全：一项比较生理学研究。

背景：终末期肾病 (ESRD) 的有氧能力受损，降低生活质量和寿命。虽然极限运动不耐受的决定因素已经明确，但对次极限运动的限制知之甚少。通过比较 ESRD 和健康对照，本研究的目的是通过评估静息和运动期间的心肺生理来表征 ESRD 运动不耐受的机制。方法：对 20 名 ESRD 参与者和 20 名年龄和性别匹配的健康对照进行静息肺量测定和超声心动图检查。在最大心肺运动试验 (CPEX) 和 30 分钟次最大恒定负荷运动 (CLEX) 期间，通过通气气体交换和中央血流动力学评估运动耐力。结果：左心室质量（292 ± 102 vs. 185 ± 83 g；p = 0。01) 和填充压力 (E/e': 6.48 ± 3.57 vs. 12.09 ± 6.50 m/s; p = 0.02) 在 ESRD 中更高；用力肺活量 (3.44 ± 1 vs. 4.29 ± 0.95 L/min; p = 0.03) 和峰值 VO₂ (13.3 ± 2.7 vs. 24.6 ± 7.3 ml.kg ^-1 .min ^-1 ; p < 0.001) 较低。在 CLEX 期间，尽管以较高百分比进行运动，但 ESRD中 (av) O ₂差异（13 ± 18 对 74 ± 18%）和心率（32 ± 18 对 75 ± 29%）的相对增加较少最大 VE (48 ± 3 vs 39 ± 3%) 和 HR (82 ± 2 vs. 64 ± 2%)。结论：通气和变时功能不全导致 ESRD 的运动不耐受。两者都是医疗和生活方式干预的潜在目标。