Department of Sport Science, Medical Section, University of Innsbruck, Innsbruck, Austria.
Diabetes Care. 2013 Aug;36(8):2183-9. doi: 10.2337/dc12-2113. Epub 2013 Mar 27.
Hypoxia may cause functional autonomic imbalance in diabetes. Intermittent hypoxia (IH), a technique improving the adaptation to hypoxia, might improve cardiorespiratory reflexes and, ultimately, blood glucose concentrations in patients with type 2 diabetes. We tested whether a single bout of IH could initiate a long-lasting response potentially leading to better adaptation to hypoxia.
In 14 patients with type 2 diabetes without autonomic complications, we measured blood pressure, heart rate, oxygen saturation, chemoreflex (hypoxic and hypercapnic ventilatory responses, ventilatory recruitment threshold), and baroreflex sensitivity before, immediately after, and 3 and 6 h after a 1-h single bout of IH (6-min breathing of 13% oxygen mixture 5 times each separated by 6-min recovery). The measurements were repeated on a placebo day (at least 1 week apart, in random sequence) when subjects were only breathing room air (single-blind protocol).
IH significantly increased hypercapnic ventilatory responses and reduced ventilatory recruitment threshold, and increased oxygen saturation and blood pressures, whereas increases in heart rate variability and baroreflex sensitivity were not significant. Blood glucose significantly decreased after IH. No such changes were observed during the placebo day, except an increase in oxygen saturation. Some of the effects lasted 3 h after IH, and some even persisted until 6 h after IH.
A single bout of IH induced an initial adaptation to hypoxia, with improvement in cardiorespiratory reflexes and reduction in blood glucose. Patients with type 2 diabetes could potentially benefit from the application of a full (>2 weeks) IH intervention.
缺氧可能导致糖尿病患者的自主神经功能失衡。间歇性低氧（IH）是一种改善对缺氧适应的技术，可能改善 2 型糖尿病患者的心肺反射，最终改善血糖浓度。我们测试了单次 IH 是否可以引发潜在的持久反应，从而更好地适应缺氧。
在 14 名没有自主神经并发症的 2 型糖尿病患者中，我们在单次 IH（6 分钟呼吸 13%氧气混合物 5 次，每次间隔 6 分钟恢复）前、后即刻以及 3 小时和 6 小时测量血压、心率、氧饱和度、化学反射（缺氧和高碳酸血症通气反应、通气募集阈值）和压力反射敏感性。在至少相隔 1 周、随机顺序的安慰剂日（单盲方案），当患者只呼吸室内空气时，重复进行这些测量。
IH 显著增加了高碳酸血症通气反应，降低了通气募集阈值，增加了氧饱和度和血压，而心率变异性和压力反射敏感性的增加不显著。IH 后血糖显著降低。在安慰剂日期间没有观察到这种变化，除了氧饱和度增加。一些影响在 IH 后持续 3 小时，甚至持续到 IH 后 6 小时。
单次 IH 诱导了初始的缺氧适应，改善了心肺反射并降低了血糖。2 型糖尿病患者可能受益于应用完整的（>2 周）IH 干预。
