Department of Internal Medicine, University of Pavia, Pavia, Italy.
Department of Internal Medicine and Endocrinology, IRCCS Fondazione S.Maugeri, Pavia, Italy.
Int J Cardiol. 2017 Oct 1;244:254-259. doi: 10.1016/j.ijcard.2017.06.047. Epub 2017 Jun 15.
Cardiovascular (baroreflex) and respiratory (chemoreflex) control mechanisms were studied separately in diabetes, but their reciprocal interaction (well known for diseases like heart failure) had never been comprehensively assessed. We hypothesized that prevalent autonomic neuropathy would depress both reflexes, whereas prevalent autonomic imbalance through sympathetic activation would depress the baroreflex but enhance the chemoreflexes.
In 46 type-1 diabetic subjects (7.0±0.9year duration) and 103 age-matched controls we measured the baroreflex (average of 7 methods), and the chemoreflexes, (hypercapnic: ventilation/carbon dioxide slope during hyperoxic progressive hypercapnia; hypoxic: ventilation/oxygen saturation slope during normocapnic progressive hypoxia). Autonomic dysfunction was evaluated by cardiovascular reflex tests.
Resting oxygen saturation and baroreflex sensitivity were reduced in the diabetic group, whereas the hypercapnic chemoreflex was significantly increased in the entire diabetic group. Despite lower oxygen saturation the hypoxic chemoreflex showed a trend toward a depression in the diabetic group.
Cardio-respiratory control imbalance is a common finding in early type 1 diabetes. A reduced sensitivity to hypoxia seems a primary factor leading to reflex sympathetic activation (enhanced hypercapnic chemoreflex and baroreflex depression), hence suggesting a functional origin of cardio-respiratory control imbalance in initial diabetes.
心血管（压力反射）和呼吸（化学反射）控制机制在糖尿病中分别进行了研究，但它们的相互作用（在心力衰竭等疾病中众所周知）从未得到全面评估。我们假设普遍存在的自主神经病变会抑制这两种反射，而通过交感神经激活导致的普遍自主神经失衡会抑制压力反射，但增强化学反射。
在 46 名 1 型糖尿病患者（病程 7.0±0.9 年）和 103 名年龄匹配的对照者中，我们测量了压力反射（使用 7 种方法的平均值）和化学反射（高碳酸血症：在吸氧渐进性高碳酸血症期间的通气/二氧化碳斜率；低氧血症：在正常碳酸血症渐进性低氧血症期间的通气/氧饱和度斜率）。自主神经功能障碍通过心血管反射测试进行评估。
糖尿病组的静息氧饱和度和压力反射敏感性降低，而整个糖尿病组的高碳酸血症化学反射显著增加。尽管氧饱和度较低，但糖尿病组的低氧化学反射呈下降趋势。
心肺呼吸控制失衡是早期 1 型糖尿病的常见发现。对低氧的敏感性降低似乎是导致反射性交感神经激活（增强的高碳酸血症化学反射和压力反射抑制）的主要因素，因此提示初始糖尿病中心肺呼吸控制失衡的功能起源。
