Skeletal muscle deoxygenation during exercise in diabetics Medecine

1.糖尿病患者运动时红细胞氧转运受损我们证明了糖化血红蛋白，已知其对氧的亲和力增加，与运动能力呈负相关。与健康人相比，运动时糖尿病患者P50（氧分压，血液中氧饱和度为50%）的升高促进了氧合血红蛋白的解离，而运动时P50的升高降低，这可能是糖尿病患者运动不耐受的原因之一。2.运动性乳酸酸中毒促进氧合血红蛋白的解离在糖化血红蛋白升高的患者中不发生。在匹配的次最大功率下，糖尿病患者的乳酸增加大于健康受试者。与健康组相比，糖尿病患者P50相对于乳酸增加的增加斜率显著降低。糖尿病患者运动时乳酸增加促进氧合血红蛋白分解，而糖化血红蛋白升高则不会导致运动能力降低。3.近红外光谱技术检测糖尿病患者运动时骨骼肌氧合的变化采用近红外光谱技术检测糖尿病患者和健康人股外侧肌组织氧合的变化。患者的氧利用率和组织氧合明显低于正常人。运动时糖化血红蛋白水平升高可引起骨骼肌缺氧。

1.Impaired red cell oxygen transport during exercise in diabeticsWe demonstrated glycosylated hemoglobin, known to have an increased affinity for oxygen, was inversely related to exercise capacity. The increase in P50(oxygen tension at which blood is 50% saturated with oxygen), promoting oxyhemoglobin dissociation, was reduced in patients compared with that in healthy subjects during exercise, which should contribute to exercise intolerance in diabetics.2.Facilitating oxyhemoglobin dissociation by exercise lactic acidosis does not occur in elevated glycosylated hemoglobin.Lactate increase during exercise is known to facilitate oxyhemoglobin dissociation. At matched submaximal work rates, lactate increase was greater in diabetic patients than in healthy subjects. The slope of the increase in P50 relative to lactate increase for diabetics was significantly reduced compared that for healthy groups. Facilitating oxyhemoglobin dissociation by lactate increase during exercise does not occur in elevated glycosylated hemoglobin, which could reduce exercise capacity in diabetics.3.Skeletal muscle deoxygenation during exercise in diabetics demonstrated with near-infrared spectroscopyChanges in tissue oxygenation of vastus lateralis muscle were measured by near-infrared spectroscopy in diabetics and healthy subjects. Oxygen availability and tissue oxygenation were significantly less in the patients than in the normal subjects. The elevated level of glycosylated hemoglobin could cause skeletal muscle deoxygenation during exercise.