Scalzo Rebecca L, Bauer Timothy A, Harrall Kylie, Moreau Kerrie, Ozemek Cemal, Herlache Leah, McMillin Shawna, Huebschmann Amy G, Dorosz Jennifer, Reusch Jane E B, Regensteiner Judith G
1Division of Endocrinology, Department of Medicine, University of Colorado School of Medicine (UCSOM), 12801 E17th Ave, Aurora, CO 80045 USA.
5Department of Medicine, Center for Women's Health Research, University of Colorado School of Medicine (UCSOM), Aurora, CO USA.
Diabetol Metab Syndr. 2018 Feb 14;10:7. doi: 10.1186/s13098-018-0306-9. eCollection 2018.
People with type 2 diabetes (T2D) have impaired exercise capacity, even in the absence of complications, which is predictive of their increased cardiovascular mortality. Cardiovascular dysfunction is one potential cause of this exercise defect. Acute infusion of vitamin C has been separately shown to improve diastolic and endothelial function in prior studies. We hypothesized that acute vitamin C infusion would improve exercise capacity and that these improvements would be associated with improved cardiovascular function.
Adults with T2D (n = 31, 7 female, 24 male, body mass index (BMI): 31.5 ± 0.8 kg/m) and BMI-similar healthy adults (n = 21, 11 female, 10 male, BMI: 30.4 ± 0.7 kg/m) completed two randomly ordered visits: IV infusion of vitamin C (7.5 g) and a volume-matched saline infusion. During each visit peak oxygen uptake (VOpeak), brachial artery flow mediated dilation (FMD), reactive hyperemia (RH; plethysmography), and cardiac echocardiography were measured. General linear mixed models were utilized to assess the differences in all study variables.
Acute vitamin C infusion improved diastolic function, assessed by lateral and septal E:E' ( < 0.01), but did not change RH ( = 0.92), or VOpeak ( = 0.33) in any participants.
Acute vitamin C infusion improved diastolic function but did not change FMD, forearm reactive hyperemia, or peak exercise capacity. Future studies should further clarify the role of endothelial function as well as other possible physiological causes of exercise impairment in order to provide potential therapeutic targets. NCT00786019. Prospectively registered May 2008.
2型糖尿病（T2D）患者即使在无并发症的情况下，运动能力也会受损，这预示着其心血管死亡率会增加。心血管功能障碍是这种运动缺陷的一个潜在原因。先前的研究分别表明，急性输注维生素C可改善舒张功能和内皮功能。我们假设急性输注维生素C会改善运动能力，且这些改善与心血管功能的改善相关。
患有T2D的成年人（n = 31，女性7名，男性24名，体重指数（BMI）：31.5±0.8kg/m²）和BMI相似的健康成年人（n = 21，女性11名，男性10名，BMI：30.4±0.7kg/m²）完成了两次随机排序的访视：静脉输注维生素C（7.5g）和等容量的生理盐水输注。在每次访视期间，测量峰值摄氧量（VO₂peak）、肱动脉血流介导的舒张（FMD）、反应性充血（RH；体积描记法）和心脏超声心动图。采用一般线性混合模型评估所有研究变量的差异。
急性输注维生素C改善了舒张功能，通过侧壁和间隔E:E'评估（P<0.01），但在任何参与者中均未改变RH（P = 0.92）或VO₂peak（P = 0.33）。
急性输注维生素C改善了舒张功能，但未改变FMD、前臂反应性充血或峰值运动能力。未来的研究应进一步阐明内皮功能以及运动受损的其他可能生理原因的作用，以便提供潜在的治疗靶点。NCT00786019。2008年5月前瞻性注册。
