Department of Exercise and Medical Physiology Verve, Oulu, Finland.
Front Physiol. 2011 Sep 5;2:57. doi: 10.3389/fphys.2011.00057. eCollection 2011.
The incidence of cardiovascular events is higher in coronary artery disease patients with type 2 diabetes (CAD + T2D) than in CAD patients without T2D. There is increasing evidence that the recovery phase after exercise is a vulnerable phase for various cardiovascular events. We hypothesized that autonomic regulation differs in CAD patients with and without T2D during post-exercise condition.
A symptom-limited maximal exercise test on a bicycle ergometer was performed for 68 CAD + T2D patients (age 61 ± 5 years, 78% males, ejection fraction (EF) 67 ± 8, 100% on β-blockade), and 64 CAD patients (age 62 ± 5 years, 80% males, EF 64 ± 8, 100% on β-blockade). Heart rate (HR) recovery after exercise was calculated as the slope of HR during the first 60 s after cessation of exercise (HRR(slope)). R-R intervals were measured before (5 min) and after exercise from 3 to 8 min, both in a supine position. R-R intervals were analyzed using time and frequency methods and a detrended fluctuation method (α(1)).
BMI was 30 ± 4 vs. 27 ± 3 kg m(2) (p < 0.001); maximal exercise capacity, 6.5 ± 1.7 vs. 7.7 ± 1.9 METs (p < 0.001); maximal HR, 128 ± 19 vs. 132 ± 18 bpm (p = ns); and HRR(slope), -0.53 ± 0.17 vs. -0.62 ± 0.15 beats/s (p = 0.004), for CAD patients with and without T2D, respectively. There was no differences between the groups in HRR(slope) after adjustment for METs, BMI, and medication (ANCOVA, p = 0.228 for T2D and, e.g., p = 0.030 for METs). CAD + T2D patients had a higher HR at rest than non-diabetic patients (57 ± 10 vs. 54 ± 6 bpm, p = 0.030), but no other differences were observed in HR dynamics at rest or in post-exercise condition.
HR recovery is delayed in CAD + T2D patients, suggesting impairment of vagal activity and/or augmented sympathetic activity after exercise. Blunted HR recovery after exercise in diabetic patients compared with non-diabetic patients is more closely related to low exercise capacity and obesity than to T2D itself.
与无 2 型糖尿病的冠心病患者相比，2 型糖尿病合并冠心病患者发生心血管事件的几率更高。越来越多的证据表明，运动后的恢复期是各种心血管事件的脆弱期。我们假设，在运动后状态下，有和没有 2 型糖尿病的冠心病患者的自主神经调节存在差异。
对 68 名 2 型糖尿病合并冠心病患者（年龄 61±5 岁，78%为男性，射血分数（EF）67±8，100%服用β受体阻滞剂）和 64 名单纯冠心病患者（年龄 62±5 岁，80%为男性，EF 64±8，100%服用β受体阻滞剂）进行了自行车测力计上的症状限制最大运动测试。运动后心率恢复情况通过计算运动停止后前 60 秒内心率的斜率（HRR(slope)）来表示。在仰卧位时，在运动前（5 分钟）和运动后 3 至 8 分钟测量 R-R 间期。使用时间和频率方法以及去趋势波动方法（α(1)）对 R-R 间期进行分析。
体重指数（BMI）分别为 30±4 和 27±3 kg/m²（p<0.001）；最大运动能力分别为 6.5±1.7 和 7.7±1.9 METs（p<0.001）；最大心率分别为 128±19 和 132±18 bpm（p=ns）；HRR(slope)分别为 -0.53±0.17 和 -0.62±0.15 个节拍/s（p=0.004），用于患有和不患有 2 型糖尿病的冠心病患者。在调整 METs、BMI 和药物治疗后，两组之间的 HRR(slope)没有差异（ANCOVA，T2D 组的 p=0.228，例如 METs 的 p=0.030）。与非糖尿病患者相比，2 型糖尿病合并冠心病患者的静息心率更高（57±10 比 54±6 bpm，p=0.030），但在静息或运动后状态下的 HR 动力学方面没有观察到其他差异。
2 型糖尿病合并冠心病患者的 HR 恢复延迟，提示运动后迷走神经活动受损和/或交感神经活动增强。与非糖尿病患者相比，糖尿病患者运动后 HR 恢复减弱与低运动能力和肥胖的关系更为密切，而与 2 型糖尿病本身的关系不大。
