Kanaley Jill A, Baynard Tracy, Franklin Ruth M, Weinstock Ruth S, Goulopoulou Styliani, Carhart Robert, Ploutz-Snyder Robert, Figueroa Arturo, Fernhall Bo
Department of Exercise Science, Syracuse University, Syracuse, NY 13212, USA.
Metabolism. 2007 Jun;56(6):778-85. doi: 10.1016/j.metabol.2007.02.001.
This study examined the effect of glucose ingestion on cardiac autonomic function in nonobese women and obese women with and without type 2 diabetes mellitus. Heart rate variability was measured via continuous electrocardiogram, and beat-by-beat blood pressure was recorded using finger photoplethysmography (Portapres, TNO Biomedical Instrumentation, Amsterdam, The Netherlands) in a fasted state and in response to a 75-g glucose load in 42 middle-aged women (40-60 years). Upright tilt was also used as an orthostatic stress to provide a clinically relevant challenge to the cardiovascular system. Significant main effects for log-transformed (Ln) total power (TP, square milliseconds) were observed with upright tilt (P < .01) and glucose challenge (P < .05). LnTP decreased in all groups in both the fasted and fed state with upright tilt (P < .01), but glucose ingestion resulted in higher LnTP in the supine position only (P = .008). Tilt resulted in a significant main effect for low-frequency (LFnu, calculated in normalized units) and high-frequency (HFnu, calculated in normalized units) power (P < .000), whereas the glucose challenge had no effect on LFnu or HFnu power. LFnu approached significance for group differences (P = .07), such that the nonobese had lower LF power than either of the obese groups. Sympathovagal balance (LnLF/HF ratio) was affected by position (P < .000) and group (P < .05), with a lower LnLF/HF in the nonobese than in the obese women. Baroreceptor sensitivity decreased (P < .01) during upright tilt but was not changed by the glucose challenge. In conclusion, basal sympathovagal balance is higher in obese individuals with and without type 2 diabetes mellitus. Women with type 2 diabetes mellitus showed no differences in autonomic function with an orthostatic challenge or glucose load than nondiabetic, obese women. The glucose load did alter total spectral power in all of these middle-aged women but had no impact on baroreceptor sensitivity.
本研究考察了摄入葡萄糖对非肥胖女性以及患有和未患2型糖尿病的肥胖女性心脏自主神经功能的影响。通过连续心电图测量心率变异性，并使用手指光电容积描记法（Portapres，荷兰阿姆斯特丹TNO生物医学仪器公司）在空腹状态下以及对42名中年女性（40 - 60岁）给予75克葡萄糖负荷后记录逐搏血压。直立倾斜也被用作一种体位性应激，以对心血管系统提供具有临床相关性的挑战。观察到经对数转换（Ln）的总功率（TP，平方毫秒）在直立倾斜（P < 0.01）和葡萄糖激发试验（P < 0.05）时有显著的主效应。在直立倾斜状态下，所有组在空腹和进食状态时LnTP均降低（P < 0.01），但仅在仰卧位时摄入葡萄糖会导致LnTP升高（P = 0.008）。倾斜对低频（LFnu，以标准化单位计算）和高频（HFnu，以标准化单位计算）功率有显著的主效应（P < 0.000），而葡萄糖激发试验对LFnu或HFnu功率无影响。LFnu在组间差异接近显著水平（P = 0.07），即非肥胖者的低频功率低于任何一组肥胖者。交感迷走神经平衡（LnLF/HF比值）受体位（P < 0.000）和组别（P < 0.05）影响，非肥胖女性的LnLF/HF低于肥胖女性。压力感受器敏感性在直立倾斜过程中降低（P < 0.01），但未因葡萄糖激发试验而改变。总之，患有和未患2型糖尿病的肥胖个体的基础交感迷走神经平衡较高。2型糖尿病女性在体位性应激或葡萄糖负荷下的自主神经功能与非糖尿病肥胖女性相比无差异。葡萄糖负荷确实改变了所有这些中年女性的总频谱功率，但对压力感受器敏感性无影响。
