Gasic S, Winzer Ch, Bayerle-Eder M, Roden A, Pacini G, Kautzky-Willer A
Department of Internal Medicine III, Medical University of Vienna, Austria.
Eur J Clin Invest. 2007 Jan;37(1):42-7. doi: 10.1111/j.1365-2362.2007.01752.x.
Cardiac autonomic neuropathy is a common dysfunction in manifest diabetes mellitus and is associated with duration of diabetes and/or an inadequate glycaemic control. Heart rate variability (HRV) reflects autonomic heart function. The aim of the present study was to investigate whether in women with prior gestational diabetes (GD; pre-type 2 diabetes) alterations of cardiac autonomic function can be observed after delivery in relation to insulin sensitivity and glycaemic control.
Forty-eight healthy women with prior GD were consecutively admitted to the study. HRV was analysed by both time, as well as frequency, domain methods using 24-h Holter monitoring. In addition, 20 women with normal glucose tolerance during and after pregnancy were investigated as control subjects. All women underwent a frequently sampled intravenous glucose tolerance test (FSIGT) for measurement of insulin sensitivity.
Time domain analysis (standard deviation of normal RR intervals; SDNN) showed a reduced HRV in 25 out of the 48 (52%) women with prior GD. Frequency domain analysis revealed that in these 25 subjects both low and high frequency components of power spectral density (reflecting mainly sympathetic respectively parasympathetic activity) were reduced, indicating that sympathetic as well as parasympathetic functional impairment may be assumed. However, a relative predominance of the sympathetic over parasympathetic cardiac function was observed. The impairment of cardiac autonomic function (reduced SDNN) was correlated with HbA1c values and the 2-h blood glucose concentration (oral glucose tolerance test) but not with insulin sensitivity.
The present results demonstrate that in 52% of the women examined who had prior GD, an impairment of cardiac sympathetic as well as parasympathetic function was present, which related to glycaemic control, but not to insulin sensitivity. This infers that functional autonomic changes could be an early prognostic indicator in pre-type 2 diabetes.
心脏自主神经病变是显性糖尿病中常见的功能障碍，与糖尿病病程和/或血糖控制不佳有关。心率变异性（HRV）反映自主心脏功能。本研究的目的是调查既往有妊娠期糖尿病（GD；2型糖尿病前期）的女性在分娩后，心脏自主神经功能的改变是否与胰岛素敏感性和血糖控制有关。
48名既往有GD的健康女性连续纳入本研究。使用24小时动态心电图监测，通过时域和频域方法分析HRV。此外，对20名孕期及产后糖耐量正常的女性作为对照进行研究。所有女性均接受频繁采样静脉葡萄糖耐量试验（FSIGT）以测量胰岛素敏感性。
时域分析（正常RR间期标准差；SDNN）显示，48名既往有GD的女性中有25名（52%）HRV降低。频域分析显示，在这25名受试者中，功率谱密度的低频和高频成分（分别主要反映交感神经和副交感神经活动）均降低，表明可能存在交感神经和副交感神经功能损害。然而，观察到心脏交感神经功能相对于副交感神经功能占优势。心脏自主神经功能损害（SDNN降低）与糖化血红蛋白值和2小时血糖浓度（口服葡萄糖耐量试验）相关，但与胰岛素敏感性无关。
目前的结果表明，在52%接受检查的既往有GD的女性中，存在心脏交感神经和副交感神经功能损害，这与血糖控制有关，但与胰岛素敏感性无关。这意味着自主神经功能改变可能是2型糖尿病前期的早期预后指标。
