Department of Family Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Am J Med. 2010 May;123(5):432-8. doi: 10.1016/j.amjmed.2009.07.031.
Previous studies on the change of cardiac autonomic function and insulin resistance in metabolic syndrome recruited subjects with cardiovascular-related disease and defined metabolic abnormality with a more severe cutoff. We explored the alteration of cardiac autonomic function and insulin resistance in predisease community dwellers with different numbers of metabolic abnormalities.
A total of 1298 subjects were classified as none (n=539), one (n=378), 2 (n=218), and 3 or more metabolic abnormalities (n=154). Insulin resistance was calculated by homeostatic model assessment. Cardiac autonomic function included 5-minute standard deviation of R-R interval, low- and high-frequency power spectrum, and low-/high-frequency power spectrum ratio, the ratio of the longest R-R interval around the 30th beat and the shortest R-R interval around the 15th beat after standing, and the ratio of the longest expiratory R-R interval to the shortest inspiratory R-R interval during deep breathing.
Subjects with a single metabolic abnormality or more had a lower standard deviation of R-R interval and expiratory/inspiratory ratio than subjects without metabolic abnormality in multivariate analysis. Subjects with 3 or more metabolic abnormalities had a higher low-/high-frequency power spectrum ratio, but a lower high-frequency power. Insulin resistance was higher in groups with 2 metabolic abnormalities or more, but not in the group with one metabolic abnormality, than those without metabolic abnormality.
Cardiac autonomic function altered in predisease subjects with one or more metabolic abnormalities, while insulin resistance existed in subjects with 2 or more metabolic abnormalities. Thus, autonomic function change may precede insulin resistance in the initiation of metabolic syndrome.
既往研究代谢综合征中心血管相关疾病患者的心脏自主神经功能和胰岛素抵抗变化，代谢异常定义采用更严格的切点。本研究探讨不同数量代谢异常的疾病前期社区居民心脏自主神经功能和胰岛素抵抗的变化。
共纳入 1298 例研究对象，分为无（n=539）、一（n=378）、二（n=218）和三或更多个代谢异常（n=154）。胰岛素抵抗采用稳态模型评估法计算。心脏自主神经功能包括 5 分钟 R-R 间期标准差、低频和高频功率谱、低频/高频功率谱比、站立后第 30 个 R-R 间期最长和第 15 个 R-R 间期最短的比值，以及深吸气和深呼气时最长呼气 R-R 间期与最短吸气 R-R 间期的比值。
多元分析显示，有一个或多个代谢异常的受试者 R-R 间期标准差和呼/吸比值低于无代谢异常者。有 3 个或更多代谢异常者的低频/高频功率谱比值较高，高频功率较低。有 2 个代谢异常者和 3 个或更多代谢异常者的胰岛素抵抗高于无代谢异常者，但有一个代谢异常者的胰岛素抵抗与无代谢异常者相比差异无统计学意义。
疾病前期有一个或多个代谢异常者心脏自主神经功能发生改变，有 2 个或更多代谢异常者出现胰岛素抵抗。因此，代谢综合征的发生可能先于胰岛素抵抗，心脏自主神经功能改变可能先于胰岛素抵抗。
