Chhabra Sunil K, Gupta Mansi, Ramaswamy Swapna, Dash Devi Jyoti, Bansal Vishal, Deepak K K
a Department of Cardiorespiratory Physiology , University of Delhi , Delhi , India.
b Department of Physiology , Vallabhbhai Patel Chest Institute, University of Delhi , Delhi , India.
COPD. 2015;12(5):552-9. doi: 10.3109/15412555.2014.974743. Epub 2014 Dec 11.
Cardiac autonomic dysfunction is an independent determinant of adverse outcomes in many diseases. The available literature on the relative changes in sympathetic and parasympathetic components in chronic obstructive pulmonary disease (COPD) is equivocal, the clinical and physiological correlates are poorly defined and association with markers of systemic inflammation has not been explored. As both autonomic dysfunction and systemic inflammation may contribute to cardiovascular morbidity in COPD, we hypothesized that these may be associated. Sixty three stable patients of COPD and 36 controls underwent spirometry, estimation of diffusion capacity, six-minute walk test and measurements of serum interleukin-6 (IL-6) and high-sensitivity C-Reactive protein. Cardiac autonomic activity was evaluated by standard five-minute heart rate variability (HRV) recordings to obtain time- and frequency-domain indices and the averaged heart rate. We observed that HRV indices of overall autonomic modulation, the standard deviation of time intervals between consecutive normal beats (SDNN) and total power, were greater in patients with higher levels of indices of both parasympathetic and sympathetic activity. The heart rate was significantly higher in patients indicating an overall sympathetic dominance and was inversely correlated with diffusion capacity. Serum IL-6 was inversely correlated with pNN50, an index of parasympathetic activity, and positively with LF/HF ratio, a measure of sympathetic: parasympathetic balance. None of the HRV indices was significantly correlated with physiological measures of severity. It was concluded that patients with COPD have increased cardiac autonomic modulation with sympathetic dominance. This is associated with decreased lung diffusion capacity and systemic inflammation.
心脏自主神经功能障碍是许多疾病不良预后的独立决定因素。关于慢性阻塞性肺疾病（COPD）中交感神经和副交感神经成分相对变化的现有文献并不明确，临床和生理相关性定义不清，且与全身炎症标志物的关联尚未得到探讨。由于自主神经功能障碍和全身炎症都可能导致COPD患者发生心血管疾病，我们推测它们可能存在关联。63例稳定期COPD患者和36例对照者接受了肺活量测定、弥散功能评估、6分钟步行试验以及血清白细胞介素-6（IL-6）和高敏C反应蛋白的测量。通过标准的5分钟心率变异性（HRV）记录来评估心脏自主神经活动，以获得时域和频域指标以及平均心率。我们观察到，在副交感神经和交感神经活动指标较高的患者中，总体自主神经调节的HRV指标、连续正常搏动之间时间间隔的标准差（SDNN）和总功率更大。提示总体交感神经占优势的患者心率显著更高，且与弥散功能呈负相关。血清IL-6与副交感神经活动指标pNN50呈负相关，与交感神经：副交感神经平衡指标LF/HF比值呈正相关。HRV指标与严重程度的生理指标均无显著相关性。研究得出结论，COPD患者心脏自主神经调节增强且交感神经占优势。这与肺弥散功能降低和全身炎症相关。
