Cardiac autonomic neuropathy: The hidden cardiovascular comorbidity in elderly patients with chronic obstructive pulmonary disease attending primary care settings.

AIM: To quantify the prevalence of chronic comorbidities including cardiac autonomic neuropathy among elderly patients with chronic obstructive pulmonary disease (COPD).

METHODS: A cross-sectional study was carried out on 175 elderly male patients with COPD attending Ain Shams University Hospital, Cairo, Egypt. The comorbidities that might alter cardiac autonomic function in patients with COPD were identified. The patients without reported comorbidities underwent arterial blood gas analysis, pulmonary function tests and autonomic function assessment using cardiovascular reflexes.

RESULTS: A total of 69.14% of the participants presented with comorbidities (group 1), whereas 30.85% of the participants reported no comorbidity (group 2). Among the participants, the most prevalent comorbid diseases were hypertension (34.20%), cor pulmonale (31.42%), ischemic heart disease (20.00%), diabetes (18.28%) and congestive heart failure (13.70%). In group 2, 29.60% and 22.20% of the patients had early and definite cardiac autonomic neuropathy (CAN) respectively. CAN occurred early in the course of the disease with 40.90% of mild COPD cases being affected. The patients with definite CAN had the highest resting heart rate. The presence of CAN was related to hypercapnia, but not hypoxemia or COPD severity.

CONCLUSION: COPD has a complex spectrum of comorbidities. Cardiac autonomic neuropathy in elderly male patients with COPD correlated with hypercapnia, but not hypoxemia or the disease severity.