[Evaluation of relationship between apnea-hypopnea index and body mass index in chronic obstructive pulmonary disease]

Chronic Obstructive pulmonary disease [COPD] is an important disease with high mortality rate worldwide. Nocturnal ventilatory changes and gas exchange disorder are common in COPD patients. These disorders do not correlate with bronchial spasm and airway resistance. Apnea - hypopnea Index [AH] represent the total Apnea and hypopnea in one hour. There are several risk factors for sleep Apnea. Obesity is the common causes. The aim of this study is the relationship between apnea-hypopnea index and body mass index in COPD patients. We assessed 40 COPD patients with sleep disorder in sleep laboratory. Exclusion criteria were pneumonia, Ischemic heart disease, lung cancer, congestive heart failure, Diabetes mellitus, systemic hypertension, hypothyroidism, central respiratory disorders, sedative drugs and opium usage. Body mass index [BMI] and neck circumference were assessed. Next, in this cross-sectional study, patients were evaluated with total nocturnal polysomnography. AHI was recorded. The data were gathered and analyzed with standard statistical method. Median BMI, AHI were 30.77 +/- 5.85110 and 15.05 +/- 16.50571 respectively. No significant correlation was found between BMI and AHI. There were no correlation between increasing weight and apnea - hypopnea in COPD patients. Thus, in Iranian population, sleep apnea may be occur in higher level of BMI