The Evaluation of Diastolic Hypertention in Sleep Overlap Syndrome

Introduction: The overlap syndrome, consisting of obstructive sleep apnea hypopnea syndrome (OSAHS) and chronic obstructive pulmonary disease (COPD) is a major problem in COPD patients. OSHAS corresponds to the likelihood of systemic hypertension. The present study was aimed to evaluate the association between apnea-hypopnea index and diastolic blood pressure (DBP) in overlap patients. Materials and Methods: We conducted a cross-sectional study involving overnight polysomnography after measurement of resting diastolic blood pressure (DBP) in patients with overlap syndrome in Sleep Laboratory of Imam Reza Hospital, Mashhad, Iran from November 2010 to July 2012. Participants were divided into four subgroups regarding to their Apnea-Hypopnea Index (AHI) (AHI < 5, AHI: 5-15, AHI: 15-30 and AHI > 30). Descriptive statistics included age, body mass index (BMI), OSA, Apnea-Hypopnea Index (AHI), DBP, and neck circumference. Results: Sixty participants ranged between from 46 to 82 years old were entered into this study. There was statistically significant difference in mean DBP among different AHI subgroups (80±0.50, 95±0.60, and 105±0.65, respectively) (P < 0.001). Additionally, there was statistically significant correlation between AHI and DBP (r= 0.60, P=0.01). Conclusion: According to the findings of our study, DBP is an important cardiovascular concern in COPD patients with OSAHS and has a direct correlation with AHI.