Quality of Life in Patients with Obstructive Sleep Apnea: Effect of Nasal Continuous Positive Airway Pressure—A Prospective Study

The development of pulmonary hypertension is a poor prognostic sign in patients with obstructive sleep apnea (OSA) and affects both mortality and quality of life. Although pulmonary hypertension in OSA is traditionally viewed as a result of apneas and intermittent hypoxia during sleep, recent studies indicate that neither of these factors correlates very well with pulmonary artery pressure. Human data show that pulmonary hypertension in the setting of OSA is, in large part, due to left heart dysfunction with either preserved or diminished ejection fraction. Longstanding increased left heart filling pressures eventually lead to pulmonary venous hypertension. The combination of hypoxic pulmonary vasoconstriction and pulmonary venous hypertension with abnormal production of mediators will result in vascular cell proliferation and aberrant vascular remodeling leading to pulmonary hypertension. These changes are in many ways similar to those seen in other forms of pulmonary hypertension and suggest shared mechanisms. The majority of patients with OSA do not receive a diagnosis and are undertreated. Appreciating the high prevalence and understanding the mechanisms of pulmonary hypertension in OSA would lead to better recognition and management of the condition.

Air pollution is one of the leading global public health risks but its magnitude in many developing countries’ cities is not known. We aimed to measure the concentration of particulate matter with aerodynamic diameter <2.5 µm (PM_2.5), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃) pollutants in two Ugandan cities (Kampala and Jinja). PM_2.5, O₃, temperature and humidity were measured with real-time monitors, while NO₂ and SO₂ were measured with diffusion tubes. We found that the mean concentrations of the air pollutants PM_2.5, NO_2, SO₂ and O₃ were 132.1 μg/m³, 24.9 µg/m³, 3.7 µg/m³ and 11.4 μg/m³, respectively. The mean PM_2.5 concentration is 5.3 times the World Health Organization (WHO) cut-off limits while the NO_2, SO₂ and O₃ concentrations are below WHO cut-off limits. PM_2.5 levels were higher in Kampala than in Jinja (138.6 μg/m³ vs. 99.3 μg/m³) and at industrial than residential sites (152.6 μg/m³ vs. 120.5 μg/m³) but residential sites with unpaved roads also had high PM_2.5 concentrations (152.6 μg/m³). In conclusion, air pollutant concentrations in Kampala and Jinja in Uganda are dangerously high. Long-term studies are needed to characterize air pollution levels during all seasons, to assess related public health impacts, and explore mitigation approaches.