Coexistence of asthma and the obesity-hypoventilation syndrome

Introduction: With the increasing problem of obesity in the world, high prevalence of asthma in obese persons and high prevalence of sleep breathing disorders related to obesity, the number of patients with coexisting asthma and obesity hypoventilation syndrome is likely to increase. The aim: To evaluate long-term effects of obesity hypoventilation syndrome treatment in the patients with concomitant asthma.

Materials and methods: Obesity hypoventilation syndrome was diagnosed in six adult patients with asthma (body mass index 43.2±5.84 kg/m2, diurnal PaCO2 53.8±8.9 mmHg, apnea/hypopnea index 82±12.8/hour, mean SaO2 during sleep 77.7±6.6%). Four patients were treated with continuous positive airway pressure (CPAP) and two patients - with non-invasive ventilation (NIV). The patients were followed-up for 36±19 months.

Results: During the follow-up period daytime PaCO2 decreased to normal values, mean SaO2 during sleep increased to 93±3.1%, p<0.001. No asthma exacerbations were observed. In two patients significant reduction of anti-asthmatic treatment was observed, including withdrawal of chronic oral corticosteroid treatment.

Conclusions: Obese asthmatic patients with chronic respiratory insufficiency should be checked for concomitant obesity hypoventilation syndrome. Positive airway pressure treatment during sleep (CPAP or NIV) in asthmatic patients with obesity hypoventilation syndrome is well tolerated, leads to reversal of chronic respiratory insufficiency and in some patients may contribute to the improvement of asthma control.