Effect of ventilation therapy on mortality rate among obesity hypoventilation syndrome and obstructive sleep apnoea patients.

INTRODUCTION

The prevalence of obesity is continually increasing worldwide, which increases the incidence of obesity hypoventilation syndrome (OHS) and its consequent mortality.

METHODS

We reviewed the therapy mode, comorbidity and mortality of all OHS patients treated at our hospital between 2005 and 2016. The control group consisted of randomly selected patients with obstructive sleep apnoea (OSA) treated during the same period.

RESULTS

We studied 206 OHS patients and 236 OSA patients. The OHS patients were older (56.3 52.3 years, p<0.001) and heavier (body mass index 46.1 32.2 kg·m, p<0.001), and the percentage of women was higher (41.2% 24.2%, p<0.001), respectively. The OHS patients had more hypertension (83% 61%, p<0.001) and diabetes (62% 31%, p<0.001) than the OSA patients, but no higher stroke (4% 8%, p=0.058) or ischaemic heart disease (14% 15%, p=0.437) incidence. The 5- and 10-year, unadjusted survival rates were lower among the OHS patients than among the OSA patients (83% 96% and 74% 91%, respectively; p<0.001). Differences in mortality rates were not related to age, sex or body mass index; covariates such as Charlson Comorbidity Index and ventilation therapy predicted survival. The mortality rate decreased significantly (p<0.001) both in OHS and OSA patients even after adjusting for covariates.

CONCLUSIONS

The mortality rate in OHS was significantly higher than that in OSA patients even after adjusting for covariates. Ventilation therapy by continuous positive airway pressure or noninvasive ventilation have reduced mortality significantly in all patients.