Rationale: Obstructive Sleep Apnea Syndrome (OSAS) and Obesity Hypoventilation Syndrome (OHS) are the most common sleep breathing disorders. Although they share common causal factors and comorbidities, they may impact physical functioning differently. This study aimed in comparing physical activity and quality of life indices in obese individuals with either OSAS or OHS under non-invasive ventilation treatment.

Material-Methods: It is a retrospective nested case-control study. A total of 76 obese patients (OSAS: ?1=48, OHS: N2=26) of similar age (58.2±12.2 vs 63.6±9.8; p>0.05), BMI (37.2±6.2 vs 40.3±7.3; p>0.05) and baseline AHI were studied. All patients completed International Physical Activity Questionnaire (IPAQ), Short-Form Health Questionnaire (SF-36) and Hospital Anxiety and Depression Scale (HADS-A and HADS-D). SPSS version 23 was utilised for data analysis and groups comparison.

Results: Patient groups presented with similar SF-36 (OSAS: 63.5±21.1 vs OHS: 55.44±20.3; p>0.05), HADS-A (6.3±5.2 vs 6±4.7;p>0.05) and HADS-D (7.5±4.9 vs 7.4±4.3;p>0.05) scores, while prevalence of clinical cases of anxiety (HADS-A>8) and depression (HADS-D>8) was also similar. IPAQ scores were significantly higher in  OSA group (1715± 1802.3 vs 836.2± 917; P=0.023) and so was frequency of intense exercise.

Conclusion: Although quality of life indices are similar, daily physical activity seems to be more impaired among obese OHS patients, compared to obese OSAS patients with simila anthropometric characteristics. This indicates that OHS may affect physical condition more severely and, thus, physical activity needs to be seperately assessed in this patient population.