1. Obesity hypoventilation syndrome in Japan and independent determinants of arterial carbon dioxide levels.
- Author
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Harada Y, Chihara Y, Azuma M, Murase K, Toyama Y, Yoshimura C, Oga T, Nakamura H, Mishima M, and Chin K
- Subjects
- Adult, Aged, Blood Gas Analysis, Blood Gas Monitoring, Transcutaneous methods, Body Mass Index, Continuous Positive Airway Pressure methods, Female, Humans, Hypercapnia physiopathology, Japan epidemiology, Male, Middle Aged, Polysomnography methods, Prevalence, Carbon Dioxide blood, Obesity complications, Obesity diagnosis, Obesity epidemiology, Obesity Hypoventilation Syndrome blood, Obesity Hypoventilation Syndrome diagnosis, Obesity Hypoventilation Syndrome epidemiology, Obesity Hypoventilation Syndrome physiopathology
- Abstract
Background and Objective: Obesity hypoventilation syndrome (OHS) prevalence was previously estimated at 9% in patients with obstructive sleep apnoea (OSA) in Japan. However, the definition of OSA in that study was based on an apnoea-hypopnoea index (AHI) of ≥ 20/h rather than ≥ 5/h. Therefore, the prevalence of OHS in OSA was not measured in the same way as for Western countries. Our study objectives were to investigate the characteristics of Japanese patients with OHS., Methods: Nine hundred eighty-one consecutive patients investigated for suspected OSA were enrolled. At least 90% of them were from urban areas, including 162 with obese OSA (body mass index (BMI) ≥ 30 kg/m(2) and AHI ≥ 5/h)., Results: The prevalence of OHS (BMI 36.7 ± 4.9 kg/m(2) ) in OSA and that in obese OSA were 2.3% and 12.3%, respectively. Multiple regression analysis revealed that independent of age and BMI, arterial oxygen pressure (contribution rate (R(2) ) = 7.7%), 4% oxygen desaturation index (R(2) = 8.9%), carbon monoxide diffusing capacity/alveolar volume (R(2) = 8.3%), haemoglobin concentration (R(2) = 4.9%) and waist circumference (R(2) = 4.9%) were independently associated with arterial carbon dioxide pressure. After 12.3 ± 4.6 months of CPAP treatment, more than 60% of OHS patients no longer had hypercapnia., Conclusions: The prevalence of OHS in OSA in Japan was 2.3%. The mean BMI of patients with OHS in Japan was lower than that in Western countries (36.7 kg/m(2) vs 44.0 kg/m(2) )., (© 2014 Asian Pacific Society of Respirology.)
- Published
- 2014
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