Overlap syndrome involving obstructive sleep apnea syndrome associated with chronic obstructive pulmonary disease

: We reported a case of overlap syndrome involving severe obstructive sleep apnea syndrome (OSAS) associated with chronic obstructive lung disease (COPD). This patient was a 52-year-old heavy smoking man, who had suffered from snoring and apnea for five years, and was admitted to our hospital because of worsening dyspnea. His BMI was 25 Kg/M2, His jaw was very small and he had a narrow upper airway. Chest X-ray showed hyperlucency throughout both lung fields with a markedly dilatation pulmonary arteries. His PaO2 was 62Torr, PaCO2 was 47Torr, FEV(1.0%) was 59%, mean pulmonary artery pressure was 27 mmHg, PSG showed that AHI was 70, were most pronounced during rapid eye movement sleep. He was given a diagnosis of overlap syndrome of OSAS associated with COPD. Generally, Overlap syndrome was believed that chronic bronchitis type (blue bloater) was more frequent than emphysema type. This case was a very rare case, with no obesity, moderate COPD, associated with pulmonary hypertension and hypercapnea, and then to be severe OSAS. However we should be more careful about the OSAS associated with overlap syndrome of the Japanese patients, because to be one factor of exacerbation of respiratory failure.