若年者自然気胸にみられる気腫肺と喫煙の関連性に関する検討

Association Between Juvenile Spontaneous Pneumothorax and Smoking

近年，喫煙の肺への影響は広く周知され，本邦での喫煙率は減少傾向にある1）．しかしながら，世代別にみると男女問わず40歳未満の喫煙率の低下が鈍化し，肺傷害の若年化が喫緊の課題といえる．喫煙が誘因となる代表的疾患に肺の気腫化に併発する自然気胸がある．70歳以上の男性に発症のピークがある一方で，肺機能が正常であっても40歳未満の気胸例の中にも含まれるとする報告がある2）．われわれが治療した40歳未満の若年者自然気胸のうち，肺機能上正常であっても気腫肺が原因と思われる気胸がどの程度含まれたのかについて調査し，その発症と喫煙の関連性を検討したので報告する．

We assessed the relation between smoking and pneumothorax in patients aged ＜40. Of 526 patients who underwent surgery for pneumothorax in 2011～2015, 311 were under the age of 40 and they were included in this study. Of 311, 54 cases （17.4％） were diagnosed with spontaneous pneumothorax associated with emphysematous change by pathological assessment. By the multivariate analysis, 2 parameters exhibited significance for the risk of these spontaneous pneumothorax：a Brinkmann index of ≧165 and a smoking period of ≧9.5 years. It was suggested that smoking is strongly related to the onset of spontaneous pneumothorax even in the younger population less than 40 years of age.