[Recent trends and prognosis of pulmonary diseases in Japan]

To determine trends of death rates for patients with chronic pulmonary diseases the author compiled the numbers of deaths per 100,000 Japanese population per annum based on the annual reports of the Japan Vital Statistics for the past 43 years. Death rates for the newborn population as well as for the younger population decreased while those for the aged population remained unchanged. Increasing numbers of deaths from lung cancer and decreasing numbers of death from pulmonary tuberculosis were noted. The death rate from the chronic obstructive lung diseases was maintained while the death rate for diffuse fibrotic lung diseases tended to be elevated. Baseline reference values for respiratory physiology parameters, established by the Special Commission for Respiration Physiology of the Japan Society of Chest Diseases, were presented by single linear regression equations represented in terms of age covering the subject's whole age span, including the aged population. The author carried out further analyses based on the data collected in a multi-center cross-sectional survey and concerning, some parameters found consistent differences the linear regression equation calculated for the aged population from those for the younger population. A longitudinal survey conducted by follow-up observations at Keio University Hospital to determine the annual decline of parameters on respiration physiology was designed to cover healthy subjects as well as subjects with chronic pulmonary diseases. Annual declines in vital capacity, forced vital capacity, forced expiratory volume in one second, arterial oxygen tension and arterial carbon dioxide tension showed linear changes throughout the entire age span. Some parameters, such as flow max at 25% vital capacity or alveolar-arterial oxygen tension difference (AaDO2), demonstrated statistically consistent differences in annual decline between younger and older age populations. The annual decline of parameters in patients with chronic pulmonary diseases demonstrated consistently larger values compared with those for healthy subjects. In a study on the pathophysiology and prognosis of patients with respiratory failure with/or without cor pulmonale extension of the survival period for the patients with cor pulmonale was demonstrated.