Biological meaning of the prospective epidemiological study on chronic obstructive lung disease and aging

An epidemiological follow-up study on the occurrence of the chronic obstructive lung disease (COLD) in the elderly was carried out in a probability sample of Cracow inhabitants. The research dealt with defining the high risk groups. The health status of the population studied was appraised by standardized interviews and spirometric measurements. Prevalence of COLD was rather strongly related to age both in men and in women but the increase with age was not uniform, being linear below 50 yr and steep in older age groups. The logistic curve appeared to fit quite well to the empirical data regarding the frequency of COLD in relation to age. The overall relative risk of developing COLD estimated by odds ratio was also affected greatly by smoking and by respiratory symptoms. Against expectations, the study showed that the elderly run a substantial risk of developing COLD even without any respiratory symptoms and being a non-smoker. The data obtained indicate that age groups above 50 yr are more vulnerable as the pace of lung function deterioration is much higher than in younger persons. The changes produced by relatively mild pulmonary symptoms like productive cough adding to pre-existing changes caused by aging may precipitate definite chronic obstructive lung disease.