Familial Aggregation of Lung Function Impairment in Chronic Obstructive Pulmonary Disease Families in Greece

Abstract

PURPOSE: Our aim is to study the impact of family history of COPD and of the smoking habit on spirometric indices in children aged > 25 years from 240 families (with both parents alive and of age 45-75 years). METHODS: The family final distribution would be 60 families with both parents with COPD, 60 with a COPD father, 60 with a COPD mother and 60 without any COPD parent. Given that children would be males or females and smokers or nonsmokers, 16 subgroups of children will be analyzed at the termination of the study. Both parents and children performed spirometry preand post-bronchodilation according to ATS guidelines. RESULTS: Preliminary results as mean values (SD) in 50 children of age 33 (4) years old from 30 families are reported. The distribution of children and families is not balanced yet. Smokers from a both-parent COPD family (n=7) had the lowest expiratory flows (maximal midexpiratory flow MMEF 72(21)% pred, p=0.035; forced expiratory flow at 50% of vital capacity FEF50% 77 (23)% pred, p=0.040). The next subgroup with the lower and not always within normal limits expiratory flows are the smokers from a COPD father-family (n=18, MMEF 86(19)%pred, FEF50% 101(23) %pred). In contrast, children from non-COPD families, either smokers (n=7) or non-smokers (n=4), presented the highest expiratory flows (MMEF 106(15)%pred and 114(7)% pred respectively, p=0.041; FEF50% 128(26)%pred and 138(11)%pred respectively, p=0.039). Interestingly, smokers from non-COPD families have greater expiratory flows as compared either to nonsmokers from both-parent COPD families (n=6, MMEF 93(17)% pred, p=0.042; FEF50% 100(25)%pred, p=0.032) or to nonsmokers from COPD-father families (n=8, MMEF 96(15)% pred, p=0.044; FEF50% 110(21)%pred, p=0.038). CONCLUSION: It seems that there is a primary link of children's lung function with family history of COPD, and a secondary association with their own smoking habit as well, especially if they belong to a COPD family. CLINICAL IMPLICATIONS: Genetic factors and smoking influence lung function even from a young age. High risk subgroups should be aware of smoking harms and COPD and this awareness can tackle the issue of late diagnosis of COPD.