Familial transmission of chronic obstructive pulmonary disease in adoptees: a Swedish nationwide family study

Abstract

ObjectivesFamilial clustering of chronic obstructive pulmonary disease (COPD) is well established, but the familial risk of COPD has not been determined among adoptees. The aim was to determine whether the familial transmission of COPD is related to disease in biological and/or adoptive parents.DesignHistoric cohort study.Participants80 214 (50% females).MethodsThe Swedish Multi-Generation Register was used to follow all Swedish-born adoptees born in 1932–2004 (n=80 214) between 1 January 1964 and 31 December 2010 for COPD (n=1978). The risk of COPD was estimated in adoptees with at least one biological parent with COPD but no adoptive parent with COPD (n=162) compared with adoptees without a biological or adoptive parent with COPD. The risk of COPD was also determined in adoptees with at least one adoptive parent but no biological parent with COPD (n=110), and in adoptees with both affected biological and adoptive parents (n=162).Primary outcome measureCOPD in adoptees.ResultsAdoptees with COPD in at least one biological parent but no adoptive parent were more likely to have COPD than adoptees without a biological or adoptive parent with COPD (standardised incidence ratio, SIR=1.98 (95% CI 1.69 to 2.31)). The familial SIR for adoptees with both a biological parent and an adoptive parent with COPD was 1.68 (95% CI 1.39 to 2.00). Adoptees with at least one adoptive parent with COPD but no biological parent with COPD were not at an increased risk of COPD (SIR=1.12 (95% CI 0.92 to 1.35)).ConclusionsThe findings of the study show that the familial transmission of COPD is associated with COPD in biological but not adoptive parents, suggesting that genetic or early life factors are important in the familial transmission of COPD.

The Role of Mitochondria and Oxidative/Antioxidative Imbalance in Pathobiology of Chronic Obstructive Pulmonary Disease

“…Other factors, indicated as increasing the risk of development of COPD, are as follows: other than cigarette smoking form of tobacco use (e.g., cigar), marijuana, indoor pollution (such as from biomass cooking and heating in poorly ventilated dwellings), and occupational exposures to organic and inorganic dusts, chemical agents, and fumes [1]. Summarizing the contemporary knowledge, we should recognize the pathobiology of COPD as involving a complex interaction between several factors, including genetic vulnerability [57–62]. …”

“What are my chances of developing COPD if one of my parents has the disease?” A systematic review and meta-analysis of prevalence of co-occurrence of COPD diagnosis in parents and offspring

“…One study provided prevalence of COPD in both biological and adoptive parents of people with COPD (both included in the pooled prevalence calculation). 58 Evidence of heterogeneity between the studies was found ( I 2 =98.8%; P <0.0001). A study by Silverman et al (1998) included a specific group of participants (severe early-onset COPD).…”

“…Of the eight studies, three studies reported on the prevalence of COPD in offspring of people with COPD (descendent approach, Table 2 ), with a total of 204 cases and 161 controls in two case–control studies and 5,054 participants in a cross-sectional study, 51 – 53 and five studies reported on the prevalence of a parental history of COPD in people with COPD (antecedent approach, Table 3 ), with 1,545 cases and 1,995 controls in four case–control studies and 80,214 participants in a cohort study. 54 – 58 None of the studies included in this review were primarily designed as prevalence studies, and all the studies included had a variable risk of bias when appraised using the prevalence appraisal checklist ( Table S2 ). 43 …”

“…Of the eight included studies, three studies reported an OR (of the increased likelihood of offspring of people with COPD to develop COPD), 51 , 55 , 57 two studies reported enough information to calculate comparable ORs, 54 , 58 and three studies did not provide sufficient information for OR calculation. 52 , 53 , 56 A study by Khoury et al reported the prevalence of chronic bronchitis and airway obstruction in the offspring of people with COPD.…”

“… 56 Parental COPD history was self-reported by participants in all but one of the antecedent studies, 54 – 57 with the remaining study using medical records to identify COPD in parents and offspring. 58 High prevalence of undiagnosed COPD has been reported worldwide; 10 , 62 thus, identifying COPD by self-report or medical record screening may be an underestimation and not reveal the true prevalence of positive parental COPD history. 11 , 59 …”