New research to be presented at this year's European Congress on Obesity (ECO 2025, Malaga, Spain, 11-14 May) shows that having an overweight or obesity trajectory during childhood is associated with an increased risk of chronic obstructive pulmonary disease (COPD) in adulthood. The study is by Frida Richter and Professor Jennifer Lyn Baker of The Center for Clinical Research and Prevention, Copenhagen University Hospital - Bispebjerg and Frederiksberg, The Capital Region of Denmark, Copenhagen, Denmark, and colleagues.
Attention towards risk factors for COPD other than smoking is increasingly being recognised in studies of environmental, occupational, and even early life factors. Although previous studies have suggested a link between adiposity and non-allergic asthma and lung function in adults, the association with COPD remains to be elucidated. Therefore, the aim was to examine if trajectories of body mass index (BMI) in childhood were associated with COPD.
The authors included data from 276,747 Danish children (137,493 girls) born from 1930–1982, who had between 2 and 12 weight and height measurements between ages 6–15 years from the Copenhagen School Health Records Register. Using a form of statistical modelling, five distinct childhood BMI trajectories were identified: below-average, average, above-average, overweight and obesity.
The authors then followed the individuals from 1977 to 2022 in national health care registers and identified individuals with a diagnosis of COPD from age 40 years onwards. Hazard ratios (HR) for COPD were estimated separately for women and men using statistical modelling.
The authors found that across the follow-up period 18,227 women and 15,789 men were diagnosed with COPD. Compared to women with an average childhood BMI trajectory, risks of chronic COPD were 10% higher for women who had an above-average trajectory, 26% higher for women who had an overweight trajectory and 65% higher for women with an obesity BMI trajectory
Compared to men with an average childhood BMI trajectory, risks of COPD were 7% higher for men with an above-average trajectory, 16% higher for men with an overweight trajectory and 40% higher for men with an obesity trajectory.
In contrast, a lower risk of future COPD was observed only for women with a below average childhood BMI trajectory – 9% lower compared to women with an average childhood BMI trajectory.
The authors conclude: "Having a BMI trajectory above average in childhood may increase the risk of subsequent COPD. Thus, our results suggest that overweight during this early period of life is an indicator of risk for the development of COPD."
Reflecting on the potential causes of the association, they add: "Parental smoking and socioeconomic status are potential and unmeasured confounders in this study. However, since the effect estimates were consistent across birth cohorts, despite various medical, cultural, and socioeconomic changes (including smoking patterns) over the study period, the bias is considered limited meaning that overweight and obesity in childhood are likely to be independent indicators of risk for COPD in adulthood."
