Weight change across adulthood in relation to the risk of COPD

Background: Despite some studies identifying a potential association between obesity and chronic obstructive pulmonary disease (COPD) risk, previous research had overlooked the dynamic nature of body weight over time, leading to inconsistent findings. The purpose of this study is to elucidate the relationship between adult weight change and COPD risk by adjusting for potential confounding factors. Methods: We conducted a retrospective analysis using data from ten NHANES cycles (1999–2018), including adults aged 40–74 years. Weight change patterns were assessed using BMI at three time points and classified into five categories per period. Absolute weight change was also grouped into five levels. Multivariate logistic regression models, incorporating sampling weights, were used to examine associations between weight change and COPD, adjusting for demographic and lifestyle covariates. Results: Compared with participants who maintained normal weight, stable obesity participants had increased risk of COPD from age 25 years to 10 years before the survey (OR = 1.45, 95% CI = 1.15 to 1.83), in the 10 years period before the survey (OR = 1.75, 95% CI = 1.47 to 2.08), and from age 25 years to survey (OR = 1.84, 95% CI = 1.46 to 2.31). Three periods indicate that weight gain in adulthood was associated with risk of COPD. In addition, substantial weight gain of more than 20 kg was associated with a higher risk of COPD. In stratified analyses, we also observed a more significant association between weight change and the risk of COPD in never smokers compared to former smokers. Conclusions: Our study suggested that stable obesity and weight gain in adulthood were associated with an increased risk of COPD compared to those who maintain a normal weight, and that the association between weight gain and the incidence of COPD appears closer in patients who have never smoked.