Risk of COPD in relation to overweight status at childhood and at young adult age

Childhood/young adult overweight statusCases of COPDHR (95% CI)
Base model
 Normal weight/normal weight (n=33 514)585Ref.
 Overweight/normal weight (n=1368)231.00 (0.66–1.51)
 Normal weight/overweight (n=1799)471.72 (1.28–2.32)
 Overweight/overweight (n=989)171.08 (0.67–1.75)
Model adjusted for education level
 Normal weight/normal weight (n=32 523)585Ref.
 Overweight/normal weight (n=1334)231.13 (0.75–1.72)
 Normal weight/overweight (n=1753)471.52 (1.12–2.04)
 Overweight/overweight (n=961)171.02 (0.63–1.65)
Model adjusted for birthweight
 Normal weight/normal weight (n=31 714)542Ref.
 Overweight/normal weight (n=1292)211.05 (0.68–1.63)
 Normal weight/overweight (n=1713)421.67 (1.22–2.29)
 Overweight/overweight (n=941)161.12 (0.68–1.84)
Subcohort with Sweden as country of birth
 Normal weight/normal weight (n=27 979)496Ref.
 Overweight/normal weight (n=1138)201.03 (0.66–1.61)
 Normal weight/overweight (n=1469)401.72 (1.25–2.37)
 Overweight/overweight (n=821)120.92 (0.52–1.63)

Hazard Ratios (HRs) for COPD were calculated using Cox proportional hazards regression. All models were adjusted for birth year and country of birth. Base model: entire cohort, n=37 670). Model adjusted for maximal education level: n=36 571; categorised as low (n=6647, 17.6%), medium (n=16 213, 43.0%) or high (n=13 711, 36.4%). Model adjusted for birthweight: n=35 660. Subcohort of subjects born in Sweden and with parents born in Sweden: n=31 407. Normal weight/normal weight: not overweight at 8 or 20 years of age; overweight/normal weight: overweight at 8 but not at 20 years of age; normal weight/overweight: overweight at 20 but not at 8 years of age; overweight/overweight: overweight both at 8 and 20 years of age. Childhood overweight at 8 years of age was defined as body mass index (BMI) ≥17.9 kg·m−2 while young adult overweight at 20 years of age was defined as BMI ≥25 kg·m−2.