Risk of COPD in relation to overweight status at childhood and at young adult age
| Childhood/young adult overweight status | Cases of COPD | HR (95% CI) |
| Base model | ||
| Normal weight/normal weight (n=33 514) | 585 | Ref. |
| Overweight/normal weight (n=1368) | 23 | 1.00 (0.66–1.51) |
| Normal weight/overweight (n=1799) | 47 | 1.72 (1.28–2.32) |
| Overweight/overweight (n=989) | 17 | 1.08 (0.67–1.75) |
| Model adjusted for education level | ||
| Normal weight/normal weight (n=32 523) | 585 | Ref. |
| Overweight/normal weight (n=1334) | 23 | 1.13 (0.75–1.72) |
| Normal weight/overweight (n=1753) | 47 | 1.52 (1.12–2.04) |
| Overweight/overweight (n=961) | 17 | 1.02 (0.63–1.65) |
| Model adjusted for birthweight | ||
| Normal weight/normal weight (n=31 714) | 542 | Ref. |
| Overweight/normal weight (n=1292) | 21 | 1.05 (0.68–1.63) |
| Normal weight/overweight (n=1713) | 42 | 1.67 (1.22–2.29) |
| Overweight/overweight (n=941) | 16 | 1.12 (0.68–1.84) |
| Subcohort with Sweden as country of birth | ||
| Normal weight/normal weight (n=27 979) | 496 | Ref. |
| Overweight/normal weight (n=1138) | 20 | 1.03 (0.66–1.61) |
| Normal weight/overweight (n=1469) | 40 | 1.72 (1.25–2.37) |
| Overweight/overweight (n=821) | 12 | 0.92 (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.