Table 2.
Hazard ratios (95% confidence intervals) of study outcomes according to body mass index categories between individuals aged 40 and 66 years
| Age group | N | Cardiovascular diseases | Myocardial infarction | Ischaemic stroke | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Case/IR a | HR (95% CI) b | HR (95% CI) c | Case/IR a | HR (95% CI) b | HR (95% CI) c | Case/IR a | HR (95% CI) b | HR (95% CI) c | ||
| 40 years d | ||||||||||
| BMI (kg/m2) | ||||||||||
| <18.5 | 68 963 | 443/0.8 | 1.07 (0.97–1.18) | 1.11 (1.01–1.23) | 273/0.5 | 1.13 (1.00–1.28) | 1.17 (1.03–1.32) | 176/0.3 | 0.98 (0.84–1.14) | 1.01 (0.87–1.18) |
| 18.5–22.9 | 808 667 | 5276/0.8 | 1 (Ref.) | 1 (Ref.) | 3137/0.5 | 1 (Ref.) | 1 (Ref.) | 2256/0.4 | 1 (Ref.) | 1 (Ref.) |
| 23.0–24.9 | 418 738 | 3676/1.1 | 1.13 (1.08–1.18) | 1.10 (1.05–1.15) | 2258/0.7 | 1.15 (1.08–1.21) | 1.11 (1.05–1.18) | 1500/0.5 | 1.11 (1.04–1.18) | 1.08 (1.01–1.15) |
| 25.0–29.9 | 495 819 | 5824/1.5 | 1.30 (1.25–1.36) | 1.23 (1.18–1.28) | 3553/0.9 | 1.31 (1.24–1.38) | 1.23 (1.16–1.30) | 2398/0.6 | 1.28 (1.20–1.36) | 1.21 (1.13–1.30) |
| ≥30.0 | 74 404 | 1212/2.2 | 1.55 (1.45–1.66) | 1.38 (1.28–1.49) | 743/1.3 | 1.60 (1.47–1.75) | 1.43 (1.30–1.57) | 499/0.9 | 1.45 (1.31–1.60) | 1.29 (1.15–1.45) |
| P for trend | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | ||||
| General obesity | ||||||||||
| No | 1 296 368 | 9395/0.9 | 1 (Ref.) | 1 (Ref.) | 5668/0.6 | 1 (Ref.) | 1 (Ref.) | 3932/0.4 | 1 (Ref.) | 1 (Ref.) |
| Yes | 570 223 | 7036/1.6 | 1.26 (1.22–1.31) | 1.18 (1.14–1.23) | 4296/1.0 | 1.26 (1.21–1.32) | 1.18 (1.13–1.23) | 2897/0.7 | 1.25 (1.19–1.32) | 1.17 (1.11–1.24) |
| 66 years d | ||||||||||
| BMI (kg/m2) | ||||||||||
| <18.5 | 12 942 | 849/9.2 | 1.12 (1.05–1.21) | 1.19 (1.11–1.27) | 376/4.0 | 1.19 (1.07–1.32) | 1.26 (1.13–1.40) | 525/5.6 | 1.10 (1.00–1.20) | 1.16 (1.06–1.27) |
| 18.5–22.9 | 186 458 | 11 313/8.1 | 1 (Ref.) | 1 (Ref.) | 4734/3.4 | 1 (Ref.) | 1 (Ref.) | 7182/5.1 | 1 (Ref.) | 1 (Ref.) |
| 23.0–24.9 | 156 310 | 9685/8.2 | 0.99 (0.97–1.02) | 0.96 (0.93–0.98) | 3964/3.3 | 0.97 (0.93–1.02) | 0.94 (0.90–0.98) | 6187/5.2 | 1.00 (0.96–1.03) | 0.96 (0.93–0.99) |
| 25.0–29.9 | 189 944 | 12 419/8.7 | 1.02 (1.00–1.05) | 0.95 (0.92–0.98) | 5237/3.6 | 1.04 (1.00–1.08) | 0.97 (0.93–1.01) | 7821/5.4 | 1.00 (0.97–1.04) | 0.93 (0.90–0.97) |
| ≥30.0 | 18 265 | 1398/10.2 | 1.17 (1.11–1.24) | 1.03 (0.97–1.09) | 609/4.4 | 1.23 (1.13–1.35) | 1.08 (0.99–1.18) | 871/6.3 | 1.13 (1.05–1.21) | 0.99 (0.92–1.06) |
| P for trend | 0.013 | <0.001 | 0.017 | 0.088 | 0.441 | <0.001 | ||||
| General obesity | ||||||||||
| No | 355 710 | 21 847/8.2 | 1 (Ref.) | 1 (Ref.) | 9074/3.4 | 1 (Ref.) | 1 (Ref.) | 13 894/5.2 | 1 (Ref.) | 1 (Ref.) |
| Yes | 208 209 | 13 817/8.8 | 1.03 (1.01–1.06) | 0.98 (0.95–1.00) | 5846/3.7 | 1.06 (1.03–1.10) | 1.00 (0.97–1.04) | 8692/5.5 | 1.01 (0.99–1.04) | 0.96 (0.93–0.98) |
Abbreviations: BMI, body mass index; CI, confidence interval; HR, hazard ratio; IR, incidence rate.
a
Number of cases per 1000 person‐years.
b
Model 1: Adjusted for sex, income, smoking status, alcohol consumption, physical activity, hypertension, type 2 diabetes, dyslipidaemia and chronic kidney disease.
c
Model 2: Adjusted for sex, income, smoking status, alcohol consumption, physical activity, hypertension, type 2 diabetes, dyslipidaemia, chronic kidney disease and waist circumference.
d
All Ps for interaction for the associations between body mass index categories and study outcomes by age group were <0.001.