Table 1.
Estimated Hazard Ratios for Death from Any Cause among Healthy Subjects Who Never Smoked, According to Body-Mass Index and Age at Baseline.*
| Variable | Body-Mass Index | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 15.0–18.4 | 18.5–19.9 | 20.0–22.4 | 22.5–24.9 | 25.0–27.4 | 27.5–29.9 | 30.0–34.9 | 35.0–39.9 | 40.0–49.9 | |
| 20–49 yr of age | |||||||||
| No. of deaths | 68 | 196 | 916 | 958 | 844 | 477 | 529 | 214 | 114 |
| Hazard ratio (95% CI) | 1.45 (1.13–1.85) | 0.95 (0.82–1.11) | 1.04 (0.95–1.14) | 1.00 | 1.30 (1.19–1.43) | 1.44 (1.29–1.61) | 1.79 (1.61–1.99) | 2.48 (2.14–2.88) | 3.70 (3.03–4.50) |
| Annual deaths per 1000 participants | 2.3 | 1.5 | 1.7 | 1.6 | 2.1 | 2.3 | 2.9 | 4.0 | 5.9 |
| Annual excess deaths per 1000 participants | 0.7 | −0.1 | 0.1 | — | 0.5 | 0.7 | 1.3 | 2.4 | 4.3 |
| 50–59 yr of age | |||||||||
| No. of deaths | 66 | 246 | 1151 | 1942 | 1879 | 1157 | 1378 | 491 | 257 |
| Hazard ratio (95% CI) | 1.15 (0.90–1.46) | 1.14 (1.00–1.30) | 0.96 (0.89–1.03) | 1.00 | 1.10 (1.03–1.17) | 1.22 (1.13–1.31) | 1.56 (1.46–1.68) | 2.06 (1.86–2.28) | 2.77 (2.42–3.16) |
| Annual deaths per 1000 participants | 4.5 | 4.4 | 3.7 | 3.9 | 4.3 | 4.8 | 6.1 | 8.0 | 10.8 |
| Annual excess deaths per 1000 participants | 0.6 | 0.5 | −0.2 | — | 0.4 | 0.9 | 2.2 | 4.1 | 6.9 |
| 60–69 yr of age | |||||||||
| No. of deaths | 218 | 456 | 2125 | 3803 | 4067 | 2640 | 2754 | 905 | 358 |
| Hazard ratio (95% CI) | 1.49 (1.30–1.71) | 1.15 (1.04–1.27) | 1.00 (0.95–1.06) | 1.00 | 1.03 (0.99–1.08) | 1.15 (1.09–1.21) | 1.34 (1.28–1.41) | 1.77 (1.64–1.91) | 2.27 (2.03–2.53) |
| Annual deaths per 1000 participants | 12.2 | 9.4 | 8.2 | 8.2 | 8.4 | 9.4 | 11.0 | 14.5 | 18.6 |
| Annual excess deaths per 1000 participants | 4.0 | 1.2 | 0.0 | — | 0.2 | 1.2 | 2.8 | 6.3 | 10.4 |
| 70–84 yr of age | |||||||||
| No. of deaths | 152 | 254 | 845 | 1282 | 1193 | 699 | 546 | 137 | 52 |
| Hazard ratio (95% CI) | 1.65 (1.39–1.95) | 1.32 (1.15–1.51) | 1.06 (0.97–1.16) | 1.00 | 1.04 (0.96–1.13) | 1.15 (1.04–1.26) | 1.24 (1.12–1.38) | 1.59 (1.33–1.90) | 1.91 (1.44–2.52) |
| Annual deaths per 1000 participants | 27.1 | 21.6 | 17.4 | 16.4 | 17.1 | 18.9 | 20.3 | 26.1 | 31.3 |
| Annual excess deaths per 1000 participants | 10.7 | 5.2 | 1.0 | — | 0.7 | 2.5 | 3.9 | 9.7 | 14.9 |
The age categories are for the age at the time that the body-mass index (BMI) (the weight in kilograms divided by the square of the height in meters) was calculated. Participants were considered healthy if they had no cancer or heart disease at baseline. Hazard ratios were calculated with age as the underlying time scale, stratified by study, and adjusted for sex, alcohol consumption (grams per day), educational level, marital status, and overall physical activity. The annual rates of death per 1000 participants are based on the crude death rates over a median follow-up of 10 years among the healthy study participants who never smoked. The annual rates of excess deaths per 1000 participants are compared with the death rate in the reference category of 22.5 to 24.9. The P values for trend across the categories of age were as follows: P = 0.002 for participants with a BMI below 25.0 and P = 0.005 for those with a BMI of 25.0 or more when estimated with the use of the model for continuous BMI.