Table 2.
Results of Cox Proportional Hazards Regression Models Evaluating the Association of Body Mass Index and Vigorous Physical Activity to the Risk of Heart Failure
| No. of events/No. at risk (%) | Follow-Up, Person-y (Rate per 10 000 Person-y) | Hazard ratio (95% confidence interval) |
||||
|---|---|---|---|---|---|---|
| Age-adjusted | Multivariable-adjusted* | Multivariable-adjusted† | Multivariable-adjusted‡ | |||
| I. Body mass index (kg/m2) | ||||||
| A. As continuous variable | ||||||
| Per unit increment | 1109/21094 (5.3) | 431,654 (25.7) | 1.14 (1.12–1.16) | 1.13 (1.11–1.15) | 1.13 (1.11–1.15) | 1.11 (1.09–1.13) |
| B. As categorical variable | ||||||
| Lean (<25) | 484/12133 (4.0) | 251,471 (19.2) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Overweight (25 to 29.9) | 528/8032 (6.6) | 162,773 (32.4) | 1.65 (1.46–1.87) | 1.62 (1.43–1.83) | 1.61 (1.42–1.82) | 1.49 (1.32–1.69) |
| Obese (≥30) | 97/929 (10.4) | 17,411 (55.7) | 3.54 (2.85–4.41) | 3.38 (2.71–4.21) | 3.35 (2.69–4.17) | 2.80 (2.24–3.50) |
| P for trend | <0.0001 | <0.0001 | <0.0001 | <0.0001 | ||
| II. Vigorous Physical Activity | ||||||
| A. As dichotomous variable | ||||||
| Inactive (rarely/never) | 206/2841 (7.3) | 53,713 (38.4) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| Active (≥1 to 3 times a month) | 903/18253 (4.9) | 377,941 (23.9) | 0.74 (0.63–0.86) | 0.76 (0.66–0.89) | 0.79 (0.67–0.92) | 0.82 (0.70–0.96) |
| B. As 4-category variable | ||||||
| Rarely/never | 206/2841 (7.3) | 53,713 (38.4) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) | 1.00 (referent) |
| 1 to 3 times a month | 145/2991 (4.8) | 62,190 (23.3) | 0.76 (0.61–0.94) | 0.77 (0.62–0.96) | 0.76 (0.62–0.94) | 0.78 (0.63–0.97) |
| 1 to 4 times a week | 610/11813 (5.2) | 245,208 (24.9) | 0.78 (0.66–0.91) | 0.80 (0.68–0.94) | 0.82 (0.70–0.96) | 0.86 (0.73–1.01) |
| 5 to 7 times a week | 148/3449 (4.3) | 70,543 (21.0) | 0.60 (0.49–0.74) | 0.64 (0.52–0.79) | 0.69 (0.56–0.85) | 0.73 (0.59–0.90) |
| P for trend | <0.0001 | <0.001 | 0.003 | 0.016 | ||
Adjusted for age, cigarette smoking (never [referent], past only, and current), alcohol consumption (rarely/never, monthly, weekly, and daily [referent]), parental history of myocardial infarction, and random assignment to aspirin or beta-carotene in all models (baseline covariates not likely in the causal pathway).
Adjusted for aforementioned baseline covariates and vigorous physical activity (rarely/never [referent], and ≥1-3 times a month) in models IA and IB and body-mass index (lean [referent], overweight, and obese) in models IIA and IIB.
Adjusted for all above baseline covariates and presence or absence of history of hypertension, diabetes mellitus, and hypercholesterolemia (baseline covariates likely in the causal pathway)