Table 3.
Stratified analysis of the effect of weight variability on death from all causes according to subgroups of sex, initial body mass index, physical activity, and direction of weight change.
| Body mass index variability (ASV) | p for trend | ||||||
|---|---|---|---|---|---|---|---|
| First quintile | Second quintile | Third quintile | Fourth quintile | Fifth quintile | |||
| Sex | Men, events | 1,483 | 1,459 | 1,574 | 1,789 | 2,115 | |
| Person-years | 241,188 | 216,761 | 219,617 | 214,259 | 188,569 | ||
| HR (95% CI) | 1.00 (reference) | 0.99 (0.92–1.07) | 1.07 (0.99–1.15) | 1.14 (1.06–1.22) | 1.33 (1.24–1.42) | <0.001 | |
| Women, events | 427 | 490 | 577 | 734 | 1,133 | ||
| Person-years | 139,132 | 158,231 | 157,687 | 163,149 | 183,987 | ||
| HR (95% CI) | 1.00 (reference) | 0.95 (0.84–1.08) | 1.05 (0.83–1.19) | 1.17 (1.04–1.32) | 1.32 (1.18–1.48) | <0.001 | |
| Initial body mass index | <23.0 kg/m2, events | 888 | 997 | 981 | 1,119 | 1,392 | |
| Person-years | 153,299 | 154,233 | 144,679 | 136,351 | 119,840 | ||
| HR (95% CI) | 1.00 (reference) | 1.05 (0.96–1.15) | 1.07 (0.97–1.17) | 1.16 (1.06–1.26) | 1.37 (1.25–1.49) | <0.001 | |
| 23.0–24.9 kg/m2, events | 487 | 472 | 574 | 630 | 752 | ||
| Person-years | 112,017 | 108,448 | 107,032 | 105,085 | 94,028 | ||
| HR (95% CI) | 1.00 (reference) | 0.96 (0.84–1.09) | 1.13 (0.99–1.27) | 1.19 (1.05–1.33) | 1.33 (1.18–1.49) | <0.001 | |
| ≥25.0 kg/m2, events | 535 | 480 | 596 | 774 | 1,104 | ||
| Person-years | 115,005 | 112,311 | 125,593 | 135,972 | 158,688 | ||
| HR (95% CI) | 1.00 (reference) | 0.89 (0.79–1.01) | 1.00 (0.89–1.12) | 1.07 (0.96–1.20) | 1.24 (1.12–1.38) | <0.001 | |
| Physical activity | No, events | 1,047 | 1,136 | 1,248 | 1,512 | 2,104 | |
| Person-years | 166,925 | 173,562 | 175,633 | 180,330 | 191,917 | ||
| HR (95% CI) | 1.00 (reference) | 0.99 (0.91–1.07) | 1.06 (0.97–1.15) | 1.15 (1.07–1.25) | 1.31 (1.22–1.42) | <0.001 | |
| Yes, events | 863 | 813 | 903 | 1,011 | 1,144 | ||
| Person-years | 213,395 | 201,430 | 201,672 | 197,077 | 180,639 | ||
| HR (95% CI) | 1.00 (reference) | 0.98 (0.89–1.07) | 1.08 (0.98–1.18) | 1.14 (1.04–1.24) | 1.36 (1.25–1.49) | <0.001 | |
| Direction of weight change | Weight gain, events | 974 | 966 | 1,055 | 1,186 | 1,486 | |
| Person-years | 212,915 | 198,898 | 202,270 | 196,653 | 186,107 | ||
| HR (95% CI) | 1.00 (reference) | 1.01 (0.92–1.10) | 1.08 (0.99–1.17) | 1.12 (1.03–1.22) | 1.30 (1.20–1.41) | <0.001 | |
| Weight loss, events | 936 | 983 | 1,096 | 1,337 | 1,762 | ||
| Person-years | 167,405 | 176,093 | 175,034 | 180,754 | 186,449 | ||
| HR (95% CI) | 1.00 (reference) | 0.96 (0.87–1.05) | 1.06 (0.97–1.15) | 1.17 (1.07–1.27) | 1.38 (1.27–1.49) | <0.001 | |
Hazard ratio calculated by Cox proportional hazards regression analysis after adjustments for age, sex, baseline body mass index, change in body mass index, household income, smoking, alcohol consumption, physical activity, systolic blood pressure, fasting serum glucose, total cholesterol, underlying cancer, and underlying cardiovascular disease.
Acronyms: ASV, average successive variability; HR, hazard ratio; CI, confidence interval.