Table 2.
Age-and multivariable adjusted hazard ratios and 95% confidence intervals for endometrial cancer by life-course body fatness among NHS (1988-2010) and NHS II (1989-2009) participants
| No. cases/person-years | Age-adjusted HR | Multivariate-adjusted HR3 (95% CI) | Multivariate adjusted HR3 + Menstrual cycle characteristics4 (95% CI) | Multivariate adjusted HR3 + recent BMI5,6 (95% CI) | |
|---|---|---|---|---|---|
| Body fatness1 at age 5, Level | |||||
| 1 | 264 / 731,584 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 193 / 731,679 | 1.10 | 1.10 (0.91-1.33) | 1.09 (0.90-1.32) | 1.09 (0.90-1.32) |
| 3 | 136 / 553,864 | 1.02 | 1.02 (0.83-1.26) | 1.00 (0.81-1.23) | 0.91 (0.73-1.11) |
| 4 | 95 / 304,037 | 1.21 | 1.19 (0.94-1.51) | 1.16 (0.91-1.47) | 0.95 (0.74-1.21) |
| 5+ | 69 / 176,878 | 1.30 | 1.27 (0.97-1.66) | 1.23 (0.94-1.61) | 0.92 (0.70-1.21) |
| P trend | 0.05 | 0.08 | 0.15 | 0.30 | |
| Body fatness1 at age 10, Level | |||||
| 1 | 190 / 554,482 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2 | 196 / 736,442 | 1.07 | 1.09 (0.89-1.33) | 1.07 (0.87-1.31) | 1.04 (0.85-1.27) |
| 3 | 147 / 532,689 | 1.17 | 1.18 (0.95-1.47) | 1.14 (0.92-1.42) | 1.00 (0.80-1.25) |
| 4 | 100 / 374,512 | 1.12 | 1.10 (0.86-1.41) | 1.06 (0.83-1.36) | 0.83 (0.64-1.06) |
| 5+ | 124 / 299,917 | 1.58 | 1.54 (1.22-1.94) | 1.47 (1.17-1.86) | 1.05 (0.82-1.33) |
| P trend | <0.001 | 0.001 | 0.01 | 0.65 | |
| Body fatness1 at age 20, Level | |||||
| 1,2 | 270 / 839,815 | 1.00 | 1.00 | 1.00 | 1.00 |
| 3 | 222 / 915,989 | 0.95 | 0.95 (0.79-1.13) | 0.93 (0.77-1.11) | 0.82 (0.68-0.98) |
| 4 | 158 / 492,248 | 1.31 | 1.29 (1.05-1.57) | 1.24 (1.02-1.52) | 0.94 (0.77-1.16) |
| 5+ | 107 / 249,990 | 1.75 | 1.65 (1.31-2.07) | 1.61 (1.28-2.02) | 0.93 (0.73-1.20) |
| P trend | <0.001 | <0.001 | <0.001 | 0.62 | |
| Average childhood body fatness (ages 5 – 10)2, Level | |||||
| 1-2 | 381 / 1,263,067 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2.5-3 | 168 / 589,824 | 1.17 | 1.17 (0.97-1.41) | 1.14 (0.95-1.37) | 1.03 (0.85-1.24) |
| 3.5-4.5 | 138 / 483,640 | 1.17 | 1.14 (0.94-1.39) | 1.11 (0.91-1.35) | 0.89 (0.72-1.08) |
| 5+ | 70 / 161,512 | 1.47 | 1.43 (1.11-1.85) | 1.39 (1.07-1.80) | 0.97 (0.75-1.27) |
| P trend | 0.003 | 0.01 | 0.02 | 0.44 | |
| Average adolescent body fatness (ages 10 – 20)2, Level | |||||
| 1-2 | 261 / 816,097 | 1.00 | 1.00 | 1.00 | 1.00 |
| 2.5-3 | 208 / 831,429 | 1.03 | 1.03 (0.86-1.24) | 1.01 (0.84-1.21) | 0.92 (0.76-1.11) |
| 3.5-4.5 | 211 / 697,746 | 1.28 | 1.27 (1.05-1.52) | 1.22 (1.01-1.47) | 0.93 (0.77-1.13) |
| 5+ | 77 / 152,771 | 1.92 | 1.83 (1.41-2.37) | 1.76 (1.35-2.28) | 1.03 (0.78-1.36) |
| P trend | <0.001 | <0.001 | <0.001 | 0.81 | |
| BMI at age 18, kg/m2 | |||||
| ≤ 19.9 | 216 / 931,989 | 1.00 | 1.00 | 1.00 | 1.00 |
| 20.0-21.4 | 181 / 646,539 | 1.07 | 1.10 (0.90-1.34) | 1.08 (0.88-1.31) | 0.94 (0.77-1.15) |
| 21.5-22.9 | 135 / 405,503 | 1.17 | 1.19 (0.95-1.48) | 1.15 (0.93-1.44) | 0.89 (0.71-1.11) |
| ≥23.0 | 225 / 514,012 | 1.70 | 1.64 (1.35-1.99) | 1.58 (1.30-1.92) | 0.91 (0.74-1.13) |
| <0.001 | <0.001 | <0.001 | 0.34 | ||
| Recent BMI, kg/m2 | |||||
| ≤ 24.9 | 242 / 1,323,670 | 1.00 | 1.00 | 1.00 | N/A7 |
| 25.0-29.9 | 202 / 679,660 | 1.22 | 1.23 (1.01-1.49) | 1.22 (1.00-1.47) | |
| 30.0-34.9 | 150 / 295,189 | 2.14 | 2.12 (1.71-2.63) | 2.08 (1.68-2.58) | |
| ≥35.0 | 163 / 199,524 | 4.34 | 4.13 (3.29-5.16) | 4.05 (3.24-5.07) | |
| <0.001 | <0.001 | <0.001 | |||
| Weight change since age 18, kg | |||||
| Loss (≤ − 2) | 32 / 196,640 | 0.76 | 0.76 (0.48-1.21) | 0.76 (0.48-1.21) | 0.60 (0.37-0.95) |
| Stable (−2 to + 2) | 41 / 225,427 | 1.00 | 1.00 | 1.00 | 1.00 |
| Gain (+ 2 – < 5) | 55 / 305761 | 1.11 | 1.10 (0.73-1.65) | 1.10 (0.73-1.65) | 1.15 (0.76-1.73) |
| (+ 5 – < 10) | 104 / 482,117 | 1.16 | 1.16 (0.81-1.66) | 1.16 (0.81-1.67) | 1.26 (0.87-1.81) |
| (+ 10 – < 15) | 98 / 404,216 | 1.13 | 1.11 (0.77-1.60) | 1.11 (0.77-1.60) | 1.22 (0.85-1.77) |
| (+ 15 – < 20) | 100 / 290,139 | 1.45 | 1.40 (0.97-2.02) | 1.40 (0.97-2.02) | 1.54 (1.07-2.23) |
| (+20 – < 25) | 75 / 207,044 | 1.48 | 1.43 (0.97-2.10) | 1.42 (0.96-2.09) | 1.57 (1.06-2.31) |
| (≥ + 25) | 252 / 386,699 | 2.83 | 2.54 (1.80-3.59) | 2.52 (1.78-3.55) | 2.71 (1.92-3.82) |
| P trend | <0.001 | <0.001 | <0.001 | <0.001 | |
Participants were asked to recall their body fatness at ages 5, 10, and 20, using a nine-level drawing (Figure 1), where Level 1 corresponds to the leanest and Level 9 the most overweight.
Average childhood and adolescent body fatness were the average of the levels at ages 5 and 10, and ages 10 and 20 respectively.
Adjusted for smoking history [never, past, current], oral contraceptive use [never, <3 years, 3-5 years, > 5years], postmenopausal hormone use [premenopausal (reference), post-menopausal – never; postmenopausal – past; post-menopausal current – estrogen only; postmenopausal current – estrogen & progesterone / other], age at menopause [premenopausal/unknown, < 45 years, 45-< 47 years, 47 - <49 years, 49- <51 years, 51- <53 years, 53+ years], family history of colon/rectal cancer, family history of endometrial cancer, height (inches; continuous), parity and age at last birth[1-2 & <30 yrs, 1-2 & ≥ 30 yrs, 3-4 & < 30 yrs, 3-4 & ≥ 30 yrs, ≥ 5 children], physical activity [adolescent & age 20 models: <21, 21-<36, 36-<53, 54-<81, 81+ METS/week; weight change /recent BMI model: <3, 3-<9, 9-<18, 18-<27, 27+ METS/week]
Menstrual cycle characteristics: age of menarche [≤11, 12, 13, ≥14 years], menstrual cycle regularity at age 18 [regular, irregular/no periods]
BMI: body mass index
Weight change model adjusted for weight at age 18, not recent BMI
Recent BMI models not adjusted for recent BMI