Table 1.
Age-adjusted associations of participants’ baseline characteristics with arthritis risk, stratified by arthritis type, in the WHI Observational Study and Clinical Trials (n=80,551).
| Characteristic | Osteoarthritis, n=22,306 | Rheumatoid Arthritis, n=3,348 | ||||
|---|---|---|---|---|---|---|
|
| ||||||
| Cases | HR | (95% CI) | Cases | HR | (95% CI) | |
| Demographics and anthropometrics | ||||||
| Education | ||||||
| ≤High school graduate | 4,542 | 1.00 | (reference) | 869 | 1.00 | (reference) |
| Some college | 8,343 | 1.01 | (0.97, 1.05) | 1,263 | 0.78 | (0.71, 0.85) |
| College or advanced degree | 9,279 | 0.96 | (0.93, 1.00) | 1,189 | 0.63 | (0.57, 0.68) |
| Race and Ethnicity | ||||||
| Non - Hispanic White | 18,767 | 1.00 | (reference) | 2,499 | 1.00 | (reference) |
| Non-Hispanic Black | 1,608 | 0.99 | (0.94, 1.05) | 415 | 1.89 | (1.70, 2.10) |
| Hispanic/Latina | 905 | 1.19 | (1.11, 1.28) | 267 | 2.50 | (2.20, 2.84) |
| American Indian | 61 | 0.79 | (0.61, 1.03) | 17 | 1.72 | (1.07, 2.78) |
| Asian/Pacific Islander | 649 | 0.93 | (0.86, 1.01) | 78 | 0.87 | (0.69, 1.09) |
| Unknown | 316 | 1.08 | (0.96, 1.21) | 72 | 1.87 | (1.48, 2.37) |
| Body mass index, kg/m2 | ||||||
| <25 | 7,960 | 1.00 | (reference) | 1,070 | 1.00 | (reference) |
| 25–<30 | 7,876 | 1.14 | (1.10, 1.17) | 1,192 | 1.24 | (1.15, 1.35) |
| ≥30 | 6,287 | 1.37 | (1.32, 1.42) | 1,061 | 1.59 | (1.45, 1.73) |
| Lifestyle characteristics | ||||||
| Leisure Physical activity, METa-hrs/week | ||||||
| Inactive | 3,026 | 1.00 | (reference) | 507 | 1.00 | (reference) |
| <7.34 | 6,185 | 0.99 | (0.95, 1.04) | 970 | 0.95 | (0.85, 1.05) |
| 7.34–<17.5 | 5,905 | 0.94 | (0.89, 0.98) | 822 | 0.81 | (0.73, 0.91) |
| ≥17.5 | 6,036 | 0.95 | (0.90, 0.99) | 846 | 0.83 | (0.74, 0.93) |
| Smoking, pack-years | ||||||
| Non-smoker | 11,043 | 1.00 | (reference) | 1,727 | 1.00 | (reference) |
| <7 | 3,313 | 1.07 | (1.03, 1.11) | 493 | 1.00 | (0.90, 1.10) |
| 7–<24 | 3,669 | 1.12 | (1.07, 1.16) | 505 | 0.95 | (0.86, 1.05) |
| ≥24 | 3,561 | 1.10 | (1.06, 1.14) | 516 | 1.01 | (0.91, 1.11) |
| Multivitamin use | ||||||
| No | 13,392 | 1.00 | (reference) | 2,170 | 1.00 | (reference) |
| Yes | 8,913 | 1.09 | (1.07, 1.13) | 1,177 | 0.90 | (0.83, 0.96) |
| Medical history | ||||||
| Duration of estrogen + progesterone use, years | ||||||
| None | 15,577 | 1.00 | (reference) | 2,446 | 1.00 | (reference) |
| <5 | 3,325 | 1.09 | (1.04, 1.13) | 492 | 0.94 | (0.85, 1.04) |
| 5-<10 | 1,951 | 1.18 | (1.12, 1.24) | 253 | 0.93 | (0.81, 1.06) |
| 10–<15 | 1,027 | 1.20 | (1.12, 1.28) | 105 | 0.80 | (0.66, 0.98) |
| ≥15 | 426 | 1.13 | (1.02, 1.25) | 52 | 0.96 | (0.73, 1.27) |
| Duration of unopposed estrogen use, years | ||||||
| None | 14,620 | 1.00 | (reference) | 2,258 | 1.00 | (reference) |
| <5 | 2,966 | 1.12 | (1.07, 1.17) | 454 | 1.05 | (0.95, 1.16) |
| 5–<10 | 1,640 | 1.18 | (1.12, 1.24) | 230 | 1.01 | (0.88, 1.16) |
| 10–<15 | 1,209 | 1.13 | (1.06, 1.20) | 159 | 0.97 | (0.82, 1.14) |
| ≥15 | 1,871 | 1.09 | (1.04, 1.15) | 247 | 1.00 | (0.87, 1.14) |
| History of diabetes | ||||||
| No | 21,328 | 1.00 | (reference) | 3,175 | 1.00 | (reference) |
| Yes | 959 | 0.99 | (0.93, 1.06) | 172 | 1.25 | (1.07, 1.46) |
| History of heart disease | ||||||
| No | 17,749 | 1.00 | (reference) | 2,666 | 1.00 | (reference) |
| Yes | 3,329 | 1.18 | (1.13, 1.23) | 481 | 1.15 | (1.04, 1.26) |
| NSAID use | ||||||
| No | 15,187 | 1.00 | (reference) | 2,374 | 1.00 | (reference) |
| Yes | 7,119 | 1.21 | (1.17, 1.24) | 974 | 1.04 | (0.97, 1.13) |
| Memory loss | ||||||
| None | 8,973 | 1.00 | (reference) | 1,314 | 1.00 | (reference) |
| Mild | 11,105 | 1.23 | (1.20, 1.27) | 1,620 | 1.20 | (1.12, 1.29) |
| Moderate | 1,898 | 1.56 | (1.48, 1.64) | 325 | 1.49 | (1.49, 1.90) |
| Severe | 204 | 1.80 | (1.55, 2.08) | 51 | 2.75 | (2.07, 3.66) |
| Usual diet | ||||||
| Alcohol consumption, drinks/week | ||||||
| 0 | 8,527 | 1.00 | (reference) | 1,456 | 1.00 | (reference) |
| >0–<0.85 | 4,640 | 1.01 | (0.98, 1.05) | 660 | 0.83 | (0.76, 0.91) |
| 0.85–<3.74 | 4,505 | 1.00 | (0.96, 1.03) | 604 | 0.78 | (0.71, 0.86) |
| ≥3.74 | 4,624 | 1.02 | (0.98, 1.06) | 624 | 0.81 | (0.73, 0.89) |
| Fruit consumption, medium servings/day | ||||||
| <0.994 | 5,564 | 1.00 | (reference) | 975 | 1.00 | (reference) |
| 0.994–<1.64 | 5,479 | 0.96 | (0.92, 1.00) | 860 | 0.88 | (0.80, 0.97) |
| 1.64–<2.53 | 5,624 | 0.98 | (0.95, 1.02) | 760 | 0.79 | (0.72, 0.87) |
| ≥2.53 | 5,639 | 1.00 | (0.96, 1.04) | 753 | 0.79 | (0.72, 0.87) |
| Vegetable consumption, medium servings/day | ||||||
| <1.261 | 5,508 | 1.00 | (reference) | 956 | 1.00 | (reference) |
| 1.261–<1.921 | 5,534 | 0.96 | (0.93, 1.00) | 869 | 0.90 | (0.82, 0.98) |
| 1.921–<2.855 | 5,592 | 0.98 | (0.94, 1.02) | 779 | 0.81 | (0.73, 0.89) |
| ≥2.855 | 5,672 | 1.00 | (0.96, 1.04) | 744 | 0.78 | (0.71, 0.87) |
| Red meat consumption, medium servings/day | ||||||
| <0.303 | 5,411 | 1.00 | (reference) | 817 | 1.00 | (reference) |
| 0.303-<0.562 | 5,549 | 1.01 | (0.97, 1.05) | 773 | 0.93 | (0.84, 1.02) |
| 0.562 - <0.932 | 5,545 | 1.02 | (0.98, 1.06) | 815 | 0.96 | (0.87, 1.06) |
| ≥0.932 | 5,801 | 1.10 | (1.05, 1.14) | 943 | 1.13 | (1.02, 1.24) |
| Energy, calories/day | ||||||
| <1,177.4 | 5,308 | 1.00 | (reference) | 849 | 1.00 | (reference) |
| 1,177.4–<1,524.56 | 5,380 | 1.01 | (0.97, 1.05) | 809 | 0.95 | (0.86, 1.05) |
| 1,524.56–<1,946.35 | 5,783 | 1.10 | (1.05, 1.14) | 799 | 0.93 | (0.84, 1.02) |
| ≥1,946.35 | 5,835 | 1.14 | (1.09, 1.18) | 891 | 1.03 | (0.93, 1.13) |
a
Metabolic Equivalent