TABLE 1.
Comparison of characteristics of the 418 participants with knee osteoarthritis included in this study, the 497 participants with knee osteoarthritis enrolled in the ancillary study, and the 4796 participants enrolled at the Osteoarthritis Initiative baseline1
| Characteristics | Participants included in this study (n = 418) | Participants enrolled in the ancillary study (n = 497) | P2 | Participants enrolled at OAI baseline (n = 4796) | P3 |
| Age, y | 61.0 ± 9.2 | 61.2 ± 9.1 | 0.77 | 61.2 ± 9.2 | 0.74 |
| Sex | 0.94 | <0.001 | |||
| Male | 223 (53.4) | 264 (53.1) | 1992 (41.5) | ||
| Female | 195 (46.6) | 233 (46.9) | 2804 (58.5) | ||
| Race | 0.35 | 0.28 | |||
| Non-Hispanic white | 319 (76.3) | 366 (73.6) | 3768 (78.6) | ||
| Other | 99 (23.7) | 131 (26.4) | 1028 (21.4) | ||
| BMI, kg/m2 | 29.6 ± 4.6 | 29.7 ± 4.6 | 0.77 | 28.6 ± 4.8 | <0.001 |
| PASE score | 168.0 ± 81.7 | 167.9 ± 81.9 | 0.98 | 160.8 ± 82.5 | 0.09 |
| Alcohol consumption | 1.00 | 0.69 | |||
| <14 g/d | 357 (85.8) | 424 (85.8) | 4113 (86.5) | ||
| ≥14 g/d | 59 (14.2) | 70 (14.2) | 641 (13.5) | ||
| Cigarette smoking | 0.56 | 0.95 | |||
| Former or current smokers | 195 (47.0) | 222 (45.0) | 2233 (47.2) | ||
| Nonsmokers | 220 (53.0) | 271 (55.0) | 2502 (52.8) | ||
| Vitamin D intake from food and supplement, IU/d | 406 (406) | 416 (412) | 0.78 | 437 (429) | 0.07 |
| Use of vitamin D supplement | 0.69 | 0.48 | |||
| <400 IU/d | 231 (55.3) | 268 (53.9) | 2565 (53.5) | ||
| ≥400 IU/d | 187 (44.7) | 229 (46.1) | 2231 (46.5) | ||
| Calcium intake from food and supplement, mg/d | 934 (938) | 930 (935) | 0.95 | 615 (445) | <0.001 |
| History of knee injury or surgery | 0.99 | <0.001 | |||
| No | 173 (41.4) | 206 (41.5) | 2533 (52.8) | ||
| Yes | 245 (58.6) | 291 (58.6) | 2263 (47.2) |
Data were presented as means ± SDs for age, BMI, and PASE, as medians (IQRs) for vitamin D and calcium intake, and as n (%) for sex, race, alcohol consumption, cigarette smoking, use of vitamin D supplement, and history of knee injury or surgery. OA, osteoarthritis; OAI, Osteoarthritis Initiative; PASE, physical activity scale for the elderly.
P values correspond to the comparison between the 418 participants included in this analysis and the 497 participants enrolled in the ancillary study.
P values correspond to the comparison between the 418 participants included in this analysis and the 4796 participants enrolled at OAI baseline.