Table 1.
Characteristics of the 4957 Study Participants.*
| Characteristic | Analysis | |
|---|---|---|
| Normal BMD to Osteoporosis (N = 1255) | Osteopenia to Osteoporosis (N = 4215) | |
| Age — no. (%) | ||
| 67–74 yr | 971 (77.4) | 2867 (68.0) |
| ≥75 yr | 284 (22.6) | 1348 (32.0) |
|
| ||
| BMI — no./total no. (%) | ||
| <25, normal or underweight | 275/1245 (22.1) | 1696/4200 (40.4) |
| ≥25, overweight or obese | 970/1245 (77.9) | 2504/4200 (59.6) |
|
| ||
| Previous fracture after 50 yr of age — no./total no. (%) | ||
| Yes | 319/1247 (25.6) | 1512/4184 (36.1) |
| No | 928/1247 (74.4) | 2672/4184 (63.9) |
|
| ||
| Current smoker — no. (%) | ||
| Yes | 65 (5.2) | 287 (6.8) |
| No | 1190 (94.8) | 3928 (93.2) |
|
| ||
| Estrogen use — no. (%) | ||
| Current | 304 (24.2) | 653 (15.5) |
| Past | 369 (29.4) | 1295 (30.7) |
| None | 582 (46.4) | 2267 (53.8) |
|
| ||
| Oral glucocorticoid use — no./total no. (%) | ||
| Current or past | 146/1231 (11.9) | 474/4141 (11.4) |
| None | 1085/1231 (88.1) | 3667/4141 (88.6) |
|
| ||
| Self-reported rheumatoid arthritis — no. (%) | ||
| Yes | 67 (5.3) | 261 (6.2) |
| No† | 1188 (94.7) | 3954 (93.8) |
|
| ||
| Mean BMD T score | ||
| Femoral neck | −0.33 | −1.65 |
| Total hip | −0.003 | −1.35 |
*
The two analytic cohorts were not mutually exclusive; that is, 1255 women were included in the analysis of the transition from normal bone mineral density (BMD) to osteoporosis, 4215 were included in the analysis of the transition from osteopenia to osteoporosis, and 513 were included in both analyses (i.e., they had normal BMD and then had a transition to osteopenia, with further follow-up). BMI denotes body-mass index.
†
Data include 458 women (36%) with normal BMD and 1439 (34%) with osteopenia who reported that they did not know whether they had rheumatoid arthritis.