Baseline characteristics
| Variable | Crohn's disease (n=383) | Ulcerative colitis (n=434) | Normal controls (n=635) | p Value |
| Male | 117 (31%) | 160 (37%) | 324 (51%) | <0.0011-151 |
| Female | 266 (69%) | 274 (63%) | 311 (50%) | |
| Age (median, range) | 39 (8–82) | 39 (11–86) | 43 (19–93) | <0.0011-152 |
| Smoking | <0.0011-151 | |||
| Never smoked | 106 (28%) | 209 (48%) | 252 (40%) | |
| Current smoker | 188 (49%) | 72 (17%) | 215 (34%) | |
| Previous smoker | 87 (23%) | 151 (35%) | 167 (26%) | |
| Use of corticosteroids1-153 | 324 (85%) | 386 (89%) | 34 (5%) | <0.0011-151 |
| Age at first use of corticosteroids (median, range) | 28 (3–76) | 30 (10–78) | 35 (11–75) | 0.0281-152 |
| Duration of corticosteroid use | 1.001-151 | |||
| <1 year | 151 (47%) | 179 (47%) | 15 (47%) | |
| ⩾1 year | 173 (53%) | 205 (53%) | 17 (53%) | |
| Ever diagnosed with osteoporosis | 14 (4%) | 9 (2%) | 5 (1%) | 0.0071-151 |
| Family history of osteoporosis1-154 | 22 (6%) | 23 (5%) | 22 (4%) | 0.371-151 |
| Family history of fractures1-154 | 166 (38%) | 169 (39%) | 225 (40%) | 0.871-151 |
| Use of oral contraceptives1-150 | 221 (84%) | 220 (80%) | 227 (74%) | 0.011-151 |
| Age at first use of oral contraceptives (median, range)1-150 | 18 (12–37) | 18 (15–42) | 19 (13–40) | 0.0021-152 |
| Duration of oral contraceptive use1-150 | 0.0061-151 | |||
| <5 years | 71 (32%) | 88 (40%) | 105 (47%) | |
| ⩾5 years | 150 (68%) | 132 (60%) | 119 (53%) | |
| Premenopausal1-150 Postmenopausal1-150 | 206 (77%) 60 (23%) | 214 (78%) 59 (22%) | 226 (73%) 84 (27%) | 0.251-151 |
| Age at menopause in years (median, range)1-150 | 47 (34–54) | 50 (30–55) | 48 (30–58) | 0.0031-152 |
| Use of HRT after menopause1-150 | 37 (63%) | 29 (49%) | 31 (36%) | 0.0081-151 |
| Age at first HRT use in years (median, range)1-150 | 48.5 (37–60) | 49 (35–56) | 48 (40–60) | 0.921-151 |
| Duration of HRT use1-150 | 0.951-151 | |||
| <5 years | 20 (54%) | 15 (52%) | 15 (50%) | |
| >5 years | 17 (46%) | 14 (48%) | 15 (50%) |
↵1-150 Only female respondents.
↵1-151 χ2 for contingency tables (p).
↵1-152 Kruskal-Wallis test (2p).
↵1-153 Any type of corticosteroids (oral, enemas, inhaled, topical, etc).
↵1-154 A family history means occurrence of any fracture among parents or siblings.
Owing to missing values, sums may not add up.
HRT, hormone replacement therapy.