Table 1.
Clinical characteristics, bone densitometry measurements and pain scores of participants according to categories of lumbar bone mineral density levels (mean ± SD)
| All (n = 78) | Low BMD (n = 41) | Normal BMD (n = 37) | |
|---|---|---|---|
| Age (years) | 63.9 ± 7.5 | 66.3 ± 6.9** | 61.3 ± 7.4 |
| Postmenopausal length (years) | 13.2 ± 8.8 | 15.2 ± 8.3* | 10.9 ± 9.0 |
| Weight (kg) | 59.1 ± 8.3 | 56.9 ± 7.6* | 61.2 ± 8.5 |
| Height (cm) | 156.6 ± 4.4 | 155.3 ± 4.2* | 157.8 ± 4.2 |
| Body mass index (kg/m2) | 24.1 ± 3.1 | 23.6 ± 2.8 | 24.6 ± 3.3 |
| Proportion overweight (%, n) | 39.4 (26) | 39.4 (13) | 39.4 (13) |
| Proportion obese (%, n) | 16.7 (11) | 9.1 (3) | 24.2 (8) |
| Bone mineral density L1–L4 (g/cm2) | 1.02 ± 0.17 | 0.889 ± 0.076 | 1.160 ± 0.135 |
| T-score L1–L4 | −0.85 ± 1.42 | −1.89 ± 0.61 | 0.34 ± 1.10 |
| Z-score L1–L4 | 0.28 ± 1.22 | −0.46 ± 0.71 | 1.12 ± 1.12 |
| Pain NRS score at admission | 7.4 ± 2.0 | 7.4 ± 2.0 | 7.3 ± 2.0 |
| Length of hospital stay (days) | 29.7 ± 12.6 | 30.9 ± 13.9 | 28.3 ± 11.2 |
| Proportion discharged before day 15 | 12.8 (10) | 9.8 (4) | 16.2 (6) |
| Proportion discharged before day 20 | 26.9 (21) | 22.0 (9) | 32.4 (12) |
| Last recorded pain NRS score at day 15 | 4.5 ± 2.1 | 4.6 ± 2.5 | 4.3 ± 1.8 |
| Last recorded pain NRS score at day 20 | 4.0 ± 2.0 | 4.1 ± 2.2 | 3.8 ± 1.6 |
| Proportion with pain NRS score of 3 or less | |||
| At day 15 | 32.5 (25) | 34.2 (14) | 30.6 (11) |
| At day 20 | 41.6 (32) | 41.5 (17) | 41.7 (15) |
Z-score: the number of standard deviations above or below the mean for the patient’s age, sex and ethnicity
T-score: the number of standard deviations above or below the mean for a healthy 30-year-old adult of the same sex and ethnicity as the patient
* P < 0.05, Student’s t test
** P < 0.005, Student’s t test
BMD bone mineral density;
NRS numeric rating scale