Table 3. Results of logistic regression analysis—Odds Ratios (OR) calculated for a normal BMD in the proximal part of the forearm bone.
| Variable | Low BMD n = 91 | Normal BMD n = 409 | Univariate regression models | Multivariate regression modela | ||
|---|---|---|---|---|---|---|
| OR crude (95%CI) | R2 Nagelkerke | OR adjusted (95%CI) | ||||
| Place to live | Small town | 45.7 | 55.5 | 1 | 0.013 | Not included in the model |
| Agglomeration | 54.3 | 44.5 | 0.68 (0.47–0.96) | |||
| BMI | Norm | 36.1 | 38.5 | 1 | 0.012 | 1 |
| Overweight | 41.1 | 32.6 | 0.74 (0.49–1.12) | 0.84 (0.45–1.55) | ||
| Obesity | 22.9 | 28.9 | 1.18 (0.75–1.86) | 2.68* (1.39–5.13) | ||
| Biological age | Perimenopause | 16.0 | 39.0 | 1 | 0.211 | 1 |
| Premenopause | 9.6 | 27.5 | 1.18 (0.66–2.10) | 0.97 (0.44–2.15) | ||
| Postmenopause | 74.5 | 33.5 | 0.18** 0.12–0.29 | 0.35** (0.19–0.63) | ||
| Calcium (mg/day) | Deficiency | 96.1 | 72.0 | 1 | 0.153 | 1 |
| Recommended intake | 3.9 | 28.0 | 9.57** (4.89–18.7) | 3.87** (1.69–8.89) | ||
| Vitamin D (μg/day) | Deficiency | 97.9 | 94.5 | 1 | 0.011 | Not included in the model |
| Recommended intake | 2.1 | 5.5 | 2.68 (0.99–7.26) | |||
| Osteoporosis in the family | No | 79.4 | 91.3 | 1 | 0.037 | 1 |
| Yes | 20.6 | 8.7 | 0.37** (0.21–0.64) | 0.47 (0.22–0.97) | ||
| Past PA | Inactive | 16.7 | 1.8 | 1 | 0.309 | 1 |
| Moderately active | 77.3 | 52.8 | 6.20** (2.18–17.6) | 4.70 (1.28–17.3) | ||
| High | 6.0 | 45.4 | 68.4** (21.8–214) | 28.1** (6.78–116.7) | ||
| Present habitual PA | Insufficient | 72.3 | 28.0 | 1 | 0.248 | 1 |
| Sufficient | 23.4 | 55.5 | 6.13** (4.05–9.28) | 3.36** (1.95–5.77) | ||
| High | 4.3 | 16.5 | 10.0** (4.92–20.5) | 4.77** (2.03–11.2) | ||
| Past SA | Insufficient | 23.0 | 2.8 | 1 | 0.126 | 1 |
| Sufficient | 77.0 | 97.2 | 10.6 ** (4.49–24.9) | 3.22 (1.10–9.43) | ||
| Present SA | Insufficient | 79.8 | 30.3 | 1 | 0.304 | 1 |
| Sufficient | 20.2 | 69.7 | 9.09** (6.03–13.7) | 2.85** (1.68–4.85) | ||
BMD–Bone mineral density; PA- physical activity; SA- sun exposure; a—R2 Nagelkerke for the multivariate regression model = 0.359; The statistical significance
*p<0.01
**<0.001.