Table 2.
Effect of levels of serum estradiol and lifestyle factors on BMD in premenopausal women
| TBMD (g/cm2) | LSBMD (g/cm2) | FNBMD (g/cm2) | ||||
|---|---|---|---|---|---|---|
| Coefficient βa | P-value | Coefficient βa | P-value | Coefficient βa | P-value | |
| Estradiol (per 10 pg/μL) | 0.11 | 0.05 | 0.16 | 0.01 | 0.14 | 0.02 |
| Age (years) | −0.08 | 0.1 | −0.12 | 0.04 | −0.15 | 0.01 |
| Age at menarche (years) | −0.04 | 0.4 | −0.01 | 0.8 | −0.03 | 0.6 |
| Number of pregnancies | −0.01 | 0.8 | −0.03 | 0.6 | 0.04 | 0.9 |
| Breastfeeding (months) | −0.09 | 0.3 | −0.04 | 0.5 | −0.05 | 0.4 |
| Use of contraceptives (months) | 0.04 | 0.09 | 0.03 | 0.6 | 0.09 | 0.1 |
| BMI (k/m2) | 0.39 | <0.001 | 0.25 | <0.001 | 0.40 | <0.001 |
| Physical Activity (METS/week) | 0.12 | 0.02 | 0.08 | 0.2 | 0.15 | 0.01 |
| Tobacco smoking (number of cigarretes) | −0.14 | 0.3 | −0.02 | 0.8 | −0.29 | 0.03 |
| Family history of osteoporosis (yes) | −0.02 | 0.7 | −0.02 | 0.4 | −0.01 | 0.8 |
| Dietary factors | ||||||
| Energy intake (per 100 kcal/day) | 0.10 | 0.9 | 0.09 | 0.9 | 0.03 | 0.6 |
| Dietary calcium (per 100 mg/day) | 0.06 | 0.3 | 0.09 | 0.1 | 0.08 | 0.2 |
| Dietary vitamin D (per 100 IU/day) | 0.17 | 0.004 | 0.26 | 0.01 | 0.14 | 0.02 |
| Caffeine (per 100 mg/day) | −0.14 | 0.02 | −0.13 | 0.03 | −0.11 | 0.06 |
| Alcohol (g/day) | −0.06 | 0.3 | −0.03 | 0.5 | −0.07 | 0.2 |
BMD (g/cm 2 ) total bone mineral density, TBMD (g/cm 2 ) whole body bone mineral density, LSBMD (g/cm 2 ) lumbar spine bone mineral density, FNBMD femoral neck bone mineral density, BMI body mass index (normal <25.0 kg/m2, overweight ≥ 25.0 - <30.0 kg/m2, obesity ≥ 30.0 kg/m2)
a Coefficients obtained by multiple linear regression analysis