Table 1.
Baseline Characteristics, Bone Mineral Density and Bone Turnover
| Variable | Risedronate (N=55) | Placebo (N=54) | P-value |
|---|---|---|---|
| Age (years) | 65 ± 1 | 64 ± 1 | 0.58 |
| Menopausal age (years) | 50 ± 1 | 51 ± 1 | 0.65 |
| AI use prior to study (days) | 747 ± 101 | 684 ± 87 | 0.64 |
| Body mass index (kg/m2) | 31 ± 3 | 31 ± 3 | 0.905 |
| Daily calcium (mg/d) | 743 ± 48 | 827 ± 54 | 0.25 |
| Breast cancer treatment | |||
| Lumpectomy, N (%) | 43 (81) | 43(79) | 0.84 |
| Mastectomy, N (%) | 19 (35) | 17(32) | 0.73 |
| Axillary node removal | 39(75) | 48(89) | 0.06 |
| Radiation therapy, N (%) | 42 (76) | 49 (91) | 0.09 |
| Chemotherapy, N (%) | 17 (32) | 27 (50) | 0.077 |
| Aromatase inhibitor | |||
| Anastrozole, N (%) | 45 (82) | 39 (72) | 0.261 |
| Letrozole, N (%) | 4 (7) | 12 (22) | 0.033 |
| Exemestane, N (%) | 6 (11) | 3 (6) | 0.489 |
| Bone metabolism | |||
| Calcium (mg/dl) | 9.8 ± 0.1 | 9.7 ± 0.1 | 0.22 |
| 25 hydroxyvitamin D (ng/mL) | 36 ± 2 | 36 ± 2 | 1.00 |
| Bone Mineral Density (g/cm2) | |||
| Spine | 0.980 ± 0.019 | 0.994 ± 0.017 | 0.60 |
| Total hip | 0.866 ± 0.014 | 0.874 ± 0.014 | 0.69 |
| Femoral neck | 0.744 ± 0.013 | 0.744 ± 0.013 | 1.00 |
| T-score (SD) | |||
| PA Spine | −0.64 ± 0.16 | −0.45 ± 0.15 | 0.39 |
| Total hip | −0.67 ± 0.12 | −0.58 ± 0.11 | 0.60 |
| Femoral neck | −1.01 ± 0.11 | −0.95 ± 0.16 | 0.75 |
| Bone turnover markers | |||
| CTX (nmol/LBCE) | 0.38 ± 0.02 | 0.46 ± 0.03 | 0.04 |
| P1NP (µg/mL) | 62.05 ± 3.04 | 62.61 ± 3.51 | 0.9055 |