Additive effect of alfacalcidol on bone mineral density of the lumbar spine in Taiwanese postmenopausal women treated with hormone replacement therapy and calcium supplementation: a randomized 2-year study

Abstract

Objective: To evaluate the effect of 1alpha-hydroxyvitamin D3 on bone mineral density of the lumbar spine in postmenopausal women receiving hormone replacement therapy and calcium supplement.

Design: A randomized, prospective 2-year clinical trial.

Patients and measurements: A total of 240 postmenopausal women were enrolled with randomized assignment of 120 patients to each treatment group (the D + E group of 1alpha-hydroxyvitamin D3 + sequential combined HRT + calcium supplement; the E group: sequential combined HRT + calcium supplement). None of the patients had received HRT for menopausal syndrome or osteoporosis before being enrolled in our study. Serum biochemical assays, electrolytes and calcitonin were performed at baseline and after 6 and 12 months of treatment. Bone mineral density (BMD) of L2-L4 was measured by dual energy X-ray absorptiometry (DXA) at the initial assessment and after 12 and 24 months of treatment.

Results: One hundred and five patients (87.5%) in the D + E group and 92 patients (76.7%) in the E group completed the first 1-year study. Ninety-six patients (80%) in the D + E group and 80 patients (66.7%) in the E group completed the 2-year trial. Renal function, liver function, electrolytes and calcitonin showed no significant changes during the first year of follow-up. In the D + E group, the BMD of L2-4 increased 3.24 +/- 0.32% from baseline after 1 year (P < 0.05) and 5.32 +/- 0.23% after 2 years of treatment (P < 0.05). On the other hand, the changes of BMD in the E group were 1.12 +/- 0.34% after 1 year (P < 0.05) and 2.42 +/- 0.26% after 2 years of treatment (P < 0.05). The changes of BMD of L2-L4 of the D + E group were higher than the changes of the E group after both 1 and 2 years of treatment (P < 0.05).

Conclusions: Our study demonstrated that combination of 1alpha-hydroxyvitamin D3 with HRT is superior to HRT alone for the preservation of bone mineral density in postmenopausal women under calcium supplementation.