Alfacalcidol Increases the Therapeutic Efficacy of Ibandronate on Bone Mineral Density in Japanese Women with Primary Osteoporosis

Alfacalcidol Increases the Therapeutic Efficacy of Ibandronate on Bone Mineral Density in Japanese Women with Primary Osteoporosis

YUKIO NAKAMURA,^1,2 TAKAKO SUZUKI,¹ MIKIO KAMIMURA,³ SHOTA IKEGAMI,¹ SHIGEHARU UCHIYAMA¹ and HIROYUKI KATO¹

¹Department of Orthopaedic Surgery, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
²Department of Orthopedic Surgery, Showa-Inan General Hospital, Komagane, Nagano, Japan
³Center of Osteoporosis and Spinal Disorders, Kamimura Orthopedic Clinic, Matsumoto, Nagano, Japan

Bisphosphonates (BPs) increase bone mineral density (BMD) through the inhibition of osteoclast activity. Among BPs, ibandronate (IBN) is a strong inhibitor of bone resorption. However, the effects of a vitamin D analogue, alfacalcidol (ALF), on IBN treatment for osteoporosis is unknown. Fifty-three treatment-naiuml;ve post-menopausal women with primary osteoporosis were recruited and divided into IBN-treatment group (IBN group) and IBN with ALF group (IBN/ALF group). IBN (1.0 mg) was intravenously injected once a month, with or without oral ALF (1.0 μg/day). Ultimately, 19 subjects in IBN group and 26 in IBN/ALF group were analyzed. Bone turnover markers were examined at 4, 6, 12, and 18 months, and BMD was measured at 6, 12, and 18 months. Compared with pre-treatment, bone turnover markers significantly decreased in both groups after 4 months. The levels of serum N-terminal propeptide of type-1 procollagen and tartrate-resistant acid phosphatase-5b, and urinary N-terminal telopeptide of type-I collagen were significantly lower in IBN/ALF group than those in IBN group at 12 months. Lumbar 1-4 (L)-BMD significantly increased from 6 months in IBN/ALF group and at 18 months in IBN group. L-BMD was significantly higher in IBN/ALF group (6.6% increase) than in IBN group (3.4%) at 18 months. Total hip (H)-BMD significantly increased from 6 months in IBN/ALF group and tended to improve in IBN group. H-BMD was significantly higher in IBN/ALF group (4.8%) than in IBN group (3.2%) at 18 months. In conclusion, treatment with ALF in combination with IBN improves BMD in post-menopausal women with osteoporosis.

keywords —— alfacalcidol; bone mineral density; bone turnover markers; ibandronate; osteoporosis

===============================

Tohoku J. Exp. Med., 2017, 241, 319-326

Correspondence: Yukio Nakamura, M.D., Ph.D., Department of Orthopaedic Surgery, Shinshu University School of Medicine, Asahi 3-1-1, Matsumoto, Nagano 390-8621, Japan.

e-mail: yxn14@aol.jp