Improvement of periarticular osteoporosis in postmenopausal women with rheumatoid arthritis by β-alanyl-L-histidinato zinc:: a pilot study

The effect of zinc on bone metabolism in patients with rheumatoid arthritis (RA) is unknown. In the present pilot study, we investigated the effect of two antiulcer drugs, beta -alanyl-L-histidinato zinc (AHZ) and cimetidine, on bone metabolism in postmenopausal women with RA who had bilateral wrist pain. Eight patients were enrolled in a prospective, single-blind study consisting of 6-month cimetidine treatment (400 mg/day) followed by 6-month AHZ treatment (300 mg/day). Biochemical markers and bone mineral density (BMD) by dual energy X-ray absorptiometry were measured at baseline, 6 months, and 12 months. Three patients withdrew, and five patients (mean age 60; range 55-64 years) were analyzed. Their disease activity including wrist pain and dosages of prednisolone and disease-modifying antirheumatic drugs remained unchanged during the 12-month treatment. The AHZ treatment increased serum zinc (AHZ vs cimetidine, +48.0% vs +5.6%), and resulted in significant increases of serum bone-specific alkaline phosphatase (+93.5% vs -14.7%) and BMD of the bilateral ultradistal radius (+4.9% vs -5.6%). However, the AHZ treatment had no effect on BMD of the lumbar spine (-2.0% vs +1.5%) or the bilateral distal third of radius (-2.1% vs +0.2%). In the AHZ treatment, the percentage change in BMD of the unilateral ultradistal radius with more severe wrist pain was positively correlated with the percentage change in serum zinc (r = 0.97). These findings suggest for the first time that AHZ treatment improves periarticular osteoporosis, probably through an increase of bone formation, in postmenopausal women with RA. Randomized double-blind controlled trials are needed.