Efficacy and safety of weekly alendronate plus vitamin D(3) 5600 IU versus weekly alendronate alone in Korean osteoporotic women: 16-week randomized trial.

Abstract

Vitamin D (vit-D) is essential for bone health, although many osteoporosis

patients have low levels of 25-hydroxy-vit-D [25(OH)D]. This randomized,

open-label study compared the effects of once weekly alendronate 70 mg containing

5600 IU vit-D(3) (ALN/D5600) to alendronate 70 mg without additional vit-D (ALN)

on the percent of patients with vit-D insufficiency [25(OH)D <15 ng/mL, primary

endpoint] and serum parathyroid hormone (PTH, secondary endpoint) levels in

postmenopausal, osteoporotic Korean women. Neuromuscular function was also

measured. A total of 268 subjects were randomized. Overall, 35% of patients had

vit-D insufficiency at baseline. After 16-weeks, there were fewer patients with

vit-D insufficiency in the ALN/D5600 group (1.47%) than in the ALN group (41.67%)

(p<0.001). Patients receiving ALN/D5600 compared with ALN were at a significantly

decreased risk of vit-D insufficiency [odds ratio=0.02, 95% confidence interval

(CI) 0.00-0.08]. In the ALN/D5600 group, significant increases in serum 25(OH)D

were observed at weeks 8 (9.60 ng/mL) and 16 (11.41 ng/mL), where as a

significant decrease was recorded in the ALN group at week 16 (-1.61 ng/mL). By

multiple regression analysis, major determinants of increases in serum 25(OH)D

were ALN/D5600 administration, seasonal variation, and baseline 25(OH)D. The

least squares mean percent change from baseline in serum PTH in the ALN/D5600

group (8.17%) was lower than that in the ALN group (29.98%) (p=0.0091). There was

no significant difference between treatment groups in neuromuscular function.

Overall safety was similar between groups. In conclusion, the administration of

5600 IU vit-D in the ALN/D5600 group improved vit-D status and reduced the

magnitude of PTH increase without significant side-effects after 16 weeks in

Korean osteoporotic patients.