Treatment for patients with postmenopausal osteoporosis who have been placed on HRT and show a decrease in bone mineral density: effects of concomitant administration of vitamin K₂

Abstract.

 We have been using hormone replacement therapy (HRT) as the treatment of choice for menopausal symptoms and osteoporosis. Estrogen increases bone mineral density (BMD) for 2 or 3 years, and only maintains BMD thereafter. In the present study, we investigated whether BMD improved with HRT in combination with vitamin K₂. Ninety-four patients with postmenopausal osteoporosis were studied. All patients were placed on HRT for more than 1 year. Ten patients whose BMD had increased up to a plateau and showed a decreasing trend thereafter while they were receiving HRT were placed on HRT in combination with vitamin K₂. The long-term BMD (L₂-L₄) profiles of those receiving HRT alone, and the effects of HRT in combination with vitamin K₂ on the BMD profiles were examined. The rate of change in BMD (mean ± SE) of all patients who underwent HRT alone was 2.9 ± 1.2% 1 year after the initiation of HRT, 4.6 ± 1.2% 2 years later, and 5.4 ± 1.2% 3 years later. The BMD in these patients, which reached a peak increase after 3 years, no longer increased from the following year. When vitamin K₂ was administered concomitantly to 10 patients for 12 months because of the decrease in BMD, their BMD (mean ± SE) increased significantly, from 0.734 ± 0.021 g/cm² to 0.783 ± 0.026 g/cm² (P < 0.03; paired-t test). We conclude that HRT in combination with vitamin K₂ significantly improved BMD that was on the decrease after HRT alone. Therefore, as a supplementary drug for postmenopausal osteoporosis, vitamin K₂ is a good therapeutic option for patients who are placed on HRT.