Alendronate may have a beneficial effect on muscle mass in addition to its well known positive effect on bone mass, hint preliminary findings from Japan. According to Dr. Atsushi Harada from the National Center for Geriatrics & Gerontology in Aichi, there is growing evidence of a functional musclebone unit in which bone health may be directly influenced by muscle function.
“However, there are only limited studies that examined the effects of osteoporosis drugs on muscle. If alendronate, which reliably increases bone mass and contributes to reducing the risk of fracture in the elderly, is also to have a positive effect on muscle mass, its benefit would be even greater,” Dr. Harada explained.
To investigate, the researchers assessed the effects of alendronate monotherapy on muscle mass in a retrospective case-control study of patients with osteoporosis, including 199 taking alendronate and a 233 receiving no drug treatment.
At baseline, the group taking alendronate included more women and had lower height, weight, bone mineral content, and muscle mass than the control group.
At one year, after adjusting for age, sex, BMI and initial muscle mass, patients taking alendronate had a 2.5-fold increase in appendicular skeletal muscle mass and a “remarkable” 4.4-fold increase in lower limb muscle mass, relative to untreated controls.
The findings are reported in the September issue of Osteoporosis and Sarcopenia.
The researchers say it’s possible that alendronate “causes a proliferation of muscle cells or activates muscle metabolism via a direct pharmacological action on as yet unknown muscle stem cells or myocytes.”
It’s also possible that alendronate has an indirect action on bone metabolism, “based on the well-understood suppression of osteoclasts.”
“Moreover, alendronate is reported to raise bone strength and lower fracture risk, while also reducing pain, improving activities of daily living and raising quality of life. Improvement in activities of daily living may be linked to improved muscle mass through increased movement,” they suggest.
While the study has several limitations, including the retrospective design, it’s the first to suggest the possibility that alendronate monotherapy has a positive effect not only on bone but also on muscle, the researchers conclude.