Circulating levels of the neurotransmitter serotonin are inversely associated with bone mass in women, according to a new study co-funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). The work, published online in July in the Journal of Bone and Mineral Research, indicates that serotonin can serve as a marker for low bone mass. The findings also suggest that studies of serotonin synthesis and metabolism pathways are needed to develop drugs that target the neurotransmitter’s effects on bone mass without affecting the nervous system.
Co-authors Ulrike Mödder, Ph.D., Sundeep Khosla, M.D., and colleagues at the Mayo Clinic in Rochester, Minn., studied a population-based cohort of 275 women aged 21 to 97, and observed that higher blood levels of serotonin were associated with lower levels of a number of measures of bone density and structure, as well as body mass index. The findings, say the scientists, indicate a potential role for serotonin in regulating human bone mass.
Drugs called selective serotonin re-uptake inhibitors (SSRIs) have been used for treating depression, and scientists have observed that people taking these medications have reduced bone mineral density. Other studies in mice have also linked serotonin to bone metabolism regulation. Until this study, however, the relationship between serotonin and bone mass in humans was clouded.
"We’ve confirmed that serotonin is yet another player in the complex physiology of bone," says Dr. Khosla. "Perhaps as an early warning signal, it may help us prevent the diseases that beset bone, including osteoporosis."
The study also received funding from the Mayo Clinic’s Center for Translational Science Activities.
The mission of the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), a part of the Department of Health and Human Services’ National Institutes of Health, is to support research into the causes, treatment, and prevention of arthritis and musculoskeletal and skin diseases; the training of basic and clinical scientists to carry out this research; and the dissemination of information on research progress in these diseases. For more information about NIAMS, call the information clearinghouse at 301-495-4484 or 877-22-NIAMS (free call) or visit the NIAMS Web site at http://www.niams.nih.gov.
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Reference: Mödder UI, Achenbach SJ, Amin S, Riggs BL, Melton LJ, Khosla S. Relation of serum serotonin levels to bone density and structural parameters in women. J Bone Miner Res. 2009 Jul 13. [Epub ahead of print] PMID: 19594297.