Irisin and Its Role in Postmenopausal Osteoporosis and Sarcopenia

Abstract

Menopause, an extremely delicate phase in a woman’s life, is characterized by a drop in estrogen levels. This decrease has been associated with the onset of several diseases, including postmenopausal osteoporosis and sarcopenia, which often coexist in the same person, leading to an increased risk of fractures, morbidity, and mortality. To date, there are no approved pharmacological treatments for sarcopenia, while not all of those approved for postmenopausal osteoporosis are beneficial to muscles. In recent years, research has focused on the field of myokines, cytokines, or peptides secreted by skeletal muscle fibers following exercise. Among these, irisin has attracted great interest as it possesses myogenic properties but at the same time exerts anabolic effects on bone and could therefore represent the link between muscle and bone. Therefore, irisin could represent a new therapeutic strategy for the treatment of osteoporosis and also serve as a new biomarker of sarcopenia, thus facilitating diagnosis and pharmacological intervention. The purpose of this review is to provide an updated summary of what we know about the role of irisin in postmenopausal osteoporosis and sarcopenia.

The therapeutic potential of irisin to mitigate the risk of metabolic syndrome in postmenopausal women

“…Across a number of studies [recently reviewed by Falsetti et al ( 91 )] irisin levels have been found to be lowered in postmenopausal women, and across a broader range of (female and male) patients with osteoporosis irisin has often been found to correlate with bone mineral density, although this is not a consistent finding. Of particular relevance to the postmenopausal setting though, a study in OVX mice demonstrated that twice-weekly irisin administration over 5 weeks prevented the loss of trabecular bone and bone mineral density, in conjunction with greater numbers of osteoblasts ( 92 ).…”