Original Article Estrogen-mimicking isoflavone genistein prevents bone loss in a rat model of obstructive sleep apnea-hypopnea syndrome

Objective: Intermittent hypoxia was introduced to mimic obstructive sleep apnea-hypopnea syndrome (OSAHS) in rats. Then, bone mass, bone strength and bone turnover were evaluated, and the influence of ge - nistein on bone mass reduction was investigated in these rats. Methods: OSAHS animal model was established via chronic intermittent hypoxia, and genistein (2.5 mg/kg/day) was used to treat OSAHS rats. The bone mineral density (BMD), bone Histomorphometric indicators, bone biomechanics and expressions of genes related to bone formation and resorption (Runx2, Col I, ALP, Osteocalcin, OPG, RANKL and TRAP-5b) were measured after treat- ment. Results: The BMD in OSAHS+OVX group was significantly lower than that in OVX group (P<0.05). The BMD in OSAHS+OVX+Genistein group was markedly increased when compared with OSAHS+OVX group (P<0.05), accom- panied by partial improvement of the OSAHS induced damage to the lumbar biomechanics. In OSAHS+OVX group, the expressions of Runx2, Col I, ALP and Osteocalcin were significantly reduced when compared with OVX group, and rats in OSAHS+OVX+Genistein group had significantly higher expressions of Runx2, Col I, ALP and Osteocalcin and reduced TRAP-5b expression as compared to OSAHS+OVX group (P<0.05). Conclusions: Genistein can improve the reduction in bone mass and bone strength due to OSAHS in OVX rats, which may be attributed to the increase in bone formation and inhibition of bone resorption. Our findings suggest that genistein may be used to treat and prevent osteoporosis in postmenopausal women with OSAHS.