Association of High Serum Chemerin with Bone Mineral Density Loss and Osteoporotic Fracture in Elderly Chinese Women

BACKGROUND: Chemerin has been suggested to be a risk factor for osteoporosis; however, its relationship with osteoporotic fracture is poorly understood. Herein, we intend to explore the association between serum chemerin and osteoporotic fracture. METHODS: A total of 111 elderly women patients diagnosed with osteoporotic fracture were selected as the observation group, and 40 healthy subjects were enrolled as controls. Dual-energy X-ray absorptiometry, enzyme-linked immunosorbent assay, electrochemiluminescence immunoassay, and biochemical analysis were separately performed to determine body bone mineral density (BMD), chemerin levels, bone turnover markers, and other parameters. Pearson's correlation analysis was conducted to examine a relationship between chemerin and laboratory parameters. Moreover, the levels of chemokine-like receptor 1 (CMKLR), C-C motif chemokine receptor-like 2 (CCRL2), collagen type I alpha (COLA1), and runt-related transcription factor-2 (RUNX2) were confirmed by quantitative polymerase chain reaction, and the effect of chemerin on osteogenic differentiation of hFOB1.19 cells was indicated by tartrate-resistant acid phosphatase and alkaline phosphatase double staining. RESULTS: A higher level of chemerin was generally detected in patients with osteoporotic fracture compared with those without (P<0.05). Compared with controls, lower BMD levels and higher β-CTx and P1NP levels were detected in patients with osteoporotic fracture (all P<0.05). Interestingly, chemerin level was negatively correlated to BMD, but positively related to P1NP and β-CTx. Risk of osteoporotic fracture was 2.75-fold higher in subjects with each standard deviation increment of chemerin. Compared with controls, there were no significant differences in CMKLR1 and CCRL2 mRNA after incubation with osteogenic differentiation medium (all P>0.05), whereas there was a remarkable decrease of COLA1 and RUNX2 after incubation with chemerin for nine days (all P<0.05). Furthermore, prolonged incubation with chemerin enhanced osteoclast differentiation and maturation, consequently contributing to an increased risk of fracture. CONCLUSION: Chemerin is a strong and independent risk factor for osteoporosis-related fracture among elderly Chinese women.