Aim. To investigate bone metabolic characteristics in Chinese adults with nonalcoholic fatty liver disease (NAFLD).Methods. A total of 224 patients (99 males and 125 postmenopausal females) were recruited and divided into 4 groups: males without NAFLD, males with NAFLD, females without NAFLD, and females with NAFLD. Bone mineral density (BMD) was evaluated according to body mass index (BMI), waist circumference (WC), and serum biomarkers.βcell function was evaluated by HOMA2%B, HOMA2%S, and HOMA2IR.Results. Males in the NAFLD group had lower BMD of the right hip and the femoral neck (0.852±0.117versus0.930±0.123,P=0.002;0.736±0.119versus0.812±0.132,P=0.004), and females had lower BMD of the right hip (0.725±0.141versus0.805±0.145,P=0.002) even after adjusted for weight, BMI, waist, HDL, and ALT. There was no significant difference in bone metabolic markers between patients with and without NAFLD. NAFLD was an important factor that affected the bone; moreover, the effect attenuated when HOMA2IR entered into the model (R2=0.160,β=−0.172, andP=0.008).Conclusions. NAFLD exerts a detrimental effect on BMD in both males and females. Insulin resistance may play an important role in this pathophysiological process.

Background: Increased bone marrow lipid deposition in steroid-associated osteonecrosis (ON) implies that abnormalities in fat metabolism play an important role in ON development. The increase in lipid deposition might be explained by elevated adipogenesis of marrow mesenchymal stem cells (MSCs). However, it remains unclear whether there is a close association between elevated adipogenesis and steroid-associated ON development. Objective: The present study was designed to test the hypothesis that there might be a close association between elevated adipogenesis and steroid-associated ON development. Methods: ON rabbit model was induced based on our established protocol. Dynamic-MRI was employed for local intra-osseous perfusion evaluation in bilateral femora. Two weeks after induction, bone marrow was harvested for evaluating the ability of adipogenic differentiation of marrow MSCs at both cellular and mRNA level involving adipogenesis-related gene peroxisome proliferator-activated receptor gamma2 (PPARγ2). The bilateral femora were dissected for examining marrow lipid deposition by quantifying fat cell number, fat cell size, lipid deposition area and ON lesions. For investigating association among adipogenesis, lipid deposition and perfusion function with regard to ON occurrence, the rabbits were divided into ON⁺ (with at least one ON lesion) group and ON^- (without ON lesion) group. For investigating association among adipogenesis, lipid deposition and perfusion function with regard to ON extension, the ON⁺ rabbits were further divided into sub-single-lesion group (SON group: with one ON lesion) and sub-multiple-lesion group (MON group: with more than one ON lesion). Results: Local intra-osseous perfusion index was found lower in either ON⁺ or MON group when compared to either ON^- or SON group, whereas the marrow fat cells number and area were much larger in either ON⁺ or MON group as compared with ON^- and SON group. The adipogenic differentiation ability of MSCs and PPARγ2 expression in either ON⁺ or MON group were elevated significantly as compared with either ON^- or SON group. Conclusion: These findings support our hypothesis that there is a close association between elevated adipogenesis and steroid-associated osteonecrosis development.

Objective: Cytotherapy is an insufficient method for promoting bone repair in steroid‐associated osteonecrosis (SAON), and this has been attributed to impairment of the bioactivity of bone marrow–derived stem cells (BMSCs) after pulsed administration of steroids. Cryopreserved autologous bone marrow–derived mononuclear cells (BMMNCs), which contain BMSCs, might maintain their bioactivity in vitro. This study sought to investigate the effects of cryopreserved BMMNCs, before steroid administration, on the enhancement of bone repair in an established rabbit model of SAON.Methods: For in vitro study, bone marrow was harvested 4 weeks before SAON induction from the iliac crests of rabbits (n = 10) to isolate fresh BMMNCs, and the BMMNCs were then cryopreserved for 8 weeks. Both the fresh and the cryopreserved BMMNCs were evaluated for their bioactivity and osteogenic differentiation capacity. In addition, BMMNCs were isolated 2 weeks after SAON induction and subjected to the same evaluations. For in vivo study, cryopreserved BMMNCs were implanted into the bone tunnel during core decompression of the femur (n = 12 rabbits) after the induction of SAON, and tissue regeneration was evaluated by micro–computed tomography and histologic analyses at 12 weeks postoperation.Results: In vitro, there were no significant differences in the bioactivity or ability to undergo osteogenic differentiation between fresh BMMNCs and cryopreserved BMMNCs, but after SAON induction, both features were decreased significantly. In vivo, the bone mineral density, ratio of bone volume to total volume of bone, and volume and diameter of neovascularization within the bone tunnel were significantly higher in the BMMNC‐treated group compared to the nontreated control group at 12 weeks postoperation.Conclusion: Cryopreserved BMMNCs maintained their bioactivity and promoted bone regeneration and neovascularization within the bone tunnel after core decompression in this rabbit model of SAON.

Background We previously reported that the constitutional flavonoid glycosides derived from herb Epimedium (EF, composed of seven flavonoid compounds with common nuclear stem) exerted beneficial effects on the bone, including promoting bone formation and inhibiting bone marrow fat deposition. Recent in vivo study showed that Icaritin was a common metabolite of these constitutional flavonoid glycosides, indicating that Icaritin is a bioactive compound. The present study was designed to investigate whether Icaritin could promote osteogenic differentiation and suppress adipogenic differentiation of marrow mesenchymal stem cells (MSCs).