Postmenopausal osteoporosis severely jeopardizes human health. Seeking for therapeutic drugs without side effects is of great necessity. Our study was designed to investigate whether resveratrol, an agonist of SIRT1, could have favorable effect on osteoporosis and to explore the underlying mechanisms. Rat osteoporosis model (ovariectomy group, OVX) was established by bilateral ovariectomy. Three different doses of resveratrol were used: 5 mg/kg/d (low-dosed, RES^LD), 25 mg/kg/d (medium-dosed, RES^MD), and 45 mg/kg/d (high-dosed, RES^HD). Results showed that RES^LD did not show any significant effect on OVX alterations, while RES^MD and RES^HD significantly elevated the decreased bone mineral density induced by osteoporosis (RES^MD 0.205±0.023, RES^HD 0.214 ± 0.053 vs. OVX 0.165 ± 0.050 g/cm² respectively; P < 0.05). Serum markers alkaline phosphatase (ALP) and osteocalcin were moderately restored by resveratrol. Moreover, resveratrol improved bone structure in OVX rats, demonstrated by hematoxylin-eosin staining and micro-computed tomographic results. In vitro results revealed that resveratrol promoted osteoblast differentiation of bone marrow mesenchymal stromal cells, evidenced by the increase of ALP generation and mRNA expression of collagen 1 (P < 0.05; RES^MD, RES^HD vs. control group). SIRT1 gene silencing by siRNA transfection blocked these beneficial effects of resveratrol (P < 0.05; RES + SIRT1^KD vs. RES^HD). Western blot results showed that resveratrol activated SIRT1 and subsequently suppressed the activity of NF-κB with decreased expression level of p-IκBα and NF-κB p65 (P < 0.05). Our findings verified the effects of specific dosed resveratrol on postmenopausal osteoporosis through osteoblast differentiation via SIRT1-NF-κB signaling pathway. This study suggested the therapeutic potential of resveratrol against osteoporosis and stressed the importance of effective doses.

Study Design.: A retrospective radiographic study. Objective.: To explore the radiological parameters which correlated to postoperative immediately coronal imbalance in adult spinal deformity (ASD) and to determine whether preoperative coronal imbalance affects postoperative coronal imbalance following posterior multi-level fusion with instruments and osteotomy operation. Summary of Background Data.: There was paucity of literature paying attention to the postoperative immediately coronal imbalance after operation. Methods.: The study included 67 consecutive patients with ASD who underwent posterior multi-level fusion with instruments and osteotomy operation. The radiological parameters, measured on the pre- and postoperative anteroposterior and lateral radiographs, were compared and analyzed. Patients were divided into three groups (group A, B, and C) according to preoperative coronal balance distance (pre-CBD) and the relation of cervical 7 plumb line (C7PL), and the convex of curvature. To analyze the radiological parameters of the three groups. Result.: Differences of the radiological parameters between pre- and postoperation concerning Cobb angles, degree of apical vertebra rotation, thoracic kyphosis (TK), thoracic lumber kyphosis (TLK), lumber lordosis (LL), sacral slope (SS), pelvic tilt (PT), and sagittal vertical axis (SVA), were significant (P < 0.05). Pelvic incidence (PI), pre-CBD, and postoperative coronal balance distance (post-CBD) had no change (P > 0.05). The ratio of coronal imbalance in pre- and postoperation was 31.34% (21/67) and 40.30% (27/67), respectively, which had significant difference (P = 0.02). Significant correlations were observed among post-CBD, pre-CBD (P < 0.001), and d-Cobb (pre-Cobb – post-Cobb) (P = 0.002), post-CBD = –2.737 – 0.924∗d-Cobb + 0.356∗pre-CBD. The ratio of postoperative immediately coronal imbalance of the group C was much higher than other two groups (P = 0.01). Conclusion.: The sagittal alignments in ASD patients would be improved effectively after posterior multi-level fusion with instruments and osteotomy operation. There were significant correlations among post-CBD, pre-CBD, and d-Cobb. Patients in group C may be at greater risk for immediate postoperative coronal imbalance after operation. Level of Evidence: 3

Older subjects have a higher risk for vertebral compression fracture. Maintaining a higher bone mineral density (BMD) at this age can protect individuals from osteoporosis-related events. Body mass index (BMI) has been found to have a robust association with BMD. However, excessive BMI is detrimental to bone health and may cause systemic disorders. Therefore, the present study aimed to determine the association between BMI and BMD, and identify a reasonable BMI range. A total of 961 participants were recruited from community-dwelling residents between August 2021 and May 2022. A weighted multivariate linear regression model was applied to identify the relationship between BMI and BMD. Meanwhile, subgroup stratified analysis by BMI quartile and gender was also performed. A non-linear relationship and threshold value were determined based on the smooth curve fittings and threshold effects analysis model. A robust relationship was found between BMI and BMD, which remained significant in subgroups stratified by gender and BMI quartile. The BMI inflection point values in lumbar BMD and femoral neck BMD were 25.2 kg/m2 and 27.3 kg/m2, respectively. For individuals with BMI < 25.2 kg/m2, an increase in BMI was related to an increase in lumbar BMD. For BMI > 25.2 kg/m2, an increase in BMI was associated with a decrease in lumbar BMD. For subjects with BMI < 27.3 kg/m2, the femoral neck BMD rose by 0.008 kg/m2 for each unit rise in BMI. However, when BMI exceeded 27.3 kg/m2, the femoral neck BMD increased only by 0.005 kg/m2. Fracture risk assessment based on the spinal deformity index (SDI) failed to determine the optimal BMI range. This study found an inflection point between BMI and lumbar/ femoral neck BMD in older community-dwelling subjects. An appropriate BMI but not an excessive BMI may allow older adults to have a better BMD.