OBJECTIVE: To examine the hypothesis that an increase in response of postmenopausal bone to interval walking training (IWT) depends on baseline bone mineral densities (BMDs).
METHODS: Two hundred and thirty-four postmenopausal women (64±5 (SD) yr) with no medication for osteoporosis performed 5-month IWT, repeating fast and slow walking at ≥70% and ~40% peak aerobic capacity, respectively, for 3 minutes each per set, ≥5 sets/day, ≥4 days/week. They were recruited from those who had performed IWT ≥6 months before participating in the study so that their physical fitness and lifestyle-related disease symptoms had almost reached a steady state at the time of their participation. We measured BMDs for the lumbar spine (LS), bilateral femoral neck (FN), and bilateral total hip (TH) by dual-energy X-ray absorptiometry (DXA) before and after the intervention. We used a multiple regression analysis to identify significant independent factors for increasing BMDs after the intervention as baseline physical characteristics, exercise intensity, and exercise time during IWT were the candidates. For any bone site where the independent factor identified was singular, we analyzed the relationship between the identified factor vs increases in BMD after the intervention (ΔBMD) by the locally weighted scatterplot smoothing (LOWESS) method.
RESULTS: Almost all subjects completed the designated protocol with minimal adverse events. We found that significant determinants for increasing BMDs were the baseline BMDs for all bone sites, as well as age and body mass index for TH (all, P<0.02). Furthermore, the LOWESS trendline between ΔBMDs vs the baseline BMDs, divided equally into 10 bins for LS and FN, respectively, showed that ΔBMD responses (Y) were attenuated as the baseline BMDs (X) increased in the lower 4 bins and then showed a flat line (Y = ~0) in the remaining higher 6 bins for LS and FN. When the lower 4 bins and the higher 6 bins of the baseline BMD were pooled, respectively, BMDs significantly increased by 1.8% and 1.0% in the lower groups for LS and FN, respectively (both, P<0.001) while not in the higher groups after the intervention (both, P>0.3).
CONCLUSIONS: IWT may be of benefit with minimal adverse events to postmenopausal women, although the effects were greater in those with lower baseline BMDs.
BACKGROUND: UMIN000047428. https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000047428#.

UNASSIGNED: The purpose of this study was to determine whether the rates of (1) in-hospital lengths of stay (LOS), (2) readmissions, (3) medical complications, and (4) costs of care are higher for patients with depressive disorder (DD) undergoing primary total hip arthroplasty (THA) for treatment of femoral neck fractures (FNFs).
UNASSIGNED: A retrospective query of a national administrative claims database for patients undergoing primary THA from 2006 to 2014 was conducted. Patients with DD undergoing THA for treatment of FNF were 1:5 ratio propensity score matched to a cohort (DD=6,758, controls=33,708). Primary endpoints included LOS, 90-day medical complications, 90-day readmissions, and healthcare reimbursements. A P-value less than 0.05 was considered statistically significant.
UNASSIGNED: Longer LOS were observed for patients with DD compared to those without DD (5.6 days vs. 5.4 days, P<0.001). Similar readmission rates (29.9% vs. 25.0%, odds ratio [OR] 1.03, P=0.281) were observed between groups. The odds of 90-day medical complications were higher for patients with DD compared to control subjects (60.6% vs. 21.4%, OR 1.57, P<0.0001). Within the 90-day episode of care interval, patients with a history of DD incurred significantly higher healthcare expenditures ($21,382 vs. $19,781, P<0.001).
UNASSIGNED: Our findings showed longer LOS, higher odds of 90-day medical complications, and higher healthcare expenditures within the 90-day episode of care following a primary THA for treatment of FNF for patients with DD compared to the matched cohort. Thus, accordingly, patients with DD should receive counseling prior to undergoing surgery.

BACKGROUND Long-term clinical practice has suggested a possible association between ossification of cervical ligament (OCL) and primary osteoporosis (POP). However, there is a lack of relevant research data. This study aimed to clarify the potential relationship between OCL and POP, and propose new strategies for preventing the onset of POP. MATERIAL AND METHODS The study involved 107 patients. The patients\' diagnosis included OCL (ossification of the posterior longitudinal ligament, ossification of the ligamentum flavum, and ossification of the nuchal ligament) and POP. Bone mineral density (BMD), types of OCL, types of ossification of posterior longitudinal ligament, age, sex, serum calcium, serum phosphorus, alkaline phosphatase, type I collagen amino-terminal extension peptide, type I collagen degradation products, osteocalcin N-terminal molecular fragments, 25-hydroxyvitamin D, and history of taking steroid drugs were collected. SPSS24.0 and GraphPad Prism 8 were used to obtain the risk factors for POP. RESULTS One-way analysis of variance found that OCL, ossification of posterior longitudinal ligament, alkaline phosphatase, and osteocalcin N-terminal molecular fragments had statistical significance on BMD of the femoral neck (P<0.05). The independent sample t test showed that patient sex had statistical significant effect on BMD (femoral neck) (P=0.036). Incorporating the above factors into multiple linear regression analysis, it was found that OCL, alkaline phosphatase, and osteocalcin N-terminal molecular fragments were risk factors affecting BMD of femoral neck (P<0.05). CONCLUSIONS OCL, osteocalcin N-terminal molecular fragments, and alkaline phosphatase are risk factors for POP.

BACKGROUND: There is limited research providing an overall understanding of bone mineral density (BMD) changes throughout different stages of life. This study aimed to investigate the pattern of BMD changes across childhood, adolescence, adulthood, and old age, as well as exploring the critical time of peak BMD (PBMD).
METHODS: Participants of three major ethnicities from National Health and Nutrition Examination Survey 1999 to 2018 were involved: 46,381 and 20,944 participants aged 8-85 years old were included in the Lumbar spine BMD (LSBMD) and femoral neck BMD (FNBMD) studies, respectively. BMD was measured using dual-energy X-ray absorptiometry. The generalized additive model was used to construct smoothed percentile curves.
RESULTS: Both males and females experienced a sharp increase in LSBMD during puberty, with females reaching their PBMD earlier than males. Females\' LSBMD remained higher than males\' before the age of approximately 50, except for Non-Hispanic Blacks. For males, LSBMD reached a plateau at around 30 years old after reaching the peak value. Females exhibited two peak points on the fitted curves, with the second PBMD occurring around 36-37 years old. Ethnic variations were observed, with Non-Hispanic Blacks displaying the highest BMD levels at all ages. Non-Hispanic Whites and Mexican Americans had lower BMD levels, with Mexican Americans generally exhibiting the lowest BMD. FNBMD reached its peak earlier than LSBMD, and males consistently had higher FNBMD than females.
CONCLUSIONS: This nationally representative study contributes to the understanding of BMD changes across the lifespan, and might provide guidance for bone health interventions in different population groups.

Background/Objectives: Osteoporosis is a common general disease that mostly affects the skeletal system, including the jawbone. There is a link between systemic and mandibular osteoporosis. This study aimed at assessing the association between systemic (lumbar spine L1-L4, femoral neck, total hip) bone mineral density (BMD) and mandible BMD sites in Romanian postmenopausal females. Methods: A total of 97 menopausal patients were studied, 62 with osteoporosis and 35 females with no osteoporosis. For each patient, dual-energy X-ray absorptiometry (DXA) assessments of BMD in the mandible, proximal femur, total hip, and lumbar spine (L1-L4) were performed. Mandibular measurements were performed using the distal forearm software, followed by manual analysis after the bone contour was defined in each case. Results: Comparing the osteoporosis and control groups, there were significant differences in BMD at each examined location. The mandibular BMD (1.125 ± 0.181506 g/cm2) in the osteoporosis group was considerably smaller than in the control group (1.35497 ± 0.244397 g/cm2). Correlations between the BMD at different sites were significant: lumbar spine and femoral neck (r = 0.738, p < 0.0001), lumbar spine and total hip (r = 0.735, p < 0.0001), lumbar spine and mandible (r = 0.506, p < 0.0001), femoral neck and total hip (r = 0.891, p < 0.0001), femoral neck and mandible (r = 0.482, p < 0.0001), and total hip and mandible (r = 0.466, p < 0.0001). Conclusions: There were correlations between mandible BMD and lumbar spine, femoral neck, and total hip BMD, suggesting that osteoporosis affects mandibular bone density. BMD assessments at common locations may help predict mandibular BMD and the probability of osteoporosis.

BACKGROUND: The optimal treatment method for managing unstable Pauwels III femoral neck fractures remains undetermined. The aim of this study was to compare the biomechanical properties of two types of Femoral Neck Anti-rotation and Support System (FNAS) and a Femoral Neck System (FNS) in unstable Pauwels III femoral neck fractures.
METHODS: Eighteen synthetic femoral models were implanted with one of three fixation devices: FNS, FNAS I, or FNAS II. An unstable Pauwels III (OTA/AO 31-B2.3) femoral neck fracture was simulated using a custom-made needle and osteotomy guide. Torsion and axial compression loading tests were conducted, and the torque, torsion angle, load to failure, displacement, and stiffness values were recorded.
RESULTS: FNAS II exhibited significantly higher torsional stiffness (0.67 ± 0.10 Nm/°) compared to FNAS I (0.52 ± 0.07 Nm/°, P = 0.01) and FNS (0.54 ± 0.07 Nm/°, P = 0.005). FNS demonstrated significantly greater mean axial stiffness (239.24 ± 11.38 N/mm) than both FNAS I (179.33 ± 31.11 N/mm, P = 0.005) and FNAS II (190.07 ± 34.11 N/mm, P = 0.022). FNAS I (302.37 ± 33.88 N/mm, P = 0.001) and FNAS II (319.59 ± 50.10 N/mm, P < 0.001) showed significantly higher initial axial stiffness compared to FNS (197.08 ± 33.68 N/mm). Both FNAS I and II improved resistance to deforming forces at a load level before approximately 1000 N, which is sufficient to withstand the load from most daily life activities. No significant differences were observed in compression failure load among the groups. The failure patterns at the point of failure included the pull-out of the distal locking screw and reverse oblique intertrochanteric femur fracture for FNS, while for FNAS I and II, the failures were characterized by a cleft on the calcar femorale and a decrease in the load-displacement curve.
CONCLUSIONS: In unstable Pauwels III femoral neck fractures, the FNAS II enhances stability and is easier to manage for reoperation. The results of the current study support the potential of FNAS II as an alternative option for treating unstable Pauwels III femoral neck fractures in young individuals.

BACKGROUND: 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.
METHODS: 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.
RESULTS: 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.
CONCLUSIONS: 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.

The purpose of the study was to determine whether running is associated with greater bone mineral density (BMD) by comparing the BMD of regularly active male runners (AR) with inactive nonrunner male controls (INC). This cross-sectional study recruited 327 male AR and 212 male INC (aged 18-65) via a stratified recruitment strategy. BMD of the whole body (WB) and partial segments (spine, lumbar spine (LS), leg, hip, femoral neck (FN), and arm for each side) were measured by dual-energy x-ray absorptiometry (DXA) and lower leg dominance (dominant-D/nondominant-ND) was established by functional testing. An ANCOVA was used to compare AR and INC. The AR had greater BMD for all segments of the lower limb (p<0.05), but similar BMD for all segments of the upper limb (p>0.05) compared with INC. Based on the pairwise comparison of age groups, AR had greater BMD of the ND leg in every age group compared with INC (p<0.05). AR had grater BMD of the D leg in every age group except for (26-35 and 56-65) compare with INC (p<0.05). In the youngest age group (18-25), AR had greater BMD in every measured part of lower extremities (legs, hips, femoral necks) compared with INC (p<0.05). In the 46-55 age group AR had greater BMD than INC (p < 0.05) only in the WB, D Leg, D neck, and ND leg. In the 56-65 age group AR had greater BMD than INC (p<0.05) only in the ND leg. Overall, AR had greater BMD compared with INC in all examined sites except for the upper limbs, supporting the notion that running may positively affect bone parameters. However, the benefits differ in the skeletal sites specifically, as the legs had the highest BMD difference between AR and INC. Moreover, the increase in BMD from running decreased with age.

Despite numerous investigations on the influence of fibroblast growth factor 23 (FGF23), α-Klotho and FGF receptor-1 (FGFR1) on osteoporosis (OP), there is no clear consensus. Mendelian randomization (MR) analysis was conducted on genome-wide association studies (GWASs)-based datasets to evaluate the causal relationship between FGF23, α-Klotho, FGFR1 and OP. The primary endpoint was the odds ratio (OR) of the inverse-variance weighted (IVW) approach. Furthermore, we stably transfected FGF23-mimic or siRNA-FGF23 into human bone marrow mesenchymal stem cells (hBMSCs) in culture and determined its cell proliferation and the effects on osteogenic differentiation. Using MR analysis, we demonstrated a strong correlation between serum FGF23 levels and Heel- and femoral neck-BMDs, with subsequent ORs of 0.919 (95% CI: 0.860-0.983, p = 0.014) and 0.751 (95% CI: 0.587-0.962; p = 0.023), respectively. The expression levels of FGF23 were significantly increased in femoral neck of patients with OP than in the control cohort (p < 0.0001). Based on our in vitro investigation, after overexpression of FGF23, compared to the control group, the BMSC\'s proliferation ability decreased, the expression level of key osteogenic differentiation genes (RUNX2, OCN and OSX) significantly reduced, mineralized nodules and ALP activity significantly decreased. After silencing FGF23, it showed a completely opposite trend. Augmented FGF23 levels are causally associated with increased risk of OP. Similarly, FGF23 overexpression strongly inhibits the osteogenic differentiation of hBMSCs, thereby potentially aggravating the pathological process of OP.

Dietary antioxidants may have beneficial effects on bone health, but it remains uncertain in children and adolescents. This study investigates the association of composite dietary antioxidant index (CDAI) with bone mineral density (BMD) in children and adolescents aged 8-19 years from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. The study assessed the relationship between CDAI and BMD in 2994 individuals aged 8-19 years (average age 13.48 ± 3.32 years) from the NHANES 2007-2010. Multivariate linear regression analyses were utilized to detect the association between CDAI and total spine, femur neck, and total femur BMD, adjusting for confounders including age, race/ethnicity, sex, poverty income ratio (PIR), body mass index (BMI), serum phosphorus and calcium. Stratified analyses and interaction tests were performed to examine the stability of the results. The weighted characteristics showed that subjects in the fourth CDAI quartile were more likely to be older, men, and Non-Hispanic White. They have higher values of serum total calcium and phosphorus. After adjusting all confounders, CDAI was positively associated with the total spine (β = 0.0031 95% CI 0.0021-0.0040), total femur (β = 0.0039 95% CI 0.0028-0.0049), and femur neck BMD (β = 0.0031 95% CI 0.0021-0.0040) in children and adolescents. Furthermore, we found no interaction effects between different race/ethnicity, age, and sex groups. Our findings suggest that dietary intake of multiple antioxidants was positively associated with BMD in children and adolescents. These findings provide valuable evidence for improving bone health in the early stages of life. However, more prospective studies are required to validate our findings and their causal relationship.