Risk of osteoporosis and fracture in victims with burn injury

Brown Adipose Tissue Improves Angiogenesis and M2 Macrophage Polarization in Burn Wounds by Activating Interleukin-17 Signaling

BACKGROUND

Burn wound healing is a complex physiologic process that requires complicated regulation by different cells and tissues. Brown adipose tissue (BAT) plays a key role in the hypermetabolic response to severe burns. However, it is unclear whether BAT contributes to burn wound healing.

METHODS

Mice were divided into 2 groups: the BAT removal group (BR group) and the control group. Burn wounds were created on the backs of mice (weighing 20 to 25 g) exposed to 100°C hot water for 12 seconds using a homemade burn tube, resulting in a burned area measuring 10 mm in diameter. The treatments were applied once a day for 10 days. Full-thickness wound tissue was collected on days 1, 4, 7, and 10, and analyzed by immunostaining of CD31, α-SMA + , F4/80, and CD206 ( n = 3).

RESULTS

On days 4, 7, and 10, the wound-healing rate of the control group was significantly higher than that of the BR group. In the histologic analysis, evident inflammatory infiltration and severe collagen denaturation was observed in the BR group. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the interleukin-17 pathway was enriched and related genes were up-regulated in the heat map. Immunostaining and transcriptional analyses revealed that angiogenesis and fibroblasts were enhanced in the control group, and there were fewer CD206 + M2 macrophages and higher levels of inflammatory infiltration in the BR group.

CONCLUSION

BAT may reduce inflammatory signaling in burn wounds by increasing the interleukin-17A-hypoxia inducible factor-1α axis and driving M2 macrophage polarization.

CLINICAL RELEVANCE STATEMENT

Patients with severe burn injuries and difficult wounds are encouraged to convert white adipose tissue into beige adipose tissue using drug assistance beneath the wound. Then, browning adipose tissue could improve local angiogenesis and promote the formation of a better microenvironment for wound healing.

Navigating Post-Traumatic Osteoporosis: A Comprehensive Review of Epidemiology, Pathophysiology, Diagnosis, Treatment, and Future Directions

Post-traumatic osteoporosis (PTO) presents a significant challenge in clinical practice, characterized by demineralization and decreased skeletal integrity following severe traumatic injuries. This literature review manuscript addresses the knowledge gaps surrounding PTO, encompassing its epidemiology, pathophysiology, risk factors, diagnosis, treatment, prognosis, and future directions. This review emphasizes the complexity of the etiology of PTO, highlighting the dysregulation of biomineralization processes, inflammatory cytokine involvement, hormonal imbalances, glucocorticoid effects, vitamin D deficiency, and disuse osteoporosis. Moreover, it underscores the importance of multidisciplinary approaches for risk mitigation and advocates for improved diagnostic strategies to differentiate PTO from other musculoskeletal pathologies. This manuscript discusses various treatment modalities, including pharmacotherapy, dietary management, and physical rehabilitation, while also acknowledging the limited evidence on their long-term effectiveness and outcomes in PTO patients. Future directions in research are outlined, emphasizing the need for a deeper understanding of the molecular mechanisms underlying PTO and the evaluation of treatment strategies' efficacy. Overall, this review provides a comprehensive overview of PTO and highlights avenues for future investigation to enhance clinical management and patient outcomes.

Evaluation of Bone Mineral Density, Serum Osteocalcin, and Osteopontin Levels in Postmenopausal Women with Type 2 Diabetes Mellitus, with/without Osteoporosis

OBJECTIVE

Osteoporosis (OP) is a worldwide ailment; we aim to establish new biomarkers in diagnosis by determining the levels of serum osteocalcin and osteopontin along with bone mineral density (BMD) and lumbar T-score, in postmenopausal women with type 2 diabetes mellitus (T2DM) with or without OP.

METHODS

This observational study included 160 postmenopausal women who were an attendee at outpatient clinics in Al-Hussein Hospital, Thi-Qar province; subdivided into 3 groups based on their T-score testing: Group I (n = 40) comprised postmenopausal women without T2DM as controls, Group II (n = 60) comprised postmenopausal women with T2DM but without OP, and Group III (n = 60) comprised postmenopausal women with T2DM with OP. The dual-energy X-ray absorptiometry was used to measure the BMD (total body, lumbar spine, and femoral) and T-score for lumbar spine and femoral. Glycosylated hemoglobin (HbA1c), fasting blood glucose (FBG), osteocalcin, and osteopontin levels were assessed in all three groups.

RESULTS

Compared with controls, Group III demonstrated significantly lower BMD (total body, lumbar spine, and femoral), T-score for lumbar spine and femoral, serum osteocalcin, and osteopontin levels than Group II and Group I (P < 0.001). FBG and HbA1c levels were significantly higher in Group III than in Groups I and II (P < 0.001). A negative correlation was proved between HbA1c levels with BMD, osteocalcin levels, and osteopontin levels in the three groups.

CONCLUSIONS

Iraqi postmenopausal women with T2DM had a significantly lower bone mineral density, serum osteocalcin, and osteopontin levels. These results may serve as adjuvants in screening for OP, particularly among diabetic patients.

Bone mineral density and low bone mass in severely burned patients: A retrospective cohort study

INTRODUCTION

Severe burns can alter bone metabolism through different mechanisms. Despite prior published studies describing the association between burns and a decrease in bone mineral density (BMD), no clinical guidelines currently exist recommending the systematic evaluation of bone health in patients after severe burns. This study aims to describe the BMD of individuals with severe burn injuries and healthy controls and determine the frequency of low-to-normal bone mass (LNBM) and BMD below the expected range for age (BEA).

MATERIALS AND METHODS

We conducted a retrospective cohort of patients with either severe thermal or electrical burns and healthy controls paired by gender and age. We performed a dual-energy X-ray absorptiometry at least 90 days after the burn and collected data from each patient's clinical evaluation and clinical file.

RESULTS

A total of 77 patients (64 men and 13 women) and their paired controls were included in the study (age [mean ± standard deviation, SD]: 30.37 ± 8.66 years). Patients participated in the study an average of 315 ± 438 days after their burn. The BMD (grs/cm2) in total hip burned vs controls was: 0.998 ± 0.135 vs 1.059 ± 0.12 (p = 0.004); femoral neck 0.876 ± 0.121 vs 0.915 ± 0.097 (p = 0.031), spine 0.977 ± 0.127 vs 1.003 ± 0.076 (p = 0.132).The Z-scores for total hip were - 0.06 ± 1.05 vs 0.41 ± 0.80 (p = 0.002); for neck -0.39 ± 0.89 vs -0.01 ± 0.77 (p = 0.005); and for spine -0.75 ± 1.11 vs -0.32 ± 0.73 (p = 0.005). The proportion of subjects with BMD BEA in burns vs controls was 5.2 vs 1.2% (p = 0.05) in total hip, 3.9 vs 0% (p = 0.045) in the neck, and 18.2 vs 1.2% (p = 0.001) in the spine. The logistic regression model found-in burn patients vs controls-an OR of 9.83 for BMD BEA (CI 95%: 2.17-44.45, p = 003), OR = 4.05 for electrical burns (CI 95%: 1.72-20.89, p = 004) and OR = 15.16 for thermal burns (CI 95%: 2.91-79.00, p = 001). The model also found an OR = 2.48 for LNBM (CI 95%: 1.25-4.93, p = 0.009). The burn variables associated with BMD BEA at any site in the patients were BMI >25 Kg/m2 with an OR = 0.180 (CI 95%: 0.046-0.710, p = 0.014); and the lower limb amputation with an OR = 7.33 (CI 95%; 1.12-48.33, p = 0.038). Five burn patients had a fragility fracture.

CONCLUSION

BMD was significantly lower in severely burned patients than in controls, and the proportion BMD BEA cases was significantly higher in the burn patient sample. Severe burns are a strong independent predictor of bone loss, and this risk is maintained for an extended period after the burn.

Severe injury-induced osteoporosis and skeletal muscle mineralization: Are these related complications?

Severely injured patients are beleaguered by complications during convalescence, such as dysregulated biomineralization. Paradoxically, severely injured patients experience the loss of bone (osteoporosis), resulting in diminished skeletal integrity and increased risk of fragility fractures; yet they also accrue mineralization in soft tissues, resulting in complications such as heterotopic ossification (HO). The pathophysiology leading to dysregulated biomineralization in severely injured patients is not well defined. It has been postulated that these pathologies are linked, such that mineralization is "transferred" from the bone to soft tissue compartments. The goal of this study was to determine if severe injury-induced osteoporosis and soft tissue calcification are temporally coincident following injury. Using a murine model of combined burn and skeletal muscle injury to model severe injury, it was determined that mice developed significant progressive bone loss, detectable as early as 3 days post injury, and marked soft tissue mineralization by 7 days after injury. The observed temporal concordance between the development of severe injury-induced osteoporosis and soft tissue mineralization indicates the plausibility that these complications share a common pathophysiology, though further experiments are required.