Potential mechanisms linking psychological stress to bone health

Green space, genetic susceptibility, and risk of osteoporosis:a cohort study from the UK Biobank

OBJECTIVE

This study aimed to investigate the effect of residential exposure to green space on the incident osteoporosis and further explore the modification effect of genetic susceptibility.

METHODS

Participants from the UK Biobank were followed from 2006 to 2010 (baseline) to December 31st, 2022. Using land use coverage, we evaluated exposure to residential surrounding green space, natural environment, and domestic gardens. We used the Cox regression to examine the association between the residential environment and incident osteoporosis. The interactive effects between polygenic risk score (PRS) of osteoporosis and residential environments on incident osteoporosis were investigated.

RESULTS

This study included 292,662 participants. Over a median follow-up period of 13.65 years, we documented 9177 incidents of osteoporosis. Per interquartile (IQR) increase in greenness and natural environment at a 300 m buffer was associated with a 4% lower risk of incident osteoporosis [HR = 0.96 (95% CI: 0.93, 0.99)] and [HR = 0.96 (95% CI: 0.93, 0.98)], respectively. We did not identify any interactive effects between genetic risk and residential environment on incident osteoporosis.

CONCLUSIONS

This study found that public greenness and natural environments could reduce the risk of incident osteoporosis regardless of genetic predisposition. Developing sustainable and publicly accessible natural environments might benefit populations' bone health.

Effect of Occupational Stress on Periodontitis According to the Salivary RANKL Level Among Iraqi Employees

Background

Findings show that periodontitis does not affect all populations; similarly, some individuals present risk conditions such as occupational stress, making them more susceptible to developing periodontitis through unhealthy habits like poor oral hygiene and immune suppression. Periodontitis triggers an inflammatory host immune response; "Receptor Activator Nuclear Factor KB ligand (RANKL)" is the primary regulator of osteoclast differentiation and activity. It was found that osteoclastic bone damage caused by periodontitis depends on the RANKL produced by osteoblastic and periodontal ligament cells.

Objective

This study aimed to assess the effect of occupational stress on employees with periodontitis using salivary RANKL marker.

Material and Methods

A case-control analysis was done at my clinic with 90 male employees aged 30-50. The participants completed self-administered questionnaires and had periodontal exams. Employee occupational stress was estimated using a life events scale questionnaire. Calibrated dentists performed the parameters used in the periodontal assessment after collecting whole unstimulated salivary samples from each employee to measure salivary RANKL using ELISA technique.

Results

The present finding revealed a statistically significant difference among groups in "probing pocket depth, plaque index, bleeding on probing, clinical attachment level, and salivary RANKL level". They were higher in the stressed employees' group, which is not statistically significant.

Conclusion

The findings of this investigation observed that occupational stress increased clinical periodontal parameters and salivary RANKL of periodontitis in employees.

Brown adipose tissue but not tibia exhibits a dramatic response to acute reduction in environmental temperature in growing male mice

Mice are typically housed at room temperature (∼22 °C), which is well below their thermoneutral zone and results in cold stress. Chronic cold stress leads to increased adaptive thermogenesis and reductions in cancellous bone volume and bone marrow adipose tissue mass in long bones of growing mice. There is strong evidence that increased neuronal activity initiates the metabolic response of intrascapular brown adipose tissue (BAT) to cold stress, but it is less clear whether bone is regulated through a similar mechanism. Therefore, we compared the short-term response of BAT and whole tibia to a reduction in environmental temperature. To accomplish this, we transferred a group of 6-week-old male mice from 32 °C to 22 °C housing and sacrificed the mice 24 h later. Age-matched controls were maintained at 32 °C. We then evaluated expression levels of a panel of genes related to adipocyte differentiation and fat metabolism in BAT and tibia, and a panel of genes related to bone metabolism in tibia. The decrease in housing temperature resulted in changes in expression levels for 47/86 genes related to adipocyte differentiation and fat metabolism in BAT, including 9-fold and 17-fold increases in Ucp1 and Dio2, respectively. In contrast, only 1/86 genes related to adipocyte differentiation and fat metabolism and 4/84 genes related to bone metabolism were differentially expressed in tibia. These findings suggest that bone, although innervated with sensory and sympathetic neurons, does not respond as rapidly as BAT to changes in environmental temperature.

Interrelations between clinical-psychological features and bone mineral density changes in post-menopausal women undergoing anti-osteoporotic treatment: a two-year follow-up

Introduction

Psychological features have been bidirectionally associated with osteoporosis, but it is still unclear whether patient's anxiety fluctuations during the anti-osteoporotic treatment can have an impact on bone mineral density (BMD) variation. The aim of this study was to investigate the interrelations between psychological distress features, such as anxiety, depression, health-related QoL (HRQoL) and bone health in women receiving anti-osteoporotic treatment.

Methods

192 post-menopausal osteoporotic women were treated with alendronate or risedronate according to the standard procedure. The levels of anxiety, depression, and perceived HRQoL, along with BMD, were assessed at baseline and at a 2-year follow-up.

Results

At the end of the study, the patients showed a statistically significant increase of both psychic and somatic anxiety (p<0.0001) and exhibited a worsening of depressive symptoms (p<0.0001), whereas HRQoL showed no change. BMD improved and no incident fractures occurred. BMD variation (ΔBMD) at lumbar spine was significantly associated with anxiety levels (r=0.23, p=0.021). Multiple regression analysis showed that both patients' worsening anxiety levels (β = -0.1283, SE=0.06142, p=0.04) and their treatment adherence (β=0.09, SE=0.02, p=0.0006) were independently associated with ΔBMD.

Discussion

The findings of the current follow-up study suggest that BMD in post-menopausal women undergoing anti-osteoporotic treatment was predicted by treatment adherence and anxiety change over time.

Low Ca diet leads to increased Ca retention by changing the gut flora and ileal pH value in laying hens

Osteoporosis is a common degenerative metabolic bone disease in caged laying hens. Intensive egg production mobilizing large amounts of Ca from bone for eggshell formation, consequently leading to Ca deficiency, has been recognized as a critical factor causing osteoporosis in commercial laying hens. The aim of this study was to examine the effect of Ca deficiency on the function of the gut microbiota-bone axis and related egg production traits and bone health in laying hens. Twenty-four 48-week-old laying hens were fed a control diet (Control, 3.72%) or a low Ca diet (LC, 2.04%) for 60 d (n = 12). Compared to the Control hens, the LC hens had higher levels of alkaline phosphatase and tartrate resistant acid phosphatase (P < 0.05) with lower bone strength, eggshell thickness, and eggshell strength (P < 0.05). In addition, the LC hens had higher plasma estradiol concentrations, while having lower concentrations of interleukin-1 (IL-1) and IL-6. The LC hens also had a lower pH value in the ileum with an increased Ca retention. The principal co-ordinates analysis showed significantly separate cecal microbiota populations between the Control and LC hens. The Prevotellaceae_UCG-001, Subdoligranulum, Peptococcus, and Eubacterium_hallii_group (P < 0.05) were higher, while the CHKC1001 and Sutterella (P < 0.05) were lower at the genus level in the LC hens. In addition, Prevotellaceae_UCG-001, Subdoligranulum and Eubacterium_hallii_group had a negative correlation, while Sutterella was positively correlated with ileal pH values. The transcriptome analysis revealed that the low Ca diet caused 20 and 31 genes to be significantly up- and down-regulated, respectively. The gene expressions of cystic fibrosis transmembrane conductance regulator, solute carrier family 26 member 3 of the anion exchangers, and mitogen-activated protein kinase 12 of pro-inflammatory factors were lower in the LC birds, which was correlated with the lower ileal pH values. These results suggest that the hens with low Ca diet-induced osteoporosis have an increased intestinal Ca retention with a decreased ileal pH value, correlated with the changes in Prevotellaceae_UCG-001, Subdoligranulum, and Eubacterium_hallii_group of beneficial genera. The results provide insights for further understanding and preventing osteoporosis in laying hens.

Early Life Stress (ELS) Effects on Fetal and Adult Bone Development

Early life stress (ELS) refers to harmful environmental events (i.e., poor maternal health, metabolic restraint, childhood trauma) occurring during the prenatal and/or postnatal period, which may cause the 'epigenetic corruption' of cellular and molecular signaling of mental and physical development. While the impact of ELS in a wide range of human diseases has been confirmed, the ELS susceptibility to bone diseases has been poorly explored. In this review, to understand the potential mediating pathways of ELS in bone diseases, PRISMA criteria were used to analyze different stress protocols in mammal models and the effects elicited in dams and their progeny. Data collected, despite the methodological heterogeneity, show that ELS interferes with fetal bone formation, also revealing that the stress type and affected developmental phase may influence the variety and severity of bone anomalies. Interestingly, these findings highlight the maternal and fetal ability to buffer stress, establishing a new role for the placenta in minimizing ELS perturbations. The functional link between ELS and bone impairments will boost future investigations on maternal stress transmission to the fetus and, parallelly, help the assessment of catch-up mechanisms of skeleton adaptations from the cascading ELS effects.

Osteoporosis and Alveolar Bone Health in Periodontitis Niche: A Predisposing Factors-Centered Review

Periodontitis is a periodontal inflammatory condition that results from disrupted periodontal host-microbe homeostasis, manifested by the destruction of tooth-supporting structures, especially inflammatory alveolar bone loss. Osteoporosis is characterized by systemic deterioration of bone mass and microarchitecture. The roles of many systemic factors have been identified in the pathogenesis of osteoporosis, including endocrine change, metabolic disorders, health-impaired behaviors and mental stress. The prevalence rate of osteoporotic fracture is in sustained elevation in the past decades. Recent studies suggest that individuals with concomitant osteoporosis are more vulnerable to periodontal impairment. Current reviews of worse periodontal status in the context of osteoporosis are limited, mainly centering on the impacts of menopausal and diabetic osteoporosis on periodontitis. Herein, this review article makes an effort to provide a comprehensive view of the relationship between osteoporosis and periodontitis, with a focus on clarifying how those risk factors in osteoporotic populations modify the alveolar bone homeostasis in the periodontitis niche.

Complication of lengthening and the role of post-operative care, physical and psychological rehabilitation among fibula hemimelia

There is a clear clinical need for efficient physiotherapy and rehabilitation programs during and after bone lengthening and reconstruction for gaining the optimal effect and also prevention or treatment of lengthening side effects. Pin tract infection is the most prevalent side effect during lengthening which could be prevented and treated initially via proper wound care. Muscle contractures are typically a consequence of the generated tension on the distracted muscle. It can be managed by physiotherapy initially and surgically in later severe stages. Furthermore, it is essential to avoid muscle contracture development, which is the demonstration of the imbalanced muscle appeals on the joint to inhibit the following subluxation. The knee is the furthermost affected joint by the aforementioned problem due to the inherent lack of ligamentous and bony stability. Joint stiffness is the other possible unfavorable effect of lengthening. It happens because of extensive muscle contractures or may possibly be attributed to rigidity of the joint following the amplified pressure on the joint surface during the process of lengthening. Physiotherapy and occupational therapy including endurance and strength exercise as well as stretching play an important role during the rehabilitation periods for the prevention and also the treatment of muscle contracture and the following deformity and also joint stiffness. Likewise, the effect of mental and physical rehabilitation programs should not be overlooked.

Osteopenia in a Mouse Model of Spinal Cord Injury: Effects of Age, Sex and Motor Function

Simple Summary

In the first two years following spinal cord injury, people lose up to 50% of bone below the injury. This injury-induced bone loss significantly affects rehabilitation and leaves people vulnerable to fractures and post-fracture complications, including lung and urinary tract infections, blood clots in the veins, and depression. Unfortunately, little is known about the factors driving this bone loss. In fact, even though we know that injury, age, and sex independently increase bone loss, there have been no studies looking at the cumulative effects of these variables. People with spinal injury are aging, and the age at which injuries occur is increasing. It is essential to know whether these factors together will further compromise bone. To examine this, we assessed bone loss in young and old, male and female mice after spinal injury. As expected, we found that aging alone decreased motor activity and bone volume. Spinal injury also reduced bone volume, but it did not worsen the effects of age. Instead, injury effects appeared related to reduced rearing activity. The data suggest that although partial weight-bearing does not reduce bone loss after spinal cord injury, therapies that put full weight on the legs may be clinically effective.

Abstract

After spinal cord injury (SCI), 80% of individuals are diagnosed with osteopenia or osteoporosis. The dramatic loss of bone after SCI increases the potential for fractures 100-fold, with post-fracture complications occurring in 54% of cases. With the age of new SCI injuries increasing, we hypothesized that a SCI-induced reduction in weight bearing could further exacerbate age-induced bone loss. To test this, young (2–3 months) and old (20–30 months) male and female mice were given a moderate spinal contusion injury (T9–T10), and recovery was assessed for 28 days (BMS, rearing counts, distance traveled). Tibial trabecular bone volume was measured after 28 days with ex vivo microCT. While BMS scores did not differ across groups, older subjects travelled less in the open field and there was a decrease in rearing with age and SCI. As expected, aging decreased trabecular bone volume and cortical thickness in both old male and female mice. SCI alone also reduced trabecular bone volume in young mice, but did not have an additional effect beyond the age-dependent decrease in trabecular and cortical bone volume seen in both sexes. Interestingly, both rearing and total activity correlated with decreased bone volume. These data underscore the importance of load and use on bone mass. While partial weight-bearing does not stabilize/reverse bone loss in humans, our data suggest that therapies that simulate complete loading may be effective after SCI.

Association between bipolar affective disorder, use of antidepressants and osteoporosis

Introduction/Objective. Osteoporosis is one of the most common comorbid disorders in depressive mood disorder. The aim of this study was to assess the association between the use of antidepressants and osteoporosis in patients with bipolar affective disorder (BPAD). Methods. The study included 73 inpatients, aged 50?72 years, male and female, hospitalized with a depressive episode of BPAD from 2016 to 2020 at the Clinic of Psychiatry, Clinical Centre of Vojvodina, divided into two groups: a) the first group (40) was treated with selective serotonin reuptake inhibitors (SSRIs) in combination with mood stabilizer (lithium carbonate/lamotrigine); b) the second group (33) was treated with mood stabilizer only. Study included two control groups as well. Clinical measurements of bone mineral density at lumbar spine and hip was made using dual energy X-ray absorptiometry. CrossLaps and levels of calcium and vitamin D were collected from blood samples. The data was analyzed by the analysis of variance and the Kruskal?Wallis test. Results. Osteoporosis was registered in 25% of patients in the first group and in 18% of patients in the second group, while osteopenia was observed within 40% of patients in the first group and in 37% of patients in the second group. There was significant difference in value of CrossLaps, and the level of 25(OH)D vitamin between the control groups and the first two groups, as well as in prevalence of osteoporosis and osteopenia. Conclusion. Depressive episodes in BPAD is connected with higher prevalence of osteoporosis. Patients treated with SSRIs have higher prevalence of osteoporosis than patients treated with mood stabilizers only.

Curcumin plays a local anti-inflammatory and antioxidant role via the HMGB1/TLR4/NF-ΚB pathway in rat masseter muscle under psychological stress

BACKGROUND AND OBJECTIVE

Psychological stress causes structural and metabolic dysfunction of masseter muscles. The anti-inflammatory and anti-oxidative polyphenol curcumin plays a local antioxidant role in rat masseter muscles under psychological stress by an as-yet-unknown mechanism. The present study aimed to assess curcumin anti-inflammatory and anti-oxidative effects on masseter muscle and its possible molecular mechanisms.

METHODS

We constructed a rat model of chronic unpredictable moderate stress (CUMS). Psychological stress was assessed by determining the levels of adrenocorticotropic hormone (ACTH) and cortisol in serum. Enzyme-linked immunosorbent assays measured inflammatory cytokines and markers of oxidative stress in masseter muscles. Levels of high-mobility group box 1 (HMGB1), interleukin (IL)-1β, IL-6 and tumour necrosis factor-alpha (TNF-α) were determined using quantitative PCR analyses and immunofluorescent staining. Toll-like receptor 4 (TLR4) and nuclear factor kappa B (NF-κB) activation were examined using western blotting.

RESULTS

The CUMS group showed increased serum cortisol and ACTH levels. Pathological changes in the ultrastructure, oxidative stress and inflammatory cytokines in the masseter muscles were also observed. Curcumin treatment (50, 100 mg/kg) ameliorated these changes significantly by varying degrees. Mechanistically, increased levels of phosphorylated NF-κB, toll-like receptor 4 and HMGB1 were observed, which were also ameliorated by curcumin treatment.

CONCLUSION

Curcumin can reduce local pathological changes, levels of oxidative stress and inflammatory factors in masseter muscles. Psychological stress activates HMGB1 expression and increases the expression of downstream TLR4 and p-NF-κB, which could be reduced by curcumin. Thus, curcumin might exert anti-inflammatory and antioxidant effects in masseter muscles via the HMGB1/TLR4/NF-κB pathway.

Acculturation and biological stress markers: A systematic review

BACKGROUND

The association of acculturation with health among immigrant populations is believed to be mediated, in part, by acculturation-related stress and stress biology.

OBJECTIVES

To review and qualitatively synthesize empirical findings on the relationship of acculturation with stress-related inflammatory and endocrine biomarkers and composite allostatic load (AL) scores.

METHODS

A literature search was performed in the PubMed and PsycInfo databases. Article titles, abstracts or full-texts were screened and checked for match with the search criteria. Studies were eligible if they empirically tested the relationship between acculturation and inflammatory/endocrine stress biomarkers or composite AL scores, and were published in the English language.

RESULTS

Among the 41 articles identified as relevant and included in this review, the majority were published after 2010, included adult Hispanic U.S.-based populations, used cross-sectional study designs, operationalized acculturation as a unidimensional construct, and varied considerably in the selection of covariates in the analyses. Acculturation was significantly associated with stress biomarkers in 29 studies, but the direction of effects varied across studies. Specifically, acculturation, operationalized as a higher orientation towards the host culture, was associated with inflammatory biomarkers in 10 of 14 studies, with endocrine stress biomarkers in 12 of 20 studies, and with composite AL scores in 7 of 8 studies. Overall, language-based proxy measures of acculturation were related to higher levels of stress-related inflammatory and endocrine biomarkers and to lower levels of AL scores, whereas nativity-, generation status- and length of stay-based proxy measures of acculturation were related to higher levels of inflammatory biomarkers and AL score.

DISCUSSION

The majority of studies reported associations between measures of acculturation and stress biomarkers, however the directions of effects varied across studies. We suggest this heterogeneity may, in part, be a function of limitations imposed by cross-sectional research designs and unidimensional measures of acculturation measures, and we highlight the need for longitudinal studies and use of multidimensional measures of acculturation to better uncover the biobehavioral mechanisms and pathways linking acculturation with health outcomes.

Direct and Indirect Effect of Honey as a Functional Food Against Metabolic Syndrome and Its Skeletal Complications

Metabolic syndrome (MetS) refers to the simultaneous presence of hypertension, hyperglycemia, dyslipidemia and/or visceral obesity, which predisposes a person to cardiovascular diseases and diabetes. Evidence suggesting the presence of direct and indirect associations between MetS and osteoporosis is growing. Many studies have reported the beneficial effects of polyphenols in alleviating MetS in in vivo and in vitro models through their antioxidant and anti-inflammation actions. This review aims to summarize the effects of honey (based on unifloral and multi-floral nectar sources) on bone metabolism and each component of MetS. A literature search was performed using the PubMed and Scopus databases using specific search strings. Original studies related to components of MetS and bone, and the effects of honey on components of MetS and bone were included. Honey polyphenols could act synergistically in alleviating MetS by preventing oxidative damage and inflammation. Honey intake is shown to reduce blood glucose levels and prevent excessive weight gain. It also improves lipid metabolism by reducing total cholesterol, triglycerides and low-density lipoprotein, as well as increasing high-density lipoprotein. Honey can prevent bone loss by reducing the adverse effects of MetS on bone homeostasis, apart from its direct action on the skeletal system. In conclusion, honey supplementation could be integrated into the management of MetS and MetS-induced bone loss as a preventive and adjunct therapeutic agent.