Effects of exercise interventions on brain-derived neurotrophic factor levels in overweight and obesity: A systematic review and meta-analysis

Background

/Objective. An explosion in global obesity epidemic poses threats to the healthcare system by provoking risks of many debilitating diseases, including cognitive dysfunction. Physical activity has been shown to alleviate the deleterious effects of obesity-associated cognitive deficits across the lifespan. Given the strong neuroprotective role of brain-derived neurotrophic factor (BDNF) and exercise training as a known modulator for its elevation, this systematic review sought to examine the strength of the association between exercise and BDNF levels in healthy people with overweight and obesity.

Methods

Six electronic databases (PubMed, MEDLINE, EMBASE, Web of Science, Ovid Nursing Database, and SPORTDiscus) were searched from their inceptions through December 2022. The primary outcome of interest was BDNF levels. Interventional studies (randomized and quasi-experimental) with English full text available were included. Risk of bias of the included studies was assessed using the Physiotherapy Evidence Database Scale. Data were extracted for meta-analyses by random-effects models.

Results

Thirteen studies (n = 750), of which 69.2% (9/13) had low risk of bias, were included. In the meta-analysis, exercise interventions had no significant effect on resting BDNF levels (standardized mean difference: -0.30, 95% CI -0.80 to 0.21, P = 0.25). Subgroup analyses also indicated no effects of age and types of control groups being compared on moderating the association.

Conclusion

To further inform the role of BDNF in obesity-related cognitive functioning, rigorous studies with larger samples of participants and raw data available were imperatively deserved.

1245 HEALTH CARE WORKERS’ EXPERIENCES ON WORKING AT RESIDENTIAL CARE HOME FOR THE ELDERLY: AN INTEGRATIVE REVIEW

Introduction

The ageing population poses challenges to the health care industry worldwide. The huge demand for residential care home for the elderly (RCHE) services induces pressure on health care workers (HCWs) recruitment and retention. HCWs are personnel who have prominent roles in direct basic care to the older adults, and all kinds of hands-on care. Due to the “unpleasant” work nature, shift work, and physical demands for HCWs, it is essential to unfold how HCWs comprehend their working experiences.

Methods

An integrative review was conducted to synthesize various streams of literature in order to generate new knowledge. Multiple databases such as CINAHL, ERIC, LWW nursing were adopted to search for relevant literature published between 2012 and 2022.

Results

A total of 24 articles were retrieved at the initial stage, and 7 articles were sorted after in-depth review. In general, results supported that HCWs experienced positively on the works at RCHEs though there were job stresses. The HCWs perceived the roles at RCHEs as routinized and task-oriented by providing direct care to older adults. They perceived their roles at RCHEs as care providers who provided direct care to older adults. Also, their responsibilities to maintain the safety and dignity of older adults was expressed as utmost importance. The meaning of works lay on three levels: interpersonal (e.g. self-achievement), interpersonal (e.g. communication with team members), and job performance (e.g. task compliance).

Conclusions

This study reveals the experiences of working at RCHE from the HCWs’ perspective. The HCWs’ experiences reflected in this study as well as the meaning of works discovered can generate insights for policy-makers on HCWs recruitment and retention.

Acknowledgement

The work described in this abstract was fully supported by a grant from the Research Grants Council of HKSAR, China [RGC: UGC/FDS16/M12/20].

The Role of MicroRNA and Microbiota in Depression and Anxiety

Depression and anxiety are devastating disorders. Understanding the mechanisms that underlie the development of depression and anxiety can provide new hints on novel treatments and preventive strategies. Here, we summarize the latest findings reporting the novel roles of gut microbiota and microRNAs (miRNAs) in the pathophysiology of depression and anxiety. The crosstalk between gut microbiota and the brain has been reported to contribute to these pathologies. It is currently known that some miRNAs can regulate bacterial growth and gene transcription while also modulate the gut microbiota composition, suggesting the importance of miRNAs in gut and brain health. Treatment and prevention strategies for neuropsychiatric diseases, such as physical exercise, diet, and probiotics, can modulate the gut microbiota composition and miRNAs expressions. Nonetheless, there are critical questions to be addressed to understand further the mechanisms involved in the interaction between the gut microbiota and miRNAs in the brain. This review summarizes the recent findings of the potential roles of microbiota and miRNA on the neuropathology of depression and anxiety, and its potential as treatment strategies.

AdipoRon Treatment Induces a Dose-Dependent Response in Adult Hippocampal Neurogenesis

AdipoRon, an adiponectin receptor agonist, elicits similar antidiabetic, anti-atherogenic, and anti-inflammatory effects on mouse models as adiponectin does. Since AdipoRon can cross the blood-brain barrier, its chronic effects on regulating hippocampal function are yet to be examined. This study investigated whether AdipoRon treatment promotes hippocampal neurogenesis and spatial recognition memory in a dose-dependent manner. Adolescent male C57BL/6J mice received continuous treatment of either 20 mg/kg (low dose) or 50 mg/kg (high dose) AdipoRon or vehicle intraperitoneally for 14 days, followed by the open field test to examine anxiety and locomotor activity, and the Y maze test to examine hippocampal-dependent spatial recognition memory. Immunopositive cell markers of neural progenitor cells, immature neurons, and newborn cells in the hippocampal dentate gyrus were quantified. Immunosorbent assays were used to measure the serum levels of factors that can regulate hippocampal neurogenesis, including adiponectin, brain-derived neurotrophic factor (BDNF), and corticosterone. Our results showed that 20 mg/kg AdipoRon treatment significantly promoted hippocampal cell proliferation and increased serum levels of adiponectin and BDNF, though there were no effects on spatial recognition memory and locomotor activity. On the contrary, 50 mg/kg AdipoRon treatment impaired spatial recognition memory, suppressed cell proliferation, neuronal differentiation, and cell survival associated with reduced serum levels of BDNF and adiponectin. The results suggest that a low-dose AdipoRon treatment promotes hippocampal cell proliferation, while a high-dose AdipoRon treatment is detrimental to the hippocampus function.

Management decision of hospital surge: assessing seasonal upsurge in inpatient medical bed occupancy rate among public acute hospitals in Hong Kong

BACKGROUND

There were recurrent upsurges in demand for public hospital services in Hong Kong. An understanding of the contribution of some possible factors for the rise in health care burden would help to inform hospital management strategies.

AIM

To evaluate the utilization patterns of hospitalizations in medical wards among public acute hospitals in Hong Kong during surge periods.

DESIGN

Retrospective study.

METHODS

By extracting the information in press releases between 2014 and 2018, descriptive statistics about medical ward occupancy situation during six surge periods were generated. A time series model was constructed to estimate the occupancy rate at each hospital and assess its relationship with the intensity of seasonal influenza activity, extreme weather, day of week and long holidays.

RESULTS

There was a significant increase in the number of admissions to medical wards in all six surge periods. A significant variation in occupancy rate between weekdays and geographic regions was observed. The occupancy rate in 10, out of 15, hospitals was significantly associated with the influenza activity, while there was limited effect of weather on the occupancy rate. A significant holiday effect was observed during Christmas and Chinese New Year, resulting in a lower bed occupancy rate.

CONCLUSIONS

A differential burden in public hospitals during surge periods was reported. Contingency bed and staff management shall be tailored to individual hospitals, given their differences in the determinants for inpatient bed occupancy.

Roles of paroxetine and corticosterone on adult mammalian ciliary body cell proliferation

BACKGROUND

The neurogenesis in retina of adult mammals is generally abolished, and this renders the retina lack of regenerative capacity. Despite this, there is a small population of nestin-positive cells in the ciliary epithelium which retains neurogenic potential. The present study aimed at investigating the effect of two drugs, corticosterone and paroxetine, on the cell proliferation of the ciliary body.

METHODS

Adult Sprague-Dawley rats were given vehicle, corticosterone, paroxetine, or both corticosterone and paroxetine treatment for 14 days. Cell proliferation in the ciliary body was quantified using 5-bromo-2-deoxyuridine (BrdU) immunohistochemistry. Co-labelling of BrdU and stem cell marker was used to phenotype the BrdU immunoreactive cells.

RESULTS

Corticosterone treatment suppressed while paroxetine treatment increased the cell proliferation of the ciliary body. Co-labelling with cell markers revealed that the BrdU positive cells also showed nestin expression but not glial fibrillary acidic protein (GFAP).

CONCLUSIONS

The results illustrate that proliferation of retinal progenitor cells situated in ciliary body are subjected to regulation by selective serotonin reuptake inhibitors (SSRI) and corticosteroid, which is similar to our previous findings in neurogenic regions in central nervous system (CNS). Paroxetine treatment could reverse the suppressive effect of corticosterone on ciliary body cell proliferation. This provides information for future investigation of retinal stem cell biology and potential treatment of retinal degenerative diseases.