Low Skeletal Muscle Mass Is Associated With Perioperative Neurocognitive Disorder Due To Decreased Neurogenesis in Rats

Sarcopenia is a risk factor for postoperative delirium in geriatric hip fracture patients: a retrospective study

Background

Various factors contribute to postoperative delirium (POD) in elderly patients undergoing hip fracture surgeries. Sarcopenia was defined as the progressive loss of skeletal muscle mass and strength associated with aging. The aim of this study was to explore the prevalence of POD and sarcopenia in geriatric patients undergoing hip fracture surgeries and to investigate the correlation between preoperative sarcopenia and POD.

Methods

After applying specific inclusion and exclusion criteria, the information of 234 patients were retrospectively collected. POD was screened for with 4A's Test and diagnosed with DSM-5 criteria. The incidences of POD and sarcopenia were calculated. The demographic and perioperative features as well as comorbidities of delirious and non-delirious patients were analyzed and the risk factors analysis for POD in elderly hip fracture patients were conducted through univariate analysis and multivariate regression analysis.

Results

48.7% patients were diagnosed of POD, 78.95% of which were females. The average age of delirious and non-delirious patients were 84.75 years and 80.63 years, respectively. The incidence of sarcopenia was 41.02% for all the included patients with 60.53% for delirious patients and 20.55% for non-delirious patients. Results of univariate analysis showed that sarcopenia (OR:5.281, 95%CI 2.988-9.337, p = 0.000), age increase per year (OR:1.128, 95CI 1.070-1.190, p = 0.000), operation duration increase (OR:1.017, 95%CI 1.004-1.030, p = 0.011), intertrochanteric fracture (OR:2.571, 95%CI 1.517-4.358, p = 0.000), dementia (OR: 6.029, 95%CI 2.532-14.359, p = 0.000), ASA > 2 (OR: 6.955, 95%CI 3.461-13.976, p = 0.000), coronary heart disease (OR: 2.201, 95%CI 1.257-3.854, p = 0.006), renal insufficiency (OR: 2.215, 95%CI 1.187-4.133, p = 0.012) and COPD (OR: 2.554, 95%CI 1.414-4.615, p = 0.002) were risk factors for POD. Results of multivariate analysis identified sarcopenia (OR: 2.457, 95% CI 1.226-4.923, p = 0.011), ASA > 2 (OR: 3.968, 95% CI 1.805-8.722, p = 0.001), dementia (OR: 3.912, 95% CI 1.390-11.014, p = 0.010) and coronary heart disease (OR: 2.176, 95% CI 1.044-4.538, p = 0.038) as independent risk factors for POD in geriatric hip fracture patients.

Conclusion

The incidences of POD and sarcopenia in geriatric hip fracture patients are high. Sarcopenia is an independent risk factor for POD in geriatric hip fracture patients.

Association between preoperative sarcopenia and postoperative delirium in older patients undergoing gastrointestinal cancer surgery

Background

Postoperative delirium (POD) is a usual neurological complication, often leading to poor prognoses. Early identification of high-risk patients is crucial for preventing POD. Sarcopenia is an age-related geriatric syndrome characterized by the loss of skeletal muscle mass and function, and previous studies indicated that preoperative low muscle mass might be a predictor for POD. However, the association between preoperative sarcopenia and POD remains to be fully elucidated. This study was to explore the correlation between preoperative sarcopenia and POD following gastrointestinal cancer surgery in older patients.

Methods

Older patients (≥60 years) undergoing gastrointestinal cancer surgery were enrolled. Sarcopenia was defined based on the Special Interest Group on sarcopenia of the International Society of Physical and Rehabilitation Medicine (ISarcoPRM), which combined the loss of muscle mass (evaluated by ultrasound) and function (assessed by chair stand test and handgrip strength) before surgery. POD assessment was performed using the Confusion Assessment Method (CAM) or CAM for the intensive care unit (CAM-ICU) during the first 7 days after surgery or before discharge. Multivariate logistic regression analysis examined the correlation between preoperative sarcopenia and POD. Moreover, the receiver operator characteristic (ROC) curve was applied to analyze the predictive effect of the preoperative sarcopenia in POD.

Results

One hundred and thirty patients were finally included, of which 43 patients presented with sarcopenia before surgery. Twenty-four patients ultimately developed POD, and the incidence was 18.5%. The results of the multivariate analyses demonstrated that preoperative sarcopenia was still independently associated with POD after adjusting for age ≥70 years, preoperative Mini-Mental State Examination score, and intraoperative blood transfusion. The area under the ROC curve of preoperative sarcopenia in predicting POD was 0.680 (95% confidence interval 0.557-0.804).

Conclusion

Preoperative sarcopenia defined by ISarcoPRM criteria was independently associated with POD in geriatric patients after gastrointestinal cancer surgery.

The Effects of Appropriate Perioperative Exercise on Perioperative Neurocognitive Disorders: a Narrative Review

Perioperative neurocognitive disorders (PNDs) are now considered the most common neurological complication in older adult patients undergoing surgical procedures. A significant increase exists in the incidence of post-operative disability and mortality in patients with PNDs. However, no specific treatment is still available for PNDs. Recent studies have shown that exercise may improve cognitive dysfunction-related disorders, including PNDs. Neuroinflammation is a key mechanism underlying exercise-induced neuroprotection in PNDs; others include the regulation of gut microbiota and mitochondrial and synaptic function. Maintaining optimal skeletal muscle mass through preoperative exercise is important to prevent the occurrence of PNDs. This review summarizes current clinical and preclinical evidence and proposes potential molecular mechanisms by which perioperative exercise improves PNDs, providing a new direction for exploring exercise-mediated neuroprotective effects on PNDs. In addition, it intends to provide new strategies for the prevention and treatment of PNDs.

Update of the European Society of Anaesthesiology and Intensive Care Medicine evidence-based and consensus-based guideline on postoperative delirium in adult patients

Postoperative delirium (POD) remains a common, dangerous and resource-consuming adverse event but is often preventable. The whole peri-operative team can play a key role in its management. This update to the 2017 ESAIC Guideline on the prevention of POD is evidence-based and consensus-based and considers the literature between 01 April 2015, and 28 February 2022. The search terms of the broad literature search were identical to those used in the first version of the guideline published in 2017. POD was defined in accordance with the DSM-5 criteria. POD had to be measured with a validated POD screening tool, at least once per day for at least 3 days starting in the recovery room or postanaesthesia care unit on the day of surgery or, at latest, on postoperative day 1. Recent literature confirmed the pathogenic role of surgery-induced inflammation, and this concept reinforces the positive role of multicomponent strategies aimed to reduce the surgical stress response. Although some putative precipitating risk factors are not modifiable (length of surgery, surgical site), others (such as depth of anaesthesia, appropriate analgesia and haemodynamic stability) are under the control of the anaesthesiologists. Multicomponent preoperative, intra-operative and postoperative preventive measures showed potential to reduce the incidence and duration of POD, confirming the pivotal role of a comprehensive and team-based approach to improve patients' clinical and functional status.

Does the regulation of skeletal muscle influence cognitive function? A scoping review of pre-clinical evidence

Background

Cognitive impairment is a major challenge for elderlies, as it can progress in a rapid manner and effective treatments are limited. Sarcopenic elderlies have a higher risk of dementia. This scoping review aims to reveal whether muscle is a mediator of cognitive function from pre-clinical evidence.

Methods

PubMed, Embase, and Web of Science were searched to Feb 2nd, 2022, using the keywords (muscle) AND (cognition OR dementia OR Alzheimer) AND (mouse OR rat OR animal). The PRISMA guideline was used in this study.

Results

A total of 17 pre-clinical studies were selected from 7638 studies. 4 studies reported that muscle atrophy and injury harmed memory, functional factors, and neurons in the brain for rodents with or without Alzheimer's disease (AD). 3 studies observed exercise induced muscle to secrete factors, including lactate, fibronectin type III domain-containing protein 5 (FNDC5), and cathepsin B, which plays essential roles in the elevation of cognitive functions and brain-derived neurotrophic factor (BDNF) levels. Muscle-targeted treatments including electrical stimulation and intramuscular injections had effective remote effects on the hippocampus. 6 studies showed that muscle-specific overexpression of scFv59 and Neprilysin, or myostatin knockdown alleviated AD symptoms. 1 study showed that muscle insulin resistance also led to deficient hippocampal neurogenesis in MKR mice.

Conclusions

The skeletal muscle is involved in the mediation of cognitive function. The evidence was established by the response in the brain (altered number of neurons, functional factors, and other AD pathological characteristics) with muscle atrophy or injury, muscle secretory factors, and muscle-targeted treatments.

The translational potential of this paper

This study summarizes the current evidence in how muscle affects cognition in molecular levels, which supports muscle-specific treatments as potential clinical strategies to prevent cognitive dysfunction.

Low Skeletal Muscle Mass and the Incidence of Delirium in Hospitalized Older Patients: A Systematic Review and Meta-Analysis of Observational Studies

Background

Both low skeletal muscle mass and delirium are prevalent in older hospitalized patients, while their associations are unclear. This systematic review and meta-analysis aim to investigate the associations between low skeletal muscle mass and the incidence of delirium in hospitalized patients.

Methods

The PubMed, Web of Science, and Embase were searched for relevant studies published before May 2022, and we conducted this systematic review and meta-analysis according to the PRISMA and MOOSE guidelines. The summary odds ratios (OR) and 95% confidence intervals (CI) were estimated, and subgroup analyses were also conducted according to the age and major surgeries.

Results

Finally, nine studies with 3 828 patients were included. The pooled result showed no significant association between low skeletal muscle mass and the incidence of delirium (OR 1.69, 95% CI 0.85 to 2.52). However, sensitivity analysis suggested that one study caused a significant alteration of the summary result, and the meta-analysis of the remaining 8 studies showed that low skeletal muscle mass was significantly associated with an 88% increased incidence of delirium (OR 1.88, 95% CI 1.43 to 2.33). Furthermore, subgroup analyses indicated that low skeletal muscle mass was associated with a higher incidence of delirium in patients ≥75 years old or undergoing major surgeries instead of those <75 years old or without surgeries, respectively.

Conclusions

Hospitalized patients with low skeletal muscle mass might have higher incidence of delirium, particularly in those of older age and undergoing major surgeries. Therefore, great attention should be paid to these patients.