Effects of Single-Session Group Mantra-meditation on Salivary Immunoglobulin A and Affective State: A Psychoneuroimmunology Viewpoint

Yoga, Meditation, Breathing Exercises, and Inflammatory Biomarkers with Possible Implications in COVID-19: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Introduction

COVID-19, a multisystem disease, has implications for various immunity and infection biomarkers. Yoga (Y), meditation (M), and pranayama (P), and their combinations have shown positive changes on those biomarkers among other than COVID-19 patients and healthy people. So, we aimed to document the evidence of possible implication in a systematic way.

Materials and Methods

We screened 84 full texts, published in the last ten years, from three databases, from which only 44 met the eligibility criteria, and then extracted the data related to demographic characteristics, intervention, results, and strengths and limitations in two MS-Excel grids, and then presented them in tables and figures. Furthermore, we carried out meta-analysis including subgroup and sensitivity analysis using a random effects model of 11 RCTs and reported the mean difference, heterogeneity, and p value with 95% CI and presented them with forest and funnel plots and the tables.

Results

Twenty-five biomarkers of 4023 participants (range, 15-413) from 13 countries, healthy and clinical, from both sexes above 18 years, and from mainly clinical settings, were reported. YMP intervention, in solitary or in different possible combinations with varied durations among clinical and pregnant (range, 960-4800 minutes) and healthy (960-8400 minutes, excluding two studies of 20 minutes only) participants, was reported. It was revealed that 25 biomarkers, nine among the apparently healthy, 14 among the patients, and two among the pregnant, changed favourably (p < 0.05). Furthermore, either in meta- or subgroup-analysis, mean differences of IL-6 (-1.44 pg/ml) (95% CI) (-2.33, -0.55), (p = 0.002, I ²  = 82%), Cortisol (-40.75 pg/ml) (95% CI) (-64.13, -17.38), (p = 0.0006, I ²  = 87%), and TNF-α (-3.40 pg/ml) (95% CI) (-4.83, -1.98), (p < 0.0001, I ²  = 79%) showed statistically significant changes. Nonetheless, considerable heterogeneity and publication bias were observed among the studies.

Conclusion

Although more than two dozens of biomarkers in individual studies showed favourable changes, only IL-6, Cortisol, and TNF-α produced significant combined results, even then with much less certainty. Further meta-analysis of biomarkers of COVID-19 patients is highly recommended. Registration: CRD42021283894.

Effects of yoga on immune function: A systematic review of randomized controlled trials

OBJECTIVE

This systematic review attempts to confirm the added evidence to assess the effect of yoga on immune function.

METHODS

The Cochrane Library, Embase, PsycINFO, PubMed, and Web of Science electronic databases were searched according to the PRISRMA method to identify randomized controlled trials (RCTs) on the immunological effects of yoga published in the English language from January 1, 2017, to December 31, 2020. This review could only be descriptively summarized because of heterogeneity of the included RCTs.

RESULTS

Eleven potential trials were identified and included in this review. Quality appraisal of included trials ranged from 3 for unclear risk of bias and 8 for high risk of bias. There is evidence from 11 RCTs that yoga may have favorable effects for reducing the levels of anti-inflammatory markers.

CONCLUSIONS

Yoga may be used as a complementary intervention for clinical populations or healthy individuals.

Effects of transcranial direct current stimulation on cognitive dysfunction in multiple sclerosis

BACKGROUND

Around 40%-70% of patients with multiple sclerosis (MS) may experience cognitive impairments during the course of their disease with detrimental effects on social and occupational activities. Transcranial direct current stimulation (tDCS has been investigated in pain, fatigue, and mood disorders related to MS, but to date, few studies have examined effects of tDCS on cognitive performance in MS.

OBJECTIVE

The current study aimed to investigate the effects of a multi-session tDCS protocol on cognitive performance and resting-state brain electrical activities in patients with MS.

METHODS

Twenty-four eligible MS patients were randomly assigned to real (anodal) or sham tDCS groups. Before and after 8 consecutive daily tDCS sessions over the left dorsolateral prefrontal cortex (DLPFC), patients' cognitive performance was assessed using the Cambridge Brain Sciences-Cognitive Platform (CBS-CP). Cortical electrical activity was also evaluated using quantitative electroencephalography (QEEG) analysis at baseline and after the intervention.

RESULTS

Compared to the sham condition, significant improvement in reasoning and executive functions of the patients in the real tDCS group was observed. Attention was also improved considerably but not statistically significantly following real tDCS. However, no significant changes in resting-state brain activities were observed after stimulation in either group.

CONCLUSION

Anodal tDCS over the left DLPFC appears to be a promising therapeutic option for cognitive dysfunction in patients with MS. Larger studies are required to confirm these findings and to investigate underlying neuronal mechanisms.

A New Hypothesis on Anxiety, Sleep Insufficiency, and Viral Infections; Reciprocal Links to Consider in Today's "World vs. COVID-19" Endeavors

In today's ever-growing concerns about the coronavirus disease (COVID-19) pandemic, many experience sleep insufficiencies, such as difficulty falling or staying asleep, sleep-related behavioral symptoms, and out-of-phase circadian rhythmicity despite the lack of history of earlier such symptoms. Meanwhile, the disruption in sleep bioparameters is experienced more in people with a history of sleep disorders. The behavioral sleep disorders in the current situations are prevalent given the today's amount of anxiety everyone is feeling about COVID-19. On the other hand, evidences indicated that the cross-link between impaired sleep efficiency and disrupted innate immunity makes people susceptible to viral infections. The present brief review highlights the links between psychosocial stress, sleep insufficiency, and susceptibility to viral infections in relevance to COVID-19 situation. The stress management measures, including addressing sleep-related disorders and sleep hygiene, will have a notable impact by harnessing immune response and thus reducing the susceptibility to viral infections.