Clinical psychoneuroimmunology

Compression therapy, autonomic nervous system, and heart rate variability: A narrative review and our preliminary personal experience

Aims

To highlight the relationship among compression therapy (CT), the autonomic nervous system (ANS) (parasympathetic and sympathetic system), and the heart rate variability (HRV) analysis.

Background

Beyond the typical analgesic and anti-inflammatory effects of CT in patients affected by venous and/or lymphatic diseases, some literature about CT influence on wellbeing has been published as well. More specifically, CT influence on the ANS has been elucidated mostly through HRV application, providing useful quali-quantitative data for scientific and clinical purposes.

Material and Methods

A literature search was performed through several web-based search engines to investigate the available evidence concerning the possible influence of CT on the ANS and on psychoneuroendocrineimmunology. Moreover, we examined literature data regarding HRV use in the assessment of CT. Lastly, a preliminary cross-over study was performed on 10 patients affected by phlebolymphedema of the lower limbs, undergoing CT with 18–21 mmHg stockings for 10 h and investigated by means of HRV.

Results

A CT-based increase of the anti-inflammatory activity of the parasympathetic (vagal) system has been elucidated in most scientific literature. Similarly, CT application has generally resulted in an improvement of HRV, which indicates a beneficial influence on the ANS. In our preliminary experience with compression stockings and HRV, two parasympathetic-based parameters improved by 22.8% and 68.0% after 10 h, whereas they decreased in the same subjects without stockings by 2.7% and 8.2%, during normal breathing. The remaining HRV parameters did not show relevant variations, especially during diaphragmatic breathing.

Conclusions

From literature data and based on our very preliminary experience, it is possible to deduce that CT exerts different effects on the psychobiological parameters of the individual, overall improving HRV and parasympathetic activity. Incorporating both HRV/ANS assessment in phlebolymphology and the beneficial neural action of CT in health care may represent viable options in the future biomedical science.

Emotion Regulation as a Pathway Connecting Early Life Adversity and Inflammation in Adulthood: a Conceptual Framework

Chronic inflammation is implicated in a variety of diseases (e.g., cardiovascular disease and cancer). Much evidence suggests that early life adversity (ELA), such as maltreatment or neglect, can increase risk for inflammation in adulthood. ELA may program proinflammatory activity via its effects on brain areas involved in emotion regulation. Of multiple emotion regulation strategies, some are considered maladaptive (e.g., expressive suppression), while others are generally adaptive (e.g., cognitive reappraisal). We propose a conceptual framework for how emotion regulation tendencies may affect vulnerability or resilience to inflammation in adults who experienced adversity in childhood and/or adolescence. In support of this framework, we summarize evidence for the relationships between emotion dysregulation and higher inflammation (i.e., vulnerability), as well as between cognitive reappraisal and lower inflammation (i.e., resilience), in healthy adults with a history of ELA. Plausible neurobiological, physiological, psychosocial, and ELA-specific factors, as well as interventions, contributing to these associations are discussed. Strengths and limitations of the extant research, in addition to ideas for future directions, are presented.

Positive affect and peripheral inflammatory markers among adults: A narrative review

BACKGROUND

Previous research suggests that positive affect (PA) may promote health and longevity and that one potential mechanism involves inflammation. However, it remains unclear to what extent PA is associated with specific inflammatory markers and whether such associations are driven by main effects of PA and/or due to PA operating as a stress-buffer.

METHODS

The present narrative review incorporates studies (N = 28) that have examined the association between PA and peripheral inflammatory markers obtained using venous puncture or dried blood spots. We separate results by whether the study tested direct effects or stress-buffering, and by type of inflammatory marker [including C-reactive protein (CRP), and proinflammatory and anti-inflammatory cytokines], also paying close attention to type of PA assessment (state, aggregated state, or retrospective, the latter involving recall over one to two weeks), and study design (cross-sectional, longitudinal, and experimental).

RESULTS

Limited evidence suggests that studies were more supportive of a stress-buffering association, compared to a relatively direct association. When significant direct associations were observed, results suggested that studies using measures of state/aggregated PA exhibited more consistent associations with inflammatory markers than studies using retrospective PA. When significant, higher PA tended to be associated with lower pro- and anti-inflammatory markers, suggestive of lower overall inflammatory load.

DISCUSSION

Recommendations for the field and future research are discussed, including the value of utilizing state/aggregated PA measures and of examining stress-buffering mechanisms.

IL-4 Knock Out Mice Display Anxiety-Like Behavior

Inflammation is a recognized antecedent and coincident factor when examining the biology of anxiety. Little is known, however, about how reductions in endogenous anti-inflammatory mediators impact anxiety. Therefore, mood- cognition- and anxiety-associated/like behaviors were examined in IL-4 knock out (KO) mice and wild-type (WT) mice. In comparison to WT mice, IL-4 KO mice demonstrated decreased burrowing and increased social exploration. No differences were seen in forced swim or saccharine preference testing. IL-4 KO mice had similar performance to WT mice in the Morris water maze and during object location and novel object recognition. In the elevated zero-maze, IL-4 KO mice, in comparison to WT mice, demonstrated anxiety-like behavior. Anxiety-like behavior in IL-4 KO mice was not observed, however, during open-field testing. Taken together, these data indicate that IL-4 KO mice display state, but not trait, anxiety suggesting that reductions in endogenous anti-inflammatory bioactives can engender subtypes of anxiety.

Microbial endocrinology: Host-microbiota neuroendocrine interactions influencing brain and behavior

The ability of microorganisms, whether present as commensals within the microbiota or introduced as part of a therapeutic regimen, to influence behavior has been demonstrated by numerous laboratories over the last few years. Our understanding of the mechanisms that are responsible for microbiota-gut-brain interactions is, however, lacking. The complexity of the microbiota is, of course, a contributing factor. Nonetheless, while microbiologists approaching the issue of microbiota-gut-brain interactions in the behavior well recognize such complexity, what is often overlooked is the equal complexity of the host neurophysiological system, especially within the gut which is differentially innervated by the enteric nervous system. As such, in the search for common mechanisms by which the microbiota may influence behavior one may look for mechanisms which are shared by both host and microbiota. Such interkingdom signaling can be found in the shared production of neurochemical mediators that are found in both eukaryotes and prokaryotes. The study of the production and recognition of neurochemicals that are exactly the same in structure to those produced in the vertebrate organisms is known as microbial endocrinology. The examination of the microbiota from the vantage point of host-microbiota neuroendocrine interactions cannot only identify new microbial endocrinology-based mechanisms by which the microbiota can influence host behavior, but also lead to the design of interventions in which the composition of the microbiota may be modulated in order to achieve a specific microbial endocrinology-based profile beneficial to overall host behavior.