An evidence review of the association of immune and inflammatory markers with obesity-related eating behaviors

Abstract

Background: Eating behaviors contribute to disproportionate energy intake and are linked to the development of obesity. Animal studies support the role of inflammatory cytokines and chemokines in the regulation of obesity-related eating behaviors and offer a potential target to combat obesity through the modulation of inflammation. However, more complex eating behaviors are present in humans, and their relationships with immune/inflammation markers are unclear. The present study reviewed current literature to synthesize the evidence on the association of immune/inflammation markers with obesity-related eating behaviors in humans.

Methods: A systematic search of three electronic databases yielded 811 articles, of which 11 met the inclusion criteria.

Results: The majority of the included studies (91%) were either case-control or cross-sectional studies. A variety of immune/inflammation markers and obesity-related eating behaviors have been assessed in the chosen studies. Three out of four studies identified a positive relationship between C-reactive protein (CRP)/high-sensitivity CRP and loss of control eating. Other inflammatory markers that potentially have a positive relationship with obesity-related eating behaviors include fractalkine and fibrinogen. Additionally, immune molecules, including interferon gamma (INF-γ), interleukin (IL)-7, IL-10, and α-melanocyte-stimulating hormone-reactive immunoglobulin G (α-MSH/IgG) immune complex, may have negative associations with obesity-related eating behaviors. However, most findings were identified by single studies.

Conclusion: Limited studies have been conducted in humans. Current evidence indicates a potential bi-directional relationship between inflammatory/immune markers and obesity-related eating behaviors. Additional studies with sophisticated research design and comprehensive theoretical models are warranted to further delineate the relationship between immune/inflammation markers and obesity-related eating behaviors.

Keywords: cytokine; eating behavior; immune markers; inflammatory marker; obesity.

Figure 1

Literature search flow chart.

Figure 2

Mechanisms linked immune/inflammatory markers to obesity-related eating behaviors. Immune/inflammatory markers are potentially involved in several mechanisms of regulation of obesity-related eating behaviors, including modulation of orexigenic and anorexigenic signals in the hypothalamus, induction of hypothalamic inflammation, regulation of food reward circuitries, and suppression anorexigenic signals by induction of inflammation in the vagus nerve ganglia. GI, gastrointestinal tract; Hyp, hypothalamus; PFC, prefrontal cortex; OFC, orbitofrontal cortex; NAc, nucleus accumbens; Amy, amygdala; VTA, ventral tegmental area.