New Adjuvant Therapies for Obesity-Related Disorders Associated with Meta-Neuroinflammation

Obesity is a complex, heterogeneous, chronic, and progressive disease, which correlates with an augmented risk of developing several comorbidities, including painful conditions, such as osteoarthritis. In this review, authors present for the first time the term meta-neuroinflammation for describing how the chronic, low-grade systemic inflammation, that occurs in obesity, may trigger oxidative stress and neuroinflammatory processes. Both the peripheral and the central nervous system are involved in neuroinflammation, leading to central sensitization and pain chronification, which leads to the observed increased incidence in obese patients of chronic pain syndromes, particularly osteoarthritis, low back pain, fibromyalgia, headache, and diabetic peripheral neuropathy. Possible mechanisms by which obesity may cause meta-neuroinflammation include adiposopathy, gut microbiota dysbiosis, and compromised integrity of blood–brain barrier, which could explain obesity-related depressive and neurodegenerative disorders. Preclinical data suggest the meta-neuroinflammation as a potential target of treatment in obese patients with degenerative joint disease. Based on these observations, targeted therapeutic strategies may include systemic administration of ultramicronized palmitoylethanolamide (um-PEA), well known for its neuroprotective, anti-neuroinflammatory, and analgesic actions, and comicronized PEA–rutin and hydroxytyrosol to restore intestinal eubiosis, with beneficial effects on body weight and mental disorders. Finally, Adelmidrol, as a PEA congener, could be considered for mitigating intra-articular meta-neuroinflammation in knee osteoarthritis.