We are pleased to speak with Dr. Assaf Rudich, and Dr. Matthais Blüher, authors of an innovative new publication of interest to the global obesity medical and scientific community. Their work in identifying human obesity sub-types may lead to improvements in clinical management of patients with obesity.
Congratulations to both of you on this collaboration between Ben-Gurion University of the Negev, Beer-Sheva, Tel Aviv University, and The University of Leipzig.
At present, in order to identify obesity phenotypes, practitioners use clinical-based stratifications, both cross-sectionally and prospectively.
Please give us the top line message from your new research.
This study hypothesized that greater adipose tissue accumulation of Mast cells – a specific immune cell – would indicate a more inflammatory adipose tissue, and therefore, would associate with a high cardio-metabolic risk obesity subphenotype. The results, confirmed in 3 independent cohorts of patients with obesity (BMI≥30 kg/m2), indicate the opposite:
Higher accumulation of Mast cells in visceral adipose tissue associates with a “better”, lower cardio-metabolic risk, obesity phenotype. This was seen even when the studied population was sub-divided to those with diabetes, division by sex, or by the degree of obesity. Yet, most importantly, beyond cross-sectional associations, the study found in 2 independent cohorts an association between higher Mast cell accumulation in adipose tissue obtained during surgery and greater weight loss response to bariatric surgery.
How can measures of adipose tissue inflammation improve our understanding of new obesity phenotypes?
Adipose tissue inflammation is a complex phenomenon, first of all because inflammation is a multi-layered process that may indicate and/mediate both chronic tissue damage as well as resolution of such damage. Macrophage infiltration of adipose tissue, especially pro-inflammatory macrophage sub-types, is linked with a more severe cardiometabolic obesity phenotype. Conversely, our study shows that Mast cells accumulation in the adipose tissue indicates the opposite. Indeed, higher expression of macrophages genes or their formations in adipose tissue (“crown-like structures”) associate with lower accumulation of mast cells. These underscore the notion that adipose tissue containes valuable information for sub-phenotyping obesity and for directing more personalized obesity management.
Can this also have an impact on identifying cardio-metabolic risk factors and to support post surgical care for patients who have had bariatric surgery?
Potentially yes! Assuming our findings are confirmed in additional cohorts and in studies pre-defined to test the predictive value of Mast cell accumulation on bariatric surgery outcome, one can envision the following: A fat biopsy is taken during bariatric surgery and sent for Pathology. Using histology and/or molecular analyses, if the pathologist reports back to the managing clinician that Mast cell accumulation is low, this may indicate rather sub-optimal weight-loss response to the surgery. The clinician can then better tailor the post-operative care of the patient to achieve improved weight-loss response by, for example, intensifying the post-operative means to enhance weight loss.