RESUMEN
BACKGROUND AND OBJECTIVES: A previous pre-clinical study on electromagnetic muscle stimulation (EMMS) suggested that fat cell apoptosis occurs following treatment in a porcine model. While EMMS can induce changes in muscle, the effect on fat tissue is not established. This clinical study sought to assess adipose tissue response to EMMS in comparison to cryolipolysis treatment. STUDY DESIGN/MATERIALS AND METHODS: Study subjects were recruited prior to abdominoplasty to receive body contouring treatments and subsequently to obtain tissue for histological analysis. Non-invasive abdominal treatments were delivered using a commercially available (n = 6) or prototype (n = 3) EMMS system or a cryolipolysis system (n = 2). Subjects received a single EMMS treatment (100% intensity for 30 minutes) or a single cryolipolysis treatment (-11°C for 35 minutes) to the abdomen. Superficial and deep (i.e., adjacent to muscle layer) subcutaneous adipose tissue was harvested at set timepoints post-treatment. The presence or absence of an inflammatory response was evaluated using standard hematoxylin and eosin (H&E) staining. As adipocytes that are destined to become apoptotic cannot be distinguished by traditional H&E staining during the early phases of injury, irreversible fat cell injury was assessed using perilipin immunofluorescence. RESULTS: Following H&E histological analysis at 3, 10, 11, and 17 days post-treatment, no EMMS-treated samples showed an inflammatory response in either the superficial or deep subcutaneous adipose tissue. For the cryolipolysis-treated adipose tissue, however, the H&E staining revealed a marked inflammatory response with an influx of neutrophils, lymphocytes, and macrophages at timepoints consistent with previous histological studies. Further, loss of perilipin staining provided clear visual evidence of irreversible fat cell injury in the cryolipolysis-treated adipose tissue. In contrast, the electromagnetic muscle stimulation-treated samples showed persistence of perilipin staining of adipose tissue indicating that all fat cells were viable. CONCLUSION: This study failed to demonstrate either fat cell injury or inflammatory response following EMMS treatment. While electromagnetic muscle stimulation may non-invasively induce muscle changes, this clinical study found no evidence of an impact injurious or otherwise on subcutaneous fat. © 2020 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.