The Impact of the Number and Duration of Treatments With a 1064 nm Diode Laser on Adipocyte Apoptosis: Implications for Noninvasive Fat Reduction Strategies.

Background: Noninvasive treatment with a 1064 nm diode laser, generating hypodermal temperatures between 42 and 47 °C, induces adipocyte cell death, offering a solution to reduce fat in problematic areas. Objectives: The objective of the authors of this study is to determine whether a 15 min treatment provides similar efficacy as the standard 25 min treatment. Methods: Pigs underwent a 15 or 25 min 1064 nm laser treatment on 6 × 6 cm areas of abdominal skin. Single treatments were administered 14 or 28 days before biopsy, whereas dual treatments were performed at both 14 and 28 days prebiopsy. Hematoxylin and TUNEL staining were used to detect histological changes and apoptosis in harvested skin tissue. Results: Pig skin subjected to a 25 min diode laser treatment exhibited nearly twice the apoptotic counts in the hypodermis compared with the 15 min treatment (10.5 vs 5.7) at 28 days following treatment. The degree of apoptosis increased with time following the treatment, with nearly twice the apoptosis counts at 28 days than at 14 days following a single 25 min treatment (10.5 vs 5.8). When testing 1 vs 2 treatments, 2 treatments (28 and 14 days before harvesting the tissue) did not result in significantly higher apoptosis than 1 treatment 28 days before harvesting. Apoptosis was primarily localized to adipocytes in the hypodermis and the dermis/hypodermis junction. There were no adverse side effects in the animals. Conclusions: The degree of apoptosis following a 1064 nm laser treatment was proportional to the treatment duration. The 25 min treatment produced significantly more apoptosis than the 15 min treatment. The process of apoptosis continued over several weeks. Level of Evidence 4 Therapeutic: