Biomechanical properties of skin in massive weight loss patients

Background: The aim of this study is to assess skin strength in MWL patients relative to control cosmetic abdominoplasty patients biophysically, biochemically, and histologically. Growing success of weight loss programs has brought about an increase in the MWL population. Skin quality is thought to be impaired by MWL, but there are no compelling studies that have fully addressed the structural mechanisms involved. Methods: Skin from the medial and lateral abdomen was harvested fresh from patients undergoing cosmetic abdominoplasty (n=6) or abdominal panniculectomy for MWL (n=35), and burst strength was tested in the horizontal and vertical directions. Collagen content was measured, and histological studies were performed to assess epidermal and dermal thickness, vascularity as well as the morphology and density of the collagen fibers. Results: In all groups, skin stretched horizontally was stronger than skin stretched vertically (p<0.001). The skin of MWL patients was stronger medially compared to the skin of cosmetic patients. (p=0.047) Newly formed collagen was diminished in MWL than that in the control group, but the results were not statistically significant. Epidermal thickness was significantly higher medially in MWL (p=0.049). Elastin fibers were decreased in the MWL group, while dermal vascularity was higher in the MWL group. Conclusions: The skin of MWL patients demonstrated stronger mechanical parameters than that of cosmetic patients in the medial part of the abdomen; however, the decrease in elastic fibers associated with a decrease in newly formed collagen seemingly provides a contradiction. Skin changes with MWL merits further study to understand it more completely.