Body mass index and dermal remodelling

Age-related changes in elastographically determined strain of the facial fat compartments: a new frontier of research on face aging processes

Introduction

Our study goal was verification of shear-wave elastography (SWE) as an assessment tool enabling quantitative analysis of facial fat tissue elasticity, using the example of the deep medial cheek fat compartment (DMCFC), due to its major role in pseudoptosis etiology.

Aim

Furthermore, we determined the age-specific reference values for DMCFC elasticity and analyzed its correlation with body mass index (BMI) and DMCFC thickness.

Material and methods

The study included 89 female patients (age: 18–63 years, mean: 45.9 ±14.2 years) with intact facial skin. Prior to the procedure, all participants were subjected to SWE of the DMCFC. Reference ranges for elastographic parameters were defined as ± 2 standard deviations (SD), or estimated by means of ROC analysis.

Results

The DMCFC elasticity correlated inversely with DMCFC thickness (R = –0.292, p < 0.001), age (R = –0.838, p < 0.001) and BMI of the study subjects (R = –0.258, p = 0.001). Age was found to be the only independent determinant of DMCFC elasticity on multiple linear regression analysis (β = –0.837, p < 0.001). The cut-off values for DMCFC elasticity estimated during ROC analysis provided excellent accuracy in distinguishing between women from various age categories, and to a large degree overlapped with the reference intervals defined as ± 2 SD.

Conclusions

Shear-wave elastography enables quantitative evaluation of facial fat pad elasticity, creating a new frontier in research on age-related processes. The results indicate that elasticity of the DMCFC decreases significantly with age. Tissue elasticity might be an indirect indicator of metabolic and structural properties of facial adipose tissue and its extracellular matrix.

Skin aging: are adipocytes the next target?

Dermal white adipose tissue (dWAT) is increasingly appreciated as a special fat depot. The adipocytes in this depot exert a variety of unique effects on their surrounding cells and can undergo massive phenotypic changes. Significant modulation of dWAT content can be observed both in intrinsically and extrinsically aged skin. Specifically, skin that has been chronically photo-damaged displays a reduction of the dWAT volume, caused by the replacement of adipocytes by fibrotic structures. This is likely to be caused by the recently uncovered process described as "adipocyte-myofibroblast transition" (AMT). In addition, contributions of dermal adipocytes to the skin aging processes are also indirectly supported by spatial correlations between the prevalence of hypertrophic scarring and the appearance of signs of skin aging in different ethnic groups. These observations could elevate dermal adipocytes to prime targets in strategies aimed at counteracting skin aging.