Influence of subcutaneous adipose tissue mass on dermal elasticity and sagging severity in lower cheek

Background: Subcutaneous adipose tissue lies just beneath the dermal layer, but the interaction between the two is not well understood. Recently, we showed that the subcutaneous adipose layer affects dermal properties in an obese rodent model. Objective: To explore the influence of the subcutaneous adipose layer on dermal properties and morphology in humans. Methods: Subcutaneous adipose mass was measured by ultrasound using a Prosound alpha 5^®, dermal elasticity was measured using an in vivo suction skin elasticity meter (Cutometer MPA 580^®), and sagging severity were evaluated morphologically using photograph‐based grading criteria at the lower cheek in 70 Japanese female volunteers (age; 31–59, BMI; 17.1–36.2). The correlations among the results were examined. Results: Thickness of the subcutaneous adipose layer was significantly and negatively correlated with dermal elasticity parameters, i.e., elastic deformation, elastic deformation recovery, extensibility, total deformation recovery, ratio of viscoelasticity to elastic distention and overall elasticity, including creep and creep recovery. Furthermore, we investigated their influence on facial morphology, such as sagging. The subcutaneous adipose mass was significantly and positively correlated with sagging severity at the lower cheek (R=0.442, P<0.001), and there was a significant negative correlation between dermal elasticity and sagging severity (R=?0.358, P<0.01). Conclusion: These results indicate that increment of subcutaneous adipose mass impairs dermal elasticity, which in turn exacerbates sagging severity.     

Development of a non-invasive measurement system to the thickness of the subcutaneous adipose tissue layer

Background/purpose: It is important to measure the thickness of hypodermis, including the subcutaneous fat layer in several fields such as global assessment of nutritional status and monitoring of dietary manipulation. It also provides useful information concerning the amount of peripheral adipose tissue and can be used as an index of obesity. Methods: To measure the thickness of the subcutaneous adipose tissue layer, the optical properties of tissue components, several lipids and animal tissue samples in vitro were measured over the wavelength range from 1000 to 1700 nm, using the transmittance measurement system and the diffuse reflectance measurement system. A wavelength range for the thickness measurements was selected from the experimental result. The corresponding signal according to the changes of adipose tissue thickness was measured. Results: Experimental data measured by the non‐invasive measurement system were compared with the actual thickness of animal samples, and the results could be explained by the three‐layered tissue model. The result showed high correlation to the thickness changes (R² = 0.9954). Conclusions: The experimental result implies positive possibility for the development of a system to measure the thickness of subcutaneous adipose tissue using near infrared in vivo.