Relationship between Dermal Structural Changes on Ultrasonographic Images and Skin Viscoelasticity in Overweight and Obese Japanese Males

Abstract

It has been reported that overweight Japanese males have poorly organised dermis and their skin may be fragile to external forces because of decreased dermal echogenicity. However, it is unknown whether the changes in the dermal structure actually affect the dermal function. The objective of this study was to clarify the relationship between dermal structural parameters and dermal functional parameters in overweight and obese Japanese males. A cross-sectional, observational study was conducted on Japanese male volunteers. Two ultrasound scanners, a 20-MHz Dermascan C &reg; and an 18-MHz Mylab TM five &reg; were used to evaluate dermal structure. Echogenicity of the lower dermis and dermal thickness of the participants’ abdomens and thighs were measured. A Cutometer &reg; MPA580 was used to evaluate skin viscoelasticity, skin deformation (R0) and elasticity (R2, R7). The correlation between dermal structural parameters and skin viscoelasticity were validated using Pearson’s correlation coefficient or Spearman’s correlation coefficient by rank test. A total of 79 male volunteers were recruited of which 43 were control subjects with BMI <25 (age, 22 - 63 years), 25 were overweight subjects with BMI ≥ 25 to <30 (age, 23 - 64 years) and the 11 obese subjects had a BMI ≥ 30 (age, 26 - 47 years). There was no correlation between dermal structural parameters and skin viscoelasticity in the abdomens or thighs of all 79 participants. On the other hand, in the 36 overweight and obese participants, thigh dermal echogenicity was significantly and negatively correlated with R0 (r = -0.456, p < 0.01) and dermal thickness in the abdomen was significantly and positively correlated with R0 (r = 0.464, p < 0.01). The dermal functional parameter was significantly correlated with dermal structural parameters in overweight and obese males; in other words, a decrease in dermal function may be caused by structural changes in the dermis during obesity.