Changes in dermal structure and skin oxidative stress in overweight and obese Japanese males after weight loss: a longitudinal observation study.

BACKGROUND/PURPOSE: Previous studies have reported decreased dermal echogenicity and increased skin oxidative stress in overweight males. However, it is unknown whether these skin parameters of overweight and obese people are similar to those of individuals exhibiting a normal body weight following weight loss. The purpose of this study was to (1) compare the changes in the dermal structure parameters and levels of skin oxidative stress before and after weight loss in overweight and obese people in Japan and (2) to clarify how these aspects changed when body weight would be reduced to normal body weight. METHODS: Male volunteers with a body mass index of ≥25 kg/m2 were recruited. The dermal structure was visualized and dermal echogenicity and thickness were measured using ultrasound scanners. The mRNA expression level of heme oxygenase-1 in the hair follicles was quantitatively analyzed as a marker of skin oxidative stress. RESULTS: When overweight individuals in their 20s to 30s reduced their weight to normal, decreased dermal thickness in the abdominal region was observed in 50% of the subjects; however, no increase in dermal echogenicity was observed. A decrease in dermal thickness and an increase in dermal echogenicity in the thighs was observed in 83.3% of the subjects. No decrease in the level of dermal oxidative stress was observed. CONCLUSION: The dermal structure in the thighs of overweight young individuals can be improved to the level of the structure in those of normal body weight individuals following weight loss.

Wash or wipe? A comparative study of skin physiological changes between water washing and wiping after skin cleaning.

BACKGROUND/PURPOSE: Presently, skin-cleaning agents that claim to be removed by water or wiping alone are commercially available and have been used for the purpose of bed baths. However, there is a lack of knowledge on how water washing and wiping differently affect skin physiological functions or ceramide content. The aim of this study was to compare the effects of water washing and wiping on skin physiological functions and ceramide content. METHODS: Three kinds of the cleaning agents with different removal techniques (ie, water washing and wiping) were used in this study. Skin physiological functions (ie, transepidermal water loss, skin hydration, and skin pH) and skin ceramide content were measured before and after seven consecutive days of the application of each cleaning agent. RESULTS: No significant differences in skin physiological functions or ceramide content were observed between water washing and wiping. CONCLUSION: Cleaning agents that claim to be removed by water washing or wiping do not affect skin physiological functions or ceramide content by either removal method.

Increased level of tumour necrosis factor-alpha (TNF-α) on the skin of Japanese obese males: measured by quantitative skin blotting.

OBJECTIVE: A state of chronic inflammation, characterized by an increased level of tumour necrosis factor-alpha (TNF-α), is often found in the obese population. The negative effects of elevated TNF-α are not limited to systemic metabolism. It also reportedly affects skin integrity. Recently, the relationship between obesity and skin fragility was reported; however, there has been little insight into how the level of TNF-α in the skin in situ is related to the severity of obesity. In this study, we aimed to measure the level of TNF-α on the skin and to find the relationship between obesity and the level of TNF-α detected on the skin. METHODS: We used a novel, non-invasive method called quantitative skin blotting. Fifty-nine healthy (but some were classified as being overweight or obese) Japanese males were enrolled as subjects. The levels of TNF-α detected on the abdominal and thigh skin along with the body composition were measured, followed by a correlation analysis. RESULTS: Significant positive correlations were found between the levels of TNF-α detected on the skin and the severity of obesity such as body mass index (BMI), body fat weight and visceral fat rating. CONCLUSION: We found that high levels of TNF-α were detected on the skin of Japanese obese males, which implied the higher TNF-α in the skin. The elevation of skin TNF-α may be one factor related to skin fragility that is often found in obese individuals.

Development of an improved method for quantitative analysis of skin blotting: increasing reliability and applicability for skin assessment.

OBJECTIVE: A novel skin assessment tool named 'skin blotting' has been recently developed, which can easily predict the skin status to avoid its deterioration. The aim of this study was to propose a normalization method for skin blotting to compensate for individual differences that can hamper the quantitative comparisons and clinical applications. METHODS: To normalize individual differences, we utilized a total protein as a 'normalizer' with calibration curves. For evaluation, we performed a simple simulation experiment, in which the same concentration of a protein of interest [tumour necrosis factor (TNF)-α] was applied at different volumes as a virtual individual difference. Moreover, to demonstrate the applicability of this normalization, male volunteers were recruited for skin blotting followed by the estimation of TNF-α with normalization. RESULTS: We obtained good calibration curves for total protein (R(2)  = 0.995) and TNF-α (R(2)  = 0.997), both of which were necessary for an exact quantification. In the simulation experiment, we estimated the exact concentration of TNF-α regardless of the applied volume, demonstrating the applicability of this normalization method in skin blotting. Further, skin blotting on human subjects showed a wide range of variation in the total protein content, although the normalization was thought to reduce such individual variations. CONCLUSION: This study has proposed total protein normalization for skin blotting with calibration curves. This method may strengthen the quantitative performance of skin blotting, which may expand the applicability of this method as a skin assessment tool in broader fields, such as nursing and cosmetology.

Structural changes in dermal collagen and oxidative stress levels in the skin of Japanese overweight males.

OBJECTIVE: It has been reported that obese people have poorly organized dermal collagen structure because of the degradation of collagen fibers, which is caused by an increase in oxidative stress levels associated with the hypertrophy of subcutaneous adipose cells. However, it is unclear whether an increase in oxidative stress levels caused by the accumulation of subcutaneous adipose tissue and a change in the dermal structure also occur in overweight and obese Japanese people. The objectives of this study are to identify structural changes that occur in the dermis and to measure the levels of oxidative stress in Japanese overweight males. METHODS: The overweight group included 43 Japanese male volunteers aged between 25 and 64 years and with a body mass index (BMI) of ≥25 and <30. The control group included 47 male volunteers aged between 22 and 64 years and with BMI of <25. The 20-MHz Dermascan C® ultrasound scanner with software for image analyses was used. Echogenicity of the upper and lower dermis was measured. The mRNA expression level of heme oxygenase-1 (HMOX1) in hair follicles was quantitatively analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR) and was used as a marker of oxidative stress. Ultrasonographic imaging and collection of hair follicles were performed at the same site on the thigh, abdomen, and upper arm. RESULTS: The HMOX1 mRNA expression level in the abdomen and thigh was significantly lower in the overweight group than in the control group. Moreover, the echogenicity of the upper dermis of the abdomen and the lower dermis of the abdomen and thigh was significantly lower in the overweight group than in the control group. CONCLUSION: We detected an increase in oxidative stress levels and a decrease in the density of dermal collagen at the same site on the thigh, abdomen, and upper arm of Japanese overweight males. These findings suggest the fragility of the dermis of Japanese overweight males, which might have been caused by the accumulation of subcutaneous adipose tissue.