Analysis of Multi-Part Phenotypic Changes in Skin to Characterize the Trajectory of Skin Aging in Chinese Women

Purpose

As the human body’s largest organ exposed to the external environment, the skin suffers from internal and external aging factors, leading to wrinkles, loss of elasticity, sagging, and rough appearance. However, little is known of the characteristics of skin aging of different body parts in Chinese women. Here, we study the signs of extrinsic skin aging in different body parts to identify the knowledge map of manifestations of aging in Chinese women.

Patients and Methods

Wrinkle and texture phenotypes and collagen samples from the face, neck, hands, and arms of 326 Chinese women were collected. The correlations between phenotypes and ages and the differences in phenotypes by age were evaluated.

Results

The wrinkle and texture phenotypes around the eyes and mouth and of the hands were strongly correlated with age. Ages 32 and 58 showed the largest number of differentially changed aging phenotypes. The number of aging phenotypes increased sharply between the ages of 24 and 30, suggesting that the skin was undergoing rapid aging. Eye aging was the most rapidly changing phenotype between 19 and 30 years old. Wrinkles at the corner of the eyes showed a significant difference in the older group, suggesting an early onset and long-term effects.

Conclusion

This is the first study to be performed on the characteristics of skin aging among Chinese women that takes account of multiple areas of the body. It was found that 24 years old was the time point at which the skin begins to age in Chinese women. This provides important clues for aging-related research and personalized skin care.

Ultrasound Analyses of the Dorsal Hands for Volumetric Rejuvenation

BACKGROUND

Volumetric hand rejuvenation of the dorsal hands is increasingly applied for aged, skeletonized dorsal hand skin, with prominent veins, tendons, and joints due to volumetric loss of subcutaneous fat. However, the aging process of the fatty laminae remains unexplored.

OBJECTIVES

We aim to investigate the impact of aging and potential determinants on the fatty laminae to improve the therapeutic effect of volumetric injection.

METHODS

This cross-sectional study enrolled 105 Taiwanese participants aged ≥20 years, divided into five age groups per decade. Thicknesses of the dorsal superficial lamina (DSL), dorsal intermediate lamina (DIL), and dorsal deep lamina (DDL) were measured via ultrasonography by a single-blinded practitioner. The potential determining factors of the laminae thickness (age, sex, body mass index, and hand dominance) were analyzed.

RESULTS

The thicknesses of the three laminae decreased with aging, with the mean decrease in thickness from the 20s to >60 years in DSL, DIL, and DDL being 0.21 mm (30.0%), 1.38 mm (63.89%), and 0.31 mm (20.95%), respectively. DIL thickness decrease was the greatest and most significant since the 30s. Multiple linear regression analysis showed age as the only determinant for thicknesses of the 3 laminae (all P<0.001), whereas DIL was significantly thicker in men (P<0.001).

CONCLUSIONS

Volumetric fat loss was noted in the three fatty laminae of dorsal hands during aging; DIL has the greatest progressive fat loss since the 30s. Volumetric rejuvenation of the 3 laminae may result in the most esthetic appearance, especially in women.

Skin aging risk factors: A nationwide population study in Mongolia risk factors of skin aging

The world population is aging and no country is immune to the consequences. We are not aware of any country-specific skin aging risk factors data for the Mongolian people. Thus, we aimed to study the risk factors associated with skin aging in the Mongolian population. A population-based cross-sectional study of 2720 study participants 18 years of age and older was performed evaluating the severity of skin aging based on cutaneous microtopography. Questionnaire data and skin physiological measurements were obtained. The odds ratios for skin aging grades associated with risk factors were estimated using ordinal logistic regression. Study participant’s mean age was 45 years, ranging from 18 to 87. After adjustment for known risk factors, skin aging was associated with demographic risk factors such as increasing age (aOR = 1.19, 95% CI 1.18–1.20), living in an urban area (aOR = 1.31, 95% CI 1.12–1.55) and lifestyle factors including being a smoker (aOR = 1.32, 95% CI 1.09–1.61), having a higher body mass index (aOR = 1.04, 95% CI 1.02–1.06) and higher levels of sun exposure time (aOR = 1.03, 95% CI 1.00–1.06) were significantly associated with higher skin aging grades. Having dry (aOR = 1.94, 95% CI 1.45–2.59) and combination skin (aOR = 1.62, 95% CI 1.22–2.16) types were also independent risk factors associated with skin aging. Having very low skin surface moisture at the T-zone (aOR = 2.10, 95% CI 1.42–3.11) was significantly related to skin aging. Older age, urban living and toxic working conditions were independent demographic risk factors related to skin aging. Smoking, higher BMI, greater levels of sun exposure were significant lifestyle risk factors. Having a skin type other than normal was a physiologic risk factor for skin aging.

Investigation of symptoms of hand skin changes with aging in Korean women and development of a new standard grading scale for hand aging

BACKGROUND

Skin aging, particularly facial skin, has been actively studied. However, hand skin research is limited.

METHODS

Aging symptoms of 100 hands of Korean women aged from 20s to 60s were measured by noninvasive and bioengineering methods. Standard grade images were produced.

RESULTS

As people got older, skin wrinkles were getting worse and skin tone was uneven with the occurrence of structural flexion. For each symptom, a suitable standard photograph of the skin of the hand was chosen and a new grading scale was made.

CONCLUSIONS

The new grading scale developed in the present study could be employed in studies to explore aging of hand skin as one of objective indicators.

A randomized study showing improved skin quality and aesthetic appearance of dorsal hands after hyaluronic acid gel treatment in a Chinese population

BACKGROUND

Patients are increasingly aware of the aesthetic appearance of aging hands.

AIMS

To evaluate efficacy and safety of a hyaluronic acid gel for improving skin quality in aged skin of the dorsal hand.

METHODS

This was a 15-month randomized, multi-center, evaluator-blinded, split-hand, no treatment-controlled study. Three treatments with hyaluronic acid gel were administered in the same hand in adult Chinese subjects with grade 2 or 3 (mild or moderate aging) on the Hand Grading Scale (HGS). The primary objective was to evaluate the difference at 3 months between treated and untreated hands, based on the blinded evaluator's HGS assessment. Secondary assessments included the Global Aesthetic Improvement Scale (GAIS), biophysical measurements (skin elasticity, skin roughness and hydration), and subject satisfaction. Safety was evaluated by incidence of adverse events.

RESULTS

A total of 100 subjects were enrolled. Clinically relevant differences in HGS favored HA gel (P < .0001). At 15 months, 87%-96% of treated hands were still improved according to GAIS (per evaluator and subject, respectively). Objective measures of skin quality improved, confirmed by evaluators and highly satisfied subjects. Treatment was well tolerated.

CONCLUSIONS

Hyaluronic acid treatment improved skin quality and reduced the aging appearance of the hand, with high subject satisfaction.

Association between serum melatonin and skin aging in an urban population of Mongolia

BACKGROUND

Melatonin has been implicated in skin functions such as hair growth cycling and skin pigmentation. Furthermore, melatonin receptors are expressed in several skin cells.

AIMS

To study the association between serum melatonin levels and skin aging grades among people aged 20-69 years in Ulaanbaatar city.

PATIENTS/METHODS

We performed an analytical cross-sectional study that used parametric testing through analyses to test the relationship between melatonin levels and skin aging grades. A total of 946 people were assessed for skin aging using a moisture checker, sebum tape, and a digital camera. Blood samples were collected between 8:00 am and 10:00 am, and melatonin was measured using an enzyme-linked immunosorbent assay analyzer.

RESULTS

There was a statistically significant association between age and skin aging grade (P < .001). A multiple factor analysis revealed that lower levels of melatonin in the serum increased with skin aging grade 4 (odds ratio [OR], 1.9; 95% confidence interval [CI], 0.4-8.0), (OR, 2.4; 95% CI, 0.5-9.5), grade 5 (OR, 3.8; 95% CI, 0.8-15.7), and grade 6. There were weak associations between melatonin levels and potential covariates (skin pigmentation and skin hydration) taken from the correlation matrix. There was a weak positive correlation between skin pigmentation and age (r = .28), a weak negative correlation between skin pigmentation and sleep status (r = -.20), and a weak negative correlation between skin hydration and age (r = -.27).

CONCLUSIONS

Serum melatonin decreases with age, indicating that its loss may stimulate the process of earlier skin aging.

Characteristic features of neck skin aging in Chinese women

INTRODUCTION

Neck skin aging is of particular interest to skin scientists and dermatologists because of the increasing demand for neck wrinkle improvement. This study aimed to determine the neck aging features of Chinese women and to investigate the clinical alterations and mechanical, topographical, and biophysical properties of neck skin.

METHODS

A total of 450 Chinese women (age range: 16-66 years) were clinically examined and graded by the same dermatologist using standardized photographs. The skin properties were assessed by noninvasive skin measuring devices.

RESULTS

The results showed that different neck aging signs, including the horizontal neck fold, neck sagging, hollowing of emaciated neck, platysmal bands, and neck texture, appeared in different ages, and all of them worsened age-dependently since they manifested. The skin elasticity markedly changed before the onset of most of the aging signs and showed a negative correlation with both age and the severity of these signs. Transepidermal water loss (TEWL) was positively correlated with age, whereas hydration and pH were not significantly correlated with age. We also found that wrinkles (SEw) and average roughness (Ra) were significantly correlated with age. SEw, smoothness, the average depth of roughness (Rz), TEWL, and erythema index were significantly and positively correlated with the severity of the horizontal neck fold, neck sagging, hollowing of emaciated neck, and platysmal bands.

CONCLUSION

This is the first study to emphasize that age causes diverse changes in Chinese women's neck skin. The changes in skin elasticity may effectively predict neck aging before the onset of most of the neck aging signs.

An Analysis of Human Dorsal Hand Skin Texture Using Hyperspectral Imaging Technique for Assessing the Skin Aging Process

Skin texture has become an important issue in recent research with applications in the cosmetic industry and medicine. In this paper, we analyzed the dependence of skin texture features on wavelength as well as on different parameters (age and gender) of human participants using grey-level co-occurrence matrix and hyperspectral imaging technique for a more accurate quantitative assessment of the aging process. A total of 42 healthy participants (men and women; age range, 20-70 years) was enrolled in this study. A region of interest was selected from the hyperspectral images. The results were analyzed in terms of texture using the gray-level co-occurrence matrix which generated four features (homogeneity, contrast, entropy, and correlation). The results showed that most of these features displayed variations with wavelength (the exception was entropy), with higher variations in women. Only correlation in both sexes and contrast in men proved to vary statistically significant with age, making them the targeted variables in future attempts to characterize aging skin using the complex method of hyperspectral imaging. In conclusion, by using hyperspectral imaging some measure of the degree of damage or the aging process of the hand skin can be obtained, mainly in terms of correlation values. At the present time, reasonable explanations that can link the process of skin aging and the above mentioned features could not be found, but deeper investigations are on the way.

Quantitative evaluation methods of skin condition based on texture feature parameters

In order to quantitatively evaluate the improvement of the skin condition after using skin care products and beauty, a quantitative evaluation method for skin surface state and texture is presented, which is convenient, fast and non-destructive. Human skin images were collected by image sensors. Firstly, the median filter of the 3 × 3 window is used and then the location of the hairy pixels on the skin is accurately detected according to the gray mean value and color information. The bilinear interpolation is used to modify the gray value of the hairy pixels in order to eliminate the negative effect of noise and tiny hairs on the texture. After the above pretreatment, the gray level co-occurrence matrix (GLCM) is calculated. On the basis of this, the four characteristic parameters, including the second moment, contrast, entropy and correlation, and their mean value are calculated at 45 ° intervals. The quantitative evaluation model of skin texture based on GLCM is established, which can calculate the comprehensive parameters of skin condition. Experiments show that using this method evaluates the skin condition, both based on biochemical indicators of skin evaluation methods in line, but also fully consistent with the human visual experience. This method overcomes the shortcomings of the biochemical evaluation method of skin damage and long waiting time, also the subjectivity and fuzziness of the visual evaluation, which achieves the non-destructive, rapid and quantitative evaluation of skin condition. It can be used for health assessment or classification of the skin condition, also can quantitatively evaluate the subtle improvement of skin condition after using skin care products or stage beauty.

Relation between skin micro-topography, roughness, and skin age

BACKGROUND

The topography of the skin surface consists of lines, wrinkles, and scales. Primary and secondary lines form a network like structure that may be identified as polygons. Skin surface roughness measurements are widely applied in dermatological research and practice but the relation between roughness parameters and their anatomical equivalents are unclear. This study aimed to investigate whether the number of closed polygons (NCP) per measurement field can be used as a reliable parameter to measure skin surface topography. For this purpose, we analysed the relation between skin surface roughness parameters and NCP in different age groups.

METHODS

Images of the volar forearm skin of 38 subjects (14 children, 12 younger, and 12 older adults) were obtained with the VisioScan VC98. The NCP was counted by three independent researchers and selected roughness parameters were measured. Interrater reliability of counting the number of closed polygons and correlations between NCP, roughness parameters, and age were calculated.

RESULTS

The mean NCP/mm² in children was 3.1 (SD 1.1), in younger adults 1.0 (SD 0.7), and in older adults 1.0 (SD 0.9). The interrater reliability was 0.9. A negative correlation of NCP/mm² with age was observed, whereas measured roughness parameters were positively associated with age. NCP/mm² was weakly related to skin roughness.

CONCLUSION

The NCP/mm² is a reproducible parameter for characterizing the skin surface topography. It is proposed as an additional parameter in dermatological research and practice because it represents distinct aspects of the cutaneous profile not covered by established roughness parameters.