Modeling of global skin aging indices among Caucasian and Asian women

BACKGROUND

The skin aging process is defined as the gradual degradation of several skin properties such as firmness, color, or the appearance of wrinkles. These properties can be assessed by trained experts, who perform an overall evaluation of the entire face.

OBJECTIVE

The objective of this paper is the construction of two Global Skin Aging Indices specifically designed to model the overall skin aging process of Caucasian and Asian women.

METHODS

Two hundred forty Asian women and 129 Caucasian women aged between 20 and 60 years old are recruited. Parameters related to wrinkles, sagging, elasticity, and skin tone are measured (clinically or instrumentally). The global skin aging index is defined as the normalized projection on the first principal component of a principal component analysis of the skin measurements. Then, linear regressions are performed between the indices and age of both panels.

RESULTS

The first principal component carries around 50% of the initial variance for both indices. Both Global Skin Aging Indices statistically correlate with age (R2 ≥ 0.7, p-value < 0.05). An equation linking the indices with age is computed.

CONCLUSION

The proposed indices are good indicators of the overall aging process for Caucasian and Asian women. They offer new approaches to assess antiaging product efficacy.

Age-Induced Reduction in Human Lipolysis: A Potential Role for Adipocyte Noradrenaline Degradation

Gao et al. report that the observed reduction in adipose lipolysis with age in women could be explained by an upregulation of the catecholamine-degradation pathway in subcutaneous adipocytes. However, in contrast to findings in mice, these pathways are enriched in adipocytes and not in immune cells, suggesting species-specific differences in aging mechanisms.

SpectraCam® : A new polarized hyperspectral imaging system for repeatable and reproducible in vivo skin quantification of melanin, total hemoglobin, and oxygen saturation

BACKGROUND

An accurate way to determine skin pigmentation is to acquire the spectral reflectance of a skin sample and to quantify chromophores by reverse calculation from physical models of light propagation. Therefore, we tested a new hyperspectral imaging device and software suite, the SpectraCam^® system, and evaluated its accuracy to quantify skin chromophores.

METHODS

Validation of the SpectraCam^® system was performed by, firstly, comparing the known and the acquired reflectance spectra of color phantoms. Repeatability and reproducibility were then evaluated by two operators who performed acquisitions at different time points and compared the acquired reflectance spectra. The specificity of the system was tested by quantitative analysis of single chromophore variation models: lentigo and pressure relief. Finally, we tested the ability of the SpectraCam^® system to detect variations in chromophore in the eye region due to the daily application of a new anti-dark circle cosmetic product.

RESULTS

The SpectraCam^® system faithfully acquires the reflectance spectra of color phantoms (r² >0.90). The skin reflectance spectra acquired by different operators at different times are highly repeatable (r² >0.94) and reproducible (r² >0.99). The SpectraCam^® system can also produce qualitative maps that reveal local variations in skin chromophore or underlying structures such as blood vessels. The system is precise enough to detect melanin variation in lentigo or total hemoglobin and oxygen saturation variations upon pressure relief. It is also sensitive enough to detect a decrease in melanin in the eye region due to the application of an anti-dark circle cosmetic product.

CONCLUSION

The SpectraCam^® system proves to be rapid and produces high-resolution data encompassing a large field of view. It is a robust hyperspectral imaging system that quantifies melanin, total hemoglobin, and oxygen saturation and is well adapted to cosmetic research.

Tolerance profile of a sterile moisturizer and moisturizing cleanser in irritated and sensitive skin

BACKGROUND

This study evaluates the tolerance of preservative free sterile cleanser and sterile moisturizer in irritated and sensitive face skin.

MATERIALS AND METHODS

An exploratory, open-label study using the cleanser and the moisturizer in combination was performed with 98 patients with a documented history of allergic contact dermatitis. The 2 products could each be used once or twice daily for 28 days. The assessment parameters at baseline and end of treatment (day 28) included the intensity of erythema, dryness/scaling by the investigator and subjective signs (burning, pruritus and stinging), according to a defined 4-point scale (absent to severe). In addition, a global assessment of the change from baseline and the overall tolerance of the products were performed by the investigator at the end of treatment.

RESULTS

Ninety-four patients were included for the efficacy analysis and 96 patients for the safety analysis. At baseline, a majority of patients expressed some degree of erythema (63%), and dryness/scaling (56%). Fewer patients experienced subjective signs at baseline (44%). At the end of treatment, the results showed a statistically significant improvement of all the objective signs of irritated skin (P = .0001, Mac Nemar test), as well as the subjective signs of sensitive skin (P < 0.02). This was confirmed by the overall investigator assessment, showing an excellent or good response in 90% of the patients. In the safety analysis, 1 patient developed contact allergy to 1 ingredient of the test products (carbomer), and 3 patients exacerbated their dermatitis.

CONCLUSION

Taken together, these results suggest that adequately formulated cosmetics might reduce both irritated and sensitive skin, with clinical improvement of dryness, erythema and stinging.

A low-salt medical water reduces irritancy of retinoic acid in facial acne

Although effective medications are available for the treatment of acne, tolerance problems may preclude adequate treatment regimens such as topical retinoic acid, and reduce patient compliance. The present study was conducted to evaluate whether a medical water (Avène) in conjunction with retinoic acid may improve local tolerance in acne. A controlled, open, randomised, multicentric study was completed after 28 days of treatment in 69 acne patients, 34 applying a retinoic acid preparation alone, and 35 applying retinoic acid in association with the water spray used ad libitum. Topical retinoic acid treatment induced prominent signs of irritation in both groups. However, a statistically significant reduction between the two treatment groups could be demonstrated on scaling at all assessment visits (p< or =0.02, Wilcoxon test). No significant water effect on erythema, burning and itching was shown during the treatment period. The overall tolerance assessed by the investigator was significantly improved with the water (p = 0.04, Wilcoxon). Taken together, water with a low mineral content appears to be a promising adjunctive treatment for improving the tolerance of topical retinoids in acne.