One-year topical stabilized retinol treatment improves photodamaged skin in a double-blind, vehicle-controlled trial.

BACKGROUND: Retinol, a precursor of retinoic acid, has great potentials as a topical anti-aging molecule; however, only a handful of clinical investigations have been published to date. OBJECTIVE: This study aimed to assess the efficacy and safety of 0.1% stabilized retinol on photodamaged skin during a one-year treatment. METHODS: The investigation included two 52-week, double-blind, vehicle-controlled studies. In the main study, 62 subjects applied either a stabilized retinol formulation or its vehicle to the full face. A second exploratory study evaluated histological/histochemical markers in 12 subjects after 52 weeks of either retinol or vehicle use on contralateral dorsal forearms. RESULTS: The retinol group showed significant photodamage improvement over vehicle at all timepoints during the study. After 52 weeks, retinol had improved crow's feet fine lines by 44%, and mottled pigmentation by 84%, with over 50% of subjects showing +2 grades of improvement in many parameters. Additionally, at week 52, histochemical data confirmed the clinical results, showing increased expression of type I procollagen, hyaluronan, and Ki67 as compared to vehicle. CONCLUSION: This study confirms that a stabilized retinol (0.1%) formulation can significantly improve the signs of photoaging, and improvements in photodamage continue with prolonged use.

Age and ethnic variations in sebaceous lipids.

This study was conducted to compare lipid components of sebum from persons from three ethnic backgrounds-Caucasian, African American and Northern Asian. Men and women with no acne in two age groups (18‒25 y and 35‒45 y) were recruited. Skin surface hydration (SkiCon 200EX and NovaMeter), barrier function (Delfin VapoMeter), high-resolution clinical imaging, self-assessments and two pairs of sebutapes on the forehead that extracted the lipids on the surface of their skin were used. Significant differences (p < 0.05) in skin hydration between African Americans and Caucasians in both age groups were noted, with the order from highest to lowest absolute values: African American > Northern Asian > Caucasian. Transepidermal water loss (TEWL) measurements demonstrated that African Americans and Caucasians were significantly different (p < 0.05), with the trend being the inverse of the hydration trend-Caucasian > Northern Asian > African American, which would indicate better barrier function for African Americans with a lower TEWL. African American women had more total lipid production than Northern Asian or Caucasian women. When analyzing the three lipid classes (free fatty acids, triglycerides and wax esters), the trend became significant (p < 0.05) in the wax ester fraction when directly comparing African Americans with Caucasians. Additionally, six lipids were identified in the wax ester fractions that were significantly different in quantity (p < 0.05) between African Americans and Caucasians. These results identified significant differences in sebaceous lipid profiles across ethnic groups and determined that the differences correlated with skin barrier function.