Objective: To evaluate the effectiveness of topical retinol (vitamin A) in improving the clinical signs of naturally aged skin.
Design: Randomized, double-blind, vehicle-controlled, left and right arm comparison study.
Setting: Academic referral center.
Patients: The study population comprised 36 elderly subjects (mean age, 87 years), residing in 2 senior citizen facilities.
Intervention: Topical 0.4% retinol lotion or its vehicle was applied at each visit by study personnel to either the right or the left arm, up to 3 times a week for 24 weeks.
Main outcome measures: Clinical assessment using a semiquantitative scale (0, none; 9, most severe) and biochemical measurements from skin biopsy specimens obtained from treated areas.
Results: After 24 weeks, an intent-to-treat analysis using the last-observation-carried-forward method revealed that there were significant differences between retinol-treated and vehicle-treated skin for changes in fine wrinkling scores (-1.64 [95% CI, -2.06 to -1.22] vs -0.08 [95% CI, -0.17 to 0.01]; P<.001). As measured in a subgroup, retinol treatment significantly increased glycosaminoglycan expression (P = .02 [n = 6]) and procollagen I immunostaining (P = .049 [n = 4]) compared with vehicle.
Conclusions: Topical retinol improves fine wrinkles associated with natural aging. Significant induction of glycosaminoglycan, which is known to retain substantial water, and increased collagen production are most likely responsible for wrinkle effacement. With greater skin matrix synthesis, retinol-treated aged skin is more likely to withstand skin injury and ulcer formation along with improved appearance.
Trial registration: ClinicalTrials.gov NCT00272610.