Wednesday, May 30, 2007

Vitamin A (Retinol) Effaces Wrinkles in Naturally Aged Skin

Topical vitamin A (retinol) effaces fine wrinkles associated with natural aging, according to the results of a small randomized trial in elderly patients published in the May issue of the Archives of Dermatology.
"Because accelerated skin aging due to excessive sun exposure has marked collagen deficiency and effective treatments for photoaging promote procollagen synthesis, we hypothesized that similar therapies might also improve the collagen deficiency found in intrinsic aging," write Reza Kafi, MD, from the University of Michigan Medical School in Ann Arbor, and colleagues. "Compared with retinoic acid, the ability of retinol to induce skin irritation is notably less, at least according to a 4-day patch test (an occlusive treatment). Thus, retinol has the potential to deliver retinoic acid–like effects to human skin with improved tolerability."
In this double-blind, vehicle-controlled, left-and-right-arm comparison study at an academic referral center, 36 elderly participants received topical 0.4% retinol lotion or its vehicle applied at each visit by study personnel to either the right or the left arm, as often as 3 times weekly for 24 weeks. Mean age was 87 years, and all patients lived in 1 of 2 senior citizen facilities.
Primary endpoints were clinical assessment using a semiquantitative scale (0, none; 9, most severe) and biochemical measurements from skin biopsy specimens obtained from treated areas. Analysis was by intent-to-treat, using the last-observation-carried-forward method.
After 24 weeks, changes in fine wrinkling scores were different between retinol-treated and vehicle-treated skin (-1.64 [95% confidence interval [CI], -2.06 to -1.22] vs -0.08 [95% CI, -0.17 to 0.01]; P < .001). In a subgroup, retinol treatment was associated with increased glycosaminoglycan expression (P = .02 [n = 6]) and procollagen I immunostaining (P = .049 [n = 4]) compared with vehicle.
The retinol preparation was relatively well tolerated.
"Topical retinol improves fine wrinkles associated with natural aging," the authors write. "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."
The Babcock Endowment for Dermatologic Research, the Merck-American Federation for Aging Research, Alpha Omega Alpha Student Research Fellowship, and the National Institutes of Health supported this study. Four of the authors have disclosed being named inventors on an issued patent application concerning methods of treating skin aging, and they will receive royalties under the University of Michigan's Intellectual Property Policy in the event that a commercial license is signed and a product is sold.
Arch Dermatol. 2007;143:606-612.

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