A history of smoking may be associated with a higher degree of aging in skin not regularly exposed to light, such as that of the upper inner arm, according to an article in the March issue of Archives of Dermatology, one of the JAMA/Archives journals.
The features of skin aged by the sun and exposure to light are well documented and include coarseness, wrinkling, discoloration and a pale yellow tint, according to background information in the article. The progression of this type of aging can be measured with photonumeric scales, which use standard photographs to assign numbers that correspond to grades of severity. However, no such scale exists for photo-protected (not exposed to sunlight) skin in areas such as the buttocks and upper arm. The principle sign of aging in this type of skin is fine wrinkling.
Yolanda R. Helfrich, M.D., and colleagues at the University of Michigan, Ann Arbor, used photographs of 82 healthy participants’ upper inner right arms to create a nine-point scale on which to grade aging of photo-protected skin as well as to analyze factors that affect the degree of aging. Participants ranged from age 22 to 91 and had an average age of 56.1, were 46 percent male and 54 percent female, and were all photographed in the same position by a professional medical photographer. Five photographs were selected from each individual to be analyzed by three separate judges and graded for severity of aging on a scale of zero (no fine wrinkling) to eight (severe fine wrinkling). Interviews were conducted to obtain health and lifestyle information.
The three judges largely agreed on the grading scale for each participant; the maximum range of difference in scores for a single individual was less than one unit on the nine-point scale. "These results indicate that this scale is an uncomplicated evaluation system for the clinical investigator involved in the assessment and treatment of photo-protected aging skin," the authors write.
"In this study examining non-facial, photo-protected skin, we found that the number of packs of cigarettes smoked per day, total years of smoking and pack-years of smoking [an average of packs per day over the number of years were smoking] were correlated with the degree of skin aging. After controlling for participant age and other variables in a multiple regression model, we found that only packs of cigarettes smoked per day was a major predictor of the degree of photo-protected skin aging," they continue. "In participants older than 65 years, smokers had significantly more fine wrinkling than non-smokers. Similar findings were seen in participants aged 45 to 65 years."
The process by which photo-protected skin ages, and how smoking may affect that process, remains unclear. Additional research is needed to shed light on independent risk factors for fine wrinkles in this skin type, the authors note.
(Arch Dermatol. 2007;143:397-402. Available pre-embargo to media at www.jamamedia.org.)
Editor’s Note: This study was supported in part by grants from the Babcock Endowment for Dermatologic Research and the National Institutes of Health. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.
Journal
Archives of Dermatology