LISBON – Overweight or obesity is independently associated with a twofold increased prevalence of moderate to severe acne in adolescent girls, according to a large population-based Norwegian study.
No such association was apparent in adolescent boys, Dr. Jon A. Halvorsen reported at the annual congress of the European Academy of Dermatology and Venereology.
He presented a cross-sectional questionnaire study of 3,774 Oslo teenagers aged 18-19 years. He and his coworkers undertook the study because the relationship between acne and body mass index has seldom been examined. The only prior study addressing the issue dates back to 1956; it found no association between acne and overweight in a group of young male soldiers (Br. Med. J. 1956;1:1268-70).
In the new Oslo study, overweight or obesity marked by a body mass index (BMI) of at least 25 kg/m2 was present in 9.5% of girls and 15.4% of boys. Self-reported moderate or severe acne, as defined using validated criteria, was present in 13.1% of girls and 14% of boys.
In the multivariate logistic regression analysis adjusted for mental health issues, sociodemographic factors, and diet, the prevalence of moderate or severe acne in overweight or obese girls was 18.5%, compared with less than 12% in the normal-weight comparison group of girls with a BMI of 18.5 to less than 23, reported Dr. Halvorsen of the University of Oslo. Girls with a BMI of 23 to less than 25 were 30% more likely than the comparison group to have significant acne, a trend that didn’t reach significance.
The situation was quite different in boys. The highest prevalence of moderate or severe acne (18%) occurred in underweight boys having a BMI less than 18.5. Normal-weight boys had less than a 12% prevalence of significant acne, while in overweight or obese boys the prevalence was slightly greater than 13%.
Dr. Halvorsen stressed that since these findings come from a cross-sectional study, they don’t establish a causal relationship between acne and BMI. But the data do raise questions worthy of further investigation.
"Can overweight cause acne? How important is inflammation in the pathogenesis of acne? How important are hormonal factors in adolescent acne? What about physical activity: Is it related to acne prevalence? How important are lifestyle factors?" he asked.
A lack of hormonal measurements is an important limitation of the Norwegian study. It’s an issue because polycystic ovary syndrome is known to be a risk factor for both overweight and acne, he noted.
The dietary variables incorporated in the analysis included rates of consumption of soft drinks, fatty junk foods, and raw vegetables. An audience member observed that milk consumption has previously been linked to acne; however, milk intake wasn’t recorded in the study.
Dr. Halvorsen reported having no financial conflicts of interest.