According to a large cohort study published on Jan.
“The potential for ‘catching up’ in children with atopic dermatitis seen in our study can be explained by atopic dermatitis resolution or successful treatment,” writes senior author Aaron M. Drucker, MD, ScM, of the Department of Dermatology . University of Toronto and Women’s College Hospital in Toronto, Canada, and colleagues. They postulated that while the association between AD and shorter height is “likely multifactorial,” it can be caused in part by AD-induced sleep loss or corticosteroid treatment for AD, both of which can lead to growth retardation and subsequent increases in BMI.
Researchers used data from TARGet Kids !, a prospective longitudinal study examining multiple health conditions in children from general pediatric and family doctor practices across Toronto. Their study included 10,611 children for whom there were data on height, weight, BMI, and standardized z-scores that account for age and gender differences in anthropometric characteristics. Clinically relevant covariates collected included age, gender, birth weight, history of asthma, family income, maternal and paternal ethnicity, and maternal height and BMI.
The mean age of the children in the study when they entered the cohort was 23 months and they were followed up for a median of 28.5 months, with a median of two visits. At baseline, 947 (8.9%) children had parent-reported AD, and that number rose to 1,834 (17.3%) during follow-up.
After adjusting for covariates, AD was associated with a lower mean Z-height (P <0.001), a higher mean Z-BMI (P = 0.008), but a lower mean Z-weight (P <0.001) compared to children without AD . Using the World Health Organization's growth tables, researchers estimated that "children with atopic dermatitis were on average about 0.5 cm shorter by 2 years and 0.6 cm shorter by 5 years than children without atopic dermatitis" after covariates have been adjusted. They also estimated that children with AD had "on average about 0.2 more BMI units by the age of 2" than children without AD. The associations between AD and height decreased at the age of 14, as did the association between AD and BMI at the age of 5½ years.
“Since we found that children with neurodermatitis, measured by Z-weight, were slightly less heavy than children without neurodermatitis and that this relationship with age did not weaken, it is possible that our results for BMI and possibly those of studies to date have been mainly explained by height differences, “the authors write.” This distinction has obvious clinical significance – rather than focusing on obesity and obesity behavior as a problem in children with atopic dermatitis, research may be better directed to the To understand the connection between atopic dermatitis and initially lower stature. “
To comment on the study results, Jonathan Silverberg, MD, PhD, MPH, Associate Professor of Dermatology, George Washington University School of Medicine and Health Sciences, Washington, DC, told Medscape Medical News that he would have preferred to use the phrase “in addition” to use “focus on obesity” rather than focus on obesity.
“We shouldn’t ignore diet and sedentary activity as major factors,” he said, referring to another recent study that found higher rates of eating disorders-related AD.
Silverberg said he was not familiar enough with the cohort sample to comment on how representative it is of the Canadian population or how generalizable the results are to other regions and populations. Generalizability, he added, “is an important issue as we previously noted regional differences in the relationship between AD and obesity.”
Additionally, he noted that the study defined AD as “ever had a medical history” rather than “last year or now,” so while this is a longitudinal study, “it really looks at how AD is in everyone Point in patients’ lives is related to weight or stature, “he explained. But, he added, “many childhood AD cases ‘burn out’ or become milder / clearer as the children get older. So if the AD goes away, then one would expect the associations to weaken as the children get older. This tells us nothing about how persistent AD into later childhood or adolescence is related to height or weight. “
Previous studies found that short stature and obesity were particularly linked to moderate – and even more severe – atopic dermatitis, Silverberg said. It is likely that most of the patients in this primary care cohort had mild illness, he noted that effect sizes are likely to be weakened by the mostly mild illness “and not relevant to the more persistent and severe AD patients encountered in dermatology practice will.”
JAMA dermatol. Published online 17 November 2021. Executive summary
The study was supported by the Department of Medicine, Women’s College Hospital, and the Canadian Institutes of Health Research.
One author reported receiving compensation from the British Journal of Dermatology (reviewer and section editor), the American Academy of Dermatology (guideline writer), and the National Eczema Association (grant reviewer) and served as a paid consultant for the Canadian Medicines Agency and Technologies in Health outside of the work submitted. No further information was given. Silverberg has not disclosed any relevant financial relationships.
Kate Johnson is a Montreal-based freelance medical journalist who has been writing on all fields of medicine for more than 30 years.