CHICAGO – Atopic dermatitis in adulthood was associated with a twofold increase in the risk of developing dementia late in life, based on results from a large longitudinal cohort study presented at the annual meeting of the Society for Investigative Dermatology.
“After adjusting for potential mediators such as smoking status, depression, cardiovascular disease, and asthma or rhinitis, the effect was decreased slightly but still remained strongly statistically significant,” reported Katrina Abuabara, MD, of the University of California, San Francisco.
Atopic dermatitis is the latest in growing list of chronic inflammatory conditions that have been associated with an increased risk of dementia, according to Dr. Abuabara, who cited a body of evidence suggesting that inflammation triggers or exacerbates the processes that drive risk of developing dementia late in life.
Interest in the potential association of atopic dermatitis and dementia has been triggered “by a paradigm shift in which we now think of atopic dermatitis as a systemic inflammatory condition.” Dr. Abuabara reported.
In a primary care database of more than 1 million patients, both atopic dermatitis and dementia were common in those aged 60 years or older. The two disorders were identified in 6.75% and 6.49% of patients, respectively.
Cox proportional hazard ratios were employed to determine the relationship between the presence of atopic dermatitis and subsequent development of dementia. The median follow-up was 8 years. Atopic dermatitis was classified as mild, moderate, or severe involvement based on treatment records.
Patients with dementia associated with infectious diseases such as HIV, alcoholism, and other exogenous toxins were excluded from the analysis.
For those with atopic dermatitis relative to those without, the unadjusted hazard ratios were 1.91 for dementia of any type, 2.14 for Alzheimer’s dementia, and 2.25 for vascular-related dementia. After adjustment for confounders such as age, sex, and socioeconomic status, these hazard ratios, respectively, were only somewhat lower and remained statistically significant.
There was a trend for greater dementia risk with greater atopic dermatitis severity, rising from 2.07 in those with mild atopic dermatitis to 2.72 to those with severe disease, according to Dr. Abuabara.
“The important next step is to determine if better control of atopic dermatitis results in a lower risk of dementia,” she said.
According to Dr. Abuabara, some experimental studies have supported the hypothesis that downregulation of systemic markers of inflammation may be protective.
“Even if you reduced risk by a small amount, it would translate into a large health impact because of the large and growing prevalence of dementia,” she said.
Dr. Abuabara is a consultant for thestudy, sponsored by Target PharmaSolutions.