Unlike other inflammatory dermatologic conditions, alopecia areata does not appear to increase risk for cardiovascular disease, and it may even protect against stroke, new research suggests.

Researchers compared 1,377 alopecia areata patients to 4,131 control subjects. They found that patients with alopecia areata had a decreased risk for stroke, and there was a trend toward decreased risk of myocardial infarction, but this trend was not statistically significant.

The findings appear in the July 2016 issue of the Journal of the American Academy of Dermatology.

“Even though psoriasis and likely hidradenitis suppurativa may be related to increased cardiovascular events, patients with alopecia areata do not appear to be at elevated risk,” study author Arash Mostaghimi, MD, MPA, MPH, director of Dermatology Inpatient Service at Brigham and Women's Hospital in Boston, tells Practical Dermatology®. “This is consistent with the clinical impression that although alopecia areata causes substantial psychosocial morbidity, most patients with alopecia areata are very healthy.  Physicians should use these findings to help alleviate fears for patients with alopecia areata who are concerned that their disease may be related to systemic illness.”

It is unclear why, or even if, alopecia areata would be protective against cardiovascular events. “If there is a decreased risk of cardiovascular disease the link may be related to lipids,” Dr. Mostaghimi says. “We know that Vytorin (simvastatin/ezetimibe) is a lipid-lowering combination therapy that has been used successfully to regrow hair in patients with alopecia areata. While the mechanism of action for Vytorin is unknown, it’s thought that lipids may have a role in maintaining immune privilege of the hair.  There may also be differences in lipid behavior or metabolism that account for differences in cardiovascular risk.”

Dr. Mostraghimi says he was surprised by the findings.  ”Our motivation in performing this analysis was the notion that alopecia areata is a chronic inflammatory disease of the skin, akin to psoriasis, and we thought that it may confer increased risk of disease.”

The new study shows a decreased risk, which is in contrast to a prior study from Taiwan showing increased risk, he says.  “The real answer is probably in the middle, that there is either a small decrease in risk or potentially once multiple and larger studies are done no significant difference at all,” he says.

“Our study was able to account for differences in risk factors such as smoking which were omitted from the Taiwanese article but as a retrospective study we are still limited by an inability to quantify the extent of alopecia areata in our patients and other potential confounders such as BMI,” Dr. Mostaghimi says.

“Further studies would be needed to assess whether these results can be replicated in another AA cohort and whether or not their is a relationship among stroke, acute myocardial infarction and alopecia areata severity," the study authors conclude.