Women who experience trauma or have post-traumatic stress disorder are at higher risk of developing systemic lupus erythematosus, a study suggests.
The research, which appeared in the journal Arthritis & Rheumatology, was titled “Association of trauma and posttraumatic stress disorder with incident systemic lupus erythematosus (SLE) in a longitudinal cohort of women.”
A number of studies have shown links between high levels of stress and the development of autoimmune diseases.
Post-traumatic stress disorder, or PTSD, stems from severe psychological distress. Combat can trigger it, as can a violent crime or another extremely stressful situation.
Research has shown that PTSD may increase the risk of a person developing an autoimmune disease such as rheumatoid arthritis, autoimmune thyroiditis, inflammatory bowel disease, multiple sclerosis, or psoriasis.
And some studies have linked lupus, another autoimmune disorder, with high levels of anxiety and psychological distress. In fact, stress or emotional distress often trigger lupus flare-ups.
Scientists also know that lifestyle factors that are more common in those with PTSD — including smoking, obesity, and using oral contraceptives — are known risk factors for the development of an autoimmune disease, including lupus.
But researchers had yet to study possible connections between traumatic experiences, severe stress, or PTSD, on the one hand, and the development of lupus on the other.
A team decided to rectify that by looking at whether women who have experienced trauma or who have PTSD are at higher risk of developing lupus. If the researchers found an association, they also wanted to know if lifestyle played a role in it — specifically, smoking, drinking, having a sedentary lifestyle, obesity, and using oral contraceptives.
The study involved 54,763 women whom researchers followed for 24 years. The team looked at whether the women had been exposed to trauma, had PTSD, or had developed lupus.
Researchers divided the women into four categories of traumatic or stressful experiences: those who had not experienced trauma, those who had experienced trauma but displayed no PTSD symptoms, those with one to three symptoms indicating they might have PTSD, and those with four to seven symptoms that indicated they probably had PTSD.
Seventy-three women developed lupus during the follow-up period, researchers said.
A key finding was that the risk of the women in the probably-PTSD group developing lupus was three times higher than in the no-trauma group. Women in the might-have-PTSD group were also at higher risk of developing lupus, but it was not statistically significant.
Another important finding was that whether or not a woman had PTSD symptoms, a history of being exposed to trauma tripled her risk of developing lupus.
And the risk of a woman who was likely to have PTSD developing lupus was much higher than women in the no-trauma group even when researchers took lifestyle into account. With lifestyle factored in, the risk was 2.6 times higher. This indicated that lifestyle alone cannot explain the association between PTSD and lupus.
“Our study contributes to growing evidence that psychosocial trauma and associated stress responses lead to autoimmune disease,” the researchers concluded. “Identification of the biological pathways by which psychosocial trauma may increase risk for autoimmune disease is crucial and may provide greater insight into disease etiology, as well as strategies for prevention.”