Patients with prior PTSD twice as likely to develop lupus
Patients with PTSD demonstrated a two-fold higher likelihood of being diagnosed with systemic lupus erythematosus, compared to those without PTSD, according to data published in Arthritis Care & Research.
“Traumatic events, such as combat and sexual assault, have been linked to changes in the immune system, and cohort studies have found higher rates of a variety of autoimmune diseases in persons with posttraumatic stress disorder,” Siobhan M. Case, MD, MHS, of Brigham and Women’s Hospital, in Boston, and colleagues wrote. “It has been hypothesized that exposure to extreme stress, and the subsequent development of PTSD, may be causally related to SLE incidence.”
“Studies have shown potentially higher risks of a variety of different autoimmune diseases among people with PTSD, including in American military populations and in people exposed to the September 11th terrorist attack, and the civilian population in Sweden,” they added. “However, this association has not been investigated in diverse population including males and females of a variety of socioeconomic, racial/ethnic and cultural backgrounds.”
To examine the association between PTSD and SLE in a large, diverse population, Case and colleagues conducted a case-control study of Medicaid data. The researchers included data from patients aged 18 to 65 years who had been enrolled in Medicaid for at least 1 year and resided in one of the 29 most populated U.S. states between Jan. 1, 2007, and Dec. 31, 2010. Cases of SLE and PTSD were identified based on validated patterns and ICD-9 codes, with the index date defined as the date of their first SLE code.
In all, Case and colleagues included 10,942 patients with SLE and matched them 1:10 with 109,420 control participants with no SLE codes, based on age, sex and race. Individuals in the control group had a non-SLE inpatient or outpatient code on the index date. The researchers used conditional logistic regressions to calculate odds ratios and 95% confidence intervals for the association between PTSD and SLE, adjusting for smoking, obesity, use of oral contraceptives and other covariates.
According to the researchers, the prevalence of PTSD cases among patients diagnosed with SLE was 10.74 per 1,000 (95% CI, 9.37-12.31), compared with 7.83 per 1,000 (95% CI, 7.42-8.27) among the control individuals. The multivariable-adjusted odds ratio for SLE among those with PTSD was 2 (95% CI, 1.64-2.46).
“Our main finding was that patients who had a prior diagnosis of PTSD had twice the odds of a later diagnosis of SLE, even after accounting for sociodemographic characteristics and other risk factors for developing SLE,” Case told Healio Rheumatology. “This study suggests that there are common pathways between PTSD and SLE. Further studies are needed to look into this relationship and identify possible targets for intervention.”