Possible link of Interleukin-6 and Interleukin-2 with psychiatric diagnosis, ethnicity, disaster or BMI

Background Cytokines are of increasing interest as markers for stress responses, mental disorders and general health. We assessed associations of two cytokines with several factors among relocated hurricane survivors and controls. Methods: We examined 40 relocated hurricane survivors and 40 demographically matched (frequency matching) Oklahoma controls to assess relationships of Interleukin-2 (IL-2) and Interleukin-6 (IL-6) with psychiatric diagnoses (SCID-IV), demographic variables, hurricane exposure and body mass index (BMI). Participants were predominantly African American (n = 70, 87.5%). Results: Relocated Katrina survivors had higher proportions of current PTSD, major depression and psychiatric diagnoses than controls. Unexpectedly, exposure to Katrina with relocation was not by itself associated with differences in IL-2 or IL-6 levels. The mean IL-2 level was significantly higher in African American participants than other ethnicities (8 Caucasians, 2 Asians) and in those with a current psychiatric disorder. The mean IL-6 level was higher in females than males and in participants with any current psychiatric diagnosis. IL-6 level also correlated positively with participants' BMI. Conclusions: Results suggest that cytokines studied were influenced non-specifically by the presence of a mental disorder, and by demographic variables of gender, ethnicity and BMI. Implications of these findings are discussed, as well as possible long-term impact of the identified interleukin differences on immunologic, inflammatory, neuropsychiatric and other systems.