Fibromyalgia is a multifactorial disease, of which etiology is based on interaction between genetic susceptibility and environment. However, few studies attempted to identify the risk factors.
To investigate the genetic influence and its interaction with environmental quality and stress, as possible risk factors for fibromyalgia development.
This cross-sectional study investigated two groups of women, of which 47 had a clinical diagnosis of fibromyalgia, and 41 women comprising thre control group, all from the town of Novo Hamburgo, RS. The apolipoprotein E (APOE) gene polymorphism was analyzed in DNA extracted from total blood, in both samples. Environmental factors were studied through Lipp's Inventory of Stress Symptoms for Adults and by applying the WHOQOL-100 domain V.
Among the patients, more women had high stress levels when compared to the control sample (P < 0.001); moreover, the average scores of the WHOQOL-100 domain V, which analyze environment quality, were lower in this group (P < 0.001). APOE genotypic and allelic frequencies were similar between the two groups. Multivariate analysis showed that low WHOQOL-100 scores increase the chance of disease development by 57.7 times (P < 0.001), and that high stress levels were related with the disease (OR = 197.2; P < 0.001). This approach pointed out an interaction between stress and presence of E*2 allele (P = 0.028). Fibromyalgia was much more frequent in patients with high stress levels that were E*2 non-carriers (estimated OR = 265.1), when compared to patients with the same stress level, but E*2 carriers (estimated OR = 1.06).
E*2 allele presence could have a protective action regarding the association between fibromyalgia and stress.