Background Since 2010, fibromyalgia is modelled as a syndrome of progressive severity where non-specific symptoms other than pain precede the establishment of clinical disease. Detecting those symptoms is expected to improve sensitivity by widening the spectrum of clinical features, namely in early stages of the disease. However, little is known about the frequency and predictors of the non-pain component of the fibromyalgia syndrome in early adulthood.
Objectives To quantify the prevalence of fibromyalgia (2010 ACR), to describe its components – symptom severity score and widespread pain index – and to identify psychosocial predictors of the severity of symptom severity score and widespread pain using a population-based sample of male and female young adults.
Methods Participants were part of the 21-year-old follow-up of the EPITeen cohort study, which was set up during the 2003/2004 school year and gathered subjects born in 1990 attending schools in Porto, Portugal (n=1561, 51.3% women). Data on socioeconomics (work situation, parental and individual education and household income), lifestyle factors (smoking, alcohol drinking and sports practice) and psychological characteristics (health-related quality of life, sleep quality, depressive symptoms, eating disorders and maladaptive personality traits) were collected using structured face-to-face and self-administered questionnaires. Data on fibromyalgia and the severity of its two main components were collected using the Fibromyalgia Survey Questionnaire. Medians of symptom severity score and widespread pain index severity were compared according to each psychosocial factor using the Mann-Whitney test or the Kruskal-Wallis one-way analyses of variance.
Results The overall point-prevalence of fibromyalgia was 1.1%, higher in women than in men (1.5% vs. 0.7%, p=0.110). Women scored significantly higher both in symptom severity score (median (P25; P75)=3.0 (2.0; 5.0) vs. 2.0 (1.0; 4.0), p<0.001) and widespread pain index (median (P25; P75)=1.0 (0.0; 1.0) vs. 0.0 (0.0; 1.0), p<0.001). Both in female and male young adults, socioeconomics, lifestyle factors and psychological features were not significantly associated with higher scores in widespread pain index. Socioeconomic indicators, such as work situation (employed vs never worked: median (P25; P75)=4.0 (2.0; 5.0) vs 3.0 (2.0; 5.0), p<0.01), and lifestyle factors, such as smoking (smokers vs non-smokers: median (P25; P75)=4.0 (2.0; 5.0) vs 3.0 (2.0; 5.0), p<0.05), were significantly associated to higher scores in symptom severity score in female sex. Additionally, most adverse psychological characteristics (poor quality of life, decreased sleep quality, relevant depressive symptoms, eating disorders and maladaptive personality traits such as interpersonal distrust, interoceptive awareness and ineffectiveness) were significantly associated with higher scores in symptom severity score in both sexes.
Conclusions In young adults, prevalence of fibromyalgia was similar to other high burden chronic diseases. Using the symptom severity score may be useful in widening case ascertainment to young adults whose main clinical manifestations are related to psychological distress.
Disclosure of Interest : None declared