Researchers in Finland suggest that fibromyalgia (FM) could be predicted through symptoms related to regional pain, frequent headache, persistent back/neck pain, sleeping problems, and excess weight. The study, “Predictors of fibromyalgia: a population-based twin cohort study,” was published in MC Musculoskeletal Disorders.
The American College of Rheumatology classified FM as a syndrome in 1990, using as criteria: 1) a history of widespread pain concentrated particularly on axial skeletal, left/right sides of the body as well as above/below the waist, and 2) sensation of pain in at least 11 of 18 specific tender sites in the body. Compared to previous decades, FM is now relatively better understood. However, mechanisms in its development and symptoms remain unclear.
In a large prospective twin-cohort study, researchers at the University of Helsinki and Helsinki University Hospital examined various potential predictors for FM, as well as the possible genetic factors assessed 9–15 years before the evaluation of FM symptoms.
“Prospective population-based studies on the incidence and predictors of FM are few, whereas many cross-sectional and tertiary clinic studies assess predictors. In a cross-sectional setting, the sequential relationship remains unclear, and one can only identify an association, not a prediction,” the authors wrote in their report.
A total of 8,343 people from the older Finnish Twin Cohort, who answered health questionnaires in 1975, 1981, and again in 1990, were included in the study. From results of the completed 1990 FM-symptom questionnaires, three latent classes (LC) were identified: LC1 grouped people with no or few symptoms, LC2 those with limited symptoms, and LC3 were people with abundant FM symptoms.
Researchers then examined common predictors for symptoms reported in each class using baseline data from 1975 and 1981 related to headache/migraine, regional pain, sleeping problems, body mass index (BMI), smoking, zygosity, and physical activity. They adjusted the results by taking into account gender, age, and education, and subjects with higher possibilities of FM at baseline were not included in the analysis.
Results suggested that patients with abundant FM symptoms (LC3) showed predictors related to regional pain, excessive weight, and sleeping problems. The most common non-genetic predictor symptoms were frequent headaches followed by persistent back and neck pain.
“Headache, back and neck pain, sleeping problems, and high BMI were predictors of FM symptoms, predictors which may be connected. Sleeping problems and high BMI were influenced by familial factors. The intensity and persistence of regional pain was associated with increased risk for FM symptoms,” the authors wrote.
In addition, researchers observed that “heritability plays an important role in FM symptoms, but also in many of the predictors. Therefore that headache and regional pain are predictors independent of family background is an important finding. Further studies must evaluate possibilities of preventing FM by treatment and management of such predictors.”