This study aimed to determine whether there are some differences in the treatment responses to a multidisciplinary fibromyalgia (FM) treatment related with the baseline body mass index (BMI) of the participants. Inclusion criteria consisted of female sex, a diagnosis of FM (American College of Rheumatology criteria), age between 18 and 60 years, and between 3 and 8 years of schooling. Baseline BMI was determined, and patients were assigned at random to one of the two treatment conditions: conventional pharmacologic treatment or multidisciplinary treatment. Outcome measures were pain intensity, functionality, catastrophizing, psychological distress, health-related quality of life, and sleep disturbances. One hundred thirty patients participated in the study. No statisticaly significant differences regarding pre-treatment outcomes were observed among the different BMI subgroups, and between the two experimental conditions for each BMI category. General linear model analysis showed a significant interaction group treatment×time in pain intensity (p<.01), functionality (p<.0001), catastrophizing (p<.01), psychological distress (p<.0001), sleep index problems (p<.0001), and health-related quality of life (p<.05). No significant interactions were observed in BMI×time, and in BMI×group treatment×time.
There aren't any differences among normal weight, overweight and obese patients with FM regarding their response to a multidisciplinary treatment programme for FM which combines pharmacological treatment, education, physical therapy and cognitive behavioural therapy.