Fibromyalgia and Obesity

The Association Between Body Mass Index and Disability, Depression, History of Abuse, Medications, and Comorbidities

Carmen E. Gota, MD; Sahar Kaouk; William S. Wilke, MD


J Clin Rheumatol. 2015;21(6):289-295. 

In This Article

Limitations and Attributes

Our study has several important limitations. The data reflect the characteristics of an FM population seen in a tertiary care center with overall more severe disease than in previous studies, thus not necessarily reflective of the general FM population seen in community. The size of the cohort was relatively small compared with other studies.[31] In addition, the cross-sectional design may not be the best to answer the complex questions about causation. For instance, we cannot determine whether weight loss would improve process or outcome factors. Prospective studies have demonstrated that decrease in BMI is associated with a wide array of improvements in FM.[11,16,17] In addition, sleepiness has been shown to correlate with weight gain. In a prospective study, and although ESS did not associate with BMI in our study, the limited number of FM patients with sleep apnea (who ought to be sleepy) tended to be obese.[53] We also cannot objectively determine whether FM causes obesity. The observation from our data that disease duration was not associated with BMI argues against that hypothesis, but does not disprove it.

Finally, our finding that BMI does not associate with FM core process factors is not intuitive, given an earlier analysis of this same cohort.[54] In that study, we found that mood was associated with all core process factors in FM. In this article, increased BMI is associated with poor mood but not core process FM factors. Only future prospective controlled inception studies may provide answers: factors correlated with weight during the course of FM disease and any causal relationships of weight to FM phenotype and symptom severity.

This study has the following attributes: our data were collected in a naturalistic setting by registering consecutive patients who underwent comprehensive, uniform evaluations. This design has allowed us to perform 1 of the most detailed evaluations of the relationships of BMI in an FM cohort, not only with questionnaire-driven data, but also with a large array of symptoms, physical examination findings, and exercise, demographics, mood, and medications, beyond the scope of previous studies.