Fibromyalgia and Obesity
There appears to be some association between Fibromyalgia and obesity. In general, certain symptoms are commonly experienced by both obese individuals and Fibromyalgia patients – including increased musculoskeletal pain, knee osteoarthritis, carpal tunnel syndrome, and low back pain. In addition, some studies show an increased incidence of Fibromyalgia in obese and overweight individuals when compared to persons who are at healthier weights [Ursini et al., 2011]. Although studies related to Fibromyalgia and obesity are limited in number, the data they have produced are convincing enough to suggest an association between Fibromyalgia and obesity, and to spur research that continues to investigate this potential link.
Most studies that have looked into the association between Fibromyalgia and obesity use the Body Mass Index, or BMI, as an indicator of body composition. An individual with a BMI between 25 and 29 is considered to be overweight, whereas someone with a BMI between 30 and 34 is considered to be obese. In basic terms, the higher a person’s BMI number, the more body fat they have. Many studies conducted to date have shown that an increased number of Fibromyalgia patients are either obese or overweight. In addition to the increased frequency of Fibromyalgia among obese/overweight individuals, a number of clinical features have been found to be common across several studies. Some research has shown that both fatigue and the number of tender points increase as BMI increases (Yunus et al., 2002), while others have shown that BMI is negatively related to quality of life measures and tenderness threshold, and positively related to physical dysfunction and tender point count (Neumann et al., 2008). Other studies have shown that Fibromyalgia symptoms become worse as BMI increases (Kim et al., 2011; Okifuji et al., 2010).
A large internet-based survey of over 2,500 Fibromyalgia patients found that 70% of respondents had a BMI greater than 25 and 43% had a BMI greater than 30, suggesting an association between the presence of Fibromyalgia and obesity/overweight (Bennett et al., 2007). Another evaluation of 100 female Fibromyalgia patients found that 28% were overweight while 45% were obese. In addition, the researchers found that those who had higher BMI scores were more likely to report lower levels of quality of life, higher pain sensitivity, and higher degrees of physical dysfunction (Neumann et al., 2008). A similar investigation in 38 Fibromyalgia patients discovered that half were obese and roughly one-quarter were overweight (Okifuji et al., 2009). Finally, a study of 364 patients with systemic lupus erythematosus (commonly called lupus) found that those who had an increased BMI were more likely to have Fibromyalgia. Of the 364 patients studied, 28% were obese. This particular study also found a direct association between obesity and the presence of Fibromyalgia (Chaiamnuay et al., 2007).
Research has also been conducted to see if a weight loss program can help Fibromyalgia patients, and the results are encouraging. In one study, the patients all followed restricted diets, increased their physical activity levels, and followed a behavior modification program to help control stimuli that trigger excessive eating and hunger. By the end of the program, patients showed significant improvements in depression, anxiety, quality of life measures, and various measures of Fibromyalgia pain assessment (Shapiro et al., 2005).
The reasons for the potential link between Fibromyalgia and obesity are unclear. Some researchers believe that the answer may somehow be related to the fact that both conditions are frequently characterized by poor sleep. Other researchers think that depression may play a role, since Fibromyalgia is strongly associated with depression and other similar psychological illnesses, and obesity is linked to depression as well. Finally, some research suggests that a low-functioning thyroid gland (a condition called hypothyroidism) may be to blame. In one study of Fibromyalgia patients with hypothyroidism, the authors found that Fibromyalgia symptoms improved greatly once the thyroid condition was treated (Carette et al., 1988).
In summary, there is a growing amount of research that focuses on the link between Fibromyalgia and obesity. Although the reasons for the association are not very clear, there does appear to be an increased incidence of Fibromyalgia among obese and overweight individuals, and the severity of Fibromyalgia symptoms appears to increase as BMI increases. Some research suggests that interventions to help patients lose weight and control thyroid function may be effective strategies to control – and possibly lessen – the symptoms of Fibromyalgia. Regardless, more research needs to be done before firm conclusions can be drawn.