Fibromyalgia and Weight Gain
Research is emerging to suggest a link between fibromyalgia and weight gain. The nature of this relationship is unclear, however studies have shown an increased incidence of fibromyalgia among obese and overweight individuals (Bennett et al., 2007; Okifuji et al., 2009; Chaiamnuay et al., 2007), and symptom severity has been demonstrated to increase with increasing body weight (Ursini et al., 2011; Kim et al., 2011; Okifuji et al., 2010). For example, Yunus et al. (2002) have shown that both fatigue and tender point counts increase as BMI (body mass index) increases, and other researchers have shown that fibromyalgia patients with higher BMIs have decreased quality of life, increased tenderness, more physical dysfunction, and higher tender point counts (Neumann et al., 2008).
The adverse relationship between increased weight and symptom severity can result in negative feedback loops for the patient. Negative feedback loops are essentially chain reactions of events that have negative consequences, each event being fed by the previous one in a cycle, which continues until something occurs to stop it. These negative feedback loops can perpetually worsen symptoms and potentially lead to the development of new ones. For example, an overweight individual with fibromyalgia may have severe knee pain due to the stress that their excess weight places on their joints. As a result, the patient is unable to get around without substantial effort and/or assistance from a walking aid. This limited mobility may have a negative impact on the patient’s mental health and lead to the development of depression. This depression may feed the patient’s pain until something breaks the cycle, such as the patient losing weight (and improving their mobility), or the patient receiving treatment for their depression.
In light of the demonstrated relationship between weight and symptom severity, it is not surprising that studies have found weight loss programs to be of benefit to fibromyalgia patients in terms of improving depression, anxiety, quality of life, and pain (Shapiro et al., 2005). Numerous studies have offered evidence to support the use of exercise as part of a comprehensive treatment program for fibromyalgia (Busch et al., 2011; Busch et al., 2009; Hauser et al., 2010; Cazzola et al., 2010).
The research linking fibromyalgia and weight gain, the demonstrated benefits of exercise, and the potential for negative feedback loops complicating and worsening symptoms, weight management is an essential component to the effective management of fibromyalgia. Unfortunately, this is easier said than done, as weight-management can often be difficult, regardless of whether or not an individual has fibromyalgia. Nevertheless, its importance cannot be understated. Successful weight management will likely involve a combination of exercise, dietary modifications, and possibly even counseling. Although there are no formal dietary recommendations for fibromyalgia (Friedlander et al., 2011), a healthy diet should be consumed, and recommendations for particular dietary interventions should be discussed with the appropriate members of each patient’s treatment team. In addition, counseling to identify psychological and behavioral aspects associated with weight gain and obesity may also be needed for some patients.
Apart from diet and exercise, fibromyalgia patients should also be aware of the potential for weight gain as a side effect of various medications they may take to treat their fibromyalgia. It is well-known that many tricyclic antidepressants, such as Pamelor and Elavil, can cause considerable weight gain for many who use them. Newer antidepressants, such as Lexapro, Paxil, Prozac, Zoloft, Effexor, and Pristiq may also cause weight gain. In contrast, Cymbalta and Savella, which are two of three medications approved by the U.S. Food and Drug Administration (FDA) to treat fibromyalgia have been shown in clinical studies to either have little impact on weight or even result in weight loss (Gaynor et al., 2011). The third such medication, Lyrica, has been shown to have minimal impact on weight gain with long-term use (Cabrera et al., 2012). However, it is very important to understand that medication side effects will vary considerably between patients, and drugs that cause weight gain in one patient may not cause it in another. As with other factors related to fibromyalgia management, this potential for drug-related weight gain speaks to the need for systematic tracking of symptoms and treatments, as well as detailed documentation and ongoing evaluation of treatment-related side effects.