“Stress exacerbates pain in the everyday lives of women with fibromyalgia syndrome” – This title for a recent study has a serious “duh” factor attached to it. I think anyone who lives with Fibromyalgia or near a woman (or man) with Fibromyalgia could tell you that stress increases pain in Fibromyalgia. It’s certainly true for me. Surely, this study by Fischer et al. has to tell us something we don’t know, so let’s take a look.
The first takeaway from this study is that while those of us with Fibro seem to know that stress is linked to our symptoms and there have been studies that used self-reports to confirm that, this is the first study to use empirical testing to show a connection between the two. In this study Fischer and colleagues tested biological markers of stress, rather than relying on self reports. Specifically, they measured salivary cortisol levels and alpha-amylase. Cortisol is known as the stress hormone (it increases when we are under stress), while alpha-amylase is a digestive enzyme that can be used to measure autonomic nervous system activity.
They hypothesized that increases in stress would precede increases in pain. Because high pain can increase stress they also tested whether increased pain preceded stress.
The sample consisted of 32 women diagnosed with Fibromyalgia. These women used an Ipod Touch to answer questions about their state throughout the day (the Ipod provided prompts at specific times). Immediately after answering the prompts the women collected saliva samples on themselves. The first prompt and sample was given prior to getting out of bed. This continued for 14 consecutive days.
There was a positive correlation between stress in the moment and pain that moment. This finding held even when items such as sleep quality, medication, and time since waking were controlled for. They also that higher stress predicted higher pain levels at the next measurement (3-4 hours later). However, stress the previous day did not significantly impact pain the next day. When the question was reversed they did not find that pain was predictive of later stress levels. What they found was that participant’s cortisol levels correlated with pain. The higher the participant’s cortisol levels the higher the pain they reported. However, they did not find a connection between alpha-amylase (or autonomic nervous system function) and pain intensity.
Fischer and colleagues believe that the lack of finding that pain predicts stress may be due to the higher percentage of adaptive copers in their study. They feel this is because they excluded patients with depression and other mental disorders. Therefore, they may have skewed the group. Adaptive coping helps reduce stress while allowing the patient to better cope with pain. Alternatively, they suggested that it may be possible that pain doesn’t actually increases stress rather it just increases emotional distress (which does not increase cortisol).
Fischer, S., Doerr, J. M., Strahler, J., Mewes, R., Thieme, K., & Nater, U. M. (2016). Stress exacerbates pain in the everyday lives of women with fibromyalgia syndrome—The role of cortisol and alpha-amylase. Psychoneuroendocrinology, 6368-77. doi:10.1016/j.psyneuen.2015.09.018