Chronic pain and mortality
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Helge Kasch
In this issue of the Scandinavian Journal of Pain, Nitter and Forseth report the mortality rate in women with self-reported chronic pain in a 17-year follow-up study [1]. This is by far the longest observation period reported on this subject, and the study supports previous findings of raised mortality in patients with chronic pain.
In two studies by McBeth et al. they found that widespread body pain was related to an increased incidence of cancer and, furthermore, to a reduced probability of survival after cancer and cardiovascular disease [2,3]. In patients with muscular and widespread pain, other comorbidities are found as well. Having widespread pain or chronic regional pain was shown to be significant in 95 discordant twins [4], with pain affecting physical health, functioning, and sleep suggesting that acquired chronic pain was a risk factor. But chronic pain may also lie in the genes. Recent genetic pain studies seem to point out different types of response to pain and other psychophysical events based on e.g. the catechol-O-methyltransferase gene polymorphism [5]. Having a high pain-sensitive COMTgenotype was in some studies related to the development of fibromyalgia/widespread pain [6], but others, including the Norwegian HUNT studies, found neither this association nor an association with mortality, psychiatric illness, or other comorbidities [7,8,9].
The study by Nitter and Forseth in this context (see “Highlights” of the paper)
Nitter and Forseth were interested in development of fibromyalgia and widespread pain and set up a study in which a minor proportion was physically examined, but most of the patients were followed only by questionnaire. Mailed pain questionnaires were sent to approx. 2500 women, with 2038 responders in Arendal, Norway. The women were aged 20–50 years at the time of inclusion. First assessment took place in 1990 and the following assessments after 5 and 17 years, and finally data were linked to Death Registry data.
This long-term follow-up study confirms the findings reported by McBeth of higher mortality rates in patients with chronic pain and widespread pain, but does not confirm an increased risk of cancer death or cardiovascular death. In contrast, Nitter and Forseth found that chronic pain patients died more often from unknown or other causes not related to cardiovascular disorder, cancer, or suicide. McBeths population consisted of both sexes, but similar cohort size of women was obtained in the present study.
Again, patients with chronic widespread pain showed higher mortality rates than patients with chronic regional pain, which was also associated with a higher mortality than controls.
As was the case with the McBeth studies, in this cohort we have no information on concurrent use of medication and other comorbidities, no information on use of drugs/alcohol, activity level, job, social and marital status or level of leisure activities.
As shown in Table 1, the crude mortality rate was increased by a factor of 2.4 in chronic regional pain patients and 4.9 in chronic widespread pain patients, but also anxiety and sleep disturbances influenced mortality [1].
Conclusion and implications
Long-term follow-up studies are needed in order to detect any development in comorbidity and mortality in chronic pain patients. The strength comes when combining these questionnaires with central registries, and, as for the HUNT 2 and 3 studies, blood tests with genetic testing. This study includes information about age, SF-36 related issues, and background statistics from the region, but not about co-morbidity, other risk factors [10] social factors, use of medication, smoking habits, alcohol consumption, and physical activity. Finding an increased mortality risk in chronic pain patients is of importance, but should be interpreted with caution. The study, however, confirms previous findings of a significantly increased mortality rate in females. The debate is still open, but further studies are needed as concluded by the authors. Important also for the future organization of pain treatment, if mortality is raised by a factor 5 in chronic widespread pain, we should further improve facilities for pain treatment and funding for pain research.
DOI of refers to article: http://dx.doi.org/10.1016/j.sjpain.2012.12.002.
References
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© 2013 Scandinavian Association for the Study of Pain
Articles in the same Issue
- Editorial comment
- From clear reporting to better research models
- Topical review
- Transparency in the reporting of in vivo pre-clinical pain research: The relevance and implications of the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines
- Editorial comment
- Altered central pain processes behind fibromyalgia? Are they restored by antidepressants as indicated by an innovative fMRI-study?
- Clinical pain research
- Using fMRI to evaluate the effects of milnacipran on central pain processing in patients with fibromyalgia
- Editorial comment
- The obligation to publishing negative outcome data from neuropathic pain clinical trials
- Clinical pain research
- Evaluation of a novel chemokine receptor 2 (CCR2)-antagonist in painful diabetic polyneuropathy
- Editorial comment
- Chronic pain and mortality
- Clinical pain research
- Mortality rate and causes of death in women with self-reported musculoskeletal pain: Results from a 17-year follow-up study
- Editorial comment
- A novel approach of analyzing characteristics of sensory nerve fibers
- Original experimental
- Discriminative sensory characteristics of the lateral femoral cutaneous nerve after mepivacaine-induced block
- Editorial comment
- Conditioned pain modulation: A useful test paradigm in research and in clinical practice
- Original experimental
- Painful heat attenuates electrically induced muscle pain in men and women
- Editorial comment
- Amplification of osteoarthritis pain by peripheral and central nervous systems pain mechanisms
- Original experimental
- Relating clinical measures of pain with experimentally assessed pain mechanisms in patients with knee osteoarthritis
- Editorial comment
- The value of critical values from normative data
- Clinical pain research
- Percentile normative values of parameters of electrical pain and reflex thresholds
- Erratum
- Erratum to “Epithelial growth factor receptor (EGFR)-inhibition for relief of neuropathic pain–A case series” [Scand. J. Pain 4 (2013) 3–7]
Articles in the same Issue
- Editorial comment
- From clear reporting to better research models
- Topical review
- Transparency in the reporting of in vivo pre-clinical pain research: The relevance and implications of the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines
- Editorial comment
- Altered central pain processes behind fibromyalgia? Are they restored by antidepressants as indicated by an innovative fMRI-study?
- Clinical pain research
- Using fMRI to evaluate the effects of milnacipran on central pain processing in patients with fibromyalgia
- Editorial comment
- The obligation to publishing negative outcome data from neuropathic pain clinical trials
- Clinical pain research
- Evaluation of a novel chemokine receptor 2 (CCR2)-antagonist in painful diabetic polyneuropathy
- Editorial comment
- Chronic pain and mortality
- Clinical pain research
- Mortality rate and causes of death in women with self-reported musculoskeletal pain: Results from a 17-year follow-up study
- Editorial comment
- A novel approach of analyzing characteristics of sensory nerve fibers
- Original experimental
- Discriminative sensory characteristics of the lateral femoral cutaneous nerve after mepivacaine-induced block
- Editorial comment
- Conditioned pain modulation: A useful test paradigm in research and in clinical practice
- Original experimental
- Painful heat attenuates electrically induced muscle pain in men and women
- Editorial comment
- Amplification of osteoarthritis pain by peripheral and central nervous systems pain mechanisms
- Original experimental
- Relating clinical measures of pain with experimentally assessed pain mechanisms in patients with knee osteoarthritis
- Editorial comment
- The value of critical values from normative data
- Clinical pain research
- Percentile normative values of parameters of electrical pain and reflex thresholds
- Erratum
- Erratum to “Epithelial growth factor receptor (EGFR)-inhibition for relief of neuropathic pain–A case series” [Scand. J. Pain 4 (2013) 3–7]
