Sex hormones and pain in regularly menstruating women with fibromyalgia syndrome.
ABSTRACT Fibromyalgia syndrome (FMS) is more prevalent in women than in men. The skewed sex distribution in the prevalence has prompted questions of if and how sex hormones may be involved in the pathophysiology of FMS. In this study, we evaluated the levels of sex hormones and pain sensitivity at different phases of a menstrual cycle in regularly menstruating women with FMS relative to age-matched healthy women. Participants (n = 74 in each group) underwent a 9-day urine test to identify the date of ovulation. Three laboratory visits were scheduled to ascertain the varying levels of estrogen (E) and progesterone (P): Late-follicular phase (high E, low P); mid-luteal phase (high E, high P); and perimenstrual phase (low E, low P). At each visit, blood was drawn and ischemic pain testing was performed. The groups did not differ in the fluctuation of luteal hormone, follicular-stimulating hormone, E, and testosterone across a menstrual cycle. FMS patients showed slightly elevated P levels during the mid-luteal phase relative to healthy women but levels were within the normal range. Women with FMS showed consistently lower pain thresholds and tolerance relative to healthy women throughout the menstrual cycle. Pain threshold at the late follicular phase was modestly related to the P level. The results suggest that the disproportionate prevalence of females with FMS is not likely to be attributable to hormonal factors. Furthermore, the role of sex hormones in pain sensitivity for both FMS and healthy women seems to be limited. PERSPECTIVE: Normally menstruating women with FMS and healthy women do not seem to show fluctuating threshold and tolerance to the ischemic pain test. The role of sex hormones in the hyperalgesia of FMS appears limited.
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ABSTRACT: Most chronic non-cancer pain (CNCP) conditions are more common in women and have been reported to worsen particularly during the peak reproductive years. This phenomenon suggests that ovarian hormones might play a role in modulating CNCP pain. To this end, we reviewed human literature aiming to assess the potential role of ovarian hormones in modulating the following CNCP conditions: musculoskeletal pain, migraine headache, temporal mandibular disorder, and pelvic pain. We found 50 relevant clinical studies, the majority of which demonstrated a correlation between hormone changes or treatments and pain intensity, threshold, or symptoms. Taken together, the findings suggest that changes in hormonal levels may well play a role in modulating the severity of CNCP conditions. However, the lack of consistency in study design, methodology, and interpretation of menstrual cycle phases impedes comparison between the studies. Thus, while the literature is highly suggestive of the role of ovarian hormones in modulating CNCP conditions, serious confounds impede a definitive understanding for most conditions except Menstrual Migraine and endometriosis. It may be that these inconsistencies and the resulting lack of clarity have contributed to the failure of hormonal effects being translated into medical practice for treatment of CNCP conditions.Pain 08/2014; 155(12). DOI:10.1016/j.pain.2014.08.027 · 5.64 Impact Factor
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ABSTRACT: Fibromyalgia is a prevalent disorder characterized by chronic widespread pain (CWP) and complex comorbid symptoms. A CWP model is developed through repeated unilateral intramuscular injections of acid saline resulting in bilateral mechanical hyperalgesia in rats. The present study aims to evaluate whether both anxious and depressive comorbidities exist in this acid-induced pain model, similarly to patients with CWP syndromes. The anxiety-like behaviors were evaluated using the open field and elevated plus maze tests, and depression-like behaviors were measured by the forced swimming, sucrose consumption, and sucrose preference tests. The pain group receiving acidic saline displayed significantly lower paw withdrawal thresholds for 4 weeks than animals in the vehicle group after repetitive intramuscular injections. The pain group showed a significantly shorter duration of exploring the central zone of the open field and the open arms of the elevated plus maze compared to the vehicle group. The pain group had a significantly lower preference for and consumption of the hedonic sucrose. Moreover, rats with chronic pain showed significantly longer immobility than the vehicle group in the forced swimming test. The results indicate that psychiatric behaviors are exacerbated in the CWP model. This study provides evidence for the validity of the acid-induced pain model analogous to patients with CWP syndromes.Physiology & Behavior 05/2014; 131:105–110. DOI:10.1016/j.physbeh.2014.03.030 · 3.03 Impact Factor