Fibromyalgia (FM), affecting between 4 -12 million people, mostly women, has been profiled as a ‘stress-related’ functional disorder with observed stress physiology components such as: 1) blunting of the hypothalamic-pituitary-adrenal stress hormone axis such as low 24-hour blood levels of free cortisol, and a weak cortisol response to administered ACTH or CRH; 2) postural change abnormalities, implying autonomic nervous system (ANS) dysfunction; and 3) reported and recorded sleep abnormalities. The purpose of this descriptive comparative study was to describe differences in 1) ANS function from 24-hour heart rate variability indicators (HRV) and 2) sleep/wake patterns from 24-hour sleep/wake actigraphy indicators. Methods included using ambulatory, non-invasive, biobehavioral measures and comparing women with FM (n=18, mean age=48 yrs) and women without FM (n=20, mean age 41yrs). All subjects were sedentary and postmenopausal or in the mid-follicular stage of the menstrual cycle. Results validated that the women with FM compared to without FM had significantly higher myalgic scores (p=<0.001) and lower HRV (SDNN, p=0.042; SDANN, p=.028) with a dominant sympathetic HRV frequency component (p=0.49). Differences between groups on sleep/waking actigraphy indicators were not evident. These results indicate that women with FM tend to have altered autonomic regulation of their heart rate that could predispose them over time to cardiovascular problems. Although they perceive poor sleep, this is not validated by use of actigraphy. These data are suggestive that women with FM might benefit from stress reduction interventions to reset the ANS.
Session #1216 - Poster Session II
The 29th Annual MNRS Research Conference (April 1-4, 2005)