A comparative study of heart rate variability and physical fitness in women with moderate and severe fibromyalgia

The aim of this study was to compare the physical fitness and cardiac autonomic activity among women with moderate and severe fibromyalgia (FM) and healthy women. This study included 35 women with FM (age: 46.2±8.9 years) and 17 healthy women (age: 44.3±9.9 years). Participants with FM were divided into moderate FM (n=15) and severe FM (n=20) according to the total score obtained in FM impact questionnaire. The heart rate variability was monitored using a portable cardiac monitor with participants resting in supine position during 10 min. Thereafter, the participants performed the chair sit and reach test, the chair stand test, and the 6-min walk test to measure the lower-body flexibility, lower-body muscle strength, and cardiorespiratory fitness, respectively. The lower-body muscle strength and cardiorespiratory fitness were both reduced in moderate and severe FM compared to healthy women (P<0.01), with greater reduction in severe FM when compared to moderate FM (P<0.05). In addition, the parasympathetic indexes of heart rate variability were all similarly decreased in both moderate and severe FM, when compared to healthy women (P<0.05). The cardiac parasympathetic activity is similarly decreased in women with both moderate and severe FM in comparison to healthy women, despite a greater physical deconditioning in severe FM.