Background Fibromyalgia women report poorer sleep quality, fewer hours of sleep, greater nighttime awakenings, and non-restorative sleep compared with healthy people and other clinical populations (Diaz-Piedra et al., 2015). Previous literature has shown a positive effect of exercise training on sleep quality in women with fibromyalgia (Munguía-Izquierdo et al., 2008). Given the close relationship between exercising and physical fitness improvement, it is important to ascertain the individual influence of physical fitness components on sleep quality in this population.
Objectives To examine the individual association of physical fitness components with sleep quality in women with fibromyalgia.
Methods A total of 444 women with fibromyalgia (means±sd =51.3±7.5 years old) from Andalusia (southern Spain) were included in this cross-sectional study. The Senior Fitness test battery was used to assess physical fitness. This battery consists of the chair sit-and-reach, back scratch, 30-second chair stand, arm curl, 8-foot up-and-go (lower score indicates better performance) and 6-minute walk tests, which assess lower body flexibility, upper body flexibility, lower body strength, upper body strength, speed agility and cardiorespiratory fitness, respectively. Sleep quality was measured using the total score of the Pittsburgh Sleep Quality Index (PSQI) questionnaire (greater score indicates worse sleep quality). Linear regression was used to explore the association of each physical fitness component with global sleep quality. Analyses were controlled for age, total body fat percentage, marital status, educational level, medication for relaxation/sleep and regular menstruation.
Results Lower body flexibility (b=-0.033, β=-0.103), upper body flexibility (b=-0.031, β=-0.096), lower body strength (b=-0.191, β=-0.157), upper body strength (b=-0.111, β=-0.142) and cardiorespiratory fitness (b=-0.008, β=-0.154) were inversely associated with greater scores in the PSQI questionnaire (all, p<0.05). Speed-agility (b=0.282, β=0.128) was positively associated with the score in the PSQI (p<0.01).
Conclusions The current study showed that higher physical fitness is generally associated with better sleep quality in women with fibromyalgia. It is important to mention that all the physical fitness components seem to be associated with sleep quality. Lower body strength and aerobic capacity were the components that showed the strongest associations with sleep quality. Future studies are warranted to elucidate the causality of these relationships.
Diaz-Piedra, Carolina et al. 2015. Sleep Disturbances of Adult Women Suffering from Fibromyalgia: Asystematic Review of Observational Studies. Sleep Medicine Reviews 21:86–99.
Munguía-Izquierdo, D. & Legaz-Arrese, A. Assessment of the effects of aquatic therapy on global symptomatology in patients with fibromialgia síndrome: a randomized controlled trial. Arch. Phys. Med. Rehabil. 2008, 89:2250–2257.
Acknowledgements This study was supported by the Spanish Ministry of Economy and Competitiveness (I+D+I DEP2010–15639; DEP2013–40908-R).
Disclosure of Interest None declared