07.05.2015

Women with fibromyalgia are more sedentary and less physically active than their peers without fibromyalgia, but neither group meets recommended levels of physical activity. These are the findings of a study using accelerometers to measure physical activity in a sample of women with fibromyalgia and age-matched controls, according to Spanish researchers.

“Women with fibromyalgia spent, on average, 48% [approximately 8 hours/day] of their waking time in sedentary behaviors,” the authors wrote in Arthritis and Rheumatology. “Although they spent, on average, approximately 45 min per day in MVPA [moderate-vigorous physical activity], overall, these activities were not continuous for at least 10 minutes. Only 20.6% of women with fibromyalgia met the weekly PA recommendations whereas 46.3% of controls did.

Further, the investigators found that only 16% of the women with fibromyalgia fulfilled current recommendations for the number of steps per day (at east 10,000/day), compared with 44.7% of the controls.

They recruited 413 women with fibromyalgia and 188 age-matched controls from the Andalusian population who agreed to wear an accelerometer.

Women with fibromyalgia presented with higher weight, body mass index, and fat percentage, and lower height than controls (all P<0.01), and were less likely to be working than the controls (25.7 vs. 40.4%, respectively, P<0.001).

Among women with fibromyalgia, older, obese and nonworking women spent more time in MVPA than younger, non-obese and working women (all P<0.05). Women with fibromyalgia who were not obese, those who did not attend a university, and those working spent less time in sedentary behaviors and more time in light physical activity than those who were obese, those who attended a university, and nonworkers, respectively (all P<0.05).

Married women were more likely to engage in light physical activity than unmarried women (P=0.039) in both fibromyalgia and controls (both P<0.05).

Sedentary time was greater (by a mean of 39.8 min/day, P<0.001) and time spent in light, moderate or moderate-vigorous physical activity was less (by a mean of 21.7 min/day, P=0.005, 17.3 min/day, P<0.001, and 19.3 min/day, P<0.001, respectively) in women with fibromyalgia compared with controls.

Women with fibromyalgia accumulated a mean of 1,880 fewer steps/day than controls (P<0.001).

Some 75.1% of women with fibromyalgia and 93.6% of controls accumulated at least 150 min/week of MVPA (P<0.001), and 42.9% and 71.3%, respectively, accumulated 300 min/week or more of MVPA (P<0.001).

However, only 20.6% of women with fibromyalgia and 46.3% of controls met the 150 min/week of MVPA recommendation when the criterion considered bouts of at least 10 minutes of MVPA at a time of MVPA (P<0.001). Ten continuous minutes of MVPA “is the minimum required to provide some protection against selected chronic diseases and all-cause mortality,” the authors note. Women with fibromyalgia engaged in 70 fewer minutes/week of 10-minute MVPA bouts than controls, “which might be considered clinically relevant,” they state.

The proportion of women satisfying the steps recommendation was lower in fibromyalgia compared with controls (16.0% versus 44.7%, P<0.001). “Of note is that both women with fibromyalgia and controls tended to be less physically active during weekend, both spending around 40 min/day less on total PA compared with the weekdays,” they found.

Women with fibromyalgia accumulated less counts per minute (accelerometer vector magnitude), spent more time in sedentary activities, spent less time in light (except 2 week days), moderate, and MVPA intensities, and took fewer steps than controls on every day of the week (all P<0.05).

The authors conclude that only 16% to 20% of Spanish women with fibromyalgia fulfilled the physical activity and steps recommendations, but these percentages are still higher than those observed in international studies with adult populations, which show that approximately 5% of patients with fibromyalgia fulfill these criteria.

They add that encouraging women with fibromyalgia and without fibromyalgia to engage in daily physical activity behaviors, especially on the weekend, is important “since they usually are less physically active in this period compared to weekdays.”

Limitations of the study include its cross-sectional design, the lack of men in the sample, and the potential underestimation of some types of physical activity, such as those involving continuous upper body movement that is not captured by an accelerometer.