Functional Status and Body Mass Index in Postmenopausal Women with Fibromyalgia: A Case-control Study

Abstract

Reduced functional capacity is a common characteristic of fibromyalgia (FMS). We aimed to investigate the relationship between functional status and body mass index (BMI) in a population with and without FMS. A pilot case-control study was performed in 34 women with FMS and 22 healthy controls which were classified according to their BMI. The main outcome measures were: Balance (MiniBestest, One Leg Stance Test), functional mobility (Timed up and Go), physical disability (Health Assessment Questionnaire Disability Index), spinal range of motion (Spinal Mouse), level of physical activity at work (Leisure Time Physical Activity Instrument), and home and leisure time (Physical Activity at Home and Work). Statistical differences were observed between overweight/obese healthy controls and women with FMS for several indicators of functional capacity. FMS patients reported worse dynamic (p = 0.001) and static balance (right: p = 0.002, left: p = 0.001), poorer functional mobility (p = 0.008), and higher levels of physical disability (p = 0.001). Functional status is altered in FMS women compared to the healthy control group, independently of nutritional status; therefore, BMI is unlikely to play a main role in functional capacity indicators in postmenopausal FMS women. Only dynamic balance seems to reduce the obesity status in this population.

Keywords: body mass index; disability; fibromyalgia; physical conditioning; postmenopause.

Figure 1

Levels of dynamic balance measured with the MiniBest and Timed up and go tests in women with fibromyalgia and healthy controls grouped by their body mass index (normal-weight versus overweight/obese). In the box plots, the boundary of the box closest to zero indicates the 25th percentile, the black line within the box marks the median, and the boundary of the box farthest from zero indicates the 75th percentile. Whiskers above and below the box indicate the 10th and 90th percentiles.

Figure 2

Levels of static balance measured with One leg stance test in cases of women with fibromyalgia and healthy controls grouped by their body mass index (normal-weight versus overweight/obese). In the box plots, the boundary of the box closest to zero indicates the 25th percentile, the black line within the box marks the median, and the boundary of the box farthest from zero indicates the 75th percentile. Whiskers above and below the box indicate the 10th and 90th percentiles.