Background/Purpose

Previous studies suggest that FM may be associated with worse balance and falls. Balance requires the coordination of motor, sensory (ex. visual and vestibular), and cognitive abilities.  These may be affected by the psychological symptoms present in FM. Depression, anxiety, and stress, have both cognitive (reduced attention) and somatic features (poor sleep quality and psychomotor slowing); and may therefore be related to the balance problems in FM. We intend to evaluate these relationships in this study.

Methods

We analyzed baseline data from a randomized trial comparing Tai Chi to aerobic exercise in individuals with FM. Balance was measured using a One-Leg Balance Test (OLBT): time standing on preferred leg with eyes closed; max time = 30 seconds. Psychological symptoms of depression, anxiety, and stress were measured using validated scales: Beck Depression Inventory (BDI-II); Participant-Reported Outcomes Measurement Information System (PROMIS) Emotional Distress rating of Anxiety; and Perceived Stress Scale (PSS).  Higher scores reflect greater symptom severity.  The mental component of the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36 MCS) measured mental health related quality of life. Higher scores indicate better health status. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Higher scores reflect poor sleep quality. Chronic Pain Self-Efficacy Scale (CPSS) measured confidence in ability to perform a particular behavior or task. Higher scores reflect improved status. We used a logistic regression model to detect associations between balance times ≤3.02 seconds (defined by first quartile) and measures of psychological symptoms, self-efficacy, mental health-related quality of life, and sleep quality. Independent variables were analyzed in tertiles. Analyses were adjusted for age, gender, and BMI.

Results

234 screened participants were included in our analysis. 90% were female. Mean age was 51.3±11.8 years and mean BMI was 29.7±6.8 kg/m². The median performance on OLBT was 4.7 seconds. Table 1 shows the odds ratios for OLBT ≤3.02 seconds and BDI-II, PSS, SF-36 Mental Component, PROMIS anxiety, PSQI, and CPSS. Better sleep quality and fewer depressive symptoms were weakly associated with improved balance, but no significant associations were found between balance and measures of psychological symptoms and sleep quality.

Conclusion

We were unable to demonstrate any significant associations between balance and psychological symptoms or sleep quality.  Small sample size may limit data interpretation and evaluation of the results.  We recommend that future studies assess factors more directly related to balance such as muscle strength, proprioception, and attention.  Such research is critical to understanding the mechanisms underlying balance problems in FM and may identify novel therapeutic targets for future longitudinal studies.