Bodily Distress Syndrome Is Associated with Impaired Physical Fitness—A Population Based Cross-Sectional Study (DanFunD)

<b>Background and Aim:</b> Functional somatic disorders (FSDs) are a unifying diagnosis that includes functional somatic syndromes (FSSs) as well as the unifying diagnostic construct of bodily distress syndrome (BDS). FSDs are characterized by persistent and troublesome physical symptoms that are prevalent across all medical settings and for which no clinical tests can establish a definitive diagnosis. The aim of this study was to explore associations between BDSs and objective measurements of body composition, cardiorespiratory health, and physical performance. <b>Methods:</b> Analyses are based on data from the Danish population-based cohort study, DanFunD, comprising data on 9656 participants aged 18-76 years and BDS case status, which was established using self-reported questionnaires. Adjusted multiple linear regression analysis was employed to evaluate associations between BDS and different measures of body composition, cardiorespiratory health, and physical performance assessed as part of a general health examination. <b>Results:</b> Compared to controls, individuals with single- or multi-organ BDS exhibited less optimal body compositions characterized by a higher BMI and fat percentage and larger waist circumference, as well as impaired cardiorespiratory health and reduced physical performance (lower maximal oxygen consumption and lower hand grip strength). Further, individuals categorized with multi-organ BDS had a less healthy body composition, lower cardiorespiratory health, and lower physical performance compared to individuals with single-organ BDS. <b>Conclusions:</b> In this cross-sectional study, we found BDS to be associated with suboptimal body composition, impaired cardiorespiratory health, and reduced physical performance. Individuals with multi-organ BDS tended to exhibit lower physical fitness or reduced cardiorespiratory health than individuals with single-organ BDS.