Foot pain severity is associated with the ratio of visceral to subcutaneous fat mass, fat-mass index and depression in women.

Body composition and poor mental health are risk factors for developing foot pain, but the role of different fat deposits and psychological features related to chronic pain are not well understood. The aim of this study was to investigate the association between body composition, psychological health and foot pain. Eighty-eight women participated in this study: 44 with chronic, disabling foot pain (mean age 55.3 SD 7.0 years, BMI 29.5 SD 6.7 kg/m), and 44 age and BMI matched controls. Disabling foot pain was determined from the functional limitation domain of the Manchester Foot Pain and Disability Index. Body composition was measured using dual X-ray absorptiometry and psychological health (catastrophisation, central sensitisation and depression) was measured using three validated questionnaires. Between-group analyses found that foot pain was not significantly associated with body composition variables, but was significantly associated with all psychological health measures (P < 0.001-0.047). Within-group analyses found that the severity of foot pain was significantly correlated with body composition measures: fat mass (total, android, gynoid, and visceral), fat-mass ratios [visceral/subcutaneous (VAT/SAT), visceral/android], fat-mass index (FMI), and depression. In multivariable analysis, VAT/SAT (β 1.27, 95% CI 0.28-2.27), FMI (β 0.14, 95% CI 0.02-0.25) and depression (β 0.06, 95% CI 0.00-0.12) were independently associated with foot pain severity. Psychological health, not body composition, was associated with prevalent foot pain. For women with foot pain, VAT/SAT, FMI and depression were associated with severity. Further work is needed to determine if a reduction in fat mass reduces the severity of foot pain.