Fat mass in people with foot pain may be more important than body weight alone, Australian research suggests.

The findings add weight to the concept of metabolically, rather than mechanically derived foot pain, say the authors including rheumatologists Michael Shanahan and Catherine Hill from Adelaide in South Australia.

The study of almost 1,500 participants aged over 50 participating in the North West Adelaide Study found that for every unit increase in FMI, prevalent and future foot pain was increased by 8 percent and six percent respectively.

However Body Mass Index (BMI), Fat Free Mass Index (FFMI), TNF-alpha and IL-6 were not associated with either prevalent or future foot pain after adjusting for confounding variables, the multi-disciplinary research team reported in Arthritis Care and Research.

In keeping with other studies depression and arthritis also predicted future foot pain.

Overweight or obese people presenting with foot pain should be informed that fat mass is likely more important than body mass alone, advised the team of researchers including physiotherapist and NHMRC Early Career fellow Dr Tiffany Gill and podiatrist Tom Walsh.

Given the limitations of BMI, body composition determined by DXA may inform patients of their risk, they said.

A weight loss trial with body composition analysis could confirm hypotheses regarding fat mass and resolution of foot pain and would be highly relevant for clinicians, they added.