A case-control study of obesity as a risk factor for carpal tunnel syndrome in a population of 600 patients presenting for independent medical examination.

Pain, numbness, and tingling through the median nerve distribution, known as carpal tunnel syndrome (CTS), has been associated with many personal risk factors. Previous studies have implicated obesity as a risk factor for median neuropathy at the carpal tunnel. A case-control design was undertaken to explore the association between obesity and CTS. Six hundred patients presented with symptoms of upper-extremity disorders for independent medical examination related to a disability or compensation claim. The 300 patients with electrodiagnostic evidence of CTS were compared with 300 control subjects from the same initial population. All patients were categorized according to their body mass index. The analysis was stratified for the possible confounding factors of cervical spine abnormalities, Martin-Gruber interconnections, age, and sex. A statistically significant association was found between obesity and median neuropathy. The implications of such a relationship are discussed in light of the contemporary debate over the etiology of cumulative trauma disorders.