Nonoccupational risk factors for carpal tunnel syndrome

OBJECTIVE: To examine the relation between selected nonoccupational risk fa ctors and surgery for carpal tunnel syndrome. DESIGN: Case-control study using an administrative database. PARTICIPANTS: Enrollees of New Jersey Medicare or Medicaid programs during 1989 to 1991. MEASUREMENTS: The outcome of interest was open or endoscopic carpal tunnel release. We examined the relation between carpal tunnel release and diabete s mellitus, thyroid disease, inflammatory arthritis, hemodialysis, pregnanc y, use of corticosteroids, and hormone replacement therapy. MAIN RESULTS: In multivariate models, inflammatory arthritis was strongly a ssociated with carpal tunnel release (odds ratio [OR] 2.9; 95% confidence i nterval [CI] 2.2, 3.8). Row ever, corticosteroid use also appeared to be as sociated with a greater likelihood of undergoing carpal tunnel release, eve n in the absence of inflammatory arthritis (OR 1.6; 95% CI 1.2, 2.1). Diabe tes had a weak but significant association with carpel tunnel release (OR 1 .4; 95% CI 1.2, 1.8), as did hypothyroidism (OR 1.7; 95% CI 1.1, 2.8), alth ough patients with hyperthyroidism did not have any change in risk. Women w ho underwent carpal tunnel release were almost twice as likely to be users of estrogen replacement therapy as controls (OR 1.8; 95% CI 1.0, 3.2). CONCLUSIONS: Although inflammatory arthritis is the most important nonoccup ational risk factor for carpel tunnel release, these data substantiate the increase in risk associated with diabetes and untreated hypothyroidism. Fur ther investigation in detailed clinical studies will be necessary to confir m whether changes in corticosteroid use and hormone replacement therapy off er additional means of risk reduction for this common condition.