Gender, body mass and age as risk factors for ulnar mononeuropathy at the elbow.

Factors that predispose patients to ulnar mononeuropathy at the elbow (UME) are poorly defined. We compared 112 electrodiagnostic reports which met criteria for definite or probable UME to 104 reports which excluded UME. Male gender was strongly associated with definite (OR = 6.9, 95% CI = 2.4-20.4; P < 0.001) and all UME (OR = 2.2, 95% CI = 1.2-4.1; P = 0.010) after controlling for age and body mass index (BMI). Among men, UME was associated with increasing age (P = 0.008) but not a decreased BMI. Women, however, demonstrated an association between decreased BMI and UME (OR = 2.3, 95% CI = 1.3-4.2 for BMI < or =22.0 versus >22.0). These findings, in conjunction with gender differences in ulnar motor nerve parameters among UME subjects and controls, suggest that the pathophysiology of UME differs with gender.