Elevated Body Mass Index Is Associated with Secondary Hypogonadism among Men Presenting to a Tertiary Academic Medical Center

PURPOSE: To characterize the population of hypogonadal men who presented to a tertiary academic urology clinic and evaluate risk factors for primary vs. secondary hypogonadism. MATERIALS AND METHODS: We evaluated all men with International Classification of Diseases-9 diagnosis codes R68.82 and 799.81 for low libido, 257.2 for testicular hypofunction, and E29.1 for other testicular hypofunction at a tertiary academic medical center from 2013 to 2017. We included men who had testosterone (T) and luteinizing hormone (LH) drawn on the same day. We classified men based on T and LH levels into eugonadal, primary, secondary, and compensated hypogonadism. Risk factors including age, body mass index (BMI) over 30 kg/m(2), current smoking status, alcohol use greater than 5 days per week, and Charlson comorbidity index greater than or equal to 1 were investigated and measured in each group using the eugonadal group for reference. RESULTS: Among the 231 men who had both T and LH levels, 7.4%, 42.4%, and 7.4% were classified as primary, secondary, and compensated hypogonadism, respectively. Only elevated BMI was associated with secondary hypogonadism compared to eugonadal men (median BMI, 30.93 kg/m(2) vs. 27.69 kg/m(2), p=0.003). BMI, age, comorbidities, smoking, or alcohol use did not appear to predict diagnosis of secondary hypogonadism. CONCLUSIONS: Secondary hypogonadism appears to be the most common cause of hypogonadism among men complaining of low T and decreased libido at a tertiary academic medical center. Secondary hypogonadism is associated with elevated BMI and therefore obesity should be used as a marker to evaluate men for both T and LH levels.