Background: Advanced chronic obstructive pulmonary disease (COPD) is associated with weight loss and muscular weakness. Low serum testosterone level (hypogonadism) may contribute to muscle wasting.

  Objective : The aim of this study was to determine the association of hypogonadism with the severity of COPD .

  Methods: This cross sectional study was conducted in 57 patients with COPD who had medical records in the lungs clinic of Qazvin during 2012 and 2013. The patients were divided into two groups of mild and sever disease. Total and free testosterone levels and FEV1 were measured. Smoking status and history of taking corticosteroids were assessed. Data were analyzed using Chi-square test and Analysis of covariance (ANCOVA).

  Findings: Based on free testosterone level, 26.7% of patients with mild disease and 22.2% of patients with severe disease had hypogonadism. Mean total and free serum testosterone levels were not significantly different between the two groups (3.2 ± 1.5 ng/ml and 3.9 ± 1.6 pg/ml in mild group and 3.3 ± 1.1ng/ml and 4.2 ± 1.7pg/ml in sever group). After adjusting for age, body mass index, history of taking corticosteroids and smoking status, the mean total and free testosterone levels were not significantly different between the two groups.

  Conclusion: With regards to the results, hypogonadism occurs frequently in patients with COPD. It seems that serum testosterone level is not clinically associated with severity of COPD.