Introduction :During COPD, the prevalence of hypogonadism is higher than in a control population.Variations in the sex hormone-binding globulin (SHBG), influence the total testosterone concentration.The main goal was to study the relationship between severity of COPD and different forms of testosterone (total, free and bioavailable: TT, FT and BT).

Methods:We conducted a cross-sectional study that included 85 male patients with stable COPD. Serum levels of testosterone,FSH, LH were determined in all patients. Then, functional tests (6MWT, blood gas) were performed.

Results: The mean age was 63.73-year-old. The mean level of testosterone was (TT=20.90+/-8.76/FT=0.20+/-0.13) The median of BT was 6.02[4.30-8.01].TT and FT levels were normal in all patients. Nine patients had low BT level. A positive correlation was found between FEV1 (%) and each of the TT (p=0.002); FT (p=0.013) and BT (p=0.01).FVC was positively and significantly correlated to TT (p=0.022); FT (p=0.047); and BT (p=0.046). Moreover, VR/CPT% was also correlated to each of TT(p=0.027), FT(p=0.019),and BT(p=0.018).Blood analysis have shown an inversely and significant correlation between PaCO2 and BT (p=0.04). FSH was significantly correlated with FT (p=0.044), and BT(0.041), and LH was correlated with FT (0.044) and BT(0.041).A significant relationship between BMI, TT (p=0.022), FT (p=0.001) and BT (p=0.004) was found.

Conclusion :This study showed that all the serum testosterone levels were associated with lung function in COPD. This association was equivalent between the three forms.