Larger Testicular Volume Is Independently Associated with Favorable Indices of Lung Function

BACKGROUND: Men with chronic obstructive pulmonary disease, have reduced endogenous testosterone levels, but the relationship between pulmonary function and endogenous testosterone levels, is inconsistent. Testicular volume is a known indicator of endogenous testosterone levels, male fertility, and male potency. In the present study, the authors investigated the relationship, between testicular volume and lung function. METHODS: One hundred and eighty-one South Korean men age 40-70, hospitalized for urological surgery, were retrospectively enrolled, irrespective of the presence of respiratory disease. Study subjects underwent pulmonary function testing, prior to procedures, and testicular volumes were measured by orchidometry. Testosterone levels of patients in blood samples collected between 7 AM and 11 AM, were measured by a direct chemiluminescent immunoassay. RESULTS: The 181 study subjects were divided into two groups, by testicular volume (≥35 mL vs. <35 mL), the larger testes group, had better lung functions (forced vital capacity [FVC]: 3.87±0.65 L vs. 3.66±0.65 L, p=0.037; forced expiratory volume in 1 second [FEV(1)]: 2.92±0.57 L vs. 2.65±0.61 L, p=0.002; FVC % predicted: 98.2±15.2% vs. 93.8±13.1%, p=0.040; FEV(1) % predicted: 105.4±19.5% vs. 95.9±21.2%, p=0.002). In addition, the proportion of patients with a FEV(1)/FVC of <70%, was lower in the larger testes group. Univariate analysis conducted using linear regression models, revealed that testicular volume was correlated with FVC (r=0.162, p=0.029), FEV(1) (r=0.218, p=0.003), FEV(1)/FVC (r=0.149, p=0.046), and FEV(1) % predicted (r=0.178, p=0.017), and multivariate analysis using linear regression models, revealed that testicular volume was a significant predictive factor for FEV(1) % predicted (β=0.159, p=0.041). CONCLUSION: Larger testicular volume was independently associated, with favorable indices of lung function. These results suggest that androgens, may contribute to better lung function.