Individuals with psychosis present a reduced lung diffusion capacity and early spirometry alterations: Results from a cross-sectional study.

OBJECTIVE: Individuals with psychosis present a greater prevalence of chronic lung diseases, including Chronic Obstructive Pulmonary Disease (COPD). These chronic respiratory diseases are preceded by early lung function alterations; such as preserved ratio impaired spirometry (PRISm) or normal spirometry but low diffusion capacity of the lung for carbon monoxide (DLCO). However, there is no previous evidence on these lung function alterations in psychosis. The aim of this study is to evaluate the risk of having spirometry and DLCO alterations in subjects with psychosis compared with a control group.

METHODS: Cross-sectional study on a cohort of 170 individuals including 96 subjects with psychosis and 74 sex-age-and smoking habit matched healthy controls. All subjects were under 60 years-old, and without COPD or asthma. Respiratory function was evaluated through spirometry. Clinical characteristics and DLCO values were recorded.

RESULTS: Patients with psychosis showed lower spirometry results, both in terms of absolute and percentage of Forced Vital Capacity (FVC) and Forced Expiratory Volume in one second (FEV1). Absolute and percentage levels of diffusion were also lower in patients with psychosis. The percentage of individuals with DLCO<80% was higher among patients with psychosis (75% vs. 40%, p < 0.001). And the prevalence of PRISm was higher among patients with psychosis (10.4% vs. 1.4%, p < 0.001). Multivariate logistic regression analysis indicated that psychosis was an independent predictor of DLCO<80% (OR 5.67, CI95% 1.86-17.27).

CONCLUSION: Patients with psychosis and females had early alterations in lung function. These results suggest that early screening for lung disease should be encouraged in psychosis.