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.

Increased risk of early lung function alterations in people with psychosis: A cross-sectional case-control study.

BACKGROUND: Tobacco smoking has been described as the main cause of chronic obstructive pulmonary disease (COPD) and this habit is clearly more frequent among individuals with psychosis than in the general population, with rates reaching up to 60%. However, little attention has been focused on the association of COPD and psychosis. We aimed to explore the risk of presenting early lung function alterations in a group of individuals with psychosis. METHODS: Following an observational cross-sectional design we studied a cohort of individuals with established psychosis (N=128), and compared them with a sex, age, and smoking habit matched control group (N=79). We evaluated respiratory symptoms by means of mMRC, CAT and Dyspnea-12 scales. And lung function through spirometry tests. RESULTS: Individuals with psychosis presented more respiratory symptoms than controls. Similarly, we observed significant differences in the lung function tests between these two groups, where individuals with psychosis presented worse results in most of the spirometry mean values (FEV1 or forced expiratory volume in the first one second: 3.29L vs. 3.75L, p<0.001; forced vital capacity or FVC: 4.25L vs. 4.72L, p=0.002; and FEV1/FVC ratio: 0.78 vs. 0.80, p=0.052). Patients also presented worse values of lung diffusion, with lower diffusing capacity for carbon monoxide (DLCO) than controls (6.95 vs. 8.54mmol/min/kPa, p<0.001). CONCLUSIONS: The individuals with psychosis in our study presented greater respiratory symptoms and poorer lung function measured through spirometry. These signs have been described as early signs of COPD.