The prevalence of sleep-disordered breathing (SDB) after lung transplantation (LTX) is high. It is well-established that SDB is associated with decreased health-related quality of life (HRQoL), but the impact of SDB on exercise capacity is less clear. In this study we investigated HRQoL and exercise capacity in LTX recipients with or without SDB. In addition, we also investigated associations between sleep parameters and both HRQoL and exercise capacity. There were 53 stable LTX recipients (age > 18 years, 31 males, time from LTX 9-120 months) enrolled into the study. They all underwent polysomnography examination. HRQoL was assessed using the Short Form-36 (SF-36). Exercise capacity was measured using the 6-min walk test and cardiopulmonary exercise testing (CPET). We found inverse correlations between severity of SDB and both the predicted maximal workload (r = 0.24, p = 0.04) and maximal oxygen uptake (r = -0.26, p = 0.03) during CPET. Relative oxygen uptake positively correlated with sleep efficiency (r = 0.27, p = 0.03). SF-36 scores did not differ between patients with and without SDB, and were not significantly associated with SDB parameters. In conclusion, the presence of SDB is associated with a slight reduction in maximal exercise capacity in LTX recipients, and there is no appreciable relationship between SDB and HRQoL.
Keywords: Cardiopulmonary exercise testing; Disordered breathing; Exercise capacity; Lung transplantation; Quality of life; Sleep.