The relationship between diaphragmatic dysfunction and sleep, emotional state, quality of life, and functional status in patients with chronic ischemic stroke

Objectives: To examine whether hemiplegic diaphragm thickening fraction (DTF, %) is associated with functional status, walking capacity, sleep quality, mood, and stroke-specific quality of life (SS-QoL) in chronic ischemic stroke, and to determine a clinically useful DTF threshold. Materials and Methods: This single-center cross-sectional study included 68 patients with chronic ischemic stroke (≥6 months). Hemiplegic DTF was quantified by ultrasonography. Outcome measures were the Barthel index (BI), Functional Ambulation Category, 6-minute walk test (6-MWT), SS-QoL, Pittsburgh sleep quality index (PSQI), Hospital Anxiety and Depression Scale-Anxiety (HADS-A) and Hospital Anxiety and Depression Scale-Depression (HADS-D) scales, and Fugl-Meyer upper extremity (FMA-UE). Statistical analyses included non-parametric comparisons (DTF ≤20% vs. >20%), Spearman correlations, and multivariable regression adjusted for age, sex, body mass index, and stroke duration. Receiver operating characteristic and logistic regression analyses examined PSQI >5. Results: Hemiplegic diaphragm dysfunction (DTF ≤20%) was present in 36.8% of participants. Higher DTF was independently associated with better BI, 6-MWT, and SS-QoL scores, and with lower PSQI, HADS-A, and HADS-D scores (all p<0.05), but not with FMA-UE. DTF showed good discrimination for poor sleep [area under the curve: 0.779, 95% confidence interval (CI): 0.649-0.892], with an optimal threshold around 21% (sensitivity 0.77, specificity 0.83). Each 1% increase in DTF reduced the odds of poor sleep by approximately 7% (odds ratio ≈ 0.93; 95% CI: 0.89-0.98). Conclusion: In chronic ischemic stroke, greater hemiplegic DTF is independently associated with better function, mobility, and quality of life, and fewer sleep and mood problems. A DTF around 21% may serve as a practical threshold for risk stratification and rehabilitation targeting.