Plant-based and vegetarian diets are associated with reduced obstructive sleep apnoea risk.

Introduction: Obstructive sleep apnoea (OSA) and obesity commonly coexist. Weight loss and exercise are recommended management options for OSA. However, most of the current evidence on diet and OSA is focused on calorie restriction rather than diet quality. The aim of the present study was to determine the association of plant-based dietary indices (PDI) with OSA risk.

Methods: Cross-sectional data from 14 210 participants of the National Health and Nutrition Examination Survey who provided dietary information using the 24-hour recall method were used. PDI - including healthy (hPDI), unhealthy (uPDI) and pro-vegetarian diet index (PVDI) - were determined. OSA risk was determined using the STOP-BANG questionnaire. Logistic regression was used to determine the relationship between dietary indices and OSA risk.

Results: Higher adherence to PDI (odds ratio (OR)_{Q5 versus Q1}=0.81; 95% confidence interval (CI): 0.66-1.00), hPDI (OR=0.83; 95% CI: 0.69-1.01) and PVDI (OR=0.84; 95% CI: 0.68-1.05) was inversely associated with OSA risk, whereas higher consumption of an unhealthy plant-based diet (OR=1.22; 95% CI: 1.00-1.49) was positively associated with OSA. Sex differences in estimates were observed for PDI in males (OR=0.71; 95% CI: 0.56-0.90) versus females (OR=0.93; 95% CI: 0.68-1.28), hPDI in males (OR=0.90; 95% CI: 0.68-1.18) versus females (OR=0.77; 95% CI: 0.54-1.09) and uPDI in males (OR=1.13; 95% CI: 0.89-1.44) versus females (OR=1.42; 95% CI: 1.03-1.97) but not for PVDI.

Conclusions: Higher adherence to a healthy plant-based diet is associated with reduced OSA risk, while an unhealthy plant-based diet has a positive association. The magnitude of these associations differs by sex. Further longitudinal studies are warranted.