Higher refined cereal grain intake is positively associated with apnoea-hypopnoea index in patients with obstructive sleep apnoea

Background: Given that obesity is a well-known risk factor for obstructive sleep apnoea (OSA) development, dietary habits may be involved in its pathogenesis. However, little is known about the associations between dietary habits and OSA severity. The present study aimed to investigate possible associations between cereal grain intake and apnoea/hypopnoea indices in OSA patients. Methods: This was a cross-sectional study of 269 patients (21-70 years; 73.2% males) diagnosed with OSA via an attended in-hospital polysomnography. Information on demographics, medical history, anthropometric indices and lifestyle habits were collected at enrolment. Biochemical measurements were performed in all study participants using standard procedures. Cereal grain consumption was evaluated using a validated food frequency questionnaire. Severe OSA was defined as having an apnoea-hypopnoea index >= 30 events h(-1). Results: In adjusted analyses, higher intake of refined cereal grains was positively associated with apnoea-hypopnoea index (p(trend) = 0.022), after adjusting for age, sex, socio-economic parameters, smoking habits, waist circumference, physical activity level, adequacy of night-time sleep, diet's quality as assessed by a relevant score, insulin resistance and C-reactive protein levels). Multiple logistic regression analysis also showed that energy-adjusted refined grain intake was associated with increased likelihood of severe OSA (odds ratio = 1.56, 95% confidence interval = 1.06-2.30). association between apnoea/hypopnoea indices and non-refined grain intake was observed in this study. Conclusions: The findings show that obstructive sleep apnoea (OSA) is associated with cereal grain intake and suggest that a higher intake of refined cereal grains may be a risk factor for OSA severity. Highlights Data regarding the role of dietary habits in obstructive sleep apnoea severity are scarce. Higher intake of refined cereal grains is positively associated with apnoeahypopnoea index. Higher refined grain intake is associated with increased likelihood of severe obstructive sleep apnoea (OSA). Refined cereal grain intake may be a risk factor for OSA severity.