Association between dietary index for gut microbiota and obstructive sleep apnea: the mediating role of obesity indicators and inflammatory markers

Background Obstructive sleep apnea (OSA) has been shown to alter the gut microbiota. In this study, we investigated the correlation between the dietary index for gut microbiota (DI-GM), a novel indicator of gut microbiota diversity, and the risk of OSA. Methods Data from the NHANES study conducted in the period 2007-2008 and 2015-2018, comprising 9,769 participants aged 20 years and older, were enrolled in the study. The weighted multivariate logistic regression was performed to determine the correlation between DI-GM and high-risk OSA, whereas the linear or nonlinear relationship was analyzed using the restricted cubic spline (RCS) curves. Stratified analyses were conducted to assess the robustness of the results. Mediation analyses were carried out to investigate the impact of obesity indicators (BMI and BRI) and inflammatory markers (NEUT and RDW) on the association. Results Upon adjusting for covariates, we discovered that the DI-GM was adversely correlated with high-risk OSA (OR = 0.94, 95% CI = 0.89-0.99). The probability of OSA (OR = 0.76, 95% CI = 0.62-0.93) was significantly lower in the DI-GM>6 group. The analyses revealed that BMI, BRI, NEUT, and RDW could partially mediate the relationship. Among them, BRI accounted for the highest proportion of the mediating effect at 33.98%. Conclusions DI-GM may be negatively connected with the risk of OSA, and this link may be partially mediated by obesity indicators and inflammatory markers.