The predictors of the triglyceride-glucose index in subjects with newly diagnosed obstructive sleep apnea

Obstructive sleep apnea (OSA), metabolic syndrome, and insulin resistance (IR) have reciprocal relationships. Assessing IR is important but challenging in clinical practice. The triglyceride-glucose index (TyG) represents a simple marker of IR that can provide significant information on the metabolic status of patients with OSA. This study aimed to determine which parameters influence TyG in a population suspected of having OSA and to assess its association with endothelial function. We examined 131 consecutive individuals without a history of chronic diseases (except obesity) suspected of having OSA. Anthropometric parameters were measured, body mass index (BMI) was calculated, and fasting glucose and lipid profiles were assessed. Endothelial function was assessed using peripheral arterial tonometry and the reactive hyperemia index (RHI) was calculated. All participants underwent overnight polysomnography. Significant correlations were found between TyG and various anthropometric parameters (neck circumference, waist circumference, and BMI) and selected sleep parameters (arousal index, respiratory disturbance index, and oxygen desaturation index). No significant correlation with RHI was found. TyG was significantly higher in men than women (8.9 ± 0.6 vs. 8.6 ± 0.6, p = 0.010). In multivariate analysis, waist circumference (β = 0.417, p < 0.001) and male sex (β = 0.169, p = 0.034) were the only independent predictors of TyG. These findings suggest that TyG primarily reflects metabolic risk factors rather than OSA severity per se, and further studies are warranted to clarify its clinical utility in this population.