Obstructive sleep apnea (OSA) is a sleep disorder affecting the respiratory airflow, characterized byoccasional interruptions in breathing (apnea) or decreased volume of respiration (hypopnea) during sleep. The disorder is estimated to affect 3-10% of the general population, with a negative impact onthe quality of life of the affected individuals. It is also strongly correlated with other health conditions, such as coronary artery disease (CAD) and type 2 diabetes. Given its prevalence and negative impact,it is paramount to find new treatment options, including prophylactic measures, to reduce personal suffering and healthcare costs. In an earlier study, a significant correlation was found between a GLUT4 polymorphism and OSA diagnosis in a Chinese population. The purpose of the present study was to investigate potential association between the rs5418 GLUT4 polymorphism and OSA in a Swedish population. This study also examined the relationship between GLUT4 and insulin resistance in this Swedish CAD cohort. A total of 149 genomic DNA samples from the Swedish Randomized Intervention with CPAP in Coronary Artery Disease and Sleep Apnea (RICCADSA) trial was genotyped for the GLUT4 rs5418 G/A polymorphism, using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results from this study did not identify a correlation between thers 5418 GLUT4 genotype and OSA, related diseases or clinical parameters. However, the frequency of A allele was found to be associated with the apnea-hypopnea index in OSA patients. The associations of GLUT4, OSA, and insulin resistance should be further investigated in a larger study group with a healthy control population included for a more conclusive result.