ABSTRACT Objective The consequences of sleep deprivation in type 1 diabetes (T1D) patients are poorly understood. Our aim was to determine how sleep disorders influence lipid profile and insulin sensitivity in T1D patients. Materials and methods This was a cross-sectional study at a public university hospital. Demographic information and medical histories were obtained during regular scheduled visit of T1D patients to the outpatient clinic. Insulin sensitivity was obtained using the estimated glucose disposal rate (eGDR) formula. Sleep quality was assessed using the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and Berlin Questionnaire. Results The adult participants (n = 66, 62% women) had a median age of 28.0 years (interquartile range 21.8-33.0). Six patients (9%) had metabolic syndrome according to the International Diabetes Federation criteria. Thirty patients (46%) were considered poor sleepers according to the Pittsburgh Sleep Quality Index. The LDL-c and total cholesterol levels of poor sleepers were higher than those of good sleepers (103 v. 81; p = 0.003 and 178.0 v. 159.5 mg/dL; p = 0.009, respectively). Three patients (4%) were at high risk of obstructive sleep apnea syndrome (OSAS) according to the Berlin Questionnaire. The eGDR was lower in the group of patients with high probability of having OSAS (6.0 v. 9.1 mg.kg-1.min-1;p = .03). Conclusions Poor subjective quality of sleep and higher risk of OSAS were correlated with a worsened lipid profile and decreased insulin sensitivity, respectively. Therefore, T1D patients with sleep disturbances might have an increased cardiovascular risk in the future.