OBJECTIVES/SPECIFIC AIMS: This study seeks to evaluate the role of PCOS in insulin resistance and sleep apnea in adolescents. METHODS/STUDY POPULATION: 37 adolescent patients 13-21 with PCOS (27 obese, 11 lean), along with 8 controls ages 18-21 were recruited. Subjects underwent a hyperinsulinemic euglycemic clamp study and a proportion of the PCOS subjects also underwent polysomnography. Baseline parameters were compared and M/I (index of insulin sensitivity), and GIR were compared. RESULTS/ANTICIPATED RESULTS: M/I was only statistically significantly different between obese PCOS subjects vs control (0.056 vs 0.17, p=0.0061). GIR was higher in the obese PCOS group compared to the lean PCOS group (2.48 vs 6.79, p=0.0001). There were no differences in GIR between the lean PCOS subjects and control (6.79 vs 9.08, p=0.30). 21 obese PCOS subjects and 10 lean PCOS underwent polysomnography. None of the lean PCOS subjects had obstructive sleep apnea (OSA). 8 of the obese subjects had OSA. DISCUSSION/SIGNIFICANCE OF IMPACT: More studies are needed to assess insulin sensitivity and sleep apnea in adolescents with lean PCOS. Our study did not find more insulin resistance in adolescents with PCOS compared to lean controls apart from what would be expected from obesity. Of adolescent obese subjects with PCOS, OSA seems quite prevalent and providers should consider screening and referral for these patients.