Rebelos E, Bucci M, Karjalainen T, et al. - In the present study, the researchers sought to explore the correlation of insulin resistance and brain glucose uptake (BGU) during a euglycemic hyperinsulinemic clamp in a large sample of study participants across a wide range of age and insulin sensitivity. [¹⁸F]-fluorodeoxyglucose positron emission tomography data from 194 candidates scanned under clamp conditions were collected from a single-center cohort. In all brain regions, insulin sensitivity, indexed by the M value, was negatively correlated with BGU, confirming that BGU was enhanced during euglycemic hyperinsulinemia in insulin-resistant participants. The presence of type 2 diabetes was also linked to an additional increase in BGU. Age was, on the contrary, negatively linked to BGU. BGU was not associated with steady-state insulin levels, C-reactive protein and free fatty acid levels, gender, and HbA_1c. Insulin sensitivity was the best predictor of BGU in this large cohort of participants of either gender across a wide range of age and insulin sensitivity.