1310-P: Effects of Insulin Resistance on Brain Responses to Caloric Sugars and Nonnutritive Sweetener

Evidence suggests that insulin resistance (IR) affects feeding behavior by modulating neural responses to post-ingestive signals, including nutrients and taste. We examined associations between IR and activation of the hypothalamus and insula, brain regions involved in homeostasis and taste processing, to ingestion of sugars and the non-nutritive sweetener (NNS) , sucralose. Seventy-four participants (23.4±4 years; 42%male; BMI 27.2±5; HOMA-IR 5.3±5) completed 4 MRI visits with ingestion of drinks containing 75g sucrose, 75g glucose, sucralose, or water in a randomized cross-over design. Arterial spin labeling MRI was performed before, 15min and 30min after drink ingestion to measure cerebral blood flow (CBF) . Primary outcomes were associations between HOMA-IR and hypothalamic and insular CBF responses to glucose vs. sucrose, sucralose vs. water, and sucrose vs. sucralose. Mixed effects models included the following factors: drink contrasts, sex, time point, and BMI and HOMA-IR as continuous variables. Bonferroni-Holm was used to adjust for multiple comparisons. In the hypothalamus, HOMA-IR, independent of BMI, was associated with a greater hypothalamic CBF response to sucralose vs. water (p