Ketone monoester ingestion improves endothelial function during hyperglycemia in females with polycystic ovary syndrome

In a randomized, double-blind, placebo-controlled crossover study, 10 females with polycystic ovary syndrome (PCOS) and 10 age- and BMI-matched controls drank ketone monoester (482 mg/kg) or a taste-matched placebo 30 minutes before a 75-g oral glucose tolerance test (OGTT). Endothelial function was measured as flow-mediated dilation (FMD) before the test and at 0, 60 and 120 minutes. After placebo, FMD fell at 60 minutes in both groups (PCOS 6.3 vs 4.2 percent, controls 9.7 vs 6.6 percent) and stayed lower at 120 minutes in PCOS only (6.3 vs 4.0 percent). In both groups the ketone monoester reduced the plasma glucose area under the curve and improved FMD across the OGTT.