21 Pre-exercise galactose and lactose protects against hypoglycemia without inducing hyperglycemia in type 1 diabetes: a randomized, double-blind, crossover trial

Objective To test whether pre-exercise galactose and lactose reduce glycemic excursions during exercise compared to dextrose while still protecting against hypoglycemia in individuals with type 1 diabetes.Research Design and Methods In a randomized, double-blind, crossover trial, 14 physically active adults with type 1 diabetes completed four 60-minute aerobic cycling sessions. Thirty minutes before each session, participants consumed 20 g of dextrose, lactose, galactose, or placebo (noncaloric sweetener). Our primary outcome was time to hypoglycemia. Secondary outcomes were plasma glucose excursions during exercise, quantified as the change in plasma glucose from baseline to end of exercise, as well as time below range (10.0 mmol/L).Results Few hypoglycemic events occurred (none after dextrose, two after lactose, one after galactose, and four after placebo) and no differences were observed in time to hypoglycemia. Nevertheless, galactose and lactose reduced time below range compared to placebo; [1% (95% CI 0–3%) vs. 8% (95% CI 3–12%); p