What effect does adrenaline have on fasting glucose levels? One morning before an important exam at college, my fasting level was 4.5 (83) as soon as I woke up but then I began to feel intense adrenaline and nerves thinking about the exam. Half an hour later without eating or drinking anything my level rose to 5.5 or 5.6 (100 – 103). I was wondering if this happened in normal people or whether it only happened in prediabetics. Specifically, if a normal person had those numbers would they be considered prediabetic?