Does hyperglycemia increase/decrease heart rate?

Increases: If the hyerglycemia is no that severe not much. If it is and you start to g into diabetic ketoacidosos, it usually increases as a reaction to the other effects of ketoacidosis on your body.

Depends : High blood glucose can cause several problems depending on how high the levels are and how quickly they became high. Before the heart rate is affected your would have other metabolic problems including dehydration, dizziness and even coma. The heart rate may increase secondary to this. Your doctor should make the diagnosis of hyperglycemia and help you control it.