Hyperglycemia can affect the kidneys in a very significant way. Kidneys are the organs responsible for filtering the blood for the wastes, toxins or excess substances and discharging them through urine.rain Damage. Hyperglycemia can result in ischemia (blockage of blood supply to any part of the brain). This can cause loss of brain function and in turn, can cause loss of bodily functions such as movement, sight and even speech.