How do you know to what extent glucose has not entered the cell and, therefore, to what extent you need another source of energy (fatty acids)? Testing for blood-glucose levels and for ketones in the urine is the short-term answer. For the longer-term answer, testing is done for fructosamine or glycosylated serum protein (such tests show control over the last 7 to 10 days). A glycosylated-hemoglobin test, especially hemoglobin Ale! provides the longest-term answer, showing control over a period of 2 to 3 months by indicating the percent of glucose (attached to the protein in red blood) that is above normal. Without such testing, people with diabetes cannot know whether their diabetes is really controlled. Regular testing allows you to know the ongoing status of the disease. Keeping blood-sugar (glucose) levels as normal as possible is the best way to prevent or delay vascular (blood-vessel) or neurological (nerve) complications. High blood-sugar (glucose) levels lead to damage of the body cells. It is known that if animals have a blood-sugar level of 150 mg/dl (8 mmol) or more, they develop blood-vessel, kidney, nerve, and eye diseases. It is also known that Pima Indians with diabetes who participated in one study, and who maintained a blood sugar (glucose) level of 165 mg/dl (9 mmol) or higher, developed these same complications of the disease. The conclusion reached by these and many other studies is that the higher the blood sugar is allowed to be, the greater the possibility of physical problems. Unless blood-sugar levels are controlled most of the time, partial efforts are of little value.