Uncontrolled diabetes, which generally refers to glucose levels that are higher rather than lower than the target range, can lead to immediate short-term and longer- term consequences. The short-term consequences result from the very high blood glucose itself, which is described in Question 4. If severe enough or untreated for long enough, markedly high blood glucose levels can result in coma and ultimately death, due to the severe abnormalities of blood chemistry that occur. It is important to note that only a very small minority of patients with either form of diabetes will die in this way. Therefore, although immediate decompensation of diabetes is a serious and life-threatening condition, with a high death rate if detected and treated too late, the majority of people with diabetes should be more concerned about the damaging effects of diabetes that are not well controlled, yet not sufficiently poorly con- trolled to focus their attention.
The longer-term consequences of less than adequate diabetes control are the result of damage to the small (micro) and larger (macro) vessels of the circulation. The most common manifestations are diabetic eye dis- ease (retinopathy), which is the leading cause of blind- ness in working-age adults in the United States; diabetic kidney disease (nephropathy), which is the leading cause of severe kidney failure necessitating dial- ysis or transplantation in working-age adults in the United States; and nerve damage (neuropathy), which is present in about 1 out of 3 people with diabetes at the time of diagnosis and in over 7 out of 10 by the time diabetes has been present for 10 years. Both retinopa- thy and nephropathy can be entirely without symptoms
until they reach an advanced and irreversible stage, leading to blindness and the need for kidney dialysis or transplant. Diabetic neuropathy can cause very trouble- some symptoms and lead to loss of sensation, mainly in the feet, which places the patient at high risk of trauma, infection, and amputations of the legs and feet.
Disease of the large blood vessels leads to a high rate of heart attack, stroke, heart failure, and amputation of the (usually lower) limbs. About two of every three patients with diabetes will die as a result of large vessel disease. Fortunately, studies have shown that good control of diabetes can prevent or delay the progres- sion of many of these serious problems, but other con- tributing factors, such as blood pressure and cholesterol, must also be given careful attention.
However, we are only achieving target levels of dia- betes control in about half of all people with diabetes in America today.