Types of Diabetes

Diabetes is a condition in which the body is unable to properly utilize blood sugar (glucose). When we eat, our food is ultimately digested into sugar, which our body converts into energy. Insulin, a hormone made by the pancreas, is responsible for transferring excess sugar from the blood and storing it in body cells for later use. If there is not enough insulin, or, if the body is not able to use that which is available, sugar may build up in the blood stream and cause a condition known as diabetes.

There are three types of diabetes: Type 1 (frequently referred to as juvenile diabetes), Type 2 (also referred to as adult onset diabetes) and gestational Diabetes (diabetes diagnosed during pregnancy). Patients who become pregnant and have either Type 1 or Type 2 diabetes already, are considered to have pregestational diabetes.

Type 1 Diabetes

Type 1 diabetes occurs most often in children and teenagers. The exact causes are unknown, but it is thought that heredity (genetic predisposition) and viral infection may be contributing factors. The symptoms most often include excessive thirst, excessive urination, hunger, and fatigue. Individuals with Type 1 diabetes are dependent upon insulin injections for survival. At the present time, there is no cure for this form of diabetes although researchers make significant advances every year. In the future, pancreatic transplantation or other forms of therapy may be possible.

Type 2 Diabetes

Type 2 diabetes (also referred to as adult-onset diabetes) is most frequently seen in people over the age of 40, but has increased significantly over the past several years in the younger population.

Type 2 diabetes is a familial disorder and is seen more often in obese individuals. The symptoms are mild fatigue and an increase in thirst and urination. Because the symptoms can be mild, many people have this form of diabetes and do not realize it. Fifty percent of heart attack and stroke patients suffer from this form of diabetes. Treatment includes diet, exercise, weight loss and blood sugar monitoring. If these therapies are not effective, the use of medication (either pills or insulin) is necessary.

Pregestational Diabetes

Pregestational refers to diabetes (Type 1 or 2) that is preexisting when a woman becomes pregnant. Very few women with diabetes receive preconception counseling and with poor glucose control in early pregnancy, their infants are at risk for miscarriage or for developing congenital abnormalities (malformations).

Gestational Diabetes [GDM]

The reported prevalence of gestational diabetes (diabetes diagnosed during pregnancy) in the United States ranges from 1 to 14% (average 2-5%). It is usually diagnosed with a blood test at around 24 to 28 weeks of pregnancy but can develop earlier, especially in women who are predisposed to developing diabetes.
The risk factors for gestational diabetes include:

  • Obesity
  • A family history of diabetes
  • A prior history of glucose intolerance
  • A previous child weighing more than 9 pounds at birth (macrosomia)
  • A previous stillbirth or child born with birth defects
  • A history of frequent miscarriages
  • Maternal age (>25 years old)
  • Polycystic Ovary Syndrome

Certain ethnic groups are also at increased risk. These include African and Native Americans as well as women from the Pacific Islands or of Hispanic ethnicity. Despite these identified risk factors, 50% of women diagnosed with GDM have no known risk factors.

We do not know the causes of GDM but we have some clues. The placenta develops in the uterus (womb) and supplies nourishment to the baby. The mother's glucose feeds the baby by way of the placenta and the umbilical cord. The placenta makes hormones that raise a pregnant woman's blood glucose by blocking the normal action of insulin (converting glucose to energy) in the body during pregnancy. Insulin production increases by about 50% by the end of pregnancy and some women cannot make enough insulin to cover this increased need which results in GDM.

Most women are able to lower blood glucose levels by exercising and following a special diet. About 15% require treatment with insulin in addition to their diet. Once the pregnancy is over, this demand for more insulin is gone and 98% of mothers will return to normal.

Patients should be screened with a fasting blood sugar at 6 weeks after delivery to ensure that it has resolved and should be tested every year for diabetes. Approximately, 60% of women who develop GDM (especially if they required insulin to control glucose levels) will develop overt Type 2 diabetes 5-15 years after their pregnancy. There is also a 50-90% chance that GDM will recur with subsequent pregnancies.