What is Type 1 Diabetes?

Diabetes (medically known as diabetes mellitus) is the name given to disorders in which the body has trouble regulating blood glucose, or blood sugar, levels. There are two major types of diabetes: type 1 diabetes and type 2 diabetes. Type 1 diabetes, also called juvenile diabetes or insulin-dependent diabetes, is a disorder of the body's immune system. That is, its system for protecting itself from viruses, bacteria or any "foreign" substances. Type 1 diabetes diagnosed in adults over 30 may be Latent Autoimmune Diabetes in Adults (LADA), sometimes known as Type 1.5 diabetes. LADA is often misdiagnosed as type 2 diabetes because of age; however people with LADA do not have insulin resistance like those with type 2. LADA is characterized by age, a lack of family history of type 2 diabetes, a gradual increase in insulin requirements, positive antibodies, and decreasing ability to make insulin as indicated by a low C-peptide.


Type 1 diabetes occurs when the body's immune system attacks and destroys certain cells in the pancreas, an organ about the size of a hand that is located behind the lower part of the stomach. Beta cells normally produce insulin, a hormone that helps the body move the glucose contained in food into cells throughout the body, which use it for energy. But when the beta cells are destroyed, no insulin can be produced, and the glucose stays in the blood instead, where it can be very harmful to all the organ systems of the body.
For this reason, people with type 1 diabetes must take insulin in order to stay alive. This means undergoing multiple injections daily, or having insulin delivered through an insulin pump, and testing their blood sugar by pricking their fingers for blood six or more times a day. People with diabetes must also carefully balance their food intake and their exercise to regulate their blood sugar levels, in an attempt to avoid hypoglycemic (low blood sugar) and hyperglycemic (high blood sugar) reactions, which can be life threatening.

The warning signs and symptoms of type 1 diabetes include extreme thirst; frequent urination; drowsiness or lethargy; sugar in urine; sudden vision changes; increased appetite; sudden weight loss; fruity, sweet, or wine-like odor on breath; heavy, labored breathing; stupor; and unconsciousness.

Type 1 diabetes is generally diagnosed in children, teenagers, or young adults. Scientists do not yet know exactly what causes type 1 diabetes, but they believe that autoimmune, genetic, and environmental factors are involved.

Exercise and Type 1 Diabetes

This is some information that the American Diabetes Association has made available for diabetics to be aware of exercise and diabetes management.

All levels of physical activity, including leisure activities, recreational sports, and competitive professional performance, can be performed by people with type 1 diabetes who do not have complications and are in good blood glucose control. The ability to adjust the therapeutic regimen (insulin and medical nutrition therapy) to allow safe participation and high performance has recently been recognized as an important management strategy in these individuals. In particular, the important role played by the patient in collecting self-monitored blood glucose data of the response to physical activity and then using these data to improve performance and enhance safety is now fully accepted.

Hypoglycemia, which can occur during, immediately after, or many hours after physical activity, can be avoided. This requires that the patient has both an adequate knowledge of the metabolic and hormonal responses to physical activity and well-tuned self-management skills. The increasing use of intensive insulin therapy has provided patients with the flexibility to make appropriate insulin dose adjustments for various activities. The rigid recommendation to use carbohydrate supplementation, calculated from the planned intensity and duration of physical activity, without regard to glycemic level at the start of physical activity, the previously measured metabolic response to physical activity, and the patient’s insulin therapy, is no longer appropriate. Such an approach not infrequently neutralizes the beneficial glycemic lowering effects of physical activity in patients with type 1 diabetes.

General guidelines that may prove helpful in regulating the glycemic response to physical activity can be summarized as follows:

1. Metabolic control before physical activity
   
   • Avoid physical activity if fasting glucose levels are >250 mg/dl and ketosis is present, and use caution if glucose levels are >300 mg/dl and no ketosis is present.
   • Ingest added carbohydrate if glucose levels are <100 mg/dl.
2. Blood glucose monitoring before and after physical activity
   
   • Identify when changes in insulin or food intake are necessary.
   • Learn the glycemic response to different physical activity conditions.
3. Food intake
   
   • Consume added carbohydrate as needed to avoid hypoglycemia.
   • Carbohydrate-based foods should be readily available during and after physical activity.

Because diabetes is associated with an increased risk of macrovascular disease, the benefit of physical activity in improving known risk factors for atherosclerosis is to be highly valued. This is particularly true in that physical activity can improve the lipoprotein profile, reduce blood pressure, and improve cardiovascular fitness. However, it must also be appreciated that several studies have failed to show an independent effect of physical activity training on improving glycemic control as measured by the A1C test in patients with type 1 diabetes. Indeed, these studies have been valuable in changing the focus for physical activity in diabetes from glucose control to that of an important life behavior with multiple benefits. The challenge is to develop strategies that allow individuals with type 1 diabetes to participate in activities that are consistent with their lifestyle and culture in a safe and enjoyable manner.

In general, the principles recommended for dealing with physical activity in adults with type 1 diabetes, free of complications, apply to children, with the caveat that children may be prone to greater variability in blood glucose levels. In children, particular attention needs to be paid to balancing glycemic control with the normalcy of play, and for this the assistance of parents, teachers, and athletic coaches may be necessary. In the case of adolescents, hormonal changes can contribute to the difficulty in controlling blood glucose levels. Despite these added problems, it is clear that with careful instructions in self-management and the treatment of hypoglycemia, physical activity can be a safe and rewarding experience for the great majority of children and adolescents with type 1 diabetes.