Type1 diabetics tend to be at greater risk for other autoimmune disorders not caused by diabetes itself. Three autoimmune disorders are prevalent in T1D’s and are known to impact blood glucose levels: Celiac disease , Addison’s disease and Thyroid disorders. This discussion will focus on Addison’s disease also called adrenal insufficiency or hypocortisolism.
The disease is named after its discoverer Dr. Thomas Addison. It is a very rare chronic endocrine (hormonal) disorder (affecting one in a 100,000 individuals) in which the adrenal glands, located just above each kidney, produce an insufficient amount of the steroid hormone, cortisol, required for many bodily functions. Although extremely rare, Addison’s is five times more prevalent in a diabetic population than in the general non-diabetic grouping. It typically occurs in adults between 30 to 50 years of age but can occur at any age, ethnicity or gender.
The adrenal glands are composed of two sections: the outer cortex and the inner medulla. The cortex produces the hormone cortisol which aids the body in converting food to energy, stimulates the body’s immune inflammatory response and helps the body handle stressful situations. The cortex also produces the hormone aldosterone that helps maintain sodium and potassium to insure normal blood pressure levels . The medulla produces adrenaline-like hormones that help the body deal with stress.
Addison’s disease occurs as a result of autoimmune damage to the cortex resulting in reduced cortisol production. This is referred to as primary adrenal insufficiency to distinguish it from a secondary cause – damage to the pituitary gland at the base of the brain stem responsible for the release of a controlling hormone ACTH which serves to trigger the adrenal glands to release cortisol. Even though the adrenal glands may be functioning normally lack of ACTH will result in hypocortisol production.
Autoimmune destruction of the cortex is more common in developed westernized cultures where it represents about 85% of cases compared to developing countries where tuberculosis is the most common cause.
Symptoms – loss of appetite, weight loss, nausea, vomiting, a craving for salty foods, muscle weakness, fatigue, low blood pressure and darkening of the skin (hyper-pigmentation which only occurs in primary hypocortisolism)), irritability, depression and hypoglycemia (low blood sugar). Of concern to the diabetic is cortisols role in helping to balance the effects of insulin in the breakdown of sugar for energy and its regulation of metabolic activity.
The disease may progress to an Addisonian crisis, a severe illness including very low blood pressure and hypoglycemia resulting often in death. Symptoms also include sudden leg and lower back pain, abdominal pain, severe nausea and vomiting leading to dehydration, fever, and convulsions.
Diagnosis includes a combination of expressed symptoms and lab tests to determine cortisol levels.
Treatment – with proper medication (hormone replacement therapy) patients can expect to live relatively normal lives. President John F. Kennedy was one of the more prominent figures to have suffered with Addison’s.
In T1D patients and in particular brittle diabetics who develop unexplained recurring hypoglycemia the development of other autoimmune diseases that impact the endocrine system such as Addison’s should be taken into consideration. If one is found to be positive for Addison’s, thyroid functioning should be investigated as well.