Endocrine
9.3 Conditions and Diseases Related to Metabolic Regulation
Amanda Egert; Kimberly Lee; and Manu Gill
As you have just learned, the endocrine system regulates vital hormonal and enzymatic functions. Individuals with metabolic regulation disorders have trouble regulating one or more of these functions. This chapter will focus on metabolic regulation related to adrenal gland disorders, diabetes and thyroid disorders. [1]
Disorders Involving the Adrenal Glands
Several disorders are caused by the dysregulation of the hormones produced by the adrenal glands. For example, Cushing’s disease is a disorder characterized by high blood glucose levels, the development of a moon-shaped face, a buffalo hump on the back of the neck, rapid weight gain, and hair loss. It is caused by hypersecretion of cortisol. Cushing’s syndrome can also be caused by long-term use of corticosteroid medications.
In contrast, the hyposecretion of corticosteroids can result in Addison’s disease, a disorder that causes low blood glucose levels and low blood sodium levels. Addisonian crisis is a life-threatening condition due to severely low blood pressure resulting from a lack of corticosteroid levels.[2],[3],[4],[5]
Disorders of the Endocrine System: Diabetes Mellitus
Dysfunction of insulin production and secretion, as well as the target cells’ responsiveness to insulin, can lead to a condition called diabetes mellitus, a common disease that affects the ability of the body to produce and/or utilize insulin. There are two main forms of diabetes mellitus. Type 1 diabetes is an autoimmune disease affecting the beta cells of the pancreas. The beta cells of people with type 1 diabetes do not produce insulin; thus, synthetic insulin must be administered by injection or infusion. Type 2 diabetes accounts for approximately 95 percent of all cases. It is acquired, and lifestyle factors such as poor diet and inactivity greatly increase a person’s risk. In type 2 diabetes, the body’s cells become resistant to the effects of insulin. In response, the pancreas increases its insulin secretion, but over time, the beta cells become exhausted. In many cases, type 2 diabetes can be reversed by moderate weight loss, regular physical activity, and consumption of a healthy diet. However, if blood glucose levels cannot be controlled, oral diabetic medication is implemented and eventually the type 2 diabetic may require insulin.
Diabetes is diagnosed when lab tests reveal that blood glucose levels are higher than normal, a condition called hyperglycemia.[1] According to the Diabetes Canada Clincal Practice Guidelines Experts Committee, normal fasting blood glucose levels are 4.0 to 7.0 millimoles per litre (mmol/L). Glycosylated hemoglobin, also called A1C, is used to assess long-term blood glucose levels over 3 months. The Experts Committee states that A1C target levels vary according to age and health, but the generalized A1C target is less than 7%.[2]
Disorders of the Thyroid Gland: Iodine D