Endocrine System Disorders

Introduction

Endocrine glands can develop tumors and inflammations, causing them to be hyperactive (overactive) or hypoactive (underactive). Endocrine glands also have the potential to develop serious pathological conditions caused by an excessive or inadequate production of hormones.

Imagine the dire consequences if your master gland is overworked or stops working altogether. Abnormalities in hormone levels can cause a number of physical problems, ranging from fatigue to physical disfigurement to diabetes and even death. Hypersecretion is often corrected with surgery, and hyposecretion may be treated with hormone supplements. 

 

Hyperthyroidism

Hyperthyroidism is a thyroid gland disorder that causes the release of too much thyroid hormone. Hyperthyroidism most commonly results from a syndrome called thyrotoxicosis, or Graves' disease.

• Tremors or shakiness
• Palpitations
• Weakness
• Weight loss
• Insomnia (unable to fall asleep or stay asleep)
• Increased heart rate
• Sweating
• Protrusion of eyeballs

Radioactive iodine is a commonly used treatment for hyperthyroidism. Thyroid cells are the only cells that absorb iodine, so there's no ill effect of the radioactive iodine on other cells of the body. Once thyroid cells absorb radioactive iodine, they're either damaged or killed. The body then eliminates the iodine by excretion.

Surgical removal of the enlarged gland with or without iodine is another treatment option for hyperthyroidism. The surgery is called a thyroidectomy. Patients often require thyroid replacement therapy after surgery.

Medications to treat hyperthyroidism include

• Methimazole (Tapazole)
• Propylthiouracil (PTU)

 

Hypothyroidism is a thyroid gland disorder that causes the release of too little thyroid hormone. Underproduction of thyroxine or thyroid hormone slows down the body's metabolism.                                                                                                                                                                                        Hypothyroidism will often cause an increased level of TSH because the pituitary gland continues to release TSH due to a low level of thyroid hormone in the blood. (Remember the negative feedback system.) Hypothyroidism is a chronic disease that occurs more commonly in women.

• Mental and physical sluggishness
• Obesity
• Enlargement of the tongue
• Swelling of the lips and nose
• Sensitivity to cold
• Muscle weakness

The treatment for hypothyroidism is thyroid hormone replacement.

• Levothyroxine (Levoxyl, Synthroid, Levothroid) 
• Thyroid (Armour Thyroid)

 

Goiters

A goiter is a disease characterized by enlargement of the thyroid gland, causing swelling of the neck. A goiter can be cause by either hypothyroidism or hyperthyroidism. It often occurs in a particular geographical area, such as Haiti, because of insufficient dietary intake of iodine.

Most patients with a goiter are asymptomatic (show no symptoms) with the exception of airway obstruction, difficulty swallowing, and a hoarse voice due to the enlarged gland.

Treatment for goiters involves surgical removal—the patient will need thyroid replacement therapy after surgery—and radioactive iodine.

 

Cushing's Syndrome

Cushing's Syndrome is an adrenal gland disorder caused by a hyperactive adrenal gland. In most cases, hyperactivity is the result of too much ACTH secretion by the pituitary gland.

• Weight gain
• Susceptibility to bruises
• Hypertension
• Diabetes
• Weakness
• Mitotane (Lysodren)
• Cyproheptadine (Periactin)
• Ketoconazole (Nizoral)
• Surgical removal of tumor of the pituitary or adrenal gland

 

Addison's Disease

Addison's disease is due to abnormally low levels of hormones secreted by the adrenal glands. This disease may result from steroid abuse or from an autoimmune disease.

• Electrolyte imbalance
• Weight loss
• Hypoglycemia (low blood sugar)
• Muscle weakness and pain
• Hypotension

Treatment is generally the replacement of the adrenal hormones. The following two medications can be used for this purpose: 

1. Hydrocortisone (Solu-Cortef)
2. Fludrocortisone (Florinef)

 

Diabetes

Diabetes develops from a deficiency or decreased production of insulin by the pancreas. Since insulin controls glucose levels in the blood, diabetes results in an increased glucose level. There are three types of diabetes: Type 1, Type 2, and gestational diabetes.

Diabetes is diagnosed by measuring fasting blood sugar levels. Normal fasting blood sugar level in healthy individuals should be less than 100 mg/dL. A test that measures average blood sugar levels over a two- to three-month period is called hemoglobin A1c (HbA1c or A1c). A normal A1c level for healthy individuals is 4 to 6.2 percent.

Symptoms of diabetes include:

• Feeling very thirsty all the time
• Frequent urination
• Extreme fatigue or tiredness
• Weight loss
• Blurred vision
• Tingling pain or numbness in hands or feet
• Cuts or bruises that are slow to heal

Type 1

• Average time of onset is childhood, specifically 10 years of age or earlier
• Sudden onset
• Mainly caused by the destruction of insulin-producing cells of the pancreas due to genetic or environmental factors
• Accounts for less than 10 percent of all diabetes

Type 2

• Average time of onset is adulthood
• Progressive disease
• Mainly caused by decreased insulin secretion or development of insulin resistance
• Accounts for more than 90 percent of all diabetes

Gestational

• Occurs during pregnancy
• If uncontrolled or untreated, may cause birth defects

 

Diabetes leads to many chronic complications that can result in frequent hospital admissions and decreased quality of life.

Some of the major complications of uncontrolled diabetes are

• Heart disease
• Hypertension
• Stroke
• Nerve damage (diabetic neuropathy)
• Blindness (diabetic retinopathy) 
• Foot ulcers or wounds that don't heal
• Infections of resistant organisms
• Amputations (removal of part of a limb)
• Kidney failure

 

Listed below are some of the lifestyle modifications that can prevent diabetes and avoid chronic complications of the disease:

• Balanced diet
• Decreased consumption of sugars
• Exercise
• Maintaining healthy weight

 

Type 1 diabetes is treated with insulin injections. There are many oral medication options to treat type 2 diabetes. These medications are often used in combinations to treat progressive cases of the disease. Insulin injections may be required in combination with oral medications if oral agents alone fail to keep a desirable glucose level in type 2 diabetes patients.

Metformin (Glucophage)

Metformin is the first line of treatment for type 2 diabetes after lifestyle modifications fail to keep blood glucose levels in check.

Metformin works by increasing glucose uptake in muscles and inhibiting glucose release from the liver. It also increases our body's sensitivity to insulin.

Metformin causes side effects in the kidneys, so it generally isn't the drug of choice for patients with poor kidney function. Metformin doesn't cause hypoglycemia, contrary to most other oral diabetes medications.

Sulfonylureas 

These medications increase insulin release from the pancreas and also make your body cells more sensitive to insulin:

• Glipizide (Glucotrol, Glucotrol XL)
• Glyburide (DiaBeta, Micronase)
• Glimepiride (Amaryl)

A major side effect of these medications is hypoglycemia (sudden decrease in blood sugars).

Other Oral Medications

• Pioglitazone (Actos)
• Rosiglitazone (Avandia)
• Repaglinide (Prandin)
• Nateglinide (Starlix)
• Sitagliptin (Januvia)

 

Insulin is the primary treatment option for type 1 diabetes. Insulin is administered via the subcutaneous route (injection under the skin). Insulin can cause severe hypoglycemia, so regular monitoring of blood glucose levels while taking insulin is highly important. Insulin is available in short-acting, intermediate-acting, and long-acting forms. Some of the commercially available insulins are a mixture of short-acting and intermediate-acting insulins.

Short-Acting

• Work immediately (5–30 minutes)
• Typically used with meals to control increased glucose level with food
• Examples: Humulin R, Novolin R, Humalog, Novolog

Intermediate-Acting

• Work within 2–4 hours
• Typically used to control glucose levels throughout the day between meals
• Examples: Humulin N, Novolin N, Humalog 70/30

Long-Acting

• Work within 6–10 hours
• Typically used to control glucose levels throughout the day between meals
• Examples: Lantus, Levemir

The following is a list of important information regarding insulins:

• Insulins must be stored in a refrigerator.
• Insulins are administered via injection under the skin or into the veins.
• Once opened or removed from the refrigerator, an insulin vial is good for 28 days at room temperature.
• Only administer insulin via an insulin needle.
• Insulin is measured in units, not mgs or mLs (for example, 40 units).

 

Hypoglycemia

Hypoglycemia is defined as dangerously low levels of blood glucose. As mentioned previously, most diabetes medications, including insulin, can cause hypoglycemia.

• Nervousness
• Sweaty palms
• Dizziness
• Weakness
• Tachycardia
• Coma (if untreated)
• Juice consumption
• Glucose tablet intake
• Glucagon injection
• Dextrose 50% injection

 

Key Points

Know the following key points regarding insulins:

• They must be refrigerated.
• They're administered via injection under the skin.
• Once removed from a refrigerator, a vial is good for 28 days at room temperature.
• Insulins should be administered only via insulin needle.
• Insulins are measured in units, not mgs or mLs (example: 40 units).