Diabetes and Osteoporosis Recitation
What clinical symptoms reflect the metabolic changes associated with hypothyroidism?
Hypothyroidism (lack of T3 and T4) in infants and children produces mental and physical retardation (cretinism). Hyposecretion of T3 and T4 in adults results in myxedema and nontoxic goiter.
What role does glucagon play in diabetes?
As glucose is taken up by the cells, the blood glucose level falls, stimulating the secretion of glucagon by the alpha cells of the pancreas. Glucagon enables glucose to enter the circulation and enhances the conversion of amino acids to glucose. As the blood glucose level increases, insulin secretion is stimulated and the metabolic cycle begins again.
The adverse effects of thioamide drugs include
rash and myalgia
Which of the following is NOT a symptom of hypothyroidism?
tachycardia
Which of the following oral antidiabetic agents increases the incretin's duration of action?
sitagliptin
Select the long-acting insulin preparation.
Lantus
Which of the following is NOT associated with thyroid hormone actions on the body?
A. increase in blood glucose B. stimulation of protein synthesis C. decrease in serum cholesterol D. increase in circulating fatty acids E. calcitonin stimulation of osteoclasts Answer: E
Choose the true statement about oral antidiabetic drugs.
A. incretins increase glucagon secretion B. biguanides have receptors on skeletal muscle C. elderly patients are usually resistant so doses have to be increased D. insulin sensitizers (thiazolidionediones) do not stimulate insulin secretion E. they cannot be used with insulins Answer: E
Which of the following is correct?
A. lipodystropy is exacerbated by alpha glucosidase inhibitors miglitol and acarbose B. insulin is the preferred treatment in type 2 DM because there are no drug interactions C. oral antidiabetic drugs include pramlintide D. hypoglycemia is the most common adverse effect of many antidiabetic drugs E. metformin is the drug of choice in patients with metabolic acidosis Answer: D
Which of the following insulins would provide a patient diagnosed with type 1 diabetes mellitus a constant release of insulin over a 24-hour period?
A. regular insulin B. insulin aspart C. insulin glargine D. insulin lispro E. aerosolized insulin powder Answer: C
How does the action of the antithyroid drugs differ from the action of radioactive iodide?
Administration of radioactive iodide (irradiation) in hyperthyroidism is directed toward destroying the overactive tissue. When I is administered to severely hyperthyroid individuals, it reduces the thyroid mass (tumors and nodules) and destroys hormone synthesis. Occasionally, patients exposed to I become permanently hypothyroid. In these cases, hormone replacement therapy must be administered for life. Because of its destructive potential, I should never be used during pregnancy or lactation. Antithyroid drugs decrease the production and secretion of T3 and T4.
How do the insulin preparations differ?
All commercial insulin preparations produce the same metabolic effects, but preparations differ in the source of the polypeptide, their onset and duration of action, and the compatibility of products to extend the insulin action.
Why do the insulins occasionally produce allergic reactions?
Because the hormone is a polypeptide and is frequently combined with a protein (antigen), diabetics sometimes develop allergic reactions. Insulin obtained from pigs (porcine) is less antigenic than is beef insulin. Regular or lente insulins are preferred because these preparations do not contain protein complexes (protamine or globin).
When is calcitonin used?
Calcitonin, available as a synthetic polypeptide hormone, is administered to hypercalcemia patients whose thyroid and parathyroid glands function normally in order to inhibit accelerated bone resorption.
If calcium levels decrease below normal, which hormone would be released to compensate?
PTH
What factors antagonize the actions of insulin and the oral hypoglycemics?
Glucagon, epinephrine, diazoxide, chlorpromazine, and sympathomimetics counteract the action of insulin by inhibiting glucose utilization. Thus, they also antagonize the actions of the oral hypoglycemics.
Which of the following is an indicator of glycemic control in type 2 DM patients?
HbA1c level
What methods are available for treating hyperthyroidism?
Hypersecretory conditions may be corrected with antithyroid drugs, irradiation, or surgical removal of the overactive tissue. Treatment of a hyperactive thyroid usually includes a combination of these methods.
What are the side effects of hypoparathyroid therapy? Why?
Hypoparathyroidism is not usually treated by replacement of the parathyroid hormone because parathyroid hormone produces allergic reactions and drug resistance usually develops within 2 weeks. Therefore, hypocalcemia is usually managed with oral calcium salts and vitamin D derivatives.
What is the primary deficiency in diabetes?
In diabetes mellitus, the beta cells of the pancreas do not produce or secrete an adequate amount of insulin, which is essential for carbohydrate metabolism.
How does insulin control the symptoms of diabetes?
Insulin administration rapidly reduces hyperglycemia and its complications and suppresses ketosis.
What factors potentiate the hypoglycemic actions of insulin and the oral hypoglycemic
Salicylates, beta-blockers, adrenergic neuronal blockers, and MAO inhibitors reduce circulating blood glucose levels; therefore, these drugs potentiate the hypoglycemic actions of insulin. Drugs that inhibit liver enzymes, displace sulfonylureas from protein-binding sites, or inhibit glucose metabolism will potentiate the hypoglycemic actions of sulfonylureas.
What hormones control calcium metabolism? How do these hormones differ?
Serum calcium levels are strictly regulated by the secretion of two hormones: calcitonin and parathyroid hormone (parahormone, PTH). Acting directly on bone cells that store calcium, PTH mobilizes calcium ions into the blood (bone resorption) and increases the intestinal absorption and renal reabsorption of calcium ions. These two physiological processes require vitamin D and increase the level of circulating calcium ions in response to hypocalcemia. Calcitonin directly inhibits bone resorption so that calcium ions are retained in the bone. It does not affect intestinal and renal calcium absorption, and its action does not require vitamin D.
Which of the following could be used for treatment in an infant diagnosed with cretinism?
T3 and T4
What physiological effects are produced by the thyroid hormones T3 and T4?
T3 and T4 stimulate protein synthesis, increase blood glucose and circulating fatty acids, and decrease serum cholesterol. These substances are essential for cell building, repair, and energy. By stimulating cell metabolism, T3 and T4 also increase the basal metabolic rate (BMR) and heat production.
Which of the following is a hormone secreted from the thyroid gland to help regulate tissue growth?
T3, triiodothyronine
What are the common symptoms of diabetes?
The most outstanding feature of diabetes is the persistently high level of blood glucose, which leads to an increase in urine glucose (glycosuria) and glucose in circulation (hyperglycemia). Glucose in the renal tubules pulls water out of the cells, and the water is excreted into the urine with the glucose, resulting in polyuria. Patients drink large quantities of fluids (polydipsia) and may increase food consumption (polyphagia) in order to avoid fatigue and hunger. As cells use protein and fat as sources of fuel, ketone bodies increase in the blood (ketoacidosis). Ketoacidosis may enhance the loss of electrolytes (sodium, potassium, and chloride) and produce CNS depression, resulting in diabetic coma and death.
How do the oral hypoglycemic drugs differ from the insulins?
The oral hypoglycemics are occasionally useful in the treatment of type 2 diabetes. These drugs enter the beta cells and cause the release of insulin, which alters the blood glucose level, but these drugs do not have any insulin-like activity.
Why are some insulins shorter acting than others?
The size of the insulin crystal or amount of additional protein combined with the insulin determines the duration of action. Short-acting insulins are usually smaller.
What side effects are associated with the use of antithyroid drugs?
The usual side effects of thioamide drugs include rash, fever, myalgia, jaundice, and nausea. Agranulocytosis also has been reported. Cross-sensitivity occurs for all thioamide drugs in sensitive individuals.
What is the difference between type 1 and type 2 diabetes?
Type I (insulin-dependent diabetes, juvenile diabetes, or growth-onset diabetes) is characterized by a total lack of insulin production and secretion. Onset occurs before the age of 20, when growth is still evident. Type 2 (maturity-onset diabetes, adult diabetes) usually occurs after the age of 40 and is characterized by a relative insulin deficiency.
What is the rationale for the treatment of hypothyroidism?
When thyroid hormone secretion is suppressed, there is no way to inhibit the secretion of TSH from the pituitary gland. When little or no T3 and T4 circulate in the blood, TSH continues to stimulate the thyroid gland to release active hormones that are not there. This constant stimulation of the thyroid results in glandular enlargement (hypertrophy). As the thyroid increases in size, it protrudes from the front of the neck, causing a swollen appearance known as goiter. In severe cases, respiratory acidosis, electrolyte imbalance, and coma may develop (myxedema coma).
Select the causes of type 1 diabetes.
autoantibody destruction of beta cells
Therapy for a patient with hypercalcemia would include
calcitonin
Bisphosphonates
inhibit bone resorption
Which is NOT a mechanism of action of an oral antidiabetic drug?
direct stimulation of insulin receptors in skeletal muscle
Which of the following is correct about polyuria in types 1 and 2 DM?
excess glucose spills into the urine and osmotically attracts water into the renal tubule
Which of the following oral agents is categorized as a secretagogue?
glipizide
Which of the following hormones would be elevated during a fast?
glucagon
Which of the following when used together have complementary actions that increase insulin secretion?
glyburide and incretin mimetics
Irradiation and antithyroid drug administration
inactivates overactive thyroid tissue
Thyroid hormone replacement therapy
increases blood glucose levels
Beta cells secrete the following substances:
insulin and amylin
Which of the following is correct about type 2 DM?
insulin is secreted by the beta cells and insulin resistance is present
Which of the following parameters would help to differentiate between type 1 and type 2 diabetes?
ketoacidosis
Which of the following is true regarding bisphosphonates?
they should be combined with calcium supplements and vitamin D for optimal effect
A patient has just been diagnosed with hyperthyroidism. You review her labs and find that T3-T4 level is elevated; however, TSH level is low, along with TRH. You suspect the problem is occurring at the
thyroid gland
When are the oral hypoglycemics used?
treatment of mild type 2 diabetes. They have no value in the treatment of type 1 diabetes or severe diabetes that occurs in the elderly, and they cannot substitute for insulin. The advantage of the sulfonylureas over insulin is that they avoid the trauma and complications, such as lipodystrophy.
