Endocrine and Pituitary Disorders Quiz

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Questions and Answers

Which factor does NOT directly affect the absorption of drugs?

Surface area

Formulation

pKa and environment pH

Blood type (correct)

What term describes the percentage of an administered dose that is available therapeutically?

Absorption rate

Bioavailability (correct)

Metabolism ratio

Hepatic extraction

Which route of administration has the highest absorption rate?

Percutaneous

Intravenous (correct)

Oral

Intramuscular

In the context of drug absorption, what does pKa represent?

pH at which half of the drug is ionized Signup and view all the answers

Which statement about hepatic first pass metabolism is accurate?

It refers to the percentage of drug removed by liver cells after administration. Signup and view all the answers

What is the importance of molecular size in drug absorption?

Molecules must be small to pass through cell membranes. Signup and view all the answers

Which phase of drug action involves the release of the active ingredient from its formulation?

Liberation Signup and view all the answers

The absorption of oral drugs primarily occurs in which part of the gastrointestinal tract?

Proximal small intestine Signup and view all the answers

What is the primary cause of hyperparathyroidism?

Tumor or hyperplasia of the gland Signup and view all the answers

Which of the following is NOT associated with growth hormone deficiency in children?

Enhanced linear bone growth Signup and view all the answers

What secondary effect can hyperthyroidism have on patients?

Protruding eyes Signup and view all the answers

Which condition is characterized by an autoimmune destruction of the thyroid gland?

Hashimoto thyroiditis Signup and view all the answers

Which of the following describes a characteristic feature of acromegaly?

Mandibular prognathism Signup and view all the answers

Which of the following is a leading oral health issue resulting from antidiuretic hormone deficiency?

Xerostomia Signup and view all the answers

What is the most common cause of Cushing syndrome?

Use of corticosteroid medications Signup and view all the answers

Which dental condition may be a sign of hyperparathyroidism?

Malocclusion due to tooth drift Signup and view all the answers

In women of reproductive age, which disorder is the most common endocrine issue?

Polycystic ovarian syndrome (PCOS) Signup and view all the answers

What can result from uncontrolled insulin deficiency in type 1 diabetes?

Ketoacidosis Signup and view all the answers

Which of the following is a possible consequence of diabetes mellitus on oral health?

Higher risk of dental infections Signup and view all the answers

Which type of diabetes is characterized by insulin resistance and beta cell dysfunction?

Type 2 diabetes Signup and view all the answers

In Addison disease, which symptom is associated with glucocorticoid deficiency?

Hyperpigmentation of skin Signup and view all the answers

What is a common consequence of untreated congenital hypothyroidism?

Brain development delay Signup and view all the answers

Which statement about the oral manifestations of hypothyroidism is accurate?

Cardiovascular health should be a primary consideration during dental treatment. Signup and view all the answers

What causes the increased risk of oral health issues during pregnancy?

Pregnant women tend to consume more sugary snacks. Signup and view all the answers

How does polycystic ovarian syndrome (PCOS) affect oral health?

It is commonly associated with increased systemic inflammation affecting periodontal health. Signup and view all the answers

What is a critical concern for patients with hyperthyroidism during dental procedures?

The presence of anxiety can lead to a thyrotoxic crisis. Signup and view all the answers

Which of the following analgesics is preferred during pregnancy?

Paracetamol is usually considered safe. Signup and view all the answers

What oral issue is most likely to arise due to diabetes?

Xerostomia and increased root caries incidence. Signup and view all the answers

Which practice should be avoided during invasive dental procedures for hyperthyroid patients?

Use of adrenaline-containing products. Signup and view all the answers

What role do advanced glycation end products (AGEs) play in diabetes-related periodontal disease?

They increase the inflammation and degradation of oral tissues. Signup and view all the answers

What is a recommended practice for managing the oral health of patients with PCOS?

Maintenance of good oral hygiene is critical. Signup and view all the answers

What is a misconception about hormone replacement therapy during menopause?

Use of hormone therapy can have controversial consequences. Signup and view all the answers

Study Notes

Endocrine Disorders

Causes of endocrine dysfunction:
- Primary: Originate in the endocrine glands responsible for hormone production.
- Secondary: Caused by defective levels of stimulating hormones from the pituitary gland, with normal endocrine gland function.
- Tertiary: Result from hypothalamic dysfunction, affecting pituitary function.

Pituitary Disorders

Growth Hormone Deficiency

In children:
- Short stature and immature facial features.
- Impacts linear bone growth before epiphyseal fusion.
- Delayed puberty/sexual development, but normal intelligence.
- Impacts mandibular and maxillary growth, leading to malocclusion associated with smaller dental arches.
- Retarded tooth root formation.
- Delays in tooth eruption.
In adults:
- Primarily affects metabolism.
- Destruction of bone cells, leading to fractures and osteoporosis.

Growth Hormone Excess

Pituitary gigantism:
- Nearly always caused by an adenoma (tumor of the pituitary gland) that secretes GH.
- Abnormal large height and weight, but normal body proportions.
- Abnormally large hands and feet.
- Facial features can include an enlarged forehead and jaw, pronounced underbite, spreading of teeth, enlarged tongue, nose, and lips.
- Hyperglycemia and overactive beta cells in the pancreas, potentially leading to type 2 diabetes.
- Death in early childhood.
Acromegaly:
- Individuals do not grow taller, but bones become thicker and more deformed, primarily in hands, feet, and membranous bones.
- Lower jaw protrusion and hunchback can occur.
- Enlarged soft tissue organs, including the tongue, liver, heart, and kidneys.
- Increased risk of bronchitis, diabetes, and heart failure.
Craniofacial changes in acromegaly:
- Mandibular prognathism and thickening.
- Increased thickness and height of the alveolar process.
- Spacing and flaring of anterior teeth with associated malocclusion and enlargement of the tongue.
- Spiky exostosis-like growths in the alveolar bone can be an early sign.

Antidiuretic Hormone Deficiency

ADH deficiency causes diabetes insipidus, leading to excessive water loss.
Xerostomia is a leading oral issue.

Thyroid Disorders

Hyperthyroidism

Causes:
- Graves' disease: Autoimmune disorder associated with thyroid-stimulating antibodies.
- Overactive thyroid nodules or thyroiditis.
- Excessive iodine intake.
- Non-cancerous tumor of the pituitary.
Common signs and symptoms:
- Excessive sweating and increased skin temperature.
- Tachycardia or irregular heart rate.
- Tiredness, muscle weakness, but difficulty sleeping.
- Twitching, anxiety, nervousness.
- Exophthalmos (protruding eyes with lid retraction).
- Increased sensitivity to catecholamines.

Hypothyroidism (Acquired)

Causes:
- Sugary drugs like lithium.
- Excessive or lack of iodine.
- Hashimoto thyroiditis: Most common cause, an autoimmune disease that can completely destroy the thyroid gland.
Impact related to hypometabolism:
- Fatigue, weight gain despite loss of appetite, cold intolerance, and affects nearly all organ systems.
Severely advanced form (myxoedema): Puffy appearance, can lead to myxoedema crisis.

Hypothyroidism (Congenital)

Also known as cretinism.
Partial or complete loss of thyroid gland function in infants.
Common cause is iodine deficiency in the mother's diet.
Untreated, it can lead to impaired neurological function, stunted growth, and physical deformities.
Thickening of lips and macroglossia due to increased subcutaneous mucopolysaccharide accumulation.
In older children and adults, slowing metabolic processes and myxoedema can range from mild to life-threatening.

Parathyroid Glands

Hyperparathyroidism

Usually caused by a tumor or hyperplasia of the parathyroid gland.
Key sign is bone lesions associated with excessive osteoclast activity.
Malocclusion due to teeth drifting with defined spacing may be an early symptom.
Higher risk of bone fracture.

Hypoparathyroidism

Mainly affects nerve and muscle activity.
Enamel hypoplasia, delayed tooth eruption, and potentially multiple unerupted teeth can occur.
Increased susceptibility to dental caries.

Adrenal Disorders

Addison Disease

Primary adrenal cortical insufficiency: Caused by autoimmune disorders, infection (TB), trauma, cancer, or hemorrhage.
Glucocorticoid deficiency: Poor stress tolerance, hypoglycemia, lethargy, weakness, nausea, and vomiting.
Mineralocorticoid deficiency: Dehydration, low blood pressure, fatigue.
High ACTH levels: Skin hyperpigmentation (darker skin).

Addison Disease (Treatment)

Relies on hormone replacement therapy.
Long-term corticosteroid therapy (> 14 days) can suppress adrenal function (secondary adrenal insufficiency).
Limited ability of the adrenal cortex to deal with stress, predisposing patients to acute adrenal insufficiency (addisonian/adrenal crisis).
Stress reduction protocol, effective anesthesia, and postoperative analgesia are crucial in these situations.
Supplemental doses of corticosteroids can be used to help the body cope with stress.

Cushing Syndrome

Disorder resulting from long-term excess cortisol.
ACTH-dependent hypercortisolism:*
- Cushing disease: Hypersecretion of ACTH by the pituitary gland due to a pituitary adenoma.
- Ectopic ACTH syndrome: Secretion of ACTH by a non-pituitary tumor, such as small cell lung carcinoma or a carcinoid tumor.
ACTH-independent hypercortisolism:*
- Therapeutic administration of exogenous corticosteroids: Most common cause.
- Adrenocortical adenomas or carcinomas:
Signs are the exaggerated actions of cortisol:
- Altered fat metabolism and abnormal fat distribution.
- Rounding and puffiness of the face (moon face).
- Protein breakdown and muscle wasting.
- Thin and easily bruising skin.
- Osteoporosis due to calcium resorption.
- Deranged glucose metabolism, leading to hyperglycemia and increased insulin requirement (potentially leading to diabetes).
- Immune suppression.
- Increased gastric acid secretion (gastric ulceration).
- Emotional and sleep disturbance, including depression-like symptoms.
Dental concerns:
- Increased risk of infection due to immune suppression.
- Alveolar bone loss.
- Impaired wound healing.
- Comorbidities like obesity, osteoporosis, and diabetes may influence the periodontal attachment apparatus.

Diabetes Mellitus

Metabolic condition from an imbalance between the body's need for glucose and the availability/effectiveness of insulin.
Lack of secretion or reduced activity of insulin compromises glucose transport into fat and muscle cells, leading to high blood sugar levels.
Increased fat and protein breakdown to compensate and provide an energy source for cells.
The discovery of insulin in 1922 transformed diabetes from a fatal disease to a manageable condition.

Type 1 Diabetes

Prone to ketoacidosis.
Without insulin, ketone conversion happens uncontrolled, leading to ketoacidosis.
Needs insulin replacement to stop fat and protein catabolism and prevent ketoacidosis.

Type 2 Diabetes

Heterogeneous condition primarily considered a lifestyle disease.
Disorder of both insulin levels (beta cell dysfunction) and insulin function (insulin resistance), leading to hyperglycemia and wide-ranging complications.
Glucosuria: Glucose in the urine.
Polyuria: Excessive urination due to the osmotic pull of glucose in the urine and/or diuretic effect of certain medications.
Inflammatory process in dysfunctional visceral adipose tissue leads to systemic inflammation and insulin resistance.
Over time, increasing beta cell dysfunction and exhaustion can lead to an absolute insulin deficiency, requiring insulin therapy.

Other Specific Types of Diabetes

Formerly known as secondary diabetes.
Occurs with pancreatic disease, endocrine disorders (like GH excess), environmental agents, various drugs, polycystic ovarian syndrome, and pregnancy (gestational diabetes).

Diabetes Diagnosis and Treatment

Diagnostic tests:*
Blood tests based on fasting or casual plasma glucose levels, or glucose challenge tests.
Capillary blood tests: Valuable for near-patient testing in diabetic patients (normal is 4-6 mmol/L).
Glycated hemoglobin test (HbA1c): Measures how much glucose is bound to red blood cells.
- An indirect measure of average blood sugar level over the past 2-3 months (RBC lifespan is around 120 days).
- Assesses long-term glycemic control.
Lifestyle management:*
Desired outcome for both type 1 and type 2 diabetes is to normalize blood glucose levels.
Type 1: Food intake is used to adjust insulin replacement therapy. A good routine is necessary to balance insulin administration, carbohydrate intake, and glucose levels.
Type 2: Diabetics need to target glucose, lipid, and blood pressure goals, as well as weight loss if required.
Drug management:*
Incretins: Gastrointestinal peptides with blood glucose-lowering effects. Reduced levels in diabetics.
Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP): Stimulate insulin secretion, slow gastric emptying, and reduce appetite and energy intake.

Osteoporosis

Estrogens normally promote apoptosis (death) of osteoclasts.
Decrease in bone mass with diminishing hormone levels, particularly after menopause, as bone resorption by osteoclasts outpaces bone deposition by osteoblasts.
Demineralization can begin at age 30 in females and 60 in males.
Contributing factors:
- Poor diet.
- Lack of exercise.
- Smoking.
- Diabetes.
Osteoporosis medications:
- Bisphosphonates and RANK ligand inhibitors decrease osteoclast activity/bone resorption.
- Problem of medication-related osteonecrosis of the jaw (MRONJ): Associated with the use of these medications.
- Characterized by non-healing exposed bone in the maxillofacial region, which may occur following oral surgery.
- MRONJ pathophysiology is not completely understood.
- Tooth extraction is a common factor, but these teeth often have existing periodontal or periapical disease.
- Greater risk with IV antiresorptive medications compared to oral medications and with chronic use.

Polycystic Ovarian Syndrome (PCOS)

Most common endocrine disorder among women of reproductive age.
Significant negative effects on metabolic, psychological, and cardiovascular health.
Symptoms: Irregular or absent menstrual periods, infertility, acne, excess hair growth, and unintended weight gain.
Associated with other comorbidities (insulin resistance, obesity, cardiovascular disease, and periodontal disease).
Mechanisms:
- Altered secretion of GnRH.
- Defect in androgen synthesis.
- Development of insulin resistance.
Characterized by the presence of many small, fluid-filled sacs or cysts inside the ovaries.

Thyroid Disorders - Oral Manifestations

Hypothyroidism in Dental Practice

Considerations:
- Patients generally tolerate dental treatment well.
- Poor cardiovascular health may be a primary concern.
- Delayed wound healing due to decreased fibroblast activity (increased susceptibility to infections).
- Sedatives (benzodiazepines) and opioids should be used with caution due to increased sensitivity to their actions.

Hyperthyroidism in Dental Practice

Considerations:
- Patients are more prone to caries and periodontal disease, as well as other oral problems like burning mouth syndrome.
- Patients are very sensitive to adrenaline-containing products, which can cause a hypertensive crisis.
- Increased levels of anxiety, making stressful dental procedures more likely to elicit a life-threatening thyrotoxic crisis (caused by high thyroid hormone levels).
- For invasive dental therapy, it is best to liaise with the patient's physician to assess how well-controlled their condition is.

Parathyroid Glands - Oral Manifestations

Hyperparathyroidism:
- Bone changes can lead to tooth mobility and early tooth loss.
- Hyperparathyroidism can cause a "ground-glass" appearance on x-rays due to bone demineralization.
Hypoparathyroidism:
- Enamel hypoplasia and delayed tooth eruption can occur.
- Patients may have difficulties chewing and swallowing.

Pregnancy - Oral Health

Pregnancy gingivitis is the most common oral manifestation, mainly due to estrogen and progesterone enhancing the inflammatory response.
Painless tumor-like growths - pregnancy granulomas (epulis gravidarum) - typically regress following parturition (childbirth).
Increased risk of caries:
- Snacking.
- Reduced oral hygiene (gag reflex, fatigue).
- Morning sickness.
- Hormone-induced xerostomia.

Pregnancy Considerations

Routine dental care safe for both mother and child.
Weeks 14-20 are the most comfortable times for visits.
Drug use is always a concern, especially during the first trimester.
Lignocaine and mepivacaine have good safety records for use in pregnancy.
Few antibiotics (amoxicillin) and antifungals (nystatin) may be used.
Paracetamol is the preferred analgesic. NSAIDs should be avoided during the first and third trimesters.
Sedation should be avoided. If required, nitrous oxide may be used with medical consultation.

Menopause

Declining estrogen and progesterone levels impact oral health.
The use of hormone replacement therapy is controversial.
Good oral hygiene practices are essential.

Polycystic Ovarian Syndrome (PCOS) - Dental Concerns

Low-grade chronic systemic inflammation is a possible link to periodontal disease.
Gingivitis can be difficult to treat due to underlying inflammation.
Altered sex hormones may impair the epithelial barrier to bacterial injury or compromise collagen maintenance and repair.
Decline of estrogen with aging increases the risk of bone loss density.
Suspect PCOS if a patient struggles with receding gums, difficulty chewing, and tooth loss despite good oral hygiene.
Good oral hygiene is important for managing PCOS symptoms.
Prevention includes taking special care of teeth and gums: brushing, flossing, antiseptic mouthwash, and bi-annual dental visits.

Diabetes in Dental Practice

Oral signs of diabetes:
- Xerostomia due to polyuria and dehydration.
- Increased rate and severity of periodontal disease in type 1 and 2 diabetes.
- Increased incidence of root caries (due to increased root exposure from periodontitis combined with xerostomia).
- Xerostomia + high salivary glucose + impaired immune function increase susceptibility to oral infections and mucosal disorders (lichen planus, burning mouth syndrome).
- Vascular and immune dysfunctions result in poor wound healing.
Good oral health management is essential in managing diabetes and may improve diabetic control.

AGEs and Periodontal Disease in Diabetes

Advanced glycation end products (AGEs): Proteins or lipids that become glycated after exposure to sugars; pro-inflammatory mediators that link diabetes to periodontal disease (excessive formation in diabetes).
AGEs bind to receptors and accumulate in periodontal tissues, leading to an accumulation of inflammatory mediators.
A cascade of cytokine upregulation further increases levels of pro-inflammatory cytokines.
This inflammation-mediated activation of osteoclasts and destruction of oral tissues.
Uncontrolled diabetes is strongly correlated with increased alveolar bone loss.
AGEs are a significant element responsible for the development of micro and macrovascular complications in diabetes.

Pharmacokinetics Intro

Pharmacology: The study of the effects of drugs on the function of living systems.
Pharmacokinetics: How the body affects the drug.
Pharmacodynamics: How the drug affects the body.
Therapeutic concentration: The amount of drug needed for a therapeutic effect.

Phases of Drug Action

Liberation: Release of the drug from its dosage form.
Absorption: The drug enters the circulatory system.
Distribution: Drug spreads throughout the body.
Metabolism: Drug is broken down in the body.
Excretion: Removal of the drug from the body.
LADME: Acronym for the phases of drug action.

Absorption

Drugs have to enter circulation.
Barriers: Epithelial lining, endothelial lining of blood vessels, and cell membrane of target cells.
Mostly passive diffusion between cells: Concentration gradients are the driving force.

Absorption Affected By

Formulation.
Administration route.
Surface area available for absorption.
Blood flow to the absorption site.
Facilitated transport/receptors.
Solubility: How well the drug dissolves.
pKa and environmental pH.

Routes of Administration

Oral or rectal: Most common.
Intravenous: 100% absorption.
Percutaneous: Through the skin.
Intramuscular: Into muscle.
Intrathecal: Into the cerebrospinal fluid (CSF).
Inhalation: Into the lungs.

Other Routes

Ocular: Into the eye.
Buccal: Between the cheek and gum.
Sublingual: Under the tongue.
Transdermal: Through the skin.

Drugs

Small molecules: Their chemical structures influence their properties.
Weak acids, bases, ionized, and non-ionized forms:
- The proportions of these forms depend on pH and pKa.
- Ionized (A-, H+): Hydrophilic (water-loving)
- Non-ionized (AH): Lipophilic (fat-loving).

pKa

Acid dissociation constant.
Predicts the behavior of a drug at a specific pH (pH of the drug and pH of the environment).
The pH at which half of the drug is ionized.
Drugs need to be non-ionized to cross cell membranes.

Absorption in the GI Tract

Oesophagus: pH of 7
Stomach: pH of 1-2.5 (5 when fed).
Proximal small intestine: pH of 6.15-7.
Descending colon: pH of 5.2-7.
Distal small intestine: pH of 6.8-7.8.
Ascending colon: pH of 5.2-6.7.

Blood Flow

More blood flow = more absorption.

Absorption of Oral Drugs

Molecules absorbed in the GI tract enter the hepatic portal vein.
Hepatic first pass: The drug passes through the liver before entering systemic circulation, potentially leading to a reduction in the drug's bioavailability.

Hepatic First Pass

Bioavailability: Percentage of the administered dose that is available therapeutically.
- 100 % for IV administration, less for other routes.
Hepatic extraction ratio: Amount removed by liver cells.
- A higher ratio means lower bioavailability (e.g., > 0.8 = low bioavailability).

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Test your knowledge on endocrine disorders, especially focusing on their causes, such as primary, secondary, and tertiary dysfunction. Additionally, delve into growth hormone deficiency and excess, and understand their effects on children and adults. This quiz is essential for students studying endocrinology or related health sciences.