ADRENAL AND THYROID DISORDERS

Claire Nowlan MDJan 9, 2004

The Adrenal Glands Medulla - part of the sympathetic

nervous system produces epinephrine and norepinephrine

Cortex produces: 1) Aldosterone (a mineralcorticoid)– acts

mainly on the cells of the kidney tubules Regulation of plasma salts – Na and K Blood pressure Blood volume

2) Androgen and Estrogen

The Adrenal Cortex 3) Cortisol (a glucocorticoid)

Catabolizes proteins and converts the resultant amino acids to glucose

Inhibits inflammation Maintains homeostasis Secreted secondary to stress (cold, fasting,

starvation, hypotension, hemorrhage, surgery, infections, pain, severe exercise, emotional trauma)

Diurnal variation – highest in the AM Essential for life

Regulation of Secretion

s tress

A d ren a l C ortexC ortiso l

A n te rio r p itu ita ryA C TH

H yp oth a lm u sC R H

cortico trop in -re leas in g h orm on e

Synthetic glucocorticoids Most common ones are prednisone,

methylprednisone, dexamethasone. Used to decrease inflammation in :

Rheumatoid arthritis, SLE, asthma, inflammatory bowel disease, organ transplantation

Long term side effects include Hypertension, osteoporosis, diabetes,

glaucoma, delayed wound healing, peptic ulcers

Hyperadrenalism Cushing’s syndrome Commonly caused by

adrenal/pituitary neoplasm or iatrogenic

Symptoms: weight gain, weakness, easy bruisibility, depression, insomnia, impotence

Clinical symptoms: acne “moon facies”, abdominal stria

Hypoadrenalism Primary

(problems with adrenal gland)

“Addison’s disease”

Etiology includes autoimmune, Tb or HIV infections, metastatic

Secondary Etiology includes

excess steroid administration or pituitary/ hypothalmus problems

Hypoadrenalism Acute adrenal insufficiency is a medical crisis Chronic disease usually presents with vague

complaints Postural dizziness Weakness Nausea Anorexia Weight loss

Classic findings – hypotension, hyperpigmentation

If you identify a patient with adrenal insuffiency Bravo! Refer to physician, and defer dental treatment until stable

Lab tests Difficult to do 24 hour urine cortisol ACTH suppression test

Medical management Hyperadrenalism

Surgery/radiotherapy to destroy pituitary/adrenal tumour

Ketoconazole inhibits adrenal hormone biosynthesis

Hypoadrenalism Supplement mineralcorticoids,

glucocorticoids Avoid ketoconazole, P450 inducers

(rifampin, phenytoin, barbituates In surgery tx same as patient on steroids

Dental managementPatients on steroids hyperadrenalism

Select a non NSAID analgesic - re risk of peptic ulcers

Osteoporosis is related to periodontal bone loss

Monitor BP You don’t want to provoke an

adrenal crisis

Oral Steroids and procedures Determine length of time steroid

taken Determine dose of steroid For routine/minimally invasive

procedures Ensure patient has taken regular

steroid dose – preferably within 2 hours of procedure

For major procedures Using general anesthesia, 1+ hours,

significant blood loss, in sicker patients: Consider stopping steroid 1 week before ? (not

likely) ACTH test ? Surgery in the AM Consult with physician Consider doing procedure in hospital setting Treat pain aggressively Monitor blood pressure Evaluate post-op for signs of adrenal insufficiency

(weak pulse, hypotension, dyspnea, myalgia, fever) Supplement steroid intraoperatively and Q8H for

24-48 hours

The Thyroid Produces T3 and T4 which regulate

the body’s metabolic rate and increase protein synthesis

The body is responsible for converting 80% of the T4 to T3 (more potent)

Carried in the blood by TBG Thyroid Binding Globulins

Regulation of SecretionS tress C o ld

Th yro idT3 T4

(th is req u ires iod in e )

A n te rio r P itu ita ryTS H

H yp oth a lm u sTR H

Th yro id R e leas in g H orm on e

Lab Tests sTSH the best test

Goiter – thyroid enlargement Euthyroid goiter is most common

form Iodine deficiency is the most

common form of goiter in the world Eating a lot of goitrogens

(cabbages, turnips, rutabagas) coupled with low iodine

Associated with also with hypo/hyperthyroidism

Hyperthyroidism

Autoimmune (Grave’s disease) Antibody against the thyroid TSH

receptor which results in continuous stimulation

Women more at risk

Other causes Overdose on thyroid medication Early stage thyroididits Pituitary disease

Symptoms of hyperthyroidism Nervousness, anxiety, heat intolerance,

fatigue, weight loss, palpitations, rapid heart beat, warm moist skin, rosy complexion, diarrhea, tremor

Myxedema puffy, raised red areas Opthalmopathy

Edema and inflammation of the extraocular muscles – does not resolve when patient treated

Wide stare, lid lag

Thyroid Storm - lethal More likely in patients with:

Goiter Eye pathology Long history of hyperthyroidism Poorly treated

Early symptoms Restlessness, fever, tachycardia, nausea, abdominal

pain,sweating, pulmonary edema Precipitants

Infections, trauma, surgical emergencies, operations Treatment

Medical help, hydrocortisone, IV glucose, ice packs

Hypothyroidism Hashimoto’s thyroiditis

Lymphocytic infiltration of the gland Decreased peripheral conversion of T4 to

T3 In ill or elderly

Congenital Other causes

Lithium Thyroiditis Iodine excess postablative

Symptoms of hypothyroidism Increased sensitivity to cold,

constipation, weight gain, weakness, dry coarse hair and skin, alopecia outer third of the eyebrows, puffy eyelids, hoarseness, moving/thinking slowly

Myxedema

Medical treatment - hypothyroidism T4 (L-thyroxin, Synthroid) is titrated

until the patient has a normal TSH May change insulin, coumadin

requirements If untreated, can progress to a

myxedema coma – progressive weakness, hypothermia, hypoglycemia, hypoventalation leading to death – it is treated with IV T4

Dental management - Hypothyroidism Recognize signs and symptoms Patients who are untreated or

incompletely treated are more sensitive to CNS depressants

Myxedematous coma can be precipitated by stress in severe, poorly treated elderly patients

Dental management - Hyperthyroidism Recognize signs and symptoms Patient untreated or incompletely

treated are very sensitive to epinephrine – do not administer

More likely to have osteoporosis Beware thyroid storm

Medical treatment - hyperthyroidism Propylthiouracil blocks the

extrathyroidal deiodination of T4 to T3

Betablockers like propranalol can treat tremors, sweating tachycardia

Subtotal thyroidectomy/radioactive iodine

Thyroid nodules Risk factors for cancer:

Young age Male History of neck irradiation Dyspnea, dysphagia Hard consistency Single nodule Rapid growth

Fine needle biopsy is best test