Endocrine Pathology (Diabetes, Thyroid, Parathyroid, Pituitary, Adrenals, Paget's Disease) Flashcards
Diabetes (diagnostic criteria)
relative or absolute deficiency of insulin that causes glucose intolerance
- fasting sugar >126 mg/dL
- 75 gm glucose test yields glucose >200 mg/dL after 2 hours
- HbA1c > 6.5% (provides a good estimate of the average level of glucose in the blood for the previous 3 months; normal is BELOW 5-7%
Statistics related to diabetes
- 8-9% of the US population
- 73,000 deaths/year in US
- nearly 50% undiagnosed
- 14% of population is pre-diabetic (fasting glucose 100-125 of HbA1c 5.75-6.4%)
Symptoms of diabetes
- polydipsia and polyphagia
- polyuria
- unexplained weight loss
Functions of insulin: how does it affect
- uptake of glucose and amino acids
- glycogenolysis
- lipolysis
- proteolysis
- promotes glucose and amino acid uptake through the membranes of muscle (smooth, skeletal, and cardiac), fibroblasts, fat cells. It is an anabolic hormone that helps to control normal growth patterns and tissue development
- decreases glycogenolysis, lipolysis, and proteolysis
- does not affect glucose uptake in neurons, kidney, or RBCs (diabetics can have very high intracellular glucose in these tissues resulting in hyperosmotic conditions –> organ pathology)
- insulin is secreted from beta cells in pancreas
consequences of diabetes (no insulin)
- increasaed lipolysis –> ketosis and triglycerides in the blood
- increased glycogenolysis and gluconeogenesis
- protein catabolism of muscle –> muscle wasting
features of type 1 diabetes
- no natural insuling (insulin-requiring)
- young, 5% of cases, typically thin
- loss of beta cells (autoimmune process usually triggered by environment, such as viral infection
- ketoacidosis and dehydration
- deep labored breathing from the ketoacidosis
- nausea, coma, anorexia
- glucose levels usually up to 500 before diagnosis
features of type 2 diabetes
- adult onset, non insulin dependent
- insulin levels usually normal, but increased resistance to insulin
- correlates with excessive visceral fat (diet controls in about 20% of cases)
- correlates with hypertension, risk of atherosclerosis, and dyslipidemia –> metabolic syndrome
- some genetics (likely polygenic autosomal)
- obesity
minimal ketones or acidosis, but very high glucose - some ethnic groups with higher risk (Pima indians, Hispanics, African Americans, etc.)
- can result from amyloidosis (damage to pancreatic beta cells
- major metabolic complication is hyperosmolar coma
diabetes insipidus
increased urine production not related to glucose metabolism and often related to ADH abnormality. usually rare.
metabolic syndrom definition
a group of risk factors that can increase your chance of developing heart disease, diabetes, and stroke.
features/risk factors related to metabolic syndrome
- complex interaction between obesity and insulin resistance (insulin receptors refractory to insulin)
- abnormal lipid metabolism (high triglycerides and LDLs, low HDLs)
- excess fat around waist
- hypertension
- increased risk for atherosclerosis
- pro-thrombic tendency
- pro-inflammatory state (related to elevated visceral fat cells)
Pathogenesis of metabolic syndrome
- increased visceral adiposity
- decreased glucose metabolism and insulin sensitivity (inhibited by increased levels of free fatty acids)
- increased hepatic inflammation, cirrhosis, and fatty accumulation
major complications of metabolic syndrome
- very high glucose
- hyperosmolar consequences, including coma
- brain swelling due to increased osmolarity –> coma and seizures
- cardiac disease
- dehydration
features of gestational diabetes
- due to the stress of pregnancy (3-10% of pregnancies)
- usually goes away after birth of child, but can develop type II DM later
- consequences: insufficient placental function, abnormally large babies with excessive insulin secretion, early fetal hypoglycemia causing malformations (because insulin is a growth factor)
Long-term complications of diabetes
- (early) ketoacidosis, hyperosmolar coma, urinary tract infections
- issues in the eyes: ophthalmic swelling, cataracts, retinopathy, neuropathy, glaucoma, and blindness
- accelerated atherosclerosis (damaged microcirculation with high unhealthy lipid levels and consequences seen in the heart (MI), kidneys (glomerulosclerosis, pyelonephritis), and brain (stroke)
- peripheral neuropathies (loss of touch and pain sensation in extremities; gangrene)
- autonomic nerve dysfunction (abnormal GI motility, hypotonic bladder, increased UTIs)
- more prone to infections/slower healing
- symptoms worsen with stress
- renal damage (elevated sclerosis) due to inflammation and infection –> ESRD
most common cause of death in diabetics
coronary atherosclerosis that leads to myocardial infarction
oral problems seen in diabetic patients
- increased periodontal disease
- poor wound healing (issues with surgery and implants)
- infections (candidiasis)
- xerostromia –> caries
- patients should be care to avoid hypoglycemia in the dental office –> emergency situation
goal of insulin-replacement therapy
- replicate natural insulin patterns (basal background levels with burst release in response to rising glucose levels during eating)
- insulins are categorized by their onset of action, how quickly they are absorbed, and half life.
- insulin in the US is prepared in a lab (not from animals)
Release and management of thyroid hormone
- controlled by hypothalamic release of TRH, which stimulates the pituitary to release TSH
- excessive activation of the thyroid leads to a hypermetabolic state causing protein catabolism and enhanced sympathetic nervous system activity
T/F thyroid disease affects men more than women
False- it affects women more than men.
Clinical findings in hyperthyroidism
- nervousness
- hot and sweating (heat intolerant)
- weight loss
- muscle weakness
- tremors
- palpitations/tachycardia
- thyroid storm (fever, tachycardia, sweating, shaking, agitation, and unconsciousness)
- lab test show: elevated T4/T5, low TSH
Graves disease (definition and cause)
- 90% of cases of hyperthyroidism, found in 2% of females
- cause: autoimmune (antibodies function as agonists to thyroid-related receptors causing excessive activation
- possible cause is increased TSI
Symptoms of graves disease
- hyperthyroidism
- exophthalamos
- englarged thyroid gland (hyperplasia)
Plummer’s disease
- multinodular goiter
- 5-10% of hyperthyroidism cases
clinical findings of hypothyroidism
- hypo-metabolic state
- in children = “cretinism” with reduced mental and physical development
- enlarged thyroid
- low temperature
- dry coarse skin and hair
- sluggish
- cold intolerance
- modest weight gain
- myxedema (severe cases)
- high TSH (good screen for the condition)
- can be caused by iodine deficiency
Hashimoto’s disease
- type of hypothyroidism (9-10% incidence in US - most common form of thyroid deficiency)
- autoimmune, usually females
- may start as hyperthyroidism followed by permanent hypothyroidism
- hypopituitarism
- can be caused by radiation (either accidental or therapeutic)
- TSH high, but T4 low
- typically not painful
- thyroid enlarges and then atrophies