Flashcards in Endocrine Deck (81)
Loading flashcards...
1
Normal fasting blood glucose values:
72-100 mg/dl (4.0-5.7 mmol/L)
2
Normal Random blood glucose values:
<180 mg/dl (10 mmol/L)
3
Other causes of Diabetes Mellitus
1) Pancreatic disease
2) Hormonal antagonists to insulin
3) Drug & chemical induced
4) Genetic syndromes
4
Hormonal antagonists to insulin
1) Cortisol
2) Growth Hormone
3) Catecholamines
5
Genetic syndromes involved in etiology of Diabetes Mellitus
1) Down's Syndrome
2) Turner's Syndrome
6
Type 1 D.M. etiology (general)
Most cases: 1) immune mediated destruction of pancreas through autoimmune attack on pancreatic B cells
2) Genetics
3) Environmental factors
7
Type 1 D.M. etiology (genetic factors)
Association with:
1) HLA-DR3
2) HLA-DR4/DQA1
3) DQB1
8
Type 1 D.M. etiology (environmental factors)
Association with viruses:
1) Mumps
2) Coxsackie B4
3) Rubella
9
Type 2 D.M. etiology (general)
caused by combination of B cell failure and insulin resistance
10
Type 2 D.M. etiology (genetic factors)
1) Stronger than type 1 (80% concordance in identical twins)
2) No HLA associations
3) Polygenetic disorder (but environmental factors also involved -> obesity)
11
More than half of the patients with D.M. II have BMI between what?
25-29 kg/m2
12
What is the RR for DM II for BMI > 35 kg/m2?
100 fold than BMI <22 kg/m2
13
How does obesity lead to DM?
Increased production of insulin antagonists, such as fatty acids and TNF by adipose tissue, especially in central obesity.
14
Pancreatic Pathology in DM. 1
1) Selective destruction of insulin-secreting beta cells
2) Insulitis, a chronic inflammatory infiltrate of the islets affecting primarily insulin containing islets
15
Pancreatic Pathology in DM 2
1) Moderate reduction islet tissue
2) Variable degrees deposition of amyloid.
16
Long term complications of Diabetes Mellitus
1) Nephropathy
2) Neuropathy
3) Eye disease
4) Heart disease
5) Stroke
6) Problems of feet
17
Clinical symptoms of DM (prominent in uncontrolled type 1)
1) Polyuria
2) Nocturia
3) Thirst
4) Weight loss
5) Tiredness
6) Blurred vision
7) Vomiting
8) Hyperventilation (Kussmaul breathing)
18
Why is there polyuria in DM?
osmotic diuresis
19
Why is there thirst in DM?
dehydration
20
Why is there weight loss in DM?
Catabolic state
21
Why is there blurred vision in DM?
Dehydration of lens, and of aqueous and vitreous humour
22
Why is there vomiting in DM?
Ketones stimulate the area postrema
23
Why is there hyperventilation in DM?
Respiratory compensation to metabolic acidosis
24
What are the biochemical signs in DM?
1) Hyperglycemia
2) Glycosuria
3) Ketoacidosis
4) Ketonuria
5) Hyperlactemia
6) Hyperlipidemia
7) Hypovolemia
8) Hyperosmolarity
25
Why is glycosylated hemoglobin a good monitor to manage DM?
-Hemoglobin reacts with glucose non-enzymatically to produce HcA1.
-HbA1c is the major fraction of glycosylated hemoglobin
-HbA1c levels give an integrated measure of glucose concentrations over the previous 2-3 months
26
Acute complications of DM
1) Hypoglycemia (diabetes treatment complication)
2) Diabetic ketoacidosis
3) Hyperosmolar nonketotic coma
4) Lactic acidosis
27
Precipitating factors of Diabetic Ketoacidosis
1) Infection or acute illness
2) Trauma
3) Emotional disturbance
4) Missed insulin dose
28
Most common cause of hypopituitarism
Pituitary adenoma
29
Tumors which cause hypopituitarism
1) Adenoma
2) Craniopharyngioma
3) Cerebral and secondary tumors
30
Vascular causes of hypopituitarism
1) Sheehan's syndrome
2) Severe hypotension
31
Infectious causes of hypopituitarism
1) Meningitis
2) T.B.
3) Syphilis
4) HIV/AIDS
32
Hypothalamic disorders which cause hypopituitarism
1) Tumors
2) Functional disorders
3) Isolated deficiency of GHRH
4) Isolated deficiency of LH/FSH-RH (GnRH secretion)
33
Iatrogenic causes of hypopituitarism
1) Irradiation
2) hypophysectomy
34
Miscellaneous causes of hypopituitarism
1) Sarcoidosis
2) Hemochromotosis
35
Pattern of hormone deficiency of the anterior pituitary
1) LH
2) GH
3) FSH
4) ACTH
5) TSH
36
Which hormone is maintained in anterior pituitary hormone deficiency?
Vasopressin
37
Drugs that cause nephrogenic D.I.
Lithium
38
Metabolic causes of D.I.
1) Hypokalemia
2) Hypercalcemia
39
SIADH will cause?
Water retention and hyponatremia
40
Presentation of SIADH
1) Hyponatremia can be asymptomatic or assoc with nonspecific symptoms
2) Severe hyponatremia, specially if there is rapid fall in serum sodium, can cause neurological symptoms, coma and death.
41
Causes of SIADH
1) Post operative
2) Intra-cranial disease: encephalitis, meningitis, head injury
3) Neoplasms: small cell carcinoma of the lung
4) Pulmonary disease: pneumonia, tuberculosis
5) Drugs/medications
42
Possible mechanisms of non-thyoridal illness (NTI)
1) Decreased peripheral conversion of T4 to T3
2) Abnormality of binding protein
3) Effects of circulating inflammatory mediators on metabolism of thyroid hormones
43
Characterization of papillary carcinoma of the thyroid gland
-presence of papillae
-tend to spread to local lymph nodes
44
Characterization of follicular carcinoma of thyroid gland
-Well differentiated follicles, which can be difficult to differentiate from normal thyroid tissue
-Invade the capsules and spread into blood vessels
45
Disorders that stem from overactivity of adrenal cortex
1) Cushing's syndrome
2) Hyperaldosteronism
46
What are the clinical features of Addison's disease?
1) Tiredness
2) Weakness
3) Anorexia
4) Apathy
5) Abdominal pain
6) hyperpigmentation
7) postural hypotension
47
What precipitates an adrenal crisis?
Infection in a patient with adrenocortical insufficiency.
48
What characterizes an adrenal crisis?
1) Circulatory shock
2) Volume depletion
3) Anorexia
4) Nausea
5) Vomiting
49
What is secondary adrenocortical insufficiency due to?
Pituitary disorders
50
Describe the serum presentation of a person with Addison's disease
Plasma sodium - low
Postassium - high
Serum bicarbonate - low
Urea - high
Morning cortisol - low or normal
51
What is the levels of ACTH in Addison's Disease?
High
52
How do we manage patients with Addisons?
replace glucocorticoids and mineralocorticoids
53
Describe the renin activity and aldosterone levels in pt with Addisons
Renin - high
Aldosterone - low
54
What is the best test for Addisons?
Morning cortisol
55
What is a specific test for Addisons?
Short synacthen test: administration of ACTH analogues to assess the residual capacity of the adrenal glands.
56
What are the causes of Hyperadrenalism : Cushing's syndrome
1) Exogenous steroids
2) Pituitary dependent
3) Adrenal adenoma
4) Ectopic ACTH
57
What are the clinical features of hyperadrenalism: Cushing's syndrome
1) Moon facies, truncal obesity, buffalo hump
2) Hypertension
3) Thin limbs and muscular weakness
4) Purple striae, fragile skin
5) Impaired glucose tolerance
6) Psychiatric disturbances
7) Menstrual disturbances, hirsutism
58
How does one diagnose Cushing's Syndrome?
1) Exclude exogenous glucocorticoids
2) Perform one of the following tests to confirm hypercortisolism:
- 24 hour urinary free cortisol (common)
-1 mg overnight DST (Dexamethasone suppression test)
- Late night salivary cortisol: new test
59
Describe the overnight Dexamethasone suppression test for Cushing's syndrome.
Involves taking a small dose of a cortisol-like drug called dexamethasone (1 mg) at 11 p.m. and having blood drawn for cortisol the following morning.
Normal individuals typically have very low levels of cortisol in these samples (s disease.
60
Physiological causes of hyperprolactinemia
Stress
61
Drugs that cause hyperprolactinemia
1) Anti-psychotics
2) Oral Contraceptive Pill
3) Antidopamine
62
What are the associations with MEN2A
1) Medullary Thyroid Cancer
2) Pheochromocytoma
3) Parathyroid Adenoma
63
What are the associations with MEN2B
1) Medullary Thyroid Cancer
2) Marfanoid habitus/mucosal neuroma
3) Pheochromocytoma
64
What is characteristic of Papillary Carcinoma of the thyroid gland?
1) Presence of papillae
2) Orphan Annie eye nuclei
3) Spread via lymphatics
65
What is characteristic of Follicular Carcinoma of the Thyroid gland?
1) Well differentiated
2) Encapsulated
3) Hematogenous spread
4) Can only be diagnosed via visualization of capsular invasion. (Tissue biopsy, not aspiration)
5) Hurthle cells
66
Mutation of medullary carcinoma of the thyroid
RET
67
Age of presentation of Medullary Carcinoma of the thyroid?
Sporadic and Inherited are above 50, except MEN syndrome assoc, which is an early presentation.
68
What is the difference between Cushing's Syndrome and Cushing's Disease?
Disease is due to pituitary adenoma
Syndrome is ectopic ACTH caused by non-pituitary tumor (i.e. small cell carcinoma of lung)
69
First functional change in Diabetic Nephropathy
Hyperfiltration
70
First morphological change in Diabetic Nephropathy
Basement membrane thickening and mesangial expansion.
-subsequentyl nodular deposits and diffuse glomerulosclerosis
71
What is associated with established Diabetic Nephropathy?
Proteinuria (urinary albumin >300 mg/day)
72
Diabetic Neuropathy causes:
1) Pain
2) Impotence
3) Orthostatic hypotension
4) Muscle atrophy
5) Weakness
73
Two main causes of hypercalcemia:
1) Hyperparathyroidism
2) Malignant diseases
74
Other causes of Hypercalcemia
1) Excessive vitamin D: Vit. D intoxication
2) Granulomas (tuberculosis, lymphoma, sarcoidosis) because they activate vitamin D
3) High bone turnover
- thyrotoxicosis
-Paget's disease
75
What are the clinical features of hypercalcemia on the renal system?
– Polyuria and thirst
– Stones
– Nephrocalcinosis; deposition of calcium crystals in kidney
– May lead to renal failure
76
What are the associations with Primary Adrenal Insufficiency (Addisons)
Autoimmunity of other organs such as:
1) Thyroid disease
2) Premature ovarian failure
3) DM 1
77
Secondary Adrenal Insufficiency is NOT associated with:
1) Hyperpigmentation
2) Electrolyte balances
78
Adrenal crisis is characterized by:
1) Circulatory shock
2) Volume Depletion
3) Anorexia
4) Nausea
5) Vomiting
79
The low dose (2mg/day for 2 days) DST is given to rule out hypercortisolism due to what?
1) Alcoholism
2) Depression
3) Obesity
80
Conn's syndrome (hyperaldosteronism) causes what? Leading to what?
Causes: Na retention
Leading to:
1) hypertension
2) hypokalemia
3) metabolic alkalosis
81
