Endocrine Diagnostics PDF

Endocrine Diagnostics Jamie Harding MPAP, PA-C Campbell University PA Program Objectives Discuss the usefulness in regard to the diagnosis and management of each of the following diagnostic tests for diabetes mellitus; and any applicable co-morbidities that these tests could also be useful in manage...

Endocrine Diagnostics Jamie Harding MPAP, PA-C Campbell University PA Program Objectives Discuss the usefulness in regard to the diagnosis and management of each of the following diagnostic tests for diabetes mellitus; and any applicable co-morbidities that these tests could also be useful in management. a. Hemoglobin A1C b. Fasting glucose c. Oral glucose tolerance tests d. C-Peptide e. Urinalysis f. Liver function tests g. Renal function h. Lipid panel 2. Differentiate between laboratory values found in diabetic ketoacidosis and hyperosmolar (non-ketotic) hyperglycemic state. 3. Discuss the blood chemistry tests for diagnosis and management of a. Thyroid disorders b. Parathyroid disorders c. Hypo/hyper-adrenalism 4. Describe tests useful for the evaluation of disorders of anti-diuretic hormone. 1. Diabetes Mellitus Regulation of blood glucose Glucose serves as fuel for cellular functions Glucose is absorbed in the GI tract and also comes from carbohydrates that are ingested and metabolized into glucose Stored in liver as glycogen When plasma glucose is high Pancreas produces, stores and releases insulin which facilitates the move of glucose into our cells and out of bloodstream When plasma glucose is low  Pancreas produces, stores and releases glucagon which facilitates the breakdown and export of glucose into the plasma Diabetes Mellitus Type 1  Lack of endogenous insulin  Abrupt onset, usu in children  Pt is prone to ketoacidosis due to metabolism of fatty acids  Tx focused on glycemic control with diet and exogenous insulin Type 2  Endogenous insulin present but there is a problem with the way the insulin is utilized by the cells or with the release of it from the pancreas  Usu dx at older age (>40yo)  Associated with obesity and dyslipidemia  Not prone to ketoacidosis because they have insulin  Tx focused on glycemic control with diet, exercise, wt loss, etc Labs  Plasma glucose (fasting vs random)  Hemoglobin A1C  C-Peptide  Oral glucose tolerance tests  Urinalysis  Liver function tests  Renal function  Lipid panel Plasma Glucose  Preferably fasting (normal 70-99 mg/dL)  Normal random(non-fasting) is 70-140 mg/dL  Finger stick  Uses:  Can be random for screening for hypoglycemia  Used for self-monitoring of sugars (i.e. DM type 1)  Diagnosis and monitoring of DM Type 2  Fasting glucose >126mg/dL Hemoglobin A1C  Venipuncture blood draw  Checks average blood sugar over the last 3 months   Does not have to be fasting Gold standard for the evaluation and management of Diabetes C-Peptide  Protein that is a byproduct of the pancreas making insulin  Measures amount of c-peptide in the blood or urine  Uses: In the evaluation and management for type 1 DM  Not typically done in PC (used more by the Endocrinologist) Oral Glucose Tolerance Test (OGT T)  Used to measure how well the body can process a large amount of sugar  Must fast before this test for at least 8hrs  Result is the glucose level at the end of the test  Test is 2hrs if screening for type 2 DM  Can be a 1hr or 3hr test for screening for gestational DM Urinalysis  Used as a screening test for someone with ambiguous symptoms  Used to help diagnose or monitor pt’s with DM  Look for:  Protein  Ketones  Glucose Liver Function  Why?  Follow liver function as a measure of progression of diabetes  In pt’s with DM we worry about things like:    high insulin levels cause hepatocyte injury May cause the development of fatty liver which can lead to increased insulin resistance Labs:  CMP LFTs- liver function test Renal Function  Follow renal function as a measure of progression of diabetes  Why?   Hyperglycemia may cause:  Thickening of the glomerular membranes  Results in filtration decline  Increases arterial pressure Labs:  Serum Creatinine- tracks progression of kidney function  Microalbumin (urine albumin)- checking for small amounts of protein in the urine which can be early sign of renal damage Lipid Panel  Check Lipid panel as a part of the ongoing management of diabetic patients  Why?  Elevated sugar levels can affect the way glucose is stored and affect cholesterol and TG levels (increased)  In DM Type 2 you will see more elevated triglycerides, lower HDL, small LDL particles  Lab:  Lipid panel: HDL, LDL, Triglycerides DKA vs HHS Diabetic Ketoacidosis (DKA): Hyperglycemia Hyperosmolar State(HHS):  More common  Uncommon  Type 1 DM  Type 2 DM  Precipitated by infection  More severe illness  Ketoacidosis  No Ketoacidosis  Short prodromal symptomspolyuria/polydipsia, N/V, drowsiness stupor and coma  Longer prodromal symptoms- days to weeks of weakness, polyuria/ polydipsia, poor fluid intake  Mortality 5-10%  Mortality 40-60%  Age 20-29  Age 57-70yo DKA vs HHS Labs DKA:  Labs to get:   HHS: BMP, blood glucose, UA for ketones (if positive then serum ketone), arterial blood gas Findings:  Hyperglycemia  Positive ketones in urine and blood  Blood pH 310  No acidosis, anion gap  Elevated BUN and Cr Thyroid Disorders Thyroid Disorder Labs  Purpose of thyroid function tests:  Measure concentration of hormones going to/secreted by the thyroid  Screen for thyroid/ pituitary/ hypothalamus  Continual assessment of thyroid disorder treatment  Detecting antibodies to thyroid tissue Thyroid Labs TSH:  T3/T4: Released from anterior pituitary gland as a part of a negative feedback look from T4/T3   Causes thyroid to release mostly T4 and some T3 Uses:  Screening for thyroid disease and to assess thyroid function while on treatment  Measures the unbound serum T4  Uses:  In combo with TSH, used to screen for hypo/hyperthyroidism  Monitoring disease digression and medical tx for thyroid conditions Lab Abnormality Patterns   Hypothyroid:  High TSH and Low FT4  thyroid is the problem  Low/normal TSH and Low FT4 pituitary or hypothalamus is the problem Hyperthyroid:  Low/undetectable TSH and High FT4  High/normal TSH and High FT4 primary secondary Thyroid Antibody labs  Antibodies:  Thyroglobulin (Tg) Antibody  Thyroid Peroxidase (TPO) antibody:   positive in Hashimoto’s thyroiditis Text Text Thyrotropin Receptor Antibody's (TrAb)  Thyroid stimulating immunoglobulin (TSI)- Grave’s Disease Diagnostic Ordering Pearls  Screening/monitoring tx – TSH  Suspected Hypothyroidism – TSH/FT4, antibodies if Hashimoto’s is suspected  Suspected Hyperthyroidism – TSH/FT4, antibodies if Graves’s is suspected  Prior thyroid cancer - Thyroglobulin Parathyroid Disorders Parathyroid  Parathyroid glands produce Parathyroid Hormone (PTH)   Regulates calcium and phosphate levels Things to check:  Calcium: normal range 8.5-10.2mg/dL  First, verify abnormal calcium  Total calcium corrected for albumin   PTH  Vitamin D  Phosphorus Corrected calcium= serum calcium + (0.8 x [4.0 – serum albumin]) Pattern to check Parathyroid  Start with corrected Calcium  If abnormal (high or low) then check PTH  Correlate Calcium level (high or low) with PTH level (high or low)  Differentiate primary, secondary and tertiary with other labs/ PMH  Vit D , Magnesium, etc Example pattern of labs:  Hyperparathyroidism    Primary (Problem with the gland itself)  PTH elevated  Calcium elevated  Vit D Normal/elevated  Phosphorus normal/low Secondary (problem with end order, aka bone or kidneys)  PTH elevated  Calcium Low/normal Tertiary (chronic stimulation leading to overproduction of PTH)  PTH elevated  Calcium low/normal Adrenal Disorders Adrenal Disorders  Cortisol insufficiency   Low cortisol  Labs:  First initial: morning blood Cortisol level   Addison’s Disease