Endo Part Uno - DM

Whole blood (capillary), Plasma (grey sodium fluoride), Serum (red top), CSF, urine (random/24 hr)

What specimens can be used for testing glucose levels?

Convenience, small amounts needed, direct measure

Advantages of using capillary blood for testing blood glucose

checks for bacterial vs. viral meningitis

Advantages of using CSF for testing glucose

DM I (juvenile onset)

Which type of diabetes is characterized by a LACK of insulin

DM II (adult onset)

Which type of diabetes (most common form) is characterized by a lack of response to insulin or not enough insulin

Gestational (Type IV)

Which type of diabetes (most common form) is characterized by a lack of response to insulin during pregnancy

All pt. 45+, African/Asian/Hispanic/Native American/Pacific Islander ancestry, delivered a large baby, previously diagnosed gestational DM, HTN, Hyperlipidemia, obesity, 1st degree relative, previously positive testing

Who should get screened for DM every 3 years (most providers do 1)?

random blood glucose (RBG)

Which test (often included in the chem 7/20) that can be performed at any time but is NOT diagnostic for diabetes?

immediate sugar status, screening for DM, monitoring levels

What are some reasons for ordering RBGs?

repeated testing, FBG, OGTT

How can you confirm results of a RBG?

Fasting blood glucose (FBG)

Which testing requires fasting, usually performed in the morning to establish a baseline and is considered diagnostic?

not fasting (coffee, smoking, medications), acute illness, surgery/hospitalization w/in 8 wks

C/I for FBG

screening for DM (#1 draft pick), monitor changes

Reasons for ordering FBG

Oral glucose tolerance test (OGTT)

Which testing form includes a stimulation test to assess glycemic response using a standard dose of glucose under standardized conditions?

OGTT

What is the best definitive diagnostic testing for diabetes (especially in screening for gestational diabetes) because it monitors pancreatic function and tissue response to insulin?

75 g in 5 min

What is the dosage for a non pregnant adult’s 2 hour OGTT?

50g/1hr, 100g/3hr

Modified OGTT dosages and times

Testing must be done in the LAB, No walking around, optimal time is AM, normal diet/physical activity 12 hr before, stop meds/supplements that may affect testing (restart afterward)

Concerning the OGTT what are some rules of the road?

Hemoglobin A1C (Hgb A1C)

Which test is a measurement of glycated keto-amine proteins in RBCs that are formed when glucose binds Hgb which persist for the life span of the RBC?

screening, gold standard for diagnosis and monitoring

What is the reasoning behind ordering a Hgb A1C?

Under 7%, testing 2x if treatment goals are met (4x if not)

Target levels for HgbA1C in patients diagnosed with DM?

anything that messes with the blood (drugs, pregnancy, blood loss, etc)

What might throw off your HgbA1C

Specific gravity, blood/hgb, glucose, proteins, pH

What are we looking at when we are assessing the urine in DM?

specific gravity

Which assessment of the urine deals with the concentration to measure the kidneys ability to balance water and excrete waste?

blood/hgb

Which assessment of the urine deals with damage to tiny blood vessels in the kidney leak into the urine (microalbuminuria - do a CBC/CMP)

glucose

Which assessment of the urine deals with a defect in kidney filtering or reabsorption of sugar

proteins (IE albumin)

Which assessment of the urine may indicate glomerular filtration damage?

Ketone bodies

What is produced by the liver from the breakdown of lipids and used by other tissues as a fuel source during prolonged starvation?

Beta-ketoacyl-CoA transferase (not present in the liver)

What enzyme is necessary for bodies to be able to use ketone bodies?

ketonemia

accumulation of ketones in the blood

ketonuria

accumulation of ketones in the urine

sodium nitroprusside reacts with acetoacetic acid (purple = positive)

What do we use to find ketone bodies in the urine

DKA (diabetic ketoacidosis)

What is characterized by low insulin levels, increased glycolysis (forming ketones), and high blood glucose?

Type I DM

DKA is more common in which patient population?

infection, lack of therapeutic compliance, stress, starvation

What are some triggers of DKA

hyperglycemia, decreased CO2, decreased bicarb, ketoemia, acidosis, glucosuria, ketonuria (sick on presentation)

Features of DKA

Urine albumin creatinine ratio (UACR)

Which test looks for abnormal amounts of albumin in the urine compared to creatinine?

random/spot urine, early morning/timed sample, 24 hr

Specimen for a UACR

screening for esrd, diagnosis, monitoring, treatment ratio

Purpose for UACR

C-peptide

What molecule is formed by proinsulin, secreted into the circulation, and excreted by the kidneys?

calculate insulin production, evaluate beta cell function, distinguish between type 1 and 2 DM

Reasons for ordering a C-peptide

Type 2 DM, cushing syndrome, insulinoma, kidney disease, low K+

Red flags for high levels of C peptide

type 1 DM, liver disease, Addisons disease, ineffective diabetes treatment

Red flags for low levels of C peptide

Fructosamine (more sensitive than HbA1C)

What test measures circulating glycosylated proteins and reflects glucose control over 2-3 wks?

shorter term glucose monitoring, patients with short RBC life span

Reasoning for order fructosamine (serum/plasma)

GADA, IA-2A, IAA, ZnT8

What are some common antibody test for Type I DM

TBI, febrile/severe illness, overactivity of adrenal/pituitary/thyroid, hospitalization, stress, meds, lifestyle

What might cause secondary hyperglycemia in a non-diabetic patient?

illness/infection, inappropriate use of medications, poor diet, lack of exercise/activity, inappropriate weight management

What might cause secondary hyperglycemia in a diabetic patient?