Diabetes Mellitus Flashcards
What is DM?
A group of metabolic disorders of glucose metabolism characterized by hyperglycemia and insulin problems (resistance or deficiency)
What is the key to diagnosing DM?
Demonstration of significant hyperglycemia.
What are general symptoms of DM?
Polyuria
Polydipsia
Polyphagia
Circulatory issues (susceptibility to infection, blurred vision)
What are some consequences if DM is left untreated?
Retinopathy/blindness
Neuropathy (foot ulcers, amputation, pruritis)
Ketoacidosis DKA
Atherosclerosis
What is Type 1 DM?
It is insulin dependent DM that presents as absolute insulin deficiency.
What are the causes of T1DM?
Destruction of pancreatic beta cells that produce insulin which is required for survival
Genetic, autoimmune
What is the on,y effective treatment for T1DM?
Insulin supply
How does T1DM presents?
Abrupt onset in childhood
Severe hyperglycemia and increased ketone production.
What percentage of DM patients are type 1?
Less than 10%. 75% of the, show symptoms before the age of 18
If T1DM is uncontrollable, what can it result to?
DKA
What does the body do when glucose is in deficit?
The body goes into ketosis.
What is ketosis?
The breakdown of fats into ketone bodies (keto acids) for energy.
What does extremely high accumulation of ketones leads to?
An acidic pH, resulting to diabetic ketoacidosis.
In who is DKA seen mostly in the ER?
Poorly mismanaged T1DM patients, some with adverse conditions.
Does DKA occur commonly in T2DM?
No, DKA is rare in T2DM
Under what condition does DKA occur in T1DM patients?
When T1DM is not well controlled and patient is under stressful conditions such as starvation, infection.
Why do stress conditions cause DKA?
Under stress conditions, the body needs more energy so it causes increased glucose through glycogenesis and gluconeogenesis. When glucose is not enough, it turns to other sources of energy and breaks down lipids causing DKA.
What makes DKA worse?
Blood and urine is hyperpsmolar (very concentrated) as kidneys try to excrete much of the glucose in urine, water follows causing dehydration and more concentration.
What are the factors showing DKA?
Significantly increased glucose (>300-400mg/dL)
Metabolic acidosis from increased ketoacids (increased anion gap)
Coma
What is T2DM?
It is non-insulin dependent, insulin resistant DM.
What causes T2DM?
Insufficient insulin from B cells
Insulin resistance of peripheral tissues
What is the presentation of T2DM?
Usually in >40 YO obese people
What percentage of DM patients have T2?
> 90% patients
How is T2DM treated?
Diet, exercise, oral drugs.
Insulin as last resort
What happens if T2DM is uncontrolled?
Renal failure
Blindness
Peripheral neuropathy
What is another name for hemoglobin A1C?
Glycohemoglobin
Glycated hemoglobin
What is glycation? What is glycated hemoglobin?
It is the non-enzymatic addition of glucose to protein.
Non-enzymatic addition of glucose to hemoglobin.
How does HgbA1C help in identifying DM?
It is not a direct measure of glucose, but the rate of A1C formation is directly proportional to glucose concentration. By checking HA1C, you can tell if an individual’s blood glucose has been well controlled for the past 2-3 months.
What are HA1C values and what do they indicate?
<5.7% normal
5.7-6.4% pre DM
>6.5 % diabetes
What is gestational diabetes?
This is diabetes observed only during pregnancy in 2-10% of times.
How is gestational diabetes diagnosed?
When FBG >105 mg/dL and OGTT is abnormal
What causes gestational diabetes?
Predisposing factors like obesity, sedentary or diabetic risk prior to pregnancy.
Release of placental lactogen, a hormone that raises glucose during pregnancy by inhibiting the actions of insulin.
What is gestational diabetes patients at risk of?
Developing T2DM after their pregnancy
Identify other causes of DM
Pancreatic disease
Crushing’ disease (cortisol issue)
Drugs that kill insulin like Dilantin
Genetic defects if B cell function in pancreas
What is diabetes insipidus or water diabetes?
It is a condition where there is lack of vasopressin/anti-diuretic hormone (ADH) from the pituitary gland in the brain.
What does ADH do?
It regulates urine output by water only. Keeping water in the blood from urine resorption.
Decreased blood volume, increases is osmolality then increase in ADH
What are the symptoms of diabetes insipidus?
Polyuria Polydipsia Severe dehydration High blood osmolality Low urine osmolality SG (1.005) Urine output reaching ~15L/day
What is impaired glucose tolerance?
This is considered pre diabetes. When fasting blood glucose is less than that of diabetic but an OGTT result is higher than normal.
Of what is IGT a risk factor for?
DM and cardiovascular disease
Atherosclerosis and heart disease
What are risk factors of developing impaired glucose tolerance?
Unhealthy diet/weight
Family history
Advanced age
Nicotine
What is the criteria for diagnosis of DM?
Symptoms Non fasting glucose >200 mg/dL Fasting plasma glucose >126 mg/dL Hemoglobin A1C >6.5 % 2 hour Oral glucose tolerance test >200 mg/dL
What specimen is preferred for testing glucose?
Plasma, serum is okay
What time is used?
Gray top containing sodium fluoride which inhibits glycolysis and potassium oxalate additives
What is the reference value for plasma glucose?
70-110 mg/dL
What does the OGTT do?
Evaluates endogenous insulin reponse to glucose challenge.
How is the OGTT procedure performed?
Test given between 7-9 am
Fasting blood specimen is drawn
50-75 g glucose given in a beverage over 5 minutes
Blood samples are taken at 60 and 120 minutes
What are diabetic OGTT values?
> 200 mg/dL at 120 minutes
What is glucose oxidase lab analysis of glucose?
Glucose is oxidized to form gluconolactone and H2O2. H2O2 oxidizes a chromagen to form a colored product, and then measured spectrophotometrically.
How is he Hexokinase lab analysis done?
Hexokinase catalyzes the phosphorylation of glucose by ATP to form G6P and ADP. G6P and NADP react to form NADPH which is formed in direct proportion to the amount of glucose present.
Which is most specific between glucose oxidase and hexokinase?
Hexokinase. Far less interferences
What is glucose oxidase commonly used in?
Analyzers and dipstick urine testing
What are the interferences that can occur with glucose oxidase?
Elevated Uric acid
Elevated bilirubin
Elevated as orbit acid
Acidic pH
What can cause false,t deceased glucose values in hexokinase analysis?
Severe hemolysis that alters NADP levels.
