Pathophysiology of DM

Question 1

the renal threshold (RT) for glucose in the blood is what?

Answer 1

10 mmol/L

Question 2

If the glucose levels exceed 10 mmol/L, what occurs?

Answer 2

the excess glucose will appear in the urine

Question 3

How will this excess glucose appear in the urine?

Answer 3

It increases the concentration in the filtrate, therefore fluid from blood into filtrate increases urine output (polyuria)

Question 4

Define polyuria:

Answer 4

Excessive fluid loss / frequency of urination

Question 5

The full proccess of Patho T1/T2 DM…

Answer 5

Insulin Deficiency –> impaired glucose utilization –> the body senses that the cells don’t have energy, so the liver goes through glucogenesis (formation of glucose from glycogen in the liver) –> hyperglycemia (11-67 mmol/L) –>RT exceeded –> glucosuria / glycosuria –> increased osmotic pressure in the filtrate (pull pressure by the glucose) –> fluid enters filtrate –> polyuria (large volumes of urine / frequency) –> dehydration –> polydipsia (excessive thirst followed by excessive fluid intake)

Question 6

A not yet diagnosed / treated patient with DM may present with large urine output. Why?

Answer 6

The increased concentration pulls fluid into the filtrate, causing the patient to urinate more.

Question 7

DM causes impaired glucose function.. this leads to what else being metabolized in the body?

Answer 7

Lipids and Proteins

Question 8

The breakdown of lipids and proteins results in what being prsesnt in the blood?

Answer 8

Increased metabolites of lipids and proteins

Question 9

What would be a byproduct of the metabolization of lipids?

Answer 9

ketones

Question 10

what are the 2 problems that ketone accumulation can lead to?

Answer 10

1. ketoacidosis (can lead to acidotic coma & death?)

2. Ketoneuria (enhances polyuria)

Question 11

What are the MNFTS of DM?

Answer 11

1. Polyuria
2. Polyphasgia
3. Polydipsia
4. Weight loss
5. Other complications

Question 12

Define polyuria:

Answer 12

Excessive volume of urination and frequency

Question 13

Define polyphasgia:

Answer 13

Excessive hunger d/t loss of calories in the urine

Question 14

Define polydipsia:

Answer 14

dehydration, therefore you drink more, cycle continues!

Question 15

What are the 3 Acute Complications of DM?

Answer 15

1. Hypoglycemia
2. Diabetic Ketoacidosis (DKA)
3. Hyperosmolar Hyperglycemic state (HHS)

Question 16

Hypoglycemia:

1. What type of DM usually?
2. D/t what?

Answer 16

1. Type 1 DM

2. D/t missed meal, insulin overdose, overexcertion

Question 17

What is the treatment for Hypoglycemia?

1. Mild
2. Moderate
3. If patient in hypoglemic coma?

Answer 17

1. 15 mg of carbs PO
2. 20 mg of carbs PO
3. 1 mg of glucagon SC or IM

Question 18

What is occuring to the brain in a hypoglycemia coma?

Answer 18

It is being deprived of glucose

Question 19

Explain Diabetic Ketoacidosis

Answer 19

Gotta look at that figure in Porth

Question 20

Define Hyperosmolar Hyperglycemic state

1. Usually occurs in what type of DM? or who else?

2. D/t what?

Answer 20

1. Type 2, or elderly

2. Increased carb intake OR increased insulin resistance

Question 21

Explain the proccess of HHS?

Answer 21

sever hyperglycemia –> hyperosomlarity (concentration in the blood) –> cellular fluid efflux (fluid movies from cells to IS to blood because of the pull force) –> glycosuria –> water loss –> dehydration

Question 22

Why is no ketoacidosis occuring in HHS?

Answer 22

Because ketoacidosis occurs when lipids are being metabolized… In this case, there are lots of carbs, no lipid breakdown.

Question 23

When do the chronic complications of DM typically surface? What are they?

Answer 23

approximately 15 years post disease onset

1. Vascular damage –> atherosclerosis, MI, CVA
2. Retinopathy
3. Nephropathy
4. Neuropathy
5. Infections (particularly foot and UTI)

Question 24

The Vascular Damage in DM is a chronic complication, occurs d/t…

1. What affect does the altered metabolism have?
2. Explain the glycolysated proteins
3. Explain the platelet aggregation and its implications
4. Why is healing impaired? How about the anaerobic metabolism?

Answer 24

1. Altered metabolism = accumulation of lipid (ketones) / protein metabolites which inflict damage
2. Glucose + protein = glycolysated protein, ex. HB glycolysated has a higher affinity for O2, therefore wont dissociate O2 at low levels
3. Platelets aggregating will impede the blood flow
4. Impaired healing d/t impeded perfusion (d/t the platelet aggregation). Anaerobic microbes will then grow because the lack of O2 here.

Question 25

How do the abnormal metabolites inflict damage?

Answer 25

glucose + proteins = glycosylated proteins --> non -fx | ex. Hb, affinity for 02 increases, therefore at low levels 02 will not dissociate as easily

Question 26

what are other proteins that can be affected and lead to vascular damage?

Answer 26

Abs, albumins, collagen

Question 27

The glycosylated proteins deposit on where?

Answer 27

Endothelium

Question 28

The deposition of gycoslyated proteins leads to what to happen to the endothelium?

Answer 28

It thickens

Question 29

What does this thickenning of the endothelium cause to occur?

Answer 29

movement across the membrane is affected, therefore impaired capillary exchange

Question 30

What would cause the blood flow to be impeded in regards to Vascular Damage, a chronic complication of DM?

Answer 30

platelet aggregateion

Question 31

The vascular damage leads to impaired healing: why? | Why would growth of anarobic bacteria increase?

Answer 31

1. impeded perfusion | 2. thrive in low 02

Question 32

What are the Chronic Complications of DM?

Answer 32

1. Vascular Damage 2. Neuropathy 3. Nephropathy 4. Retinopathy 5. Infections

Question 33

Explain how retinopathy occurs in DM?

Answer 33

Capillaries are damage --> aneurysms --> rupture --> visual impairment causes cataracts and glaucoma

Question 34

Explain how nephropathy occurs in DM?

Answer 34

glomerular damage --> decreased renal fx --> renal failure

Question 35

Explain how neuropathy occurs in DM?

Answer 35

``` Neural ischemia (lock of 02 to the neurons) causes inadequate perfusion to neurons in the brain and others, which can lead to demylination of nerons -Leads to poor conductions (leads to neurodeficit) ```

Question 36

Neurodeficit would cause a diabetic patient what?

Answer 36

Unable to feel pain in the foot

Question 37

Why is HTN common in DM?

Answer 37

d/t damaged vessel walls and impeded perfusion

Question 38

The HTN in a diabetic patient increases their risk for what?

Answer 38

MI, CVA, nephropathy

Question 39

Why is CAD a common chronic complcation in diabetic patients?

Answer 39

hyperlipidemia (d/t altered metabolosim) --> atherosclerosis --> MI

Question 40

Why is CVA a common chronic complication in a diabetic patient?

Answer 40

hyperlipidemia --> atheroscerlosis --> CVA

Question 41

Patients with DM have an increased prevalance of infections as compared to who else?

Answer 41

Patients without DM

Question 42

What are the two most common infections in a patient with DM? Name 2.

Answer 42

1. foot | 2. UTI

Question 43

What are the 5 Tests for Diagnosing DM?

Answer 43

1. Hx 2. Random glucose above 11 mmol/L on ongoing basis 3. IFG (above or = 7 mmol/L) 4. IGT (above 11 mmol/L) 5. HBa1c (above or = 6.5%)

Question 44

What would the Hx include in diagnosing DM?

Answer 44

3 P's 1. Polyphagia 2. Polydipsia 3. Polyuria 4. unexplained weight loss

Question 45

When Dx DM, random glucose levels would be above what?

Answer 45

11 mmol/L on ongoing basis

Question 46

Dx of DM: Numbers should be above what? 1. IFG 2. IGT 3. HBa1c

Answer 46

1. above or = 7 mmol/L 2. above or = 11 mmol/L 3. above or = 6.5%

Question 47

What is considered to be a histologic marker for DM? Why?

Answer 47

Hba1c: looking for glucose bound to Hb in RBC, lasts the red blood cell life cycle (120 days) therefore you can look at over a long period of time how many of these have been bound to

Question 48

Treatment for DM includes what 2 things?

Answer 48

1. Lifestyle modifications | 2. Glycemic control

Question 49

Glycemic control of DM involves 2 main forms of medications. What are they?

Answer 49

1. Oral hypoglycemics | 2. Insulin

Question 50

Oral hypoglycemic medications are aiming to bring about what response?

Answer 50

Hypoglycemic response (decrease the blood glucose levels)

Question 51

What are 3 things that oral hypoglycemics cause to occur?

Answer 51

1. increase tissue response to insulin 2. stimulate Beta cells to secrete insulin 3. Decrease hepatic glucogensis

Question 52

What is a common oral hypoglycemic drug that is given?

Answer 52

Metformin

Question 53

When would Metformin be prescribed?

Answer 53

Hba1c still above 7% after 2-3 months of lifestyle modifcations

Question 54

If HBa1c still above 9% while on metformin, what else would be prescribed?

Answer 54

insulin

Question 55

Could oral hypoglycemic be given to a type 1 diabetic?

Answer 55

No. They do not cause the production of insulin

Question 56

Type 1 DM patients require what medication?

Answer 56

Insulin

Question 57

Why is insulin injected SC?

Answer 57

avoid intestine, so that insulin can't be broken down (insulin is a protein!)

Question 58

The Vascular Damage in DM is a chronic complication, occurs d/t... 1. What affect does the altered metabolism have? 2. Explain the glycolysated proteins 3. Explain the platelet aggregation and its implications 4. Why is healing impaired? How about the anaerobic metabolism?

Answer 58

1. Altered metabolism = accumulation of lipid (ketones) / protein metabolites which inflict damage 2. Glucose + protein = glycolysated protein, ex. HB glycolysated has a higher affinity for O2, therefore wont dissociate O2 at low levels 3. Platelets aggregating will impede the blood flow 4. Impaired healing d/t impeded perfusion (d/t the platelet aggregation). Anaerobic microbes will then grow because the lack of O2 here.

Question 59

Why are infections difficult to manage for a patient with DM? (3)

Answer 59

1. Vascular insufieciency (02, ab, nutrients) 2. impaired leukocyte function in severe hyperglycemia 3. neuropathies (unable to feel)