Diabetes Mellitus (Pathophysiology) Flashcards

1
Q

Which of the following statements is true?

A. Hyperglycemia can be a result of defects in insulin secretion, insulin action, or both
B. Glucose is stored in the pancreas as glycogen
C. Insulin is required all day long regardless of meals
D. The majority of insulin is metabolically cleared by the liver
E. A & C are correct

A

(E) A & C are correct

A - Hyperglycemia can also be caused by a defect in incretin (GLP-1)
B - Glucose is stored in the LIVER as glycogen
D - The majority of insulin is metabolically cleared by the KIDNEYS (50%)

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2
Q

Which of the following statements is false?

A. Insulin is released from pancreatic beta cells at a rate of 0.5 to 1 Unit/hour
B. Diabetic patients with renal failure would require more insulin to manage their blood glucose levels
C. Too much insulin in the blood would result in low blood sugar
D. Amylin and insulin both act to lower blood sugar
E. Glucagon acts to raise blood sugar

A

(B) - They would require LESS b/c as the patient’s kidneys worsen, they lose the ability to excrete insulin and therefore more insulin sticks around and less exogenous insulin is required

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3
Q

What is the difference between basal insulin and bolus insulin?

A

Basal insulin is the normal amount of insulin secreted by the pancreas all day long while NOT eating (12-24 Units/day)

Bolus insulin is the insulin released from the pancreas in response to a meal

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4
Q

All of the following statements regarding insulin are true, except?

A. Increases uptake of glucose by tissues
B. Decreases glycogen breakdown by the liver
C. Decreases synthesis of fatty acids
D. Promotes incorporation of AA’s into proteins
E. Increases liver glycogen levels

A

(C) INCREASES synthesis of fatty acids.

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5
Q

Which of the following statements is true?

A. Normal glucose concentration is between 40 - 160 mg/dL
B. Glucose can diffuse into the brain without insulin
C. When plasma glucose levels exceed 180 mg/dL, glucose spills into urine
D. DPP-IV enzyme reduces insulin secretion
E. All of the above

A

(E) All of the above

C - plasma glucose > 180 mg/dL exceeds the renal tubular reabsorption rate

D - DPP-IV enzyme breaks down active GLP-1 hormone (GLP-1 enhances insulin secretion so if you breakdown GLP-1 it won’t enhance insulin secretion anymore and will reduce it)

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6
Q

Which of the following will occur during insulin deficiency?

A. Muscle and adipose tissue will convert AA’s and FA’s to carbohydrates
B. Tissues will metabolize stored fats
C. Free FA’s will be oxidized to ketone bodies
D. Only A & C
E. All of the above

A

(E) All of the above

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7
Q

All of the following statements regarding Amylin hormone and GLP-1 hormone are correct, except?

A. GLP-1 is secreted by the small intestine in response to food intake
B. Amylin does not alter insulin secretion
C. GLP-1 does not alter insulin secretion
D. Amylin is secreted by the pancreas
E. C & D

A

(C) GLP-1 DOES alter insulin secretion. GLP-1 enhances glucose dependent insulin secretion

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8
Q

Amylin and GLP-1 hormones have all the same actions, except?

A. Suppresses inappropriate glucagon secretion
B. Reduces food intake
C. Delays gastric emptying
D. Enhances glucose dependent insulin secretion
E. None of the above

A

(D) GLP-1 enhances glucose dependent insulin secretion, but amylin DOES NOT affect insulin secretion (remember Amylin acts more centrally at the brain than GLP-1)

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9
Q

How are SGLT2 inhibitors used to treat hyperglycemia?

A

SGLT2 inhibitors help excrete glucose from the body by decreasing the reabsorption of glucose from the kidneys.

Glucose is normally reabsorbed in the kidneys. However, if the concentration is >180 mg/dL, it exceeds renal tubular reabsorption rate and it spills into urine

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10
Q

Which of the following statements is true?

A. Low levels of FFA’s inhibit the uptake of glucose by muscle
B. Amylin is co-secreted with insulin from the pancreas
C. Transient hyperglycemia is responsible for causing the major symptoms of diabetes
D. Type 1 diabetes is preventable whereas Type 2 diabetes is not
E. None of the above

A

(B) is true: Amylin is co-secreted with insulin from the pancreas

A - HIGH levels of FFA’s inhibit the uptake of glucose by muscle

C - PROLONGED hyperglycemia is responsible for the major symptoms of diabetes (i.e. retinopathy, DKA, coma, death)

D - Type 1 DM is an autoimmune disease that is NOT considered preventable. It is caused by an environmental trigger such as virus, allergen, or other

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11
Q

Inhibiting DPP-IV enzyme would have which of the following effect?

A. Decrease insulin secretion
B. Increase rate of gastric emptying 
C. Make you hungry
D. Suppress glucagon secretion
E. None of the above
A

(D) Inhibiting DPP-IV enzyme suppresses inappropriate glucagon secretion. DPP-IV enzyme normally inactivates GLP-1 so if this enzyme is inhibited, more GLP-1 effects will be seen

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12
Q

Name the classic 3 P’s symptoms of hyperglycemia?

A

Polyuria
Polydipsia - excessive thirst
Polyphagia - excessive hunger

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13
Q

Which of the following are S/S of hyperglycemia?

A. Recurrent respiratory infections
B. Blurred vision
C. Weight loss
D. B & C only
E. All of the above
A

(E) all of the above are S/S of hyperglycemia

The following are also S/S of hyperglycemia:
Classic 3 P’s, ketoacidosis, HHNK (HHS), fatigue, vaginal infection, other infections

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14
Q

True or False - destruction of pancreatic beta-cell function causes hyperglycemia b/c of an absolute deficiency in GLP-1 and incretin?

A

False - b/c of an absolute deficiency in INSULIN and AMYLIN

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15
Q

Type 2 DM can result from:

A. defect in the pancreas
B. hepatic insulin resistance
C. peripheral tissue insulin resistance
D. A & C only
E. All of the above
A

(E) All of the above

Type 2 DM results from: pancreatic defect, insulin resistance in both liver and peripheral tissues, and/or persistent hepatic glucose production

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16
Q

Which of the following statements is false?

A. Gestational diabetes occurs in 5% of all pregnancies
B. Cushing's disease can cause DM
C. Ciprofloxacin can cause DM
D. Niacin can cause DM
E. Lisinopril can cause DM
A

(E) - Lisinopril is not a BP drug that can increase blood sugar. A BP drug that CAN cause a transient increase in blood sugar is thiazide diuretics

C - Ciprofloxacin is a Fluoroquinolone drug which can induce DM

17
Q

DM is secondary to which of the following conditions?

A. Chronic pancreatitis
B. Pheochromocytoma
C. Pancreatic cancer
D. A & B only
E. All of the above
A

(E) all of the above

In addition, Cushing’s disease (excess cortisol in body) can also cause DM

Pheochromocytoma is adrenal gland cancer characterized by excessive production of NE and Epi

18
Q

DM can be induced by which of the following drugs?

A. Predisone
B. Atypical antipsychotics
C. Cocaine
D. A & B only
E. All of the above
A

(E) all of the above

C - cocaine is a sympathomimetic drug which blocks NE transporter (NET) preventing NE from being cleared from the synapse and extending its signal. Other sympathomimetic drugs can also induce DM (Phenylephrine, Methylphenidate (ritalin)

19
Q

Which of the following drugs can cause an increase in blood glucose?

A. Niacin
B. Pentamidine
C. Metoprolol
D. Fluoroquinolones
E. All of the above
A

(E) All of the above can cause an increase in blood glucose

D - ex Levofloxacin

20
Q

All of the following can contribute to metabolic syndrome, except?

A. HTN
B. Hypercholesterolemia
C. Obesity
D. Atherosclerosis
E. All of the above
A

(E) all of the above

21
Q

Determine if the following patient presenting to your Diabetes clinic would be diagnosed with DM at this time?

CG presents with fatigue and unexplained weight loss. He complains of recent blurred vision and getting up in the middle of the night to urinate. The patient just ate lunch an hour ago so you decide to perform a random glucose concentration test. The random glucose concentration results are 300 mg/dL.

Is there sufficient symptoms to warrant a DM diagnosis?

A

NO!! Although all of these are presenting symptoms of diabetes (S/S of diabetes plus random glucose concentration >200 mg/dL), TWO POSITIVE TESTS ON SUBSEQUENT DAYS are required. You would need to ask CG to come back in a day or two and repeat the same test and evaluate his symptoms.

22
Q

State the criteria for diagnosing a patient with DM using:

  1. Fasting Plasma Glucose (FPG) test
  2. Oral Glucose Tolerance Test (OGTT)
  3. HA1C test
A
  1. FPG
    >= 126 mg/dL
    and no caloric intake for at least 8 hours
  2. OGTT
    2 hr post-load glucose concentration >= 200 mg/dL
  3. HA1C
    >= 6.5%
23
Q

What is the most common DM diagnostic test given to pregnant women?

A

OGTT

24
Q

Patients are considered to have prediabetes (increased risk for DM) if they have which of the following?

A. FPG of 100-125 mg/dL
B. OGTT with 2 hour post-load glucose concentration >200mg/dL
C. HA1C 5.7% - 6.4%
D. A & C only
E. All of the above
A

(D) A & C only

B - OGTT with 2 hour post-load glucose concentration for a patient with prediabetes would have a range of 140-199mg/dL. A patient with >200mg/dL on one day is part of the criteria for diagnoses of DM

25
Q

Which of the following statements is false?

A. Patients with prediabetes can alter diet and exercise to prevent development of type 2 DM
B. Hypoglycemia is an acute complication that occurs with all treatments for DM
C. Patients taking an oral hypoglycemic agent may experience shakiness
D. DKA can be a presenting symptom for an undiagnosed type 1 DM patient
E. None of the above

A

(B) Hypoglycemia IS an acute complication of diabetes, but it only occurs in patients taking insulin or CERTAIN oral hypoglycemic agents (ex. Sulfonylureas (Glimepiride, Glipizide), Meglitinides (Repaglinide, Nateglinide), Incretin Analogues (Exenatide, Liraglutide)

26
Q

All of the following are symptoms of hypoglycemia, except?

A. Confusion
B. Hunger
C. Dizziness
D. Bradycardia
E. Sweating
A

(D) TACHYCARDIA is a symptom of hypoglycemia, NOT bradycardia

27
Q

True or False - DKA and hyperglycemic hyperosmolar non-ketotic syndrome (HHNK) are BOTH considered to be true medical emergencies?

A

True

28
Q

All of the following are chronic macrovascular complications of diabetes, except?

A. Coronary heart disease
B. Stroke
C. Intermittent claudication
D. Peripheral vascular disease
E. Retinopathy
A

(E) Retinopathy is a MICROVASCULAR complication of diabetes

29
Q

Which of the following statements is true?

A. MI is the most common cause of death in a diabetic
B. Diabetic patients with peripheral neuropathy experience chronic numbness in their feet
C. Diabetic foot ulcers can lead to amputation
D. Peristalsis is damaged in diabetic gastroparesis
E. All of the above

A

(E) All of the above are true

30
Q

All of the following are chronic microvascular complications of diabetes, except?

A. Sexual dysfunction
B. Retinopathy leading to blindness
C. ESRD
D. B & C only
E. All of the above
A

(E) All of the above

31
Q

What was the primary outcome measure of the DCCT study?

A

retinopathy

32
Q

Which of the following regarding retinopathy is false?

A. Develops in 75% of type 1 DM patients after 15 years duration
B. Was the primary outcome of the DCCT trial
C. Cannot really be treated, prevention is the best solution
D. Patients should get an eye exam once a year
E. None of the above

A

(E) None of the above are false

33
Q

How long must a patient fast before getting a fasting plasma glucose test?

A

8 hours

34
Q

Which of the following statements is false?

A. Honeymoon phase is a type 1 phenomenon
B. Somogyi effect is characterized by high morning blood glucose
C. Somogyi effect is low blood sugar at 3am with a morning high due to response of secretion of counter-regulatory hormones
D. Dawn phenomenon is due to differences in insulin resistance from the circadian rhythm
E. Insulin resistance is lower at 3am compared to breakfast time

A

(E) - insulin resistance changes with circadian rhythm. When you’re sleeping, you have GREATER insulin resistance which means your body can’t get glucose into the cells and tissues resulting in high blood sugar. The high blood sugar at 3AM is NOT due to a hypoglycemic response like in Somogyi effect, but rather a greater insulin resistance.

A - Honeymoon phase lasts 1-2 weeks. This is characterized by starting exogenous insulin, your pancreas realizes it doesn’t have to work as hard so it relaxes and releases its remaining insulin. The dose of exogenous insulin will be lower during this time period, but should never be completely stopped