Nutrition Modules 5 & 6: Diabetes Flashcards Preview

SMP - MNE Exam 1 > Nutrition Modules 5 & 6: Diabetes > Flashcards

Flashcards in Nutrition Modules 5 & 6: Diabetes Deck (100):
1

Where is amylase found? What is its function?

Saliva and small intestine (pancreas secretion)
Breaks down 1,4-glycosidic bonds to give glucose and maltose

2

What are the 3 brush-border enzymes?

1. Maltase
2. Sucrase
3. Lactase

3

What are the 3 monosaccharides absorbed by the small intestine? Through which transport mechanism?

1. Glucose: active transport
2. Galactose: active transport
3. Fructose: facilitated diffusion

4

Where are monosaccharides transported once absorbed by the small intestine? How? Why?

The liver via the portal vein to
3 pathways:
1. Glycolysis
2. PPP
3. Glycogen synthesis

5

What quantity of carbs can be absorbed by the small intestine in an hour?

1g/kg

6

Which cells in the small intestine absorb monosaccharides?

Enterocytes

7

What are dietary fibers?

Plant polysaccharides that cannot be absorbed by small intestine

8

What are the 2 types of glucose protein carriers for entry into cells?

1. Energy dependent Na+/Glc co-transporters
3. GLUTs

9

Which GLUT is most widely expressed?

GLUT 1

10

GLUT 1
1. Location?
2. Function?
3. Characteristics?

1. Erythrocytes and barrier tissues
2. Basal glucose transport: absorption
3. High affinity

11

GLUT 2
1. Location?
2. Function?
3. Characteristics?

1. Liver, pancreatic B-cells, small intestine, kidney
2. Transports all 3 monosaccharides and serves as the "glucose sensor"
3. Low affinity, high capacity

12

GLUT 3
1. Location?
2. Function?
3. Characteristics?

1. Testes and brain
2. Primary Glc transporter in neurons
3. High affinity for Glc and Gal

13

GLUT 4
1. Location?
2. Function?
3. Characteristics?

1. Adipose tissue, skeletal muscle, heart
2. Glucose uptake
3. High affinity when insulin present

14

GLUT 5
1. Location?
2. Function?
3. Characteristics?

1. Small intestine
2. Fructose transporter
3. High affinity for fructose

15

What are the 4 monosaccharide transporters of the small intestine?

1. Energy dependent Na+/Glc co-transporters
2. GLUT 1
3. GLUT 2
4. GLUT 5

16

When is the PPP stimulated?

When glucose is high

17

In which 4 organs/cells does the PPP happen?

1. RBCs
2. Liver
3. Adipose tissue
4. Adrenal glands

18

What are the 3 types of precursors for gluconeogenesis?

1. Glycerol
2. Lactate
3. Some AAs

19

In which 2 organs does gluconeogenesis occur?

1. Liver
2. Kidneys

20

What is the Cori cycle?

Gluconeogenesis in liver using the lactate produced in muscle because of anaerobic glycolysis

21

What % of glucose is recycled through the Cori cycle?

20%

22

Describe glycogen synthesis.

1. G6P converted to G1P
2. G1P activated by UTP and added to existing glycogen by glycogen synthase

23

How is glycogen synthase activated?

High G6P

24

How does glucagon stimulate glycogen breakdown? In which tissues?

1. Activates glycogen phosphorylase in muscles, liver, and kidney by phosphorylating it
2. Inhibits glycogen synthase by phosphorylating it

25

What are the 3 short-term complications of DM?

1. Ketoacidosis
2. Hyperosmolarity
3. Lactacidosis

26

What are the 3 long-term complications of DM?

1. Microvascular: diabetic retinopathy, nephropathy
2. Macrovascular: peripheral, cerebrovascular, CVD
3. Neuropathological

27

How is DM diagnosed?

1 of the following:
1. Random plasma glucose > 200 mg/dL + DM symptoms
2. FPG > 126 mg/dL*
3. PG > 200 mg/dL 2 hrs after 75g glucose load*
4. Hb A1C > 6.5%

* need to be repeated the next day

28

What % of DM cases are T1?

5-10%

29

What % of DM cases are T2?

90-95%

30

T1D peak onset?

11-12 yo

31

T2D peak onset?

50-60 yo

32

State of beta cells in T2D patients at diagnosis?

Intact

33

What 5 metabolic processes does insulin stimulate?

1. Glucose uptake
2. FA/TAG synthesis
3. Glycogen synthesis
4. AA uptake/protein synthesis
5. Glycolysis

34

What 4 metabolic processes does insulin inhibit?

1. Glycogen breakdown
2. Lipolysis
3. Proteolysis
4. Gluconeogenesis

35

Describe the glucose uptake mechanism by GLUT 4 (3 steps)

1. Insulin/GLUT 4 dimerization
2. Autophosphorylation of receptor tyrosine kinase
3. Signaling cascase promoting glucose entry via GLUT 4 fusion with plasma membrane

36

Describe how chromium contributes to glucose uptake.

Chromium enhances the activity of tyrosine kinase by binding chromodulin, which then binds to the receptor => it enhances glucose uptake

37

What is the result of chromium deficiency?

Insulin resistance

38

Can increase chromium intake help T2D patients?

NOPE

39

What 4 metabolic processes does glucagon stimulate?

1. Glycogen breakdown
2. Gluconeogenesis
3. Ketogenesis
4. Lipolysis

40

What 2 metabolic processes does glucagon inhibit?

1. Glycolysis
2. Glycogen synthesis

41

What kind of receptors does glucagon bind?

G-coupled

42

What 3 metabolic processes are stimulated by epinephrine?

1. Glycogenolysis
2. Gluconeogenesis
3. Lipolysis

43

How long after eating does the fasting state occur?

3-4 hours after

44

What are the 3 ways in which cortisol increases blood glucose levels?

1. Activates PEPCK to promote gluconeogenesis
2. Proteolysis to maintain gluconeogenesis from protein
3. Stimulates lipolysis

45

How does insulin stimulate glycogen synthesis?

1. Activates glycogen synthase by dephosphoralating it
2. Inhibits glycogen phosphorylase by dephosphoralating it

46

Does glucagon affect muscles?

NOPE

47

What are the 9 populations at risk of T2D?

1. BMI >=25
2. First-degree relatives with DM (DIRECT FAMILY)
3. Birthed baby > 9 lbs
4. History of gestational diabetes
5. Minorities
6. Hypertension
7. Physically inactive
8. Low HDL or high TAG
9. Impaired glucose tolerance

48

How often should high risk patients be tested?

Every 3 years

49

When should ALL patients be tested?

After 45 yo

50

Describe the obesity cycle of insulin resistance leading to T2D.

Obesity => high FAs => gluconeogenesis => hyperglycemia => increased insulin secretion => further weight gain => insulin can't secrete enough insulin => T2D

51

How can gestational diabetes affect the fetus? 2 options

1. Macrosomia
2. Restricted fetal growth

52

What % of pregnancies are affected by gestational diabetes?

15-20%

53

What are the 4 risk factors for gestational diabetes?

1. Obesity
2. Family history of DM or GDM
3. Glycosuria
4. Previous pregnancies with large babies

54

What is gestational diabetes due to?

Placental hormones interfere with maternal responsiveness to insulin

55

When is gestational diabetes diagnosed?

After the 1st trimester (24-28 weeks) at the first prenatal visit

56

What are the 3 parts of treatment for GDM?

1. Diet: caloric targets (less than 45% carbs), and dietician counseling
2. Exercise
3. Insulin therapy if nutrition fails to maintain blood glucose OR if fetus is abnormally large (macrosomia)

57

How does exercise help diabetes patients? 2 parts

1. Increase muscle contractions = glucose uptake activation = insulin sensitivity increases = increase glucose uptake
2. Increase in catecholamines and glucagon increase gluconeogenesis and lipolysis (weight loss and better lipid profiles)

58

What kinds of questions should be avoided when assessing nutritional status of patients?

Leading questions (eg: what do you eat for breakfast, which assumes they eat breakfast) and questions about what was eaten the day before (focus on USUAL intake)

59

What is the downside of fat-free foods?

High in sugar

60

How should the 2h post-prandial glucose level be compared to the fasting glucose level?

Higher

61

What % weight loss is sufficient to control diabetes in T2D patients?

5-10% GRADUAL weight loss

62

What helps maintain glucose homeostatis?

Energy balance:
Eintake = Erequirement

63

What is the normal fasting BG?

70-99 mg/dL

64

What is the normal 2h postprandial BG?

Below 140 mg/dL

65

How do fats and proteins ingested with carbs affect absorption?

They increase insulin so delay absorption

66

How long after eating do glucose levels peak?

An hour after

67

What are the 3 main factors that influence the glycemic response?

1. Individual variation
2. Carb source
3. Meal size/composition

68

What 6 carbs will lower the glycemic response?

1. Whole grains
2. Carbs with a high amylose/amylopectin ratio
3. Less cooked carbs
4. Less processed carbs
5. Reduced ripeness
6. Viscous fibers: gum, pectin

69

What kinds of foods will increase the glycemic response?

Insoluble (incompletely fermented) fibers: cellulose (wheat, vegetable skin), hemicellulose (corn kernel skin, brown rice), lignin (broccoli stems, seeds, nuts)

70

What is the glycemic index of a food?

Compares its quality to a reference 50g of sugar or white bread

71

What are 3 limitations of glycemic index?

1. Does not account for food condition (eg: ripeness)
2. Ignores other foods ingested
3. Fibers could be influencing results

72

Are complex carbs absorbed at the same rate as simple carbs?

Yes

73

How should DM patients ingest carbs?

Small amounts throughout the day

74

What are 4 symptoms of hypoglycemia I did not know about?

1. Sweating
2. Blurry vision
3. Poor coordination
4. Seizures

75

What are 3 potential causes of hypoglycemia?

1. Inadequate food intake
2. Medications
3. Excessive exercise

76

What is ketoacidosis caused by in DM patients?

Hyperglycemia but no insulin to trigger glucose uptake so ketone bodies are produced (same mechanism as starvation)

77

What do Hb A1C levels represent? How?

Average blood glucose over 2-3 months because glucose binds to Hb in RBCs in proportion to ambiant glucose and HbA1C (glycated RBC) remains in blood for the lifespan of the RBC

78

What is the KEY strategy to achieve glycemic control?

Monitor carb intake

79

What are the 2 types of symptoms associated with hyperglycemia?

1. Hyperosmolar symptoms
2. Impaired glucose uptake symptoms

80

What are the 4 hyperosmolar symptoms of hyperglycemia?

1. Polydipsia: excessive thirst
2. Polyuria: excessive peeing
3. Norturia: awakening to peeing
4. Sudden unexplained weight loss

81

What are the 5 symptoms of hyperglycemia due to impaired glucose uptake?

1. Polyphagia
2. Poor wound healing
3. Chronic/recurrent skin infections
4. Confusion
5. Neurological symptoms

82

What did the Diabetes Control and Complications Trial (DCCT) prove? With what patients?

Intensive management of T1D prevents complications:
1. Test blood glucose 4x/day
2. Insulin pump or injection 4x/day
3. Adjust insulin
4. Diet + exercise plan
5. See docs/monthly

83

What are the 3 goals of DM individualized nutrition therapy?

1. Improve lipid profile
2. Achieve/maintain ideal body weight
3. Adapt to culture and lifestyle preferences

84

Foods rich in what 3 things should be avoided by DM patients?

1. Saturated FAs
2. Trans FAs
3. Cholesterol

85

What information is needed to calculate the daily carb requirement?

1. Weight
2. Height
3. Age
4. Physical activity

86

How many grams of carbs in 1 carb serving?

15 g

87

What are the 7 foods that have 0 carbs?

1. Meat
2. Poultry
3. Fish
4. Eggs
5. Nuts
6. Cheese
7. Salad greens (they have a little but not counted)

88

How does alcohol affect metabolism?

It inhibits gluconeogenesis by the liver

89

What are the 2 home glucose monitoring methods?

1. Finger stick
2. Urine ketones

90

How many calories should a DM patient burn each day exercising?

200-300 kcal

91

What is the target fasting BG for DM patients?

90-130 mg/dL

92

What is the target random BG for DM patients?

Below 180 mg/dL

93

What is the target HbA1C for DM patients?

Below 7%

94

What is the target HDL for DM patients?

> 50 mg/dL

95

What is the target LDL for DM patients?

Below 100 mg/dL

96

What is the target TAG for DM patients?

Below 150 mg/dL

97

What is the main measurable target for DM patients?

HbA1C

98

How often should HbA1C levels be tested?

2-4 times/year

99

What are the 5 glucose management tools?

1. Individualized meal plan
2. Self-monitoring blood glucose
3. Medical monitoring blood glucose
4. Medication as needed
5. Physical activity

100

What are the basal/eating/total a day secretions of insulin by units?

Basal: 1/hr
Eating: 4-6/hr
Total a day: 40 units