Lecture 23 - Nutritional Aspects of Diabetes Mellitus

Question 1

What is the mechanism for secondary diabetes?

Answer 1

Hyperglycemic hormones (such as cortisol) contribute to insulin resistance

Question 2

What percentage of those afflicted with DM have Type 2 DM?

Answer 2

90%

Question 3

At what percentage of normal insulin output (or beta cell “capacity”) do symptoms of diabetes mellitus appear?

Answer 3

Less than 20% beta cell capacity

Question 4

What is thought to cause the gradual beta cell destruction seen in Type I diabetes?

Answer 4

immunological event/trigger such as a viral illness

Question 5

What are the three classic signs of Type 2 DM?

Answer 5

polydipsia, polyuria, and polyphagia

Question 6

Why is weight loss seen more in Type I diabetics as opposed to Type 2 diabetics?

Answer 6

Increased lipolysis and muscle proteolysis due to decreased insulin

Question 7

The muscle breakdown seen in Type 1 diabetes leads to what physiologic consequence with respect to homeostasis?

Answer 7

Negative nitrogen balance

Question 8

What causes the polyuria in diabetes?

Answer 8

Hyperglycemia –> glycosuria –> osmotic diuresis –> polyuria

Question 9

What are the three main risk factors for Type 2 DM?

Answer 9

1) age
2) sedentary lifestyle
3) abdominal obesity

Question 10

What is the threshold for diagnosing insulin resistance?

Answer 10

> 200 IU of insulin/day

Question 11

What are the three effects of insulin resistance on adipocytes?

Answer 11

1) increased leptin
2) decreased adiponectin
3) increased secretion of pro-inflammatory cytokines

Question 12

What are the two hormones needed for insulin sensitivity?

Answer 12

1) adiponectin

2) leptin

Question 13

What are other effects of insulin resistance on serum biomarkers?

Answer 13

Increased free fatty acids. Decreased glucagon-like peptide (GLP-1). Increased IL-6 and TNF-alpha secretion

Question 14

Which GI hormones produce increased insulin secretion?

Answer 14

Incretins

Question 15

When Type II DM is diagnosed insulin levels are [decreasing/peaking/increasing]?

Answer 15

Peaking

Question 16

What causes insulin levels to fall in Type 2 DM?

Answer 16

beta cell fatigue

Question 17

How does insulin deficiency affect glucose release uptake and release in the body?

Answer 17

1) Liver: increased glucose release

2) Muscle/fat: decreased uptake of glucose

Question 18

Where are GLUT-4 receptors predominantly found?

Answer 18

Heart, muscle, and fat

Question 19

What are the four characteristics of atherogenic profile?

Answer 19

1) increase in LDL-B (small, dense LDL)
2) decrease in HDL levels
3) increase in TAG, decrease in LPL activity
4) increase in circulating free FAs

Question 20

What are the two serum markers for insulin resistance?

Answer 20

1) increase in serum free fatty acids

2) increase in TAG:HDL ratio

Question 21

What are the three ways to diagnose DM?

Answer 21

1) fasting plasma glucose above 126 mg/dl
2) random blood glucose over 200 mg/dl with symptoms
3) HbA1c above 6.5%

Question 22

What is considered the gold standard in diagnosing DM?

Answer 22

oral glucose tolerance test

Question 23

How do you perform a OGTT?

Answer 23

1) fasting state
2) administer 75 gm of glucose (weight-adjusted)
3) serial serum glucose measurements every 30 minutes for two hours

Question 24

What is a normal fasting blood glucose? 2 hour post-glucose test?

Answer 24

fasting: less than 100

2 hour post-prandial: less than 140

Question 25

What are the diagnostic criteria for prediabetes?

Answer 25

1) fasting blood glucose 100 to 126
2) OGTT between 140-200
3) HbA1c between 5.7 and 6.4%

Question 26

How does sulfonylurea work?

Answer 26

Stimulates endogenous insulin secretion

Question 27

How does metformin work?

Answer 27

Improves insulin sensitivity

Question 28

What is the definition of impaired fasting glucose?

Answer 28

fasting blood glucose between 100 and 126

Question 29

What is the definition of impaired glucose tolerance?

Answer 29

OGTT between 140 and 200