Lecture 23 - Nutritional Aspects of Diabetes Mellitus Flashcards
Jan 30, 2019
What is the mechanism for secondary diabetes?
Hyperglycemic hormones (such as cortisol) contribute to insulin resistance
What percentage of those afflicted with DM have Type 2 DM?
90%
At what percentage of normal insulin output (or beta cell “capacity”) do symptoms of diabetes mellitus appear?
Less than 20% beta cell capacity
What is thought to cause the gradual beta cell destruction seen in Type I diabetes?
immunological event/trigger such as a viral illness
What are the three classic signs of Type 2 DM?
polydipsia, polyuria, and polyphagia
Why is weight loss seen more in Type I diabetics as opposed to Type 2 diabetics?
Increased lipolysis and muscle proteolysis due to decreased insulin
The muscle breakdown seen in Type 1 diabetes leads to what physiologic consequence with respect to homeostasis?
Negative nitrogen balance
What causes the polyuria in diabetes?
Hyperglycemia –> glycosuria –> osmotic diuresis –> polyuria
What are the three main risk factors for Type 2 DM?
1) age
2) sedentary lifestyle
3) abdominal obesity
What is the threshold for diagnosing insulin resistance?
> 200 IU of insulin/day
What are the three effects of insulin resistance on adipocytes?
1) increased leptin
2) decreased adiponectin
3) increased secretion of pro-inflammatory cytokines
What are the two hormones needed for insulin sensitivity?
1) adiponectin
2) leptin
What are other effects of insulin resistance on serum biomarkers?
Increased free fatty acids. Decreased glucagon-like peptide (GLP-1). Increased IL-6 and TNF-alpha secretion
Which GI hormones produce increased insulin secretion?
Incretins
When Type II DM is diagnosed insulin levels are [decreasing/peaking/increasing]?
Peaking
What causes insulin levels to fall in Type 2 DM?
beta cell fatigue
How does insulin deficiency affect glucose release uptake and release in the body?
1) Liver: increased glucose release
2) Muscle/fat: decreased uptake of glucose
Where are GLUT-4 receptors predominantly found?
Heart, muscle, and fat
What are the four characteristics of atherogenic profile?
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
What are the two serum markers for insulin resistance?
1) increase in serum free fatty acids
2) increase in TAG:HDL ratio
What are the three ways to diagnose DM?
1) fasting plasma glucose above 126 mg/dl
2) random blood glucose over 200 mg/dl with symptoms
3) HbA1c above 6.5%
What is considered the gold standard in diagnosing DM?
oral glucose tolerance test
How do you perform a OGTT?
1) fasting state
2) administer 75 gm of glucose (weight-adjusted)
3) serial serum glucose measurements every 30 minutes for two hours
What is a normal fasting blood glucose? 2 hour post-glucose test?
fasting: less than 100
2 hour post-prandial: less than 140
What are the diagnostic criteria for prediabetes?
1) fasting blood glucose 100 to 126
2) OGTT between 140-200
3) HbA1c between 5.7 and 6.4%
How does sulfonylurea work?
Stimulates endogenous insulin secretion
How does metformin work?
Improves insulin sensitivity
What is the definition of impaired fasting glucose?
fasting blood glucose between 100 and 126
What is the definition of impaired glucose tolerance?
OGTT between 140 and 200
