FINAL REVIEW Flashcards
What disease is associated with the body producing less insulin and the insulin produced is not effectively binding to the receptor?
T2DM
What ratio causes insulin resistance?
Low insulin: glucagon ratio
What are the modifiable risk factors for T2DM
impaired fasting glucose (hyperglycemia and insulin resistance
What are the dietary goals for prevention of T2DM
reduce insulin resistance, improve insulin sensitivity
body weight control (adiposity)
reduce risk of CVD
What three factors affect the relationship between CHO and T2DM?
Sugars
High GI/GL Diet
Fiber
What are two mechanisms of sugar increasing the risk of T2DM
- insulin receptor inactivation
2. excess calories - adiposity
Explain the sugar mechanism of insulin receptor inactivation and T2DM
Sugar overload increases lipogenesis (TAG), which decreases tyrosine phosphorlation of insulin receptors. This inhibits the PIP cascade, where GLUT 4 is not translocated and is not engaged in glucose clearance
Explain the sugar mechanism of excess calories and T2DM
The intake of sugar provides a low satiating food, which leads you to eat more calories which leads to weight gain. Which leads to insulin resistance and dyslipidemia.
What are two mechanisms of High GI/GL diet causing hyperglycemia leading to T2DM
- Beta cell exhaustion and 2. adiposity and insulin resistance
Explain the High GI/GL mechanism of beta cell exhaustion of and increasing hyperglycemia in T2DM
A high GI/GL diet leads to increased postprandial glucose, and increased insulin demand, which leads to beta cell exhaustion and hyperglcemia
Explain the High GI/GL mechanism of adiposity and insulin resistance and increasing hyperglycemia in T2DM
A high GI/GL diet increases plasma FFA which increases ectopic fat deposits, leading to increased insulin resistance and hyperglycemia.
What are two mechanisms of a fiber diet reducing the risk of T2DM
- Satiety and body weight and 2. fermentation
Explain the fiber mechanism of adiposity and satiety and body weight and reducing the risk of T2DM
Fiber intake increases post meal satiety, which possibly decreases caloric intake of subsequent meals, which leads to decreased body weight, improved insulin sensitivity and decrease risk of T2DM
Explain the fiber mechanism of fermentation and reducing risk of T2DM
Fiber intake increased fiber fermentation in the gut which leads to the production of SCFA. This acts as an allosteric inhibitor of gluconeogenesis which decreases hepatic glucose output. Then this acts as a ligand to stimulate PPAR, which up-regulates GLUT 4 expression and increases glucose uptake
What are the overall recommendations for beneficial effects of CHO and T2DM
- Increase dietary fiber, cereal fiber, fruit fiber (MetS)
- Increase whole grain intake: at least 3 serv/d
- Increase legumes and bean consumption
- Fiber, low GI/GL, other nutrients/non-nutrients - Focus on a low GI/GL diet
What are the overall recommendations for detrimental effects of CHO and T2DM
- Consumption of High GI/GL foods recommendation is toDecrease consumption of high GI/GL foods
- Decrease intake of Potatoes, white rice, noodles, other high GI/GL foods
- Decrease consumption of SSB and added sugars
What three factors affect the relationship between FA and for T2DM?
Palmitic acid/Stearic acid Vaccenic acid Oleic acid N-3 ALA N-6 LA Red Meat, Processed Meat Egg Dairy Nuts
What is a mechanisms of Palmimtic and stearic acid increasing the risk of T2DM
- Biomarker for palmitic and stearic acids do not correlate to SFA intake, instead act as CHO
Explain Palmitic and stearic acid intake increasing risk of T2DM
Mimics high GI CHO intake, high GI CHO intake increases lipogenesis, producing palmitic and stearic acids. This increases TAG which increases insulin resistance
What is the association between Vaccenic acid and T2DM
Vaccenic acid is Inversely related to T2DM, inconsistent findings
What is the association between Oleic acid and T2DM
Insignificantly protective, source matters
Oleic is also synthesized from stearic acid, which is detrimental for T2Dm risk
What are two mechanisms of N-3 ALA consumption reducing the risk for T2DM
- Increase membrane fluidity 2. rapid oxidation
Explain the n-3 ALA mechanism of increased membrane fluidity on reducing the risk of T2DM
ALA increases membrane fluidity which improves the insulin binding to receptor tyrosine kinase which decreases insulin resistance.
Explain the n-3 ALA mechanism of rapid oxidation on reducing the risk ofT2DM
ALA is rapidly oxidized for energy and used less for storage, which lowered adiposity, therefore decreased insulin resistance
What is the potential mechanism of n-6 LA on reducing risk of T2DM
n-6 may influence membrane fluidity, which improves the insulin binding to receptor tyrosine kinase which decreases insulin resistance.
What are the two mechanisms of Red meat/processed meat on increasing risk of T2DM
- synergistic effect of cholesterol and SFA
2. Non lipid factors of heme iron
Explain the mechanism of red meat/ processed meat on synergistic effect of cholesterol + SFA on in increasing risk of T2DM
Increased meat consumption increased inflammation and endothelial dysfunction which increases insulin resistance
Explain the mechanism of red meat/ processed meat on lipid factors of heme iron on increasing risk of T2DM
Increased meat consumption leads to increase in advanced glycation products, which then leads to AGE the increase of oxidative stress and inflammation which increases insulin resistance.
What is the potential mechanism for 3 or more eggs per week in increasing T2DM
Cholesterol has no effects glycemic control and IR
possible background diet i.e. bacon and eggs potential Choline derivative trimethylamine oxide
What are two mechanisms of 400 g/d of dairy on lowering risk of T2DM
- Fermentation of dairy reduces inflammation
2. SCFA and MCFA
Explain the total dairy mechanism of fermentation of dairy which lowers risk of T2DM
fermentation of dairy reduces inflammation by modifying colonic bacteria profile (prebiotics), which may reduce inflammation and therefor lowering IR
Explain the total dairy mechanism of SCFA and MCFA on reducing the risk for T2DM
Increases fat oxidation pathway uncertain, which reduces adiposity and lowers IR
What is the mechanism for Nuts insignificantly reducing risk for T2DM
- fiber, nutrients (Mg, and K), antioxidants may reduce inflammation, oxidative stress, endothelial dysfunction, IR, and insulin secretion
What are beneficial dietary lipid foods affecting T2DM
- fermented dairy products, 2. tree nuts, especially walnuts
What are detrimental dietary lipid foods affecting T2DM
- SFA (palmitic and stearic especially),
- Recommended to reduce egg intake to below 3-5 per week,
- Recommended to reduce red and processed meat intake
Which dietary lipid foods have neutral effect on T2DM
fatty fish or EPA, DHA
What are the two fiber mechanisms that lowers risk of CVD and blood lipids
- increased viscosity
2. fermentability
Which type of fiber specifically lowers blood lipids
soluble fiber
Explain the fiber mechanism of increased viscosity on lowering blood lipids
Soluble fiber intake has gel like material that interferes with micelle formation. Which creates an increase in bile acid and free cholesterol that is then excreted into feces. There is an increased conversion of cholesterol in the liver to replenish the bile. There is then a decreased intracellular cholesterol pool which influences the up regulation of LDL receptors and increased clearance of plasma LDL-c
Explain the fiber mechanism of fermentability fermentability on lowering blood lipids
Soluble fiber intake creates fermentation by colocnic bacteria that produces SCFA. The propionate from SCFA is taken up by the liver where it allosterically inhibits HMG CoA reductase. This causes the intracellular cholesterol pool to decrease, causing up regulation of LDL receptors and increased clearance of plasma LDL-c
What are the factors that influences Plasma TAG
- CHO
2. SUGAR
What is the sugar mechanism that increases plasma triglycerides
- Fructose increasing de novo lipogenesis
2. insulin resistance
Explain the sugar mechanism of fructose increasing lipogenesis and its increase on TAG
High fructose consumption is independent of insulin cell uptake, so it bypasses PFK-1 regulation where is is phosphorlyated to fructose 1-P and converted to glycerol 3-P. Glycerol 3-P is the backbone for TAG formation. Then there is an up regulation of CoA carboxylase via stimulating SREBP, and there fore there is an overall TAG synthesis and VLDL synthesis.
What are recommendations for sugar and TAG
- quantity matters
- <55-60% CHO - Quality matters (low Gi /GL foods)
- Limited added sugars to 10% or less
- avoid HFCS, high GI foods/diet, SSB
-Increase whole grains
Factors to consider: Apo E, Gender, abdominal obesity
What two mechanisms explain how UFAs lowers Total cholesterol and LDL-C
- UFAs are preferred substrate for ACAT
2. PUFAs Molecular Mechanism