Relationship of Nutrition to Blood Glucose Control

1
Relationship of Nutrition to Blood Glucose
Control

• Arline McDonald, Ph.D.
• December 4, 2001

2
Blood Glucose Responses to Diet
3
Blood Glucose Abnormalities
4
Conditions Requiring Dietary Management for Blood
Glucose Control

• Diabetes mellitus
• Type I
• Type II
• Hypertension
• Hyperlipidemia
• Liver disease
• Renal disease
• Cancer
• Obesity

• Trauma
• Sepsis
• Treatment with
• Hydrochlorothiazide
• Chlorpropamide
• Propranolol
• Prednisone
• Sulfonylureas

5
Diabetes Prevention Program3-year Incidence of
Type II Diabetes
6
Relationship of Source of Energy to Incidence of
Type I Diabetes1



NS


140 countries ecologic data
plt0.05 plt0.01 plt0.001 plt0.0001
AJCN 2000711525-9.
7
The Postprandial Plasma Glucose Response (Glucose
Tolerance)
Area Under Curve
8
Plasma Glucose Response to Different Carbohydrate
Sources
9
Fate of Dietary Carbohydrate
10
Proposed Etiology of Diet-Induced Insulin
Resistance
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Receptor Modification in Insulin Resistance

• ? Receptor number
• ? Receptor activity
• Post-receptor defect
• Enzyme activation
• Glucose transporters

• Downregulation ? dietary glycemic index ?
  dietary fat ? body fat
• Composition of dietary fat
• Stress Response ? counterregulatory hormones

12
Metabolic Consequences of Insulin Resistance
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Metabolic Consequences of Hyperglycemia
14
Glycemic Index

• Describes the incremental increase in blood
  glucose from fasting levels over a defined time
  interval following ingestion of CHO (AUC)
  relative to a standard
• Property of food sources of digestible CHO
• Function of efficiency of digestion and rate of
  absorption

15
Glycemic Indexes of Foods
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Primary Determinants of Glycemic Index

• Amount of Carbohydrate
• Portion size
• Energy density
• Availability of Carbohydrate
• Solubility
• Digestibility
• Extent of processing
• Type of processing

17

High Glycemic Index Carbohydrates

• Simple Sugars
• highly soluble
• liquid form
• low fiber content
• high energy content
• high Na content

• Starches
• highly digestible
• amylopectin gt amylose
• amylose gt resistant starch
• refined starch gt simple sugars with fiber

18
Effects of Soluble (Viscous) Dietary Fiber on
Blood Glucose Control

• Direct Effects
• decreases rate of digestion
• impedes access to digestive enzymes
• decreases rate of absorption
• slows rate of diffusion across unstirred layer
• Indirect Effects
• decreases absorption of dietary fat
• inds bile acids
• regulates appetite
• Ileal brake-second-meal effect

19
Simple Sugar (SS) with and without Soluble
Fiber (SDF)
20
Starch With and Without Soluble Dietary Fiber
(SDF)
21
Noncarbohydrate Influences On Glycemic Index

• Dietary fat
• Slows gastric emptying (short-term)
• Decreases insulin clearance (long-term)
• Dietary sodium
• Facilitates glucose transport via Na-linked
  transporter
• Physical Activity
• Increases insulin sensitivity
• improved skeletal muscle glucose transport
  kinetics

22
Effects of Dietary Fat on Blood Glucose Control

• Total Amount
• Determines gastric emptying
• Inhibits insulin clearance by increased FFA in
  portal circulation
• Contributes to body fat stores

• Fatty Acid Composition
• Saturated fat
• ? membrane fluidity receptor function
• ? number of glucose transporters
• Monounsaturated fat
• promotes insulin secretion
• ?-6?3 PUFA ratio
• membrane fluidity

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Relationship of Fasting Insulin to Dietary
Polyunsaturated Fat-C20-22
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Relationship of Fasting Insulin to Ratio of C204
(arachidonic) to C203 (eicosapentanoic)
25
Glucose Response to Monounsaturated Fatty Acids
CHO/Fat 6020 for starch and 4040 for MUFA
Diabetes Care 1993 141115.
26
Insulin Response to Monounsaturated Fatty Acids
CHO/Fat 6020 for starch and 4040 for MUFA
Diabetes Care 1993 141115.
27
Effects of Energy Intake onBlood Glucose Control

• Relates to amount of carbohydrate and fat
• Provides excess or deficiency of micronutrients
  that influence effectiveness of insulin
• Zinc, potassium, magnesium, chromium, vitamin E
• Contributes to body fat
• If not balanced with expenditure
• Preferentially deposited in abdomen (age, gender)

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Relationship of Intake to Storage Capacity for
Dietary CHO and Fat
29
Obesity and Insulin Resistance

• Abdominal vs Gluteal
• high portal free fatty acid concentration
  inhibitshepatic insulin clearance
• higher insulin level required to facilitate
  glucose uptake

30
Effects of Physical Activity on Blood Glucose
Control

• prevents weight gain
• increases muscle mass/fat mass ratio
• Promotes mobilization of free fatty acids from
  abdominal adipocytes
• reduces km of skeletal muscle glucose
  transporters
• enhances glycogenesis for up to 48 hours
  post-activity

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Effects of Distribution of Energy Intake on Blood
Glucose Control
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Effects of Dietary Protein on Blood Glucose
Control

• Minimal effect on postprandial blood glucose
  response

Glucose
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Effects of Micronutrients on Blood Glucose
Control

• Insulin Response
• Chromium
• Zinc
• Vitamin E

• Carbohydrate Metabolism
• Potassium
• Magnesium

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Summary of Dietary Effects on Postprandial
Glucose Response
35
Summary

• Short-term insulin response is dependent on
  amount and digestibility of CHO, food matrix, and
  other components of the meal
• Insulin resistance can develop as an adaptive
  response to chronic intake of high glycemic loads
• Dietary modifications can facilitate insulin
  effectiveness

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Predicting the Postprandial Plasma Glucose
Response
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What has been ingested?
High protein drink
Plasma Glucose mg/dL
Minutes from Ingestion
38
What has been ingested?
High energyrefined sugar starch
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Predicting the Postprandial Plasma Glucose
Response
Plasma Glucose mg/dL
High Soluble Fiber Starch
Minutes from Ingestion