What is diabetes? - introduction Flashcards
Define diabetes
Insufficient insulin to maintain glucose homeostasis
A group of metabolic diseases characterised by hyperglycaemia resulting from defects in insulin secretion, insulin action or both
Define type 1 diabetes
Absolute insulin deficiency - beta cell failure
Define type 2 diabetes
Inadequate insulin production/secretion and/or insulin resistance
What is the HbA1c of someone with diabetes?
>/= 48m/m
What is the fasting glucose of someone with diabetes?
>/= 7mmol/L
What is the 2hr glucose in OGTT in someone with diabetes?
>/= 11.1mmol/L
What is the random glucose of someone with diabetes?
>/= 11.1 mmol/L
What is the normal range for HbA1c?
= 41 m/m
What is the normal range for fasting glucose?
= 6mmol/L
What is the normal range for 2hr glucose in OGTT?
= 7.7 mmol/L
What is the prediabetic range for HbA1c?
42-47 mmol/L
What is the prediabetic fasting glucose range?
6.1-6.9 mmol/L
What is the prediabetic range for 2hr glucose in OGTT?
7.8 - 11 mmol/L
What are the roles of insulin?
- Converts glucose –> glycogen in the liver
- Fatty acids –> triglycerides
- Amino acids –> protein
What is th target tissue for glucagon?
Liver
What are the roles of glucagon?
- Glycogen –> glucose
- Triglycerides –> fatty acids
What are incretins?
peptides that enhance insulin secretion
Where are incretins released from?
Why does this matter?
GI tract
This means that after someone ingests glycose, the total amount of insulin secreted is higher than if the same amount of glucose had been administered IV
What are the three peptides (incretins) that enhance insulin secretion?
- Cholecystokinin (CCK)
- Glucagon-like intestinal peptide 1 (GLP-1)
- Gastric inhibitory peptide (GIP)
How to incretins work?
Act in a feed forward manner to prime the beta cells to produce insulin
What are the three things that glucagon stimulates?
- Glycogenolysis
- Gluconeogenesis
- Ketogenesis
Define glycogenolysis
Breakdown of glycogen to glucose
Define gluconeogensis
Formation of glucose from non-carbohydrate substrates e.g. pyruvate, fats, proteins
Define ketogenesis
Production of ketone bodies from the breakdown of fatty acids and Ketogenic amino acids
What type of disorder is type 1 diabetes?
Autoimmune
What happens during the autoimmune response in type 1 diabetes?
- Innate immune cells enter the pancreatic islets (priming)
- Antigens trigger T cells in the pancreatic lymph node
- T cells arrive from lymph nodes - insulitis ensues
- No intervention - disease onset. Intervention - remission