week 10 Flashcards
What causes type 1 diabetes?
loss of insulin production. The pancreas produces little to no insulin
What causes type 2 diabetes?
insulin resistance; insuffcient secretion of insulin.
Pancreatic beta cells cannot release sufficent insulin to compensate.
What causes hyperglycemia ?
loss of insulin-stimulated glucose uptake.
Loss of insulin repression of gluconeogenesis and glycogen breakdown.
What causes dislipidaemia?
Loss of insulin repression of lipolysis.
How is type 1 diabetes managed?
insulin injections, diet and exercise control
How is type 2 diabetes managed?
oral medications or insulin injections, diet and exercise control.
What is gestational diabetes? When does it develop?
2nd trimester develops and dissapears after child is born. Cause not clear but thought to be due to various hormonal changes which can block the action of insulin.
In a fasting glucose test what figures are deemed as pre-diabetic and diabetic?
pre-diabetic ; 5.5 - 6.9 mmol/l
diabetic ; over 7 mmol/l
What figure indicates diabetes in a random glucose test?
over 11 mmol/l
What HbA1c values indicate type 2 diabetes?
Over 48 mmol/mol
at 42-47 there is a risk of developing type 2 diabetes
HbA1c formation
forms as a result of a slow and irreversible reaction between hemoglobin A (HbA) and glucose.
Values give a measure of average blood glucose levels of the previous 3-4 months.
Complications of diabetes
hpyerglycaemia, vascular damage.
Acute symptoms of diabetes
dehydration, nausea and vomiting, increased fatigue, polydipsia, polyuria, polyphagia, weight loss, infections, poor wound healing, blurry vision.
Why does polyuria occur in untreated diabetes?
the amount of glucose filtered by the kidney, exceeds maximal capacity for reabsorption resulting in glucose entering urine and drawing H2O with it by osmotic diuresis.
Why is fatigue and hunger experienced in diabetes?
caused by cells that do not get energy due to glucose not being taken in.
Why is poor wound healing experienced by untreated diabetics?
damage to blood vessels limit flow of oxygen and nutrients needed for repair.
Process of Diabetic ketoacidosis (DKA)
Occurs in low insulin environments when glucose is unable to enter cells. Absence of insulin enhances free fatty acids (FFA) release from adipocytes. FFAs converted to ketones by the liver, which can serve as an energy source. Ketones cause the pH of the blood to become acidic. Liver continues to synthesize glucose; therefore, the blood glucose rises. High glucose in the urine takes water and solutes such as potassium and sodium with it- dehydration.
Is DKA life threatening?
life threatening in type 1
metabolic changes in type 2 are not usually severe enough to cause DKA.
How can DKA be treated?
fluid replacement, insulin and mineral replacement.
microvascular damage included in chronic complications of diabetes
damage to small blood vessels (capillaries) e.g. nephropathy, retinopathy, neuropathy
macrovascular damage included in chronic complications of diabetes
damage to larger blood vessels (arteries and veins) e.g. stroke and cardiovascular disease
Increased uptake and metabolism of glucose leads to an __ in ATP:ADP ratio. This leads to __ which then leads to __ . Resulting in __.
(regulation of insulin secretion by blood glucose)
increase.
Leads to a closure of ATP-sensitive K+ channels and membranes depolarization.
Leads to opening of voltage gated Ca2+ channels
Resulting in increase in cytosolic Ca2+ - promotes secretion of insulin.
How does insulin repress gluconeogenesis?
insulin stimulated AKT phosphorylates, and inhibits the transcription factor FoxO1.
The expression of gluconeogenic genes such as glucose 6 phosphate is supressed.
What impact does insulin have on;
glucose uptake
glycolysis
glycogen synthesis
fatty acid synthesis
protein syntheis
proteolysis
glycogen breakdown
lipolysis
increase
increase
increase
increase
increase
decrease
decrease
decrease
