Exam 1 alteration to metabolic function (T1D & T2D) Flashcards
what is Type 1 diabetes?
Type 1 diabetes is an autoimmune disorder where the pancreas produces little to no insulin. The body develops antibodies against insulin and/or the pancreatic B-cells that produce insulin. This eventually results in a total absence of insulin production. Antibodies to the islet cells cause a reduction of 80-90% of normal function before hyperglycaemia and other signs and symptoms occur.
What is Type 2 diabetes?
Type 2 diabetes is the most common and usually develops in adults. The body becomes resistant to insulin or doesn’t make enough insulin. Insulin resistance stimulates a compensatory increased insulin production by B cells in the pancreas.
Insulin resistance
Insulin resistance happens when theres a resistance to the hormone insulin, resulting in increased blood sugar. Insulin is a hormone that regulates blood sugar
Type 1 pathophysiology
Symptoms develop when the person’s pancreas can no longer produce sufficient insulin to maintain normal glucose. Glucose is unable to get into cells, so the body loses access to an essential source of energy, becomes dependent on other sources like fats and protein.
Type 1 pathophysiology continued:
Autoimmune condition - body develops antibodies against insulin and in the pancreatic B-cells that produce insulin in islets of langerhans in pancreas - body attacks own beta cells. Reduction of 80-90% of normal function before hyperglycaemia and other signs and symptoms occur.
3 P’s - Type 1 and Type 2
Poly dipsia - excessive thirst
Polyuria - excessive urination
Polyphagia - excessive hunger
Signs and symptoms - Type 1
high blood sugar (above 4-7.5mmol/L)
unexplained weightloss (polyphagia?)
frequent urination
excessive thirst
glucose in urine
feeling unwell, tiredness and blurred vision
Polyphagia
Hunger - glucose and lipids do not enter cells in sufficient amounts therefore cells are deprived of nutrients and cellular stores of glycogen are depleted leading to hunger. The body still thinks its hungry
Polyuria
Frequent urination: Occurs due to the kidney’s inability to manage high amounts of glucose. Glucose normally filters freely in the nephron but in diabetes the higher amount of glucose filtered cannot be fully reabsorbed (renal threshold exceeded producing osmotic duresis). Therefore glucose appears in the urine.
Polydipsia
Excessive thirst: The osmotic effect of glucose draws water into the urine. Resulting in water loss causing dehydration which triggers increased thirst
Type 2 pathophysiology
Type 2 diabetes is characterised by a combination of inadequate insulin secretion and insulin resistance. The pancreas usually produces some endogenous (self-made) insulin. However the body either does not produce enough insulin or does not use it effectively or both.
another factor of Type 2 diabetes:
Insulin resistance is a condition in which the body tissues do not respond to the action of insulin because insulin receptors are unresponsive, are insufficient in number or both. Most insulin receptors are located on skeletal muscle, fat and liver cells. When insulin is not properly used, the entry of glucose into the cell is impeded, resulting in hyperglycaemia.
treatment of Type 1 diabetes
Insulin subcutaneous injection
the only treatment for T1D is exogenous insulin
insulin is a hormone made up of amino acids - protein gets broken down in the gut so has to be injected
special insulin syringes - units
factor 2 of Type 2 diabetes
another factor in the development of Type 2 diabetes is marked decrease in the ability of the pancreas to produce insulin, as the B-cells become fatigued from the compensatory overproduction of insulin of when B-cell mass is lost.
factor 3 of Type 2 diabetes
a third factor is inappropriate glucose production by the liver. Instead of properly regulating the release of glucose in response to blood glucose levels, the liver does so in haphazard way that does not correspond to the body’s needs at the time
fourth factor of Type 2 diabetes
A fourth factor is altered production of hormones and cytokines by adipose tissue (adipokines). Adipokines secreted by adipose tissue appear to play a role in glucose and fat metabolism and are likely to contribute to the pathophysiology of Type 2 diabetes.
signs and symptoms of Type 2 diabetes
Hyperglycaemia
3 P’s (polyuria, polyphagia and polydipsia)
bouts of hypoglycaemia
insulin is produced but cells are resistant
more subtle changes
treatment for Type 2 diabetes
Metaformin is an oral biguanide hypoglycaemic agent. It causes increased peripheral uptake of glucose by increasing the biological efficiency of available exogenous or endogenous insulin.
treatment Type 2 continued:
The mode of action of metaformin may be linked to an increase of insulin sensitivity. It does not stimulate insulin release but does require the presence of insulin to exert its hypoglycaemic effect.
possible mechanisms of action include inhibition of gluconeogenisis in the liver, delay in glucose absorption from the gastrointestinal tract and an increase in peripheral uptake of glucose.
