Week 3a Glucose Regulation Flashcards
biguanides do not?
increase insulin resistance
Where does blood from the islets drain into?
the hepatic portal vein
Promotes conversion of monosaccharides, lipids and amino acids into storage forms of polysaccharides, triglycerides and proteins
Insulin
Glucagon
promotes conversion of glycogen, proteins and lipids into glucose (gluconeogenesis) and release of glucose into the blood
How do catchecholamines affect blood glucose?
they help to maintain blood glucose levels in times of stress
How does growth hormone affect blood glucose?
increases protein synthesis in all cells of the body, mobilizes fatty acids from adipose tissue and antagonizes the effects of insulin
How do glucocorticoids affect blood glucose?
They are critical to survival during periods of fasting and starvation. They also stimulate gluconeogensis by the liver.
What is the main stimulant for insulin secretion?
high serum glucose
What are the 3 functions of Insulin?
1) glucose uptake by cells
2) facilitates storage of glucose and glycogen and triglycerides
3) Prevents breakdown of other sources
What does a C-peptide level suggest?
It distinguishes between type 1 diabetes or type 2
Why is C-peptide level measured instead of insulin?
can assess a persons own insulin even if they receive injections
Gluconeogenesis
generation of glucose
Glycogenolysis
the breakdown of glycogen
What functions and the beta cell glucose sensor?
Glucokinase
What can mutations in glucokinase lead to?
early onset of mild diabetes (maturity-onset diabetes of the young - MODY)
What is the most potent stimulator of insulin release?
Glucose
Incretin-like drugs for the treatment of type 2 DM, unlike sulfonylureas, are less likely to induce?
hypoglycaemia
What is insulin secretion inhibited by?
catecholamines and somatostatin
Where are the majority of insulin receptors?
liver, muscle and fat tissue
Where are GLUT-4 ?
muscle cells and adipose tissue
GLUT -2
beta cells and liver cells.
GLUT - 1
all tissues, basal glucose uptake. Does not require the actions of insulin. Nervous system.
When does endogenous insulin peak?
35-40 mins post meal
What does endogenous insulin return to baseline after a meal?
2-3 hours
What is diabetes mellitus characterized by?
hyperglycaemia, polydipsia, polyuria and glycosuria
Diagnosis of type 1 DM includes a fasting glucose of?
> 7mmol/L
Type 1A DM involves?
a hypothetical triggering event that involves an environmental agent that incites an immune response
In Type 1B DM, there is no evidence of?
autoimmunity
Which type of people is Type 1B DM most common in?
African or asian descent
Type 1 B DM is strongly?
Inherited
What is the difference between latent autoimmune diabetes of adult hood and Type 1 DM?
LADA occurs when the body stops producing adequate insulin. LADA progresses slowly and insulin may still be produced even after diagnosis
What kind of gene condition is Maturity Onset Diabetes of the Young (MODY)
it is a single gene mutation that disrupts insulin production. It is also a dominant genetic condition
Neonatal DM
a monogenic form of diabetes, like MODY
What are the 3 metabolic abnormalities in Type 2 diabetes?
1) impaired beta cell function and insulin secretion
2) Peripheral insulin resistance
3) Increased hepatic glucose production
What are 3 major causes of beta cell dysfunction in diabetes?
1) Chronic hyperglycaemia that results in beta cell desensitization
2) Chronic elevation of free fatty acids
3) Amyloid deposition in the beta cells
metabolic syndrome
cluster of conditions such as increased blood pressure, excess body fat around the waist and abnormal cholesterol or triglyceride levels
What are some of the signs and symptoms of metabolic syndrome?
- elevated triglycerides
- Low HDL
- HTN
- Systemic inflammation
- Fibrinolysis
- abnormal function of the vascular endothelium
- Macrovascular disease
What are some consequences of reduced glucose uptake?
- lipolysis
- proteolysis
- endothelial dysfunction
How does ketonuria result?
Liver metabolism of excessive amounts of fatty acids which results in ketogenesis and ketonuria
What are some acute complications of diabetes?
1) Diabetic ketoacidosis
2) hyperosmolar hyperglycaemic state
3) hypoglycaemia
when are people with type 2 DM particularly susceptible to DKA?
during infections
In DKA what occurs in response to the marked increase in plasma osmolarity?
cellular dehydration
What electrolyte supplementation is routinely given in the treatment of DKA?
K+
What is a tell-tale symptom of DKA?
rapid breathing (kussmals respirations)
Unlike DKA, hyperosmolar nonketotic coma does not affect?
breathing
excessive thirst, dry mouth, increased urination, warm dry skin, fever, drowsiness, confusion and hallucinations are symptoms of?
Hyperosmolar hyperglycemic state
What are some chronic complications of diabetes mellitus?
- diabetic nephropathy
- diabetic retinopathy
- vascular disease
- diabetic neuropathy
When is short-acting insulin usually given?
with one or more meals per day. It should be injected 30-45 minutes before the start of a meal
When is long acting insulin usually administered?
once daily at bedtime
Onset of rapid acting insulin
10-15 minutes
Peak of rapid acting insulin
1-2 hours
Duration of rapid acting insulin
3-5 hours
onset of long-acting insulin
90 minutes
How long does long-acting insulin plateau for?
24 hours
Short acting insulin is also called
regular insulin
onset of short acting insulin
30 minutes
Peak of short acting insulin
2-3 hours
Duration of short acting insulin
6.5 hours but is dose dependent
Which type of insulin can be given IV for ketoacidosis?
Short-acting insulin
what are some examples of short acting insulin
Novolin ge toronto and Humulin R
what is the onset of intermediate acting insulin?
1-3 hours
What is the peak of intermediate acting insulin
5-8 hours
What is the duration of intermediate acting insulin?
up to 18 hours but is dose dependent
what are some of the symptoms of hypoglycaemia?
tachycardia, confusion, sweating, drowsiness, convulsions, coma and death if it is not treated
what is the treatment for a conscious patient experiencing hypoglycaemia?
4 glucose tablets, 175 mL of apple juice or 15 mL of honey
What is the treatment for an unconscious patient experiencing hypoglycaemia?
50% dextrose IV and/or glucagon IM
what is the calculation for the total daily insulin dose?
0.3 units x patients weight in kg
What is the recommended % of carb intake for a diabetic patient?
45-60%
What is the recommended % of fat intake for a diabetic patient?
20-35%
What is the recommended % of protein intake for a diabetic patient?
15-20%
what do secretagogues do?
increase insulin release
2 examples of secretagogues
sulfonylureas and meglitinides
2 examples of drugs that increase sensitivity to insulin
biguanides and Thiazolidinediones
what do glucosidase inhibitors do?
reduce absorption of glucose by preventing digestion of carbs
What do incretin enhancers do?
reduce metabolism of insulin and decrease the rate of digestion of carbs
when should you take alpha-glucosidase inhibitors
with meals
What is the action of biguanides?
increase sensitivity to insulin. Decrease production and release of glucose from the liver, increases cellular uptake of glucose, lowers lipid levels and promotes weight loss
Incretin enhancers have a low risk of?
hypoglycaemia
Meglitinides can cause?
hypoglycaemia
Nursing considerations for biguanides
risk for lactic acidosis, avoid alcohol, low risk for hypoglycaemia
sulfonylureas can cause?
hypoglycaemia
Action of Thiazolidinediones
increases insulin sensitivity in fat and muscle tissue
Nursing considerations for Thiazolidinediones
can cause fluid retention and worsening of heart failure
what is first line treatment for type 2 DM?
Biguanides (metformin)
Actions of biguanides
1) reduce gluconeogenesis
2) reduce glucose absorption
3) increase cell glucose uptake
4) do not increase insulin release
Onset of metformin
2-3 hours
Peak of metformin
10-16 hours
Contrainsidcations of metformin
CHF, hepatic disease, alcoholism, renal disease, diuretics, antibiotics, ginseng, garlic, juniper, coriander, fenugreek
Actions of sulfonylureas
1) stimulate release of insulin
2) increase sensitivity of insulin receptors
example of a sulfonylurea?
glyburide (DiaBeta)
Onset of sulfonylureas?
1 hour
Duration of sulfonylureas?
10-24 hours
How is sulfonylureas usually administered?
PO daily
taking alcohol and/or aspirin with a sulfonylurea drug can cause the development of?
hypoglycaemia
Adverse effects of Thiazolidinediones?
fluid retention, headache, weight gain and hepatotoxicity
does hypoglycaemia occur with Thiazolidinediones?
no
what is an example of a incretin enhancer?
sitagliptin
what do SGLT2 inhibitors fo?
increase glucose dieresis
what is important to asses with SGLT2 inhibitors?
renal function