carbohydrate intolerance Flashcards
what is the range that glucose should be contained in?
- 4 to 7.8mmol/ L
what is glucose in the blood essential for?
- provides constant flux of energy to the brain
what can exercise impact?
- significantly impacts plasma glucose levels as liver and muscle metabolism changes
how does the liver contribute and what does this allow the muscle to do?
- liver breaks down glycogen via glycogenolysis
- muscle can then take this up by different transporters e.g., GLUT4 to meet ATP demand
what are the processes controlled by?
- specific hormones
what hormones increase glucose?
- glucagon, cortisol, adrenaline and growth hormone
what hormones decrease glucose levels?
- insulin
describe role of glucagon
- helps to increase glucose levels
- in response to low glucose
describe role of insulin
- helps to decrease glucose levels by up taking glucose into different tissues
- secreted in response to elevated blood glucose
what are pancreatic islets? how many are there?
- clusters of pancreatic cells
- 3 million, 2g tissue
what cells make up the pancreatic islets ?
- alpha, beta, delta and epsilon
what cells produce glucagon?
- alpha cells
what cells produce insulin?
- beta cells
do pancreatic islets have good blood supply?
- yes
- good oxygenated blood supply via arteries
what does the blood supply allow?
- rapid release of insulin and glucagon into portal vein to control glucose
what is the relationship of insulin and glucagon described as?
- anatgonistic hormones
- work in balance as they go against each other to keep glucose in tight range
what happens if glucose levels go down?
- directly sensed by pancreas
- glucagon secreted by a- cells
- acts on liver to start breaking down glycogen via glycogen phosphorylase
- glucose then released into blood
what happens when glucose levels go up?
- insulin is released via b- cells
- glucose taken up by different tissues to clear some glucose from circulation
- stimulates utilisation of biomolecules (amino acid, glucose) for storage or energy
what is diabetes?
- main disorder of glucose intolerance
what is the fasting blood glucose of glucose tolerance measurement? what are you described as and why?
- 4-6 mmol/ L
- insulin sensitive
- can respond to dysregulation
when is clinical diabetes diagnosed from blood glucose tests?
- if fasting blood test is around 7.0 mmol/ L
- or random blood test glucose is over 10mmol/ L
what is HbA1c and how can this lead to clinical diagnosis?
- glycated haemoglobin
- diagnosed if > 10%
- reflects three months glucose so acts as chronic marker
- measures sugar residues attached to RBCs
what else acts as an indication for diabetes diagnosis ?
- glucose in urine present
- shows kidneys cant regulate the blood due to overwhelming amount of glucose
what other test can you use for diabetes diagnosis?
- oral glucose tolerance test
- person given 75g of glucose in a drink and ability to clear this is measured
- thresholds recorded for healthy individuals and insulin insensitive individuals
what are the symptoms of diabetes?
- excessive sweating
- high levels of fatigue
- thirsty and hunger
what causes diabetes?
- gene- environment interaction
- genetic predisposition e.g., parents diagnosed before 50 years old
what type of disease is Type 1 diabetes? what impairment does it involve?
- autoimmune disease
- impaired insulin secretion
when is type 1 diabetes typically diagnosed? what is detected and what does this cause?
- diagnosed in childhood (14)
- detect auto antibodies that have developed against pancreas
- immune cells recruited to destroy B cells and attack kidney
what does type 2 diabetes involve?
- impaired sensitivity to insulin
- pancreas is healthy but body is unable to respond to normal levels of insulin
what is altered in type 2 diabetics?
- altered cascade of events leading to GLUT4 transporter
- levels of glucose in blood becomes too high due to less intake
how do you manage diabetes? (3)
- medication
- diet
- exercise
what are the long term complications?
- retinopathy
- nephropathy
- neuropathy
- stroke
- cardiovascular disease
describe diabetic retinopathy co- morbidity
- circulation issues causes blindness
describe diabetic neuropathy co- morbidity
- non- traumatic lower extremity amputation due to problems within nerves
describe diabetic nephropathy co- morbidity
- leading cause of renal disease
describe stroke as a co- morbidity of diabetes
- 2 to 4 fold increase in CV mortality and stroke
describe cardiovascular disease as co- morbidity of diabetes
- 8 out of 10 individuals with diabetes die from CV events
what does exercise improve in diabetics?
- blood lipid profile (HDL :LDL)
- physical fitness/ function
- endothelial function
- psychological well- being
- glycaemic control
what does exercise lower in diabetics?
- diabetic complication/ lower mortality rate
- insulin requirements and improved insulin sensitivity
- risk of adverse cardiovascular events
- autoimmunity
what is exercise said to preserve? which diabetes type is this more common in?
- preserves beta cell function
- more common in type 2
what does aerobic exercise increase? where was this observed?
- GLUT4 expression in muscle
- observed in muscle fibres most frequently used i.e., Type 1 fibres
what else can exercise improve ?
- insulin sensitivity
what is the exercise response dependent on?
- type of exercise
- carbohydrates consumed
- insulin injection
what increases plasma glucose levels ?
- glucose output
- glycogenolysis/ gluconeogenesis in liver driven by epinephrine increases
what decreases plasma glucose levels?
- decreased by glucose uptake from working muscles
- mediated by insulin
what does brief maximal exercise result in?
- rapidly increases blood glucose as epinephrine stimulation to liver outweighs uptake by muscle
- up to 10mmol/ L
what does prolonged exercise result in?
- lowered plasma glucose levels
- glycogen depots are depleted overtime
- as low as 2.5mmol/ L
what is hypoglycaemia?
- glucose goes too low
- causes faintness
who needs to be careful when exercising?
- insulin dependent type 1 diabetics
- can lower glucose levels even more
what should type 1 diabetics do before exercise?
- eat before
