Diabetes Flashcards
What are symptoms of diabetes?
Symptoms of diabetes include fatigue, weight loss, intense thirst, frequent urination, hyperglycaemia, glucosuria and ketones in blood
What is type 1 diabetes?
Type 1 diabetes is due to auto immune condition that destroys beta cells in the pancreas, prevalence in NZ ~0.5%. Caused by genetics and environmental factors (viruses or toxins implicated), treated with insulin injections
What is type 2 diabetes?
Type 2 diabetes is resistance to action of insulin (have the insulin but do not response to it), prevalence in NZ ~2%. Caused by genetic and environmental factors (obesity, sedentary lifestyle implicated) treated with diet, exercise and drugs
Blood glucose in non diabetics vs. diabetics
Normal blood glucose is around 5mmol/l per day whereas a diabetics blood glucose is a lot higher and fluctuates greatly throughout the day, 15-20mmol/l
Blood glucose is in equilibrium with the amount of oxygen in the air and settled to concentration brain is used to hence keeping us alert
What happens if blood glucose goes low?
When blood glucose is low you may feel a ’shake’, if you go lower than 1mmol/L of glucose sympathetic nervous system may induce vomiting, sweating and heartbeat increases. This could cause cognitive impairment as there is no glucose to provide energy for the brain; cause aggressive moods, convulsions and coma
What happens if blood glucose goes too high?
If blood glucose is high you get glucose being covalently attached to proteins particularly at Lys residues which interrupts protein function. Examples include collagen in basement membrane of capillaries (affecting blood supply), crystalline protein of the eye, making lens go opaque (retinopathy), cardiovascular disease, nephropathy, neuropathy and peripheral vascular disease (can lead to amputations)
What is insulin?
Insulin is a peptide hormone that is synthesised by pancreas by beta cells and secreted in response to high glucose (typically after a meal). It acts on liver, muscle and adipose and brings about a range of effects associated with storing glucose
What are the actions of insulin?
Insulin stops: gluconeogenesis, ketogenesis, lipolysis, proteolysis and glycogenolysis - anti catabolic (stops breakdown and mobilisation of these energy reserves)
Insulin promotes: glucose uptake in muscle and adipose tissue, protein synthesis, glycogen synthesis and TAG uptake, fatty acid synthesis - promotes uptake and storage of fuels, anabolic processes
What are metabolic consequences of lack of insulin?
Impaired glucose uptake and storage by muscle, increased mobilisation of glycogen, increased glucose synthesis, increased lipolysis, increased ketone body synthesis, reduced removal of TAGs from blood and increased breakdown of tissue protein
Due to these consequences the body mimics starvation
What are the short term problems of insulin deficiency?
Decreased glucose uptake and increase glucose production —> hyperglycaemia (glucose in blood) —> glycosuria (glucose in urine) —> osmotic diuresis —> dehydration —> thirst —> diabetic coma
What are long term problems of insulin deficiency?
Increased lipolysis —> fatty acids —> ketone bodies —> acidosis —> nausea and vomiting —> dehydration, thirst, coma
Increased proteolysis —> muscle breakdown —> weight loss —> wasting and weakness
What is the treatment for diabetes type 1?
Treatment for type 1 diabetes includes injections of human insulins (recombinant human insulin) which aims to mimic normal rise in insulin caused by meals
Hypoglycaemia caused by too much insulin, coma when glucose less than 1.0mmol/L so needs to be regulated
What is treatment for diabetes type 2?
Treatments of type 2 diabetes aims to increase sensitivity of tissue to insulin by weight loss, increased exercise and hypoglycaemic drugs such as sulphonylureas, glitazones (up regualte transcription factors) and insulin injection (if necessary)
