Lecture 38 Flashcards
What are common diabetes symptoms and the general cause?
Diabetes symptoms include: fatigue, weight loss, intense thirst, frequent urination, hyperglycaemia (high blood glucose), glucosuria (glucose in urine) and ketones. It is caused by problems with insulin release or reception in the body. Long term probblems can be: retinopathy, nephropathy (kidney failure), neuropathy (nerve damage), peripheral vascular disease and cardiovvascular disease.
What are the two types of diabetes mellitus?
The two types of diabetes are Type I. It is insulin dependent and due to auto-immune destruction of the beta cells, it is more common in children and is caused by genetic and environmental factors and can be treated with insulin injections. Type II is non-insulin dependent and is due to resistance to action of insulin and can be trated with diet, exercise and drugs and tends to be due to obesity.
What is blood glucose levels like in diabetes and non diabetics? Where does the glucose go? What are problems caused by?
Blood glucose during the day is maintained at roughly 5 mmol/L with slight increases after meals. In diabetics the levels are much higher, up at 20 mmol/L with large increases after meals and then decreases due to sweating, vomiting and interactions with random proteins, typically collagen in basement membranes and capillaries, leading to damage to blood vessels, nerves and even the eye. The brain isn’t recieving much glucose due to no insulin and hence convulsions can occur.
Why is our normal glucose blood level what it is?
The glucose level of 5 mmol/L is good for regulating our breathing via oxidative phosphorylation, higher can lead to to many reactive oxidants. The blood glucose level is maintained at this level at all times except right after meals, at which point it is tried to stop from going to high.
What is insulin? What produces it and what does it do?
Insulin is a peptide hormone with two chains held together by a sulfide bond. it is synthesiseed by beta cells in the pancreas and secreted in response to high glucose, acting on the liver, muscle and adipose tissue to lower the levels to normal.
It stops gluconeogenesis, ketogenesis, lipolysis, proteolysis, glycogenolysis and starts glucose uptake in muscle and adipose tissue, protein synthesis, glycogen synthesis, TAG uptake and fatty acid synthesis.
How is a glucose tolerance test done?
A glucose tolerance test involves fasting overnight, taking a drink with 75g of glucose and seeing what happens, in a non diabetic the peak will be relatively small (from 5 to 6), in a diabetic the level will rise much higher and take far longer to return to normal.
What are the metabolic consequences off lack of insulin?
Metabolic consequences of lack of insulin include: impaired glucose uptake and storage by muscle, increased mobilisation of glycogen, increased glucose synthesis, increased lipolysis, increased ketone body synthesis, reduced removala of triacylglycerols from blood and increased breakdown of tissue protein. (The body essentially behaves as if it is starving).
What are the overall effects of insulin problems?
The overall effects are: decreased glucose uptake and increased production leads to osmotic siuresis and hence dehydration and therefore thirst and eventually comined with acidosis (due to increased lipolysis) a diabetic coma can occur. In creased proteolysis eads to muscle breakdown and hence weight loss (combined with the lipolysis) and therefore weakness and wasting.
What is the danger of type I diabetes treatment?
Treatment of diabetes type I is injections of recombinant human insulin to mimic the normal rise, hypoglycaemia can occur if too much is given, comaing when less the 1.0mmol/L.
What is the principle of diabetes type II treatment?
Treatment of diabetes Type II involves increasing sensitivity of the tissues to insulin via weight loss, increased exercise and hypoglycaemic drugs.
