Diabetes Mellitus Notes

Diabetes mellitus

Types of diabetes

-Type 1: insulin dependent

-Type 2: insulin independent

-Other: Gestational, tropical, malnutrition relative

Diagnose

-Oral glucose tolerance test-plasma glucose responses to 75g glucose orally

-Diabetes: there is a large rise in plasma glucose levels, remain elevated for long periods of time

-Symptoms: Polyuria, polydipsia, dehydration, fatty acid mobilisation, ketoacidosis, hyperglycaemia

Type 1

-Caused by autoimmune destruction of pancreatic B cells-insulitis

-Studies of concordance in identical twins-40%, some genetic component-polygenic

Effects:

-Pancreatic B cells measure blood glucose concentrations and secrete insulin accordingly which signals to the other tissues about the availability of energy substrates. Insulin is released from the pancreas into the liver via the hepatic portal circulation

-insulin is the only anabolic hormone, promotes anabolic reactions and suppresses catabolic reaction which is the default pathway

-Suppression of glucose production

-Stimulation of glucose uptake

-Supression of fat metabolism

-Suppression of ketogeneiss

-Activation of lipoprotein lipase

-Stimulation of net protein anabolism

-Physiological decreases in insulin concentrations are seen in starvation

-Decrease in plasma glucose concentrations, leads to a decrease in insulin release from the pancreatic B cells.

-The decrease of insulin-leads to removal of inhibition of catabolic reactions and a decrease in anabolic reactions.

i) Increase in glycogenolysis-rapid mobilisation of glycogen from the liver- raises blood plasma glucose concentration- 100 g of stores –only lasts for about a day

ii) Increase in proteolysis of proteins in skeletal muscle- especially branched chain amino acids- alpha-ketoacids are transported to the liver for gluconeogenesis- only lasts for about a week

iii) Increase in the lipase activity, increase in lipoprotein lipase. This leads to increase in fatty acid release- glucose sparing- majority of the tissues start...

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