Question

what is the relationship between increased fat metabolism and hyperglycemia

Answer 1

The acetyl CoA formed in fatty acid oxidation enters the citric acid cycle if fat and carbohydrate degradation are well balanced.The entry of acetyl CoA depends on the availability of oxaloaceic acid for the formation of citric acid.If carbohydrate is not available it is not properly utilized as in fasting or diabetes,the concentration of oxaloacetic is lowered because it is used to form glucose.Similarly, if fat breakdown predominates,there is an large increase in the amount of acetyl CoA for which sufficient oxaloacetic acid may not be available in the cells to continue the citric acid cycle.Under these circumstances,the acetyl CoA instead of being combined with oxalo-acetic acid in the first stage of TCA cycle passes to the liver.In the liver it is condensed to form acetoacetic acid.In the blood the acetoacetic acid undergoes further dissimilation forming -Hydroxybutyric acid and acetone.These are ketone bodies. Insulin deficiciency causes diabetes mellitus.This is a disorder of carbohydrate metabolism characterised by hyperglycemia .Hyperglycemia is a condition in which blood sugar increases above the normal level.Clinically,the most important causes of ketosis is diabetes mellitus.In the diabetic individual,glucose is present in excessive amounts in the fluids of the body but insulin deficiency prevents glucose utilization from operating at a normal rate.When the supply of insulin is inadequate fat metabolism is also affected,because fat must be used instead of carbohydrate for the release of energy,through cellular oxidation