Question

Case Study num22

please answer 1-5

Diabetes Mellitus

Diabetes mellitus is a common chronic disease, and every health professional will need to understand how it works and identify common emergency situations related to it. But an equally important part of the health professional's role is patient education and explaining what happens in the disease process. After they go home, diabetes patients will have to manage this complex disease every day.

You are working in the free clinic when Father X comes in. You know him well; he is a type 2 diabetic who keeps his sugar under control with diet and exercise but is often in the clinic with homeless patients from the shelter he runs in the Episcopalian church down the block.  

1. Insulin and glucagon release from the pancreas is a vital part of the negative feedback loop that regulates blood glucose levels. Write out this feedback loop and predict how insulin levels will respond to blood glucose. When will insulin levels be highest during the day? When will they be the lowest?

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On this visit, Father X has brought in a thin man in his twenties named Joe. Joe appears confused and lethargic. He is breathing heavily and has a strong fruity odor. Father X tells you he is concerned about Joe because last night Joe was up every half-hour or so to use the bathroom and get water. Father X knows these are signs of diabetes, so he wants to get Joe checked out. He also tells you that Joe has not been drinking; they have a breathalyzer at the shelter, and Joe tested clean when he checked in the night before.

Joe's blood pressure is a little low at 95/60 mm Hg and his heart rate is a little high at 96 bpm. When you take his pulse, you notice that his skin is dry and “tents” up when pinched--a sign of dehydration. His respirations are more rapid than normal, 25 breaths/min., and heavy. His blood glucose is elevated at 320 mg/dL. His urine also contains glucose, and has a lower pH than normal. When you take his history he tells you that type 1 diabetes runs in his family.  

2. Normally, urine does not contain glucose. When blood glucose levels are elevated, however, some of the glucose is lost in the urine. Apply the principle of osmosis to explain why Joe was getting up all night to use the bathroom, and why he has low blood pressure and signs of dehydration.

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3. In type 1 diabetes, the cells in the pancreas which produce insulin are destroyed. Which cells are these? The cells which produce glucagon, however, are not affected. Which cells are these? What will glucagon cause Joe's cells to do?

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4. People with type 1 diabetes commonly have high blood sugar levels but lose weight. Based on the effects insulin and glucagon have on cells, explain this. What compounds do you expect the cells to release into Joe's blood?

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5. The odor on Joe’s breath is from ketones. Why would a man with type 1 diabetes develop high blood ketone levels?

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Answer 1

1.

The levels of the insulin become highest after 30-40 minutes of food intake and lowest before the meals.

2. The Glucose has a renal threshold below which Glucose doesn't appear in the urine. If the plasma glucose becomes more than the renal threshold of glucose, the Glucose will start appearing in the urine. Glucose is an osmotically active substance. When Glucose enters in tubules, it will osmotically attract water. Therefore, along with Glucose, water is also excreted. Therefore, there occurs increase in urinary frequency called POLYDYPSIA. The excess water loss from the body results in dehydration.

3. In diabetes mellitus type I, beta cells of pancreas are destroyed which only secrete insulin. The glucagon is secreted by alpha cells which are not targeted by the antibodies. Rise in glucagon will cause anti-insulin actions. It will inhibit the cells to uptake the glucose. Therefore the levels of blood glucose rises in the body.

4. Glucagon and deficiency of Insulin favours catabolism of Proteins and fats. This increases the appetite but still catabolism prevails. This leads to weight loss. As the lipolysis occurs, there is increased concentration of free fatty acids. As proteolysis occurs, there is increased concentration of amino acids in the blood.

5. The ketoacidosis develops as the glucose is not taken up by the body cells. For nutrition, they start consuming fats and free fatty acids are released. When these free fatty acids reach the liver, they are esterified to form fatty acyl CoA whose oxidation within the hepatic mitochondria produces ketone bodies. The rate at which ketone bodies are synthesized becomes more than the utilizing capacity. Therefore ketonemia develops and further ketoacidosis occurs. The acetone is excreted through respiration. Acetone is sweet smelling gas. Therefore when it is excreted fruity odour is sensed in the breathing of the patient.