Blood Sugar Regulation PDF

Regulation of blood sugar The normal fasting concentration of glucose is 70-110 mg/dl Following a meal, the level rises rapidly 70-140 mg/dl Return to normal level within 2-3 hours. Regulation of blood sugar 1- Hormonal regulation: A- Insulin hormone B- Anti-insulin hormones: Glucagon Catech...

Regulation of blood sugar The normal fasting concentration of glucose is 70-110 mg/dl Following a meal, the level rises rapidly 70-140 mg/dl Return to normal level within 2-3 hours. Regulation of blood sugar 1- Hormonal regulation: A- Insulin hormone B- Anti-insulin hormones: Glucagon Catecholamines Corticosteroid Growth hormone 2- Organ regulation Liver Kidney  A- Hormonal regulation: I- Insulin hormone: Hypoglycemic hormone: 1- Carbohydrates: - Insulin increases glucose uptake - Stimulates glycolysis. - Stimulates glycogenesis and lipogenesis. - Inhibits gluconeogensis and glycogenolysis 2- Lipids: - Stimulates acetyl CoA carboxylase so stimulate lipogenesis. - It inhibits hormone-sensitive lipase so inhibits lipolysis. - Inhibits ketogenesis 3- Proteins: - Insulin stimulates protein synthesis  A- Hormonal regulation: II-Anti-insulin hormones 1- glucagon: - Stimulate glycogenolysis - Stimulate gluconeogenesis 2- catecholamines - Stimulate glycogenolysis 3- glucocorticoid - Stimulate gluconeogenesis 4- growth hormone - Block insulin action - Prevent glucose uptake  A- Hormonal regulation: I- Insulin hormone: Hypoglycemic hormone: II- Anti-insulin hormones 1- Carbohydrates: 1- glucagon: - Insulin increases glucose uptake - Stimulate glycogenolysis - Stimulates glycolysis. - Stimulate gluconeogenesis - Stimulates glycogenesis and lipogenesis. 2- catecholamines - Inhibits gluconeogensis and glycogenolysis - Stimulate glycogenolysis 2- Lipids: 3- glucocorticoid - Stimulates acetyl CoA carboxylase so stimulate lipogenesis. - Stimulate gluconeogenesis - It inhibits hormone-sensitive lipase so inhibits lipolysis. 4- growth hormone - Inhibits Ketogenesis - Block insulin action 3- Proteins: - Prevent glucose uptake - Insulin stimulates protein synthesis  B- Organ regulation: 1- Liver: During fed state: - Stimulates oxidation of glucose by activating the enzymes of glycolysis - Stimulates glycogenesis and lipogenesis. During fasting: - Stimulate Glycogenolysis - Stimulate gluconeogenesis - Stimulate ketogenesis  B- Organ regulation: 2- Kidney: Renal threshold - It is the blood glucose level (180 mg/dl) above which glucose appears in urine. Abnormal low renal threshold (100 mg/ dl) - Glucose appear in urine even insulin is normal due to kidney disease Abnormal high renal threshold (220 mg/ dl) - Glucose not appear in urine even the patient is diabetic  Hyperglycemia It is the rise of blood glucose above normal level. Types of diabetes: Diabetes mellitus. Diabetes insipidus: due to defect in antiduiretic hormone (ADH). Diabetes innocence: due to defect in the absorption of glucose (renal glucosuria). Bronze diabetes: due to defect in iron absorption.  Diabetes mellitus Diabetes mellitus is a syndrome due to insulin deficiency or resistance to insulin action. This leads to disturbance in carbohydrate, lipid and protein metabolism Types of diabetes mellitus 1- Insulin-dependent diabetes ( IDDM), type 1 diabetes autoimmune destruction of pancreatic β-cells, insulin is nearly absent 2- Non- insulin dependent diabetes mellitus (NIDDM), Type II insulin resistance at the cellular level , normal or elevated levels. 12 13  Biochemical disturbance of D.M I- Insulin hormone: Hypoglycemic hormone: 1- Carbohydrates: 1- On carbohydrate metabolism: - Insulin increases glucose uptake Decrease glucose uptake by tissues - Stimulates glycolysis. Decrease glucose oxidation - Stimulates glycogenesis and lipogenesis. Increase gluconeogenesis & glycogenolysis - Inhibits gluconeogensis and glycogenolysis Decrease intracellular glucose 2- Lipids: (polyphagia) - Stimulates acetyl CoA carboxylase,stimulate lipogenesis. Increase blood glucose, increase plasm - It inhibits hormone-sensitive lipase,inhibits lipolysis. osmolality, dehydration of brain & bod - Inhibits Ketogenesis cells. 3- Proteins: - Insulin stimulates protein synthesis  Biochemical disturbance of D.M I- Insulin hormone: Hypoglycemic hormone: 1- Carbohydrates: 2- On lipid Metabolism: - Insulin increases glucose uptake Excessive lipolysis in adipose - Stimulates glycolysis. tissues. - Stimulates glycogenesis and lipogenesis. Excessive ketone bodies formation lead to ketosis. - Inhibits gluconeogensis and glycogenolysis Loss of weight 2- Lipids: Hyperlipidemia - Stimulates acetyl CoA carboxylase,stimulate lipogenesis. Fatty liver. - It inhibits hormone-sensitive lipase,inhibits lipolysis. - Inhibits Ketogenesis 3- Proteins: - Insulin stimulates protein synthesis  Biochemical disturbance of D.M I- Insulin hormone: Hypoglycemic hormone: 1- Carbohydrates: - Insulin increases glucose uptake - Stimulates glycolysis. 3- On protein Metabolism: - Stimulates glycogenesis and lipogenesis. Increase protein breakdown - Inhibits gluconeogensis and glycogenolysis Muscle wasting 2- Lipids: Decrease antibody formation - Stimulates acetyl CoA carboxylase,stimulate lipogenesis. Poor healing of wounds - It inhibits hormone-sensitive lipase,inhibits lipolysis. - Inhibits Ketogenesis 3- Proteins: - Insulin stimulates protein synthesis  Type I Type II Other names: Insulin dependent diabetes Non insulin dependent mellitus (juvenile) diabetes mellitus (adult) Age During childhood After 30 years Nutritional state Usually under weight Usually obese Plasma insulin Low or absent May be normal Oral drug Has no effect Effective TTT with insulin Always necessary May not required 17 Manifestations of diabetes: Hyperglycemia: fasting blood glucose > 126 mg% Glucosuria: presence of glucose in urine when blood glucose exceeds the normal renal threshold. Polyuria: increase in urine volume (glucose is a diuretic). Polydepsia: sensation of thirst. Polyphagia: seansation of hunger 18  Types of coma in D.M: Diabetic ketoacidosis: Acidosis due to increased ketone bodies, leads to coma Hyperosmolar non-ketotic coma: due to hyperglycemia, increased osmolality and dehydration of brain cells. Lactic acidosis: due to increased lactic acid 19 1- Diabetic ketoacidosis (DKA) Lack of insulin causes the liver to turn fat into ketone bodies. Elevated levels of ketone bodies in the blood decrease the blood's pH (acidosis). - Clinically: it is manifested as hyperventilation, dry skin, rapid and weak pulse, acetone odor in breathing. - Laboratory: hyperglycemia with ketonemia and acidosis. 2- Non-ketotic hyperosmolar coma -The osmotic effect of high glucose levels combined with the loss of water will eventually lead to dehydration especially of brain cells leading to coma. -Usually in old patients and in patients have extreme hyperglycemia, glucose may reach to 800 mg/dl) 20 Diagnosis of diabetes: Diagnosis of diabetes is based on symptoms and confirmed by blood tests that measure the level of glucose in blood plasma. Urine Glucose test. Blood tests : 1- Fasting Blood Sugar or Glucose test (FBS). 2- Two-hrs Postprandial Blood Sugar Test (2-h PPBS). 3- Oral Glucose Tolerance test (OGTT). 4- Glycosylated Hemoglobin (HbA1C). 21 2- Glycated hemoglobin: Is a form of hemoglobin used primarily to identify the plasma glucose concentration over 2-3 months (life span of RBCs). Normally it is about 5-8 %. Hence people with hemolytic anemia and sickle cell disease are not suitable for this test. 3- fructose amine 22  Hypoglycemia Hypoglycemia is characterized by a drop in blood glucose to a level where, first it causes nervous system symptoms (sweating, palpitations, hunger, trembling, and anxiety), then begins to affect the brain (causing confusion, hallucinations, blurred vision, and sometimes even coma and death). An actual diagnosis of hypoglycemia requires three criteria include: Documented low glucose levels (less than 40 mg/dl). Symptoms of hypoglycemia. Reversal of the symptoms when blood glucose levels are returned to normal. 23 Types of hypoglycemia: 1- Primary hypoglycemia (fasting hypoglycemia): such as: 1. Pancreatic diseases as tumors of β-cell of pancreas causing increase insulin secretion 2. Adrenocortical diseases secreting decreased amount of adrenaline as tumors and that cause decreased glycogenolysis and gluconeogenesis. 3. Hepatic diseases as tumors and glycogen storage diseases that cause decreased glycogenolysis and gluconeogenesis 24  Reactive hypoglycemia (P.P hypoglycemia): 1. It is a medical term describing recurrent episodes of symptomatic hypoglycemia occuring 2-4 hours after a high carbohydrate meal (or oral glucose load). 2.Postgastrectomy 3.It is thought that it is due to a consequence of excessive insulin release triggered by the carbohydrate meals. 25 Treatment of hypoglycemia: Eat small meals and snacks about every 3 hours. Avoid intake of foods contain high amount of sugar, especially on an empty stomach, avoid alcohol, caffeine, and highly starchy foods such as white rice, potatoes and corn. 26