MIDTERM Carb Introduction Overview PDF

CLINICAL CHEMISTRY John Leo C. Dayrit, RMT CARBOHYDRATES  Introduction Primary energy source stored primarily as glycogen Disease status involved hyperglycemia and hypoglycemia Contain C, H, and O (Cx (H₂0)y with C=O and –OH functional groups  Introduction...

CLINICAL CHEMISTRY John Leo C. Dayrit, RMT CARBOHYDRATES  Introduction Primary energy source stored primarily as glycogen Disease status involved hyperglycemia and hypoglycemia Contain C, H, and O (Cx (H₂0)y with C=O and –OH functional groups  Introduction Classification Classification Definition Definition Monosacchari Monosacchari Cannot be hydrolyzed to a simpler des or simple des or simple form Monosaccharides sugars sugars Contain Cannot be 3, Fructose 4, 5, 6 carbon hydrolyzed glucose monosaccharides atoms form to a simpler galactose or simple sugars Disaccharides Fructose Fructose, = glucose Maltoseglucose, glucose galactose galactose + glucose Lactose = glucose + galactose Formed by interaction of two Disaccharides monosaccharides Maltose, Lactose, Sucrose Polysaccharides Linkage of many monosaccharide units Starch, glycogen and glycogen  Introduction Classification Definition Cannot be hydrolyzed to a simpler form Contain 3, 4, 5, 6 carbon atoms Monosaccharides or (triose, tetroses, pentoses and hexoses, simple sugars etc.) Examples include fructose, glucose, galactose  Introduction Classification Definition Formed by interaction of two monosaccharides Examples Disaccharides Maltose = glucose + glucose Lactose = glucose + galactose Sucrose = glucose + fructose Introduction Classification Definition Linkage of many monosaccharide units Polysaccharides Include starch, glycogen and glycogen Starch Cellulose Glycogen Glucose Metabolism Glucose Metabolism  Glucose Metabolism 1 Metabolism of glucose to lactate or pyruvate Glycolysis for production of energy Formation of glucose-6-phosphate from non Gluconeogenesis carbohydrate source Breakdown of glycogen to glucose for use as Glycogenolysis energy Glycogenesis Conversion of glucose to glycogen for storage Lipogenesis Conversion of carbohydrates to fatty acids Lipolysis Decomposition of fat  Glucose Metabolism 1 Glycolysis (EMP Pathway) Glucose –Insulin→ ATP + lactate/pyruvate Gluconeogenesis Fats → glucose + ketone bodies Protein → glucose + urea nitrogen Glycogenolysis Glycogen – Glucagon → Glucose Glycogenesis Glucose – Insulin → Glycogen Lipogenesis Conversion of carbohydrates to FA Lipolysis Decomposition of fat Glucose Metabolism 1 Glycolysis (EMP Pathway) Glucose –Insulin→ ATP + lactate/pyruvate Formation of glucose-6-phosphate from Gluconeogenesis non carbohydrate source Fats → glucose + ketone bodies Protein → glucose + urea nitrogen Glycogenolysis Glycogen –Glucagon Glucose Glycogenesis Glucose –Insulin Glycogen Lipogenesis Conversion of carbohydrates to FA Lipolysis Decomposition of fat  Regulation of Glucose Metabolism 1. Insulin 2. Glucagon 3. Epinephrine 4. Cortisol 5. Growth hormone 6. Thyroxine 7. Somatostatin  Regulation of Glucose Metabolism Insulin (Hypoglycemic agent) 1. Primary hormone responsible for decreasing ↓ glucose 2. Synthesized by the β cells of the islets of Langerhan 3. ↑ glycogenesis, glycolysis, lipogenesis; and ↓ glycogenolysis.  Regulation of Glucose Metabolism Glucagon (hyperglycemic agent) 1. Primary hormone responsible increasing blood glucose 2. Synthesized by the α cells of the islets of Langerhan (pancreas) 3. ↑ glycogenolysis and gluconeogenesis. Regulation of Glucose Metabolism Epinephrine 1. Produced by the adrenal medulla, ↑ blood glucose 2. Released during times of physical and emotional stress 3. Inhibits insulin secretion, ↑ glycogenolysis and lipolysis  Regulation of Glucose Metabolism Glucocorticosteroids Cortisol (Glucocorticoids) 1. Produced by the adrenal cortex, ↑ plasma glucose 2. ↓ intestinal entry of glucose into the cell, ↑ gluconeogenesis, glycogenolysis and lipolysis  Glucose Metabolism Growth hormone 1. Produced by the anterior pituitary gland; ↑ plasma glucose 2. ↓ glucose entry to cells, ↑ glycolysis  Glucose Metabolism Thyroxine 1. Produced by the thyroid gland; ↑ plasma glucose 2. ↑ glycogenolysis, gluconeogenesis and glucose intestinal absorption  Glucose Metabolism Somastostatin 1. Produced by the Delta cells of the islet of Langerhans in the pancreas and hypothalamus 2. ↑ plasma glucose by inhibition of insulin, glucagon, GH, etc. Hyperglycemia Increase in Plasma Glucose Increase in plasma glucose Insulin is secreted in the β cells of pancreatic islets Hyperglycemia Diabetes Mellitus Metabolic disease characterized by hyperglycemia resulting from defects in insulin secretion, insulin action or both Diabetes Mellitus 1. Type 1 (IDDM) 2. Type 2 (NIDDM) 3. Other 4. Gestational  Hyperglycemia Diabetes Mellitus Pathogenesis Classification 1. Type 1 (IDDM) β-Cell destruction Absolute insulin deficiency Autoantibodies  Hyperglycemia Diabetes Mellitus Epidemiology and Pathophysiology Classification 1. Type 1 (IDDM) 5-10% of all cases of diabetes Occurs in childhood and adolescence Absence of Insulin with excess in glucagon  Hyperglycemia Diabetes Mellitus Characteristics Classification 1. Type 1 (IDDM) Abrupt onset Insulin dependence, ketosis tendency Sign and Symptoms Polydipsia Polyphagia Polyuria  Hyperglycemia Diabetes Mellitus Epidemiology Classification 2. Type 2 (NIDDM) 90% of all cases of diabetes Adult onset  Hyperglycemia Diabetes Mellitus Pathogenesis and Pathophysiology Classification 2. Type 2 Insulin resistance w/ secretory (NIDDM) defect Relative insulin deficiency ↑ with age, obesity and lack of exercise Insulin is present (hyperinsulinemia) Glucagon secretion is attenuated  Hyperglycemia Diabetes Mellitus Characteristics Classification 2. Type 2 (NIDDM) Non Insulin dependent Ketosis tendency is seldom Greater tendency to develop hyperosmolar states Polydipsia, Polyphagia, Polyuria  Hyperglycemia Laboratory Findings 1. ↑ glucose in plasma and urine 1. ↑ urine specific gravity 1. ↑ serum and urine osmolality 1. Ketones in serum and urine (ketonemia and ↓ tbloodi and 1. k ) urine pH (acidosis) 1. Electrolyte imbalance (↓ Na,↑ K )  Hyperglycemia Diagnostic Criteria for Diabetes Mellitus Diagnostic Criteria for Diabetes Mellitus 1. Random plasma glucose ≥200mg/dL, + symptoms 1. Random plasma glucose ≥200mg/dL, + symptoms of of diabetes diabetes 2. Fasting plasma glucose ≥126 mg/dL 2. Fasting plasma glucose ≥126 mg/dL 3. 2-h plasma glucose ≥200 mg/dL during an OGTT Categories of Fasting Plasma Glucose (FPG) Provisional diabetes FPG ≤126 mg/dL diagnosis Impaired fasting glucose FBG 100-125 mg/dL Normal fasting glucose FBG