Applied Pathophysiology: Altered Nutrition Lecture Notes PDF

Lecture Material is adapted from © 2022 Wolters Kluwer Health, Lippincott Williams & Wilkins Applied Pathophysiology: A Conceptual Approach to the Mechanisms of Disease Chapter 17: Altered Nutrition Module 2: Altered Nutrition Dr. Romeo Batacan Jr. MPAT12001 Medical Pathophysiology Lecture Serie...

Lecture Material is adapted from © 2022 Wolters Kluwer Health, Lippincott Williams & Wilkins Applied Pathophysiology: A Conceptual Approach to the Mechanisms of Disease Chapter 17: Altered Nutrition Module 2: Altered Nutrition Dr. Romeo Batacan Jr. MPAT12001 Medical Pathophysiology Lecture Series Copyright © 2017 Wolters Kluwer Health | Lippincott Williams &Wilkins  Altered Nutrition Inadequate or excessive digestion, absorption, transportation, or metabolism of nutrients  Altered Nutrition Multiple causes 1. Genetic defects that impact metabolism or absorption of nutrients 2. Malformation or damage to the GI mucosa 3. Inadequate or excessive dietary intake of required nutrients 4. Excessive nutrient losses (vomiting, diarrhea, laxative use) 5. Hypermetabolic states (excessive demands due to hyperthyroidism, cancer, burns, fever, severe infection) 6. Malabsorptive syndromes 7. Ingestion of unsafe food and water sources Genetic Defects: Inherited Metabolic Disorders Most often related to errors in amino acid and lipid metabolism Commonly a problem of a genetically‐based defect in enzyme activity Nowak T, Handford AG. Pathophysiology: Concepts and Applications for Health Care Professionals. Bullock S, Hales M. Principles of pathophysiology. 1st ed. Frenchs Forest, Pearson Australia; 2012. 3rd ed. New York, McGraw‐Hill; 2004 Catabolic-Anabolic Steady State of theBody Blood concentrations of energy sources equalized between absorptive state and postabsorptive state Absorptive state four hours during and after each meal absorption of nutrients occurring anabolism exceeds catabolism Postabsorptive state GI tract empty energy sources supplied by breakdown of reserves catabolism exceeds anabolism maintains blood glucose between meals Marieb EN, Hoehn KN. Human Anatomy & Physiology. 9th ed. Boston, Pearson Education; 2013 Absorptive State: Hormonal Control Absorptive state primarily controlled by insulin Insulin secretion stimulated by Elevated blood levels of glucose and amino acids Intestinal hormone ‐ glucose dependent insulinotropic peptide (GIP) Parasympathetic stimulation  Diabetes mellitus group of disorders, characterized by the inability to regulate the amount of glucose in the body leading to inadequate metabolism of protein, fats, and carbohydrates One or a combination of the following characterizes the basic pathophysiology in various types of diabetes: 1. A complete destruction of pancreatic beta cells leading to a lack of insulin secretion 2. Reduced insulin secretion from impaired beta cell function in response to glucose stimulation 3. A peripheral resistance to insulin Diabetes mellitus Glucose unavailable to most body cells Blood glucose levels high: Hyperglycemia Cells (liver, muscle, and adipose) become deprived of glucose as an energy source Less efficient sources are used for energy: body fats, proteins Clinical manifestations Weight loss, hunger, polyphagia Polyuria, polydipsia, circulatory failure Metabolic acidosis, CNS depression, coma Postabsorptive State: Hormonal and NeuralControls Regulation of postabsorptive state is more complex Sympathetic nervous system interacts with several hormones Postabsorptive state triggered by reduced insulin release as blood glucose levels drop Postabsorptive State Glucagon ‐ hyperglycemic hormone Release stimulated by Declining blood glucose Rising amino acid levels Glucagon promotes Glycogenolysis and gluconeogenesis in the liver Lipolysis in adipose tissue  fatty acids and glycerol to blood Modulation of glucose effects after a high‐protein, low‐carbohydrate meal Marieb EN, Hoehn KN. Human Anatomy & Physiology. 9th ed. Boston, Pearson Education; 2013  Altered Nutrition Inadequate or excessive digestion, absorption, transportation, or metabolism of nutrients  Undernutrition A lack of intake of nutrients Inadequate macronutrient consumption Inadequate micronutrient consumption (vitamin, mineral) Problems with digestion, absorption, or distribution of nutrients in the body most common inadequately consumed or in great demand causing undernutrition: protein, iron, and vitamins weight loss and muscle wasting due to excess use of muscle mass and adipose stores for energy severe or prolonged illness: can affect cardiac and respiratory muscle functioning High risk: elderly in nursing homes poor appetite, alterations in the sense of taste, problems with eating or swallowing, limited income, inadequate social support, physical mobility limitations  Undernutrition Vitamin and mineral deficiencies: dependent upon the role of the deficient vitamin or mineral Nutritional disorders: Protein-Energy Malnutrition Depletion of the body’s lean tissues ‐ starvation ‐ combination of starvation and catabolic stress (breaking down molecules) High prevalence among infants and children in underdeveloped countries due to food deprivation 1. Marasmus: protein and energy deficiency progressive loss of muscle mass and fat stores due to inadequate food intake that is equally deficient in calories and protein 2. Kwashiorkor: protein deficiency deficiency in protein in diets relatively high in carbohydrates Nutritional disorders: Protein-Energy Malnutrition Industrialized societies: protein‐energy malnutrition often occurs due to trauma or illness Marasmus‐like secondary protein‐energy malnutrition chronic illnesses (chronic obstructive pulmonary disease, congestive heart failure, cancer, HIV infection) ~ half of all persons with cancer experience tissue wasting, in which the tumor induces metabolic changes leading to a loss of adipose tissue and muscle mass Kwashiorkor‐like malnutrition hypermetabolic acute illnesses (trauma, burns, sepsis) Protein-Energy Malnutrition Marasmus Overall lack of nutrients Sufficient quantities of food are not available Lack of nutrients causes people to lose weight Progressive wasting of muscle and subcutaneous tissue Fluid and electrolyte imbalance Resembles living skeleton Under age of two: immune system is too weak to fight off mild viral infection (measles) Saladin K. Anatomy and Physiology: The Unity of Form and Function. 4th ed. New York, McGraw‐Hill; 2007  Saladin K. Anatomy and Physiology: The Unity of Form Protein-Energy Malnutrition and Function. 4th ed. New York, McGraw‐Hill; 2007 Kwashiorkor Starving children with protruding bellies Sufficient calories but protein starvation Switch from protein rich breast milk to protein poor food Gruel: cereal boiled in water Children’s bellies swell with filtered fluid (“ascites”) Lost due to lack of plasma proteins Osmotic changes: water moves from blood into peritoneal space Immune system depleted of its antibodies: prone to infection Increased calorie and protein needs Marasmus: Kwashiorkor: Did not have adequate nutrition as an infant. Had adequate nutrition as an infant Became malnourished after his diet switched Saladin K. Anatomy and Physiology: The Unity of Form and Function. 4th ed. New York, McGraw‐Hill; 2007 Starvation Healthy human can survive 50‐70 days without food Starvation: hunger strikes, prisoners, sufferers of psychological eating disorders Anorexia nervosa Bulimia  Malabsorption Lack of movement of one or more nutrients across the gastrointestinal mucosa one nutrient (vitamin B12: Pernicious Anemia) all nutrients at one segment all nutrients at the entire length of the intestinal mucosa Malabsorption syndrome: several nutrients are not adequately absorbed fat and fat‐soluble substances are almost always included in the malabsorption syndrome  Malabsorption Problems with processing or digesting nutrients: pancreatic dysfunction, enzyme deficiencies, or inadequate bile secretion Problems with moving substances across the mucosa: inflammatory conditions, GI atrophy, excessive ingestion of a nutrient, use of certain medications Lymphatic obstruction: inhibits transport of nutrients once they have been absorbed across neoplasms or infectious processes  Altered Nutrition Inadequate or excessive digestion, absorption, transportation, or metabolism of nutrients  Overnutrition Excessive consumption of nutrients Excessive caloric intake: obesity Vitamin/mineral toxicity: dependent upon the role of the vitamin or mineral  General Manifestations of AlteredNutrition Cells and body tissues rely on adequate nutrition for optimal functioning Clinical manifestations are exhibited throughout the body Undernutrition: weight loss, muscle wasting, muscle weakness, dehydration, fatigue, vitamin, mineral deficiencies rapidly dividing cells particularly vulnerable: Skin: poor wound healing, purpura, ulceration, dry skin, or pallor Mucous membranes: inflamed and friable Angular cheilitis (fissure development in the corners of the mouth, associated with riboflavin deficiency) Malabsorption: rapid transit of nutrients through the intestinal lumen carbohydrate malabsorption: weight loss, diarrhea, bloating, abdominal cramping, and excessive flatulence fat malabsorption: foul‐smelling, greasy, diarrhea stools Overnutrition/Excessive nutrient intake: increase in weight and body fatness Overnutrition/Excessive vitamins and minerals: potential toxicity according to source Diagnostic and Treatment Strategies Related to Altered Nutrition Determine the cause as well as the potential effects Nutritional assessment multiple‐day dietary intake recall Body mass index (BMI), height, weight, waist circumference Basal metabolic rate (BMR) Laboratory evaluation complete blood count with red blood cell indices and a peripheral smear erythrocyte sedimentation rate (to detect inflammation) serum electrolytes urinalysis, urine culture protein status, including serum albumin, transferrin, creatinine, BUN levels blood levels of specific nutrients: iron, B12, or folate enzyme levels hormone levels if metabolic regulation is impaired stool specimens: presence of pathogens that affect absorption biopsy of the GI tract: structural cause for the nutrition imbalance Diagnostic and Treatment Strategies Related to Altered Nutrition Goal: eliminating the cause of the nutrition imbalance reducing the harmful effects specific dietary interventions: increasing intake of particular macronutrients taking vitamin and mineral supplements reducing overall caloric intake avoiding specific foods that exacerbate symptoms pharmacologic interventions administration of exogenous digestive enzymes