30 - Clinical Manifestation of Malnutrition Flashcards
Malnutrition
Condition resulting from a diet in which certain nutrients are lacking, in excess or in the wrong proportions
Hunger, and its associated malnutrition
Greatest single threat to the world’s public health
Protein-Energy Malnutrition (PEM)
Body’s needs for:
Protein
Energy fuels
or
Both
cannot be satisfied by diet
Protein-Energy Malnutrition (PEM) Syndromes
Kwashiorkor (edematous) - Predominant Protein Deficiency
Marasmus - Predominant Energy Deficiency
Marasmic Kwashiorkor (edematous) - Chronic Energy Deficiency PLUS acute or chronic Protein Defiiciency
Edematous PEM
Kwashiorkor
Marasmic Kwashiorkor
Secondary PEM - Causes
Diseases causing poor intake - Anorexia of disease
Inadequate nutrient absorption or utilization with increased losses - IBD, Celiac, CF
Increased nutritional requirements - CF, Lung, Heart, Kidney
Increasd nutrient losses - CF, Celiac
Where do most malnourished patitents live?
Developing countries
30% in Africa and Far East
15% in Latin America and Near East
33% o chidlren
PEM - Social & Economic Factors
Poverty - Low food availability, overcrowding, unsanitary conditions Ignorance Decline in practice and duration of breast feeding Inadequate weaning practices Abuse Deprivation Abandonment Dependence Taboo Fads Migration
PEM - Biologic Factors
Maternal Malnutrition
Infectious Diseases:
Measles
Diarrhea
Respiratory
Diets
PEM - Environmental Factors
Overcrowding
Unsanitary living conditions
Agricultural patterns: Droughts Floods Wars Forced migration
PEM - Age
Increased frequency in infants and young children
Older kids experience milder forms
Pregnant and lactating women have increased nutritional requirements that can lead to PEM
Elderly and unable to care for themselves also experience PEM
Adolescents, adult men, non-pregnant, non-lactating women have a low prevalence of PEM
Marasmus - Age
Most common form of PEM in children
Kwashiorkor - Age
More frequent in children >18 mo
PEM - Pathophysiology
Develops gradually over weeks to months
Series of metabolic and behavioral adjustments:
Decreased nutrient demands and nutritional equilibrium compatible with lower level of nutrient availability
The slower PEM develops, the better adaptation to current nutritional status - Maintain a less fragile metabolic equilibrium.
PEM - Adaptive mechanisms
Energy mobilization and expenditure Protein breakdown and synthesis Endocrine changes Hematologic changes Cardiovascular and renal function changes Immune changes Monokines Electrolytes GI function CNS & PNS
PEM - Energy mobilization and expenditure
Decreased energy intake
Decreased energy expenditure (body fat mobilized)
Decreased adiposity with weight loss as subQ fat is reduced
Protein catabolism with muscle wasting
PEM - Energy mobilization and expenditure - Marasmic Patients
Visceral protein usually preserved
Increased basal O2 consuption
Increased basal metabolic rate
More severe:
Decreased basal metabolic rate
Blood glucose usually normalized by glycerol from fats & gluconeogenesis of AA
PEM - Energy mobilization and expenditure - Kwashiorkor Patients
Early visceral depletion of amino acids
Decreased basal O2 consumption
Decreased basal energy expenditure/unit body mass
PEM - Protein Breakdown & Synthesis
Poor availability of dietary proteins
Decreased protein synthesis
Initial adaptations:
Sparing body protein and essential protein dependent functions
PEM - Protein Breakdown & Synthesis - Long term deficits
Loss of skeletal muscle
Increased loss of visceral protein
Death
PEM - Amino Acid Recycling
90 - 95% of dietary AAs are recycled (normal metabolism is 75%)
Proportional decrease in AA catabolism (normally 25%)
Decrease in urea synthesis
Decrease in urinary nitrogen excretion.
PEM - Albumin
Decreased rate of synthesis and breakdown
Shift of albumin from extravascular to intravascular to maintain oncotic pressure
Severe depletion: Adaptive mechanisms fail Decreased serum protein Decreased intravascular oncotic pressure Outflow of water into extravascular space Edema of Kwashiorkor
PEM - Cardiovascular & Renal Function
Decreased Cardiac Output
Decreased Heart Rate
Decreased Blood Pressure
Central circulation takes precedence over peripheral circulation
Altered cardiovascular reflexes
Postural hypotension
Decreased venous return
Severe: Peripheral circulatory failure Hemodynamic compensation Tachycardia Decreased renal plasma flow & GFR (secondary to decreased cardiac output)
Normal water clearance with normal concentration and acidification of urine
PEM - Immune System
Depletion of T-Lymphocytes from Thymus
Atrophy of Thymus gland
Decrease in complement production
Increased susceptibility to Gram (-) sepsis
Decreased functional activity of the complement system
Increased susceptibility to Gram (-) sepsis
Decreased opsonic activity of serum
Increased susceptibility to Gram (-) sepsis
Decreased phagocytosis
Decreased chemotaxis
Decreased intracellular killing
Possible defects in secretory IgA
Increased predisposition to infections and severe complications from otherwise less-important infectious diseases.
PEM - Monokines
Peptide/glycoprotein mediators of the body’s response to injury.
Decreased IL-1 - Poor febrile response and decreased leukocyte counts in infection
Increased TNF - Anorexia, muscle wasting, lipid abnormalities
PEM - Electrolytes
Decrease of total body potassium
Altered cellular exchange Na+ and K+ loss
Potassium loss
Increased intracellular Na+
Intracellular overhydration
PEM - GI Function
Impaired absorption of:
Lipids
Disaccharides
Glucose
Decreased gastric, pancreatic & bile production
Normal - low enzyme and conjugated bile
Further impairment of absorption
Diarrhea
Irregular intestinal motility
Diarrhea
Bacterial overgrowth
Diarrhea