Paediatrics JC120: The Child Is Too Thin: Nutrition And Growth, Nutritional Deficiency States Flashcards
How to know baby is thin?
- Physical examination
- ***Muscle wasting over buttock + Lack fat deposits
- Buccal muscles not reliable for assessing muscle wasting / nutritional deficiencies (∵ frequently used for feeding) - Growth parameters / dimensions
- Body proportion (compare with self)
- ***Growth record (compare with past)
- Comparison with other babies
Concept of Relativity in Early growth
- Relative to ***peers (age / sex-appropriate)
- Relative to ***other growth parameters
- Weight
- Height
- Head circumference - Relative to previous growth parameters
Best nurture environment for children
Nutrition is the basis (Balance + Sufficient)
Child growth:
- Dynamic + Interactive process
- Relative to norms
- Foundation of health + development
Key determinant of growth
Depends on **stage of life + **age of child
- Fetal / Infancy: **Nutrition most important
- Primary school: **Hormone (GH, Thyroid, Sex hormone)
***Key milestones of child growth (記)
Birthweight: 3.2 (female) - 3.4 kg (male)
Weight:
- Double by 4 months
- Triple by 10 months
Height:
- 50% adult height by 3 years
- 75% adult height by 9 years
Head circumference:
- 85% adult HC by 3 years
***Key Child Growth Indicators
- Underweight
- Stunting
- Wasting
- Failure to thrive
Z-score
- Statistical measurement of a score’s relationship to the mean in a group of scores
- Z-score of 0 —> score same as mean
- Z-score:
—> can be +ve / -ve —> indicate above / below the mean + by how many SD
WHO global database on child growth + malnutrition
- Underweight
- Z-score cut-off point of < -2 SD to classify low ***weight-for-age - Stunting
- Z-score cut-off point of < -2 SD to classify low **height-for-age
- Stunting rate under 5 yo —> **key health indicator
- more likely to have impaired ***cognitive development - Wasting (relative comparison between body weight and body height)
- Z-score cut-off point of < -2 SD to classify low ***weight-for-height
Failure to thrive
- A medical diagnosis
- Failure of expected growth in children <3 yo
- Downward crossing of 2 percentile lines in weight over 6 months
Causes:
1. Processing of nutrition
- Inadequate intake
—> Maternal factor
—> Baby’s factor
- Abnormal digestion / absorption
—> Primary
—> Secondary
- Inability to utilise
—> Genetic
—> Metabolic
- Excessive loss
- Excessive increase in calorie requirement (High metabolic rate)
- Chronic / Recurrent infection
- Chronic respiratory insufficiency
- Congenital / Acquired heart disease
- Malignancy
- Chronic anaemia
- Toxins
- Drug excess
- Endocrine disorders
(Genetic causes (SpC Revision):
Prenatal onset of growth retardation
- Russell-Silver syndrome
- Fetal alcohol syndrome
Postnatal failure + Developmental delay
- Williams syndrome
- Prader-Willi syndrome
- Costello syndrome)
Inadequate calorie intake
Maternal factors:
1. Failed breastfeeding
2. Wrong formula
3. Poor preparation (misconception / tradition)
4. Inappropriate feeding technique
Baby’s factors:
1. **Congenital anomalies e.g. cleft palate
2. **CNS disorders e.g. swallowing problem
3. **Distress e.g. due to cardiopulmonary conditions
4. **GI problems e.g. vomiting, GER
Abnormal digestion / absorption
Primary malabsorption:
- Uncommon (e.g. Cystic fibrosis)
Secondary malabsorption:
- **Post-GE (common) —> secondary dissaccharidase deficiency —> milk intolerance
- **Necrotising enterocolitis (NEC)
- **Short gut syndrome (due to post-surgical resection)
- **Food allergy / intolerance
Inability to utilise (Defective use of calories)
- Genetic diseases (syndromal)
- Metabolic disorders
- ***Inborn errors of CHO metabolism, aminoacidopathies, mitochondrial disease
Process involved in nutrition uptake
- Coordinated of sucking + swallowing
- Gastric emptying
- Intestinal motility
- Secretions (salivary, gastric, pancreatic, hepatobiliary)
- Enterocyte function: Enzyme synthesis, absorption, mucosal protection
- Metabolism of products of digestion + absorption
- Expulsion of undigested waste products
In-utero:
- Fetal GI tract is exposed to constant passage of fluid containing a range of physiologically active factors:
1. Growth factors
2. Hormones
3. Enzymes
4. Immunoglobulins
—> play a role in **mucosal differentiation + **GI development + ***swallowing / intestinal motility development
At birth:
- Gut of newborn baby: take up task of ***passing, digesting, absorbing large quantities of intermittent boluses of milk
Gut hormones
GI peptides
- found in venous cord blood at birth in levels ~ to those of fasting adults
Fetal distress:
- number of gut peptides are elevated —> account for passage of meconium (meconium stained liquor: MSL —> aspiration —> acute respiratory distress)
Enteral feeding:
- levels of gut hormones ↑ rapidly (∵ nutritional uptake)
—> **Motilin (↑ gut motility)
—> Neurotensin
—> **GIP (Gastric inhibitory peptide: stimulus to insulin release)
—> Gastrin (Intestinal mucosal + pancreatic growth)
—> ***Enteroglucagon (Tropic change to gut mucosa, Intestinal mucosal + pancreatic growth)
—> Pancreatic polypeptide (Intestinal mucosal + pancreatic growth)
Influenced by:
1. **Choice of Breast / Formula feed
2. **Enteric intake (induce epithelial hyperplasia + stimulate microvillous enzymes production)
3. ***Early enteral feeding (enteral feeding strongly encouraged to promote GI function + differentiation)
Pancreas
Pancreatic function
- relatively deficient at birth
- mature levels of pancreatic enzymes not achieved until late infancy
Pancreatic amylase activity
- ↑ after 4-6 months
Lipase:
- do NOT approach adult efficiency until about 6 months
Protein digestion in early infants
Early infancy compared to adults
1. Gastric acid
- lower than adult
- Trypsin
- activity reduced - Chymotrypsin
- low levels - Pancreatic proteases
- low levels - Intestinal mucosal peptidases
- adequate
Carbohydrates digestion in early infants
Early infancy compared to adults
1. Salivary amylase
- low levels —> compensating mechanisms: ***stay active in stomach (food in stomach for longer period)
- Pancreatic amylase
- very low levels —> compensating mechanisms: ***breast milk amylase - Disaccharidases
- adequate levels —> compensating mechanisms: ***fermentation + absorption in large intestine
Fat digestion in early infants
Early infancy compared to adults
1. Pancreatic lipase
- very low levels —> compensating mechanisms: **lingual, **gastric, ***breast milk
- Bile acids
- low levels —> compensating mechanisms: bile salt stimulated ***lipase activity
Motility: Upper GI
- Esophageal motility
- ↓ in newborn - LES
- primarily above the diaphragm - LES pressure
- less for first few months —> ***regurgitation - Gastric emptying
- may be ***delayed
Motility: Intestinal
- Intestinal motility
- more disorganised
- more frequent ***regurgitation - Prolonged transit time in upper intestines
- may ***improve absorption of nutrients -
**Rapid emptying of ileum + colon
- may reduce time for water + electrolyte absorption + ↑ risk of **dehydration
Maturation in first year
- LES tone
- ↑ after 6 months —> ↓ reflux in most infants - Pancreatic amylase
- ↑ by 6 months - Gastric acid + pepsin activity
- don’t reach adult levels until 2 years - Lipase
- reach adult level by 2 yo - Fat absorption
- not approach adult efficiency until ~6 months - Lactase activity
- ***retention of lactase activity until 3-5 yo
Kidney
- Limited ability to concentrate urine in first year (∵ immaturities of nephron + pituitary gland)
- Potential ***renal solute load determined by:
—> Nitrogenous end products of protein metabolism, Na, K, P, Cl
Renal solute load of different feedings (Low to High):
Human milk (easier to handle, less burden to kidneys) < Milk based formula < Isolated Soy protein based formula < Evaporated milk formula < Whole cow milk (***High renal solute load —> may overload premature kidney)
**Failure to thrive due to **↑ calorie requirement
- Chronic / Recurrent infection
- UTI
- TB - Chronic respiratory insufficiency
- Bronchopulmonary dysplasia (BPD)
- Cystic fibrosis - Congenital / Acquired heart disease
- Malignancy
- Chronic anaemia
- Toxins
- Lead - Drug excess
- Thyroxine - Endocrine disorders
- Hyperthyroidism
Breast feeding
Suckling
—> Hypothalamus
—> Pituitary gland
—> Prolactin + Oxytoxin
—> Myoepithelial cells
—> Lactation
Breast milk contents
Nutrients:
- Energy (67 Kcal/100ml)
- CHO: Lactose, Oligosaccharides
- Protein: Lactoferrin, α-lactalbumin, β-casein, lysozyme, cytokines, Ab
- Fat: LC-PUFA (DHA, AA, EPA)
- Micronutrients + Trace metals
- Cells: Macrophages, Neutrophils, Lymphocytes
