Nutrition 10: Stunted Growth

Infections

frequent low grade -> stunts growth (developed and developing countries) -> MAJOR reason for growth stunting problems

Zinc

good experimental evidence in animals and good META ANALYSIS in humans (supplements increase height not weight for height in children) -> cofactor for a large number of enzymes (proteins can't function without this nutrient) -> no good stores (hard to see deficiency -> type II nutrient) -> in absence of this nutrient growth stops completely

Visceral organ growth

growth is driven by functional demand -> food intake and metabolic work

Skeletal muscle growth

growth rate and target weight controlled by bone length growth, passive stretch is the physiological stimulus for growth -> muscle activity required for maximum phenotypic mass

Wasted

has low weight for age but also low weight/height ratio (2 SD below reference)

Stunted child

has low weight for age but has NORMAL weight/height ratio and low height/age (2 SD below reference) -> MOST common form (happens around 2nd year of life in developing world -> catch up may OR may not occur -> has severe co-morbidities

Stunting

most likely due to infection and lack of clean water and unsanitary home environments

Animal source foods

nutrients that influence height growth -> rich in bioavailable micronutrients and minerals -> milk given to children to increase height

Stunting

reduces psychosocial development and motor development -> stimulation helps significantly, along with supplements can get this back to normal

Undernutrition

results from a combination of disease and dietary inadequacies -> leads to appetite loss, malabsorption, immunity lowered, mucosal damage, nutrient loss -> can reinforce the primary insults -> leads ultimately to growth faltering and weight loss (primary and secondary malnutrition)

Long bone growth

Growth and the body composition is controlled mainly at this level -> primary driver of whole body growth, genetic determination of rate/time/extent course (canalization) -> regulated by endocrine and cytokine factors (both are nutritionally regulated and inhibited by infection)

Secondary malnutrition

accompanies disease which disturbs appetite or food digestion/absorption/utilization

New guinea children

added margarine and the children got fatter but not taller, added extra taro and children got fatter and a bit taller, added milk and children got less fat and taller

Epidemiology

in Denmark milk (NOT MEAT) intake positively associated with sIGF-I and height; Uganda faster height growth in children on milk and meat rather than the children on plantains; in Peru there is a strong association between protein intake and attained height of boys

Burns

increased tissue catabolism and energy usage

Bowel rest

increases chance of systemic infections -> should give enteral nutrition as much as possible after injury

Infection (cortisol, IL-1, IL-6, TNF)

inhibits chondrogenesis

Primary malnutrition

lack of/poor quality food

Calcium and phosphate

length growth not thought to be limited by mineral supply in general

Stunting and wasting

low height or weight for age

Consequences of malnutrition

major cause of death and stunts physical and mental development in developing societies, accompanies wide variety of social, psychiatric, medical and surgical conditions in developed societies

Endochondrial ossification within the growth plate

stem cells are recruited by GH/IGF-1 -> proliferate, differentiate, undergo apoptosis and mineralization -> nutrition is vital for this process (hormonal activators of chondrogenesis and maturation -> IGF-1 and T3)

Protein

strong experimental evidence in animals (slowing and restoration of bone growth in rats), has good INDIRECT data in humans