Transcript Document

Understanding
malnutrition
Modules 3 and 4
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Learning objectives
• Be familiar with the various forms of undernutrition and
the technical terms that describe them
• Understand the consequences of undernutrition for
individuals and the impact in growth and development
in the society
• Understand the reasons for prioritising acute
malnutrition in emergencies against other forms of
undernutrition
• Be aware of who is specifically vulnerable to
undernutrition and why.
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Malnutrition includes:
– Undernutrition - acute malnutrition (i.e.
wasting and/or nutritional oedema), chronic
malnutrition (i.e. stunting), micronutrient
deficiencies and intra-uterine growth
restriction (i.e. poor nutrition in the womb) and
– Overnutrition (overweight and obesity).
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Globally > 35% of under-five deaths are
attributable to undernutrition
Malaria
1%
Measles 1%
Pneumonia
15%
Diarrhoea 19%
Injuries, 3%
HIV/AIDS 1%
>35%
attributable
to
undernutriti
on
Other, 19%
Causes of Neonatal
Deaths
Other – 7%
Tetanus – 1%
Diarrhoea – 1%
Sepsis – 17%
Neonatal 42%
Asphyxia – 23%
Congenital – 12%
Source: Lancet Series on Maternal and Child Undernutrition, 2008
Preterm – 38%
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Undernutrition’s impact on post neonatal child
deaths by illness
52%
61%
Shaded: Deaths
due to
undernutrition
Total =
53%
~57%
~57%
57%
45%
7/18/2015
9 data
Source:Lancet 2005
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What is undernutrition?
• Undernutrition occurs when there is
– insufficient nutrient intake and/or
– an increase of nutrient needs that prevents
effective utilization of nutrients (i.e. morbidity)
• Nutritional requirements are defined by
– Macronutrients: needed in large amounts and
include protein, carbohydrate and fat.
– Micronutrients: needed in much smaller amounts
and include vitamins and minerals
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Forms of undernutrition
• Acute malnutrition (i.e. wasting or
presence of bilateral pitting oedema)
• Chronic malnutrition (i.e. stunting)
• Micronutrient deficiencies
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Acute malnutrition (1)
• Acute malnutrition is characterized by rapid
and extreme weight / mass loss and/or
bilateral swelling.
• Reduces resistance to disease and impairs a
whole range of bodily functions
• In the early stages can be reversed through
adequate food and health care.
– Severe weight loss increases the risk of death.
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Acute malnutrition
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The burden of undernutrition: Prevalence of SAM in
South-central Asia and sub-Saharan Africa
Source: ACF International (2010). Taking Action, Nutrition for Survival, Growth
and Development, White paper.
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Chronic malnutrition: Stunting
• Chronic malnutrition or stunting is a slow, cumulative
process that develops over the long-term as a result of
inadequate intake or repeated infections, or both.
• The presence of stunting does not necessarily mean
that current dietary intake or health is inadequate –
the growth failure may have occurred at some time in
the past.
• By two years of age, stunting may be irreversible.
• Chronic malnutrition goes mainly unnoticed and is
sometimes referred to as ‘silent malnutrition’
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Chronic malnutrition: Underweight
• Underweight is a general measure that captures
the presence of wasting and/or stunting. It is
therefore a composite indicator, reflecting
either acute or chronic undernutrition without
distinguishing between the two.
• When children weigh less than the average
weight for children of the same age and sex.
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The burden of undernutrition:
Stunting prevalence worldwide
Source: MICS, DHS and other national surveys (2003 – 2008), via UNICEF
(2009) Tracking progress on Child and Maternal Nutrition
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The global burden of undernutrition:
underweight
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The intergenerational cycle of
undernutrition
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The impact of hunger and malnutrition
throughout the life cycle
Source: ACF International (2010). Taking Action, Nutrition for Survival, Growth
and Development, White paper.
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Micronutrient deficiencies (1)
• Micronutrients include all vitamins and the
minerals that are essential for life and needed
for a wide range of normal body functions and
processes but in very small amounts.
• The micronutrient requirements of an individual
depend mainly on age and sex
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Micronutrient deficiencies: definitions
Definitions
Micronutrient malnutrition:
The existence of sub-optimal
nutritional status due to a lack
of intake, absorption, or
utilisation of one or more
vitamins or minerals. Excessive
intake of some micronutrients
may also result in adverse
effects.
Micronutrient deficiency disease
(MDD):
A clinical disease that arises due
to a lack of intake, absorption, or
utilisation of one or more
vitamins or minerals.
Concepts
Micronutrient malnutrition can
exist even when the energy and
macronutrient needs of an
individual are met. For that
reason it is often referred to as
‘hidden hunger’. People may
appear well fed but still be
suffering from debilitating and
life threatening malnutrition.
When certain micronutrients are
severely deficient specific clinical
signs and symptoms may
develop. The classic nutritional
diseases such as scurvy, beriberi
and pellagra are good examples
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of these sorts of disease.
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Micronutrient deficiencies (2)
• Type 1 nutrient deficiencies result in specific
deficiency diseases, do not always affect
growth, but will affect metabolism and
immune competence before signs are
apparent.
This category of nutrients includes vitamins A,
B1, B2, B3, B6, B12, C, D, and folic acid, as well
as iron, calcium, copper, iodine, and selenium.
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Micronutrient deficiencies (3)
• Type 2 nutrient deficiencies do not show
specific clinical signs. They affect metabolic
processes and result in growth failure, wasting,
increased risk of oedema, and lowered
immune response.
• This category of nutrients includes sulphur,
potassium, sodium, magnesium, zinc,
phosphorus, water, essential amino acids, and
nitrogen deficiencies
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Micronutrient deficiencies (4)
•
•
•
•
•
Iron deficiency leads to iron deficiency anaemia
Vitamin C deficiency leads to scurvy
Vitamin A deficiency leads to xerophthalmia
Niacin or Vitamin B3 deficiency leads to pellagra
Iodine deficiency leads to goitre and cretinism (in
infants born to iodine deficient mothers)
• Thiamin or B1 deficiency leads to beriberi
• Riboflavin deficiency leads to ariboflavinosis
• Vitamin D deficiency leads to rickets
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Assessing micronutrient deficiencies
• Indirect assessment involves the estimation of
nutrient intakes at a population level and from
this the risk of deficiency and the likely prevalence
(rate) and public health seriousness of MDD
• Direct assessment involves the measurement of
actual clinical or sub-clinical deficiency in
individuals and using that information to give a
population estimate of the prevalence of the
MDD.
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Who is most vulnerable to
malnutrition during an emergency?
• The population groups most nutritionally
vulnerable can be categorized according to
their
– physiological vulnerability
– geographical vulnerability
– political vulnerability
– internal displacement and refugee status
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Physiological vulnerability
• Individuals with increased nutrient
requirements
• Children 0-24 months
• Pregnant and lactating women
• Individuals with reduced appetite
• Older people and disabled,
• People with chronic illness, including people living
with HIV-AIDS (PLWHA) and TBC
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The window of opportunity to address
malnutrition: the first 2 years of life
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Why acute malnutrition during
emergencies?
• Rapid onset if compared with other forms
• Higher mortality risk, although chronic
malnutrition is more prevalent
• Much greater potential to be reversed with
adequate treatment if detected early
enough.
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Key messages
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Malnutrition encompasses both overnutrition and undernutrition. The latter is the main
focus in emergencies and includes both acute and chronic malnutrition as well as
micronutrient deficiencies.
Undernutrition is caused by an inadequate diet and/or disease and closely associated with
disease and death
Acute malnutrition or ‘wasting’ and/or nutritional oedema is less common than chronic
malnutrition but carries a higher risk of mortality. It can be reversed with appropriate
management and is of particular concern during emergencies because it can quickly lead
to death.
There are two clinical forms of acute malnutrition: marasmus, which may be moderate or
severe wasting; and kwashiorkor which is characterised by bilateral pitting oedema and is
indicative of severe acute malnutrition (SAM). Marasmic-kwashiorkor is a condition which
combines both manifestations. SAM is associated with higher mortality rates than
moderate acute malnutrition (MAM).
Chronic malnutrition is the most common form of malnutrition and causes ‘stunting’
(short individuals). It is an irreversible condition after 2 years of age.
In general, children are more vulnerable than adults to undernutrition due to their
exceptional needs during active growth, and their immature immune and digestive
systems (infants 0-6 months).
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