Chapter 3: Biochemical Assessment Flashcards
measurement of a nutrient and its metabolite in blood, feces, urine, or blood which has a relationship to nutritional status
biochemical assessment
considered as a more objective and precise approach than the other methods
biochemical assessment
biochemical assessment - types
measure levels of the nutrients in biological specimens on the assumption that such tests reflect the total body nutrient content or the nutrient store most sensitive to depletion
static biochemical tests
biochemical assessment - types
show the change of nutrient concentration in any given specimen which is most sensitive to nutritional change
static biochemical tests
biochemical assessment - types
measure the level rather than the function of a nutrient and provide information on the degree of deficiency of the particularly body pool sampled rather than the whole body status
static biochemical tests
biochemical assessment - types
changes in the activities of enzymes dependent on a specific nutrient or in the concentrations of specific blood components dependent on a given nutrient
functional biochemical tests
biochemical assessment - types
assess the consequence of the nutrient deficiency by measuring changes in the activities of a specific enzyme
functional biochemical tests
potential confounders of biochemical assessment
predictive values or cut-off point for a certain group, age, sex, ethnics, physiological state or environmental condition
reference/standards
potential confounders of biochemical assessment
contamination or lysis, time of collection, handling in certain temperature, exposed to sunlight, use of certain anticoagulant, method of configuration, sample storage, and transportation
specimen
commonly used specimen
(serum/plasma): protein, lipids, chon, vitamins, minerals
blood
commonly used specimen
preferred for most hematologic examinations
venous blood
commonly used specimen
gives different results compared to venous blood
capillary
commonly used specimen
reflects chronic status
erythrocyte
commonly used specimen
reflects acute nutrient status; age and size of the cell determine nutrient content
infection influences nutrients concentration in the cells
leucocyte
commonly used specimen
protein, vitamins, sodium, potassium, iodine, selenium, chromium
urine
commonly used specimen
readily available and non-invasive
urine
commonly used specimen
a pre-requisite when used as specimen to determine nutritional status
normal renal function
most preferred as concentration of nutrient metabolite is not equally distributed throughout the day
24-hr urine
influence of infection/inflammation on nutritional biomarkers
can cause immediate lower concentration of nutrient biomarkers due to increased micronutrient loss and decreased stores
infection or inflammation
influence of infection/inflammation on nutritional biomarkers
influences the concentration of serum retinol, carotenoids, pyridoxal phosphate, vitamin c, ferritin, zinc, or selenium
may not give a true indication of their status
subclinical infection
influence of infection/inflammation on nutritional biomarkers
recommended to include acute phase protein measurement when dealing with assessment of nut status
world health org
a condition in which there are no mobilizable iron stores and signs of a compromised supply of iron to tissues are noted
iron deficiency anemia
a condition where a lack of iron in the body leads to a reduction in the number of red blood cells, as reflected in low hemoglobin levels
iron deficiency anemia
is the gold standard for the quantitative determination of hemoglobin
cyanmethemoglobin
hemoglobin determination involves collecting blood through finger prick, _____ of whole blood is pipetted directly into a tube containing 5 ml of cyanmethemoglobin solution
20 ul
is defines as hemoglobin concentration below a specified cut-off point, which can change according to the age, gender, physiological status, smoking habits, and altitude at which the population being assessed lives
enamia
WHO defines anemia in children under 5 y/o and pregnant as a hemoglobin concentration _____ at sea level
<110 g/l
hemoglobin values which anemia is likely to be present in populations at sea level - normal hemoglobin level
6 mos-6 y/o
pregnant women
11.0 g/dL
hemoglobin values which anemia is likely to be present in populations at sea level - normal hemoglobin level
6.1-14 y/o
females, >15 y/o (non-pregnant/non-lactating)
lactating women
12.0 g/dL
hemoglobin values which anemia is likely to be present in populations at sea level - normal hemoglobin level
males, >15 y/o
13.0 g/dL
classification of public health significance of anemia in populations on the basis of prevalence estimated from blood levels of hemoglobin
severe
prevalence of anemia: >40.0%
classification of public health significance of anemia in populations on the basis of prevalence estimated from blood levels of hemoglobin
moderate
prevalence of anemia: 20.0-39.9%
classification of public health significance of anemia in populations on the basis of prevalence estimated from blood levels of hemoglobin
mild
prevalence of anemia: 5.0-19.9%
classification of public health significance of anemia in populations on the basis of prevalence estimated from blood levels of hemoglobin
low
prevalence of anemia: <4.9%
is the lack of vitamin a in the body
vitamin a deficiency
occurs where diets contain insufficient vitamin a for meeting the needs for growth and development, physiological functions and illness
vitamin a deficiency
leading cause of blindness in children and increases the risk of disease and death from sever infections, may be aggravated by high rates of infection, esp. diarrhea and measles
vitamin a deficiency
blood concentrations of _____ in plasma or serum are used to assess subclinical vitamin a deficiency
retinol
a plasma or serum retinol concentration _____ umol/l indicates subclinical vitamin a deficiency in children and adults
<0.70 umol/l
indicate severe vitamin a deficiency
<0.35 umol/l
guidelines used for the interpretation of vitamin a biochemical data - ug/dL
deficient
<10 ug/dL
guidelines used for the interpretation of vitamin a biochemical data - ug/dL
low
10-19 ug/dL
guidelines used for the interpretation of vitamin a biochemical data - ug/dL
acceptable
20-49 ug/dL
guidelines used for the interpretation of vitamin a biochemical data - ug/dL
high
> 50 ug/dL
guidelines used for the interpretation of vitamin a biochemical data - umol/L
deficient
<0.35 umol/L
guidelines used for the interpretation of vitamin a biochemical data - umol/L
low
0.35-0.69 umol/L
guidelines used for the interpretation of vitamin a biochemical data - umol/L
acceptable
0.70-1.74 umol/L
guidelines used for the interpretation of vitamin a biochemical data - umol/L
high
> 1.75 umol/L
prevalence cut-offs to define vitamin a deficiency in a population and its level of public health significance
mild
2 - <10%
prevalence cut-offs to define vitamin a deficiency in a population and its level of public health significance
moderate
10- <20%
prevalence cut-offs to define vitamin a deficiency in a population and its level of public health significance
severe
> 20%
main indicator of iodine status in all age groups, because its measurement is relatively non-invasive and easy to perform
median iodine concentration
adequate iodine nutrition is considered to pertain when the median urinary iodine concentration is
100-199 ug/l
the indicator of iodine deficiency “elimination” is a median value of _____, that is, 50% of the sample should be above 100 ug/L and not more than 20% of the samples should be below
100 ug/L
urinary iodine excretion determination: urine collection field storage and transport
15 ml mid-stream
epidemiological criteria for assessment of iodine nutrition in a population based on median or range of urinary iodine concentrations in school-aged children (>6 y/o)
iodine intake: insufficient
iodine status: severe iodine deficiency
urinary iodine excretion (UIE): ? ug/L
<20 ug/L
epidemiological criteria for assessment of iodine nutrition in a population based on median or range of urinary iodine concentrations in school-aged children (>6 y/o)
iodine intake: insufficient
iodine status: moderate iodine deficiency
urinary iodine excretion (UIE): ? ug/L
20-49 ug/L
epidemiological criteria for assessment of iodine nutrition in a population based on median or range of urinary iodine concentrations in school-aged children (>6 y/o)
iodine intake: insufficient
iodine status: mild iodine deficiency
urinary iodine excretion (UIE): ? ug/L
50-99 ug/dL
epidemiological criteria for assessment of iodine nutrition in a population based on median or range of urinary iodine concentrations in school-aged children (>6 y/o)
iodine intake: adequate
iodine status: optimal
urinary iodine excretion (UIE): ? ug/L
100-199 ug/dL
epidemiological criteria for assessment of iodine nutrition in a population based on median or range of urinary iodine concentrations in school-aged children (>6 y/o)
iodine intake: more than adequate
iodine status: risk of induced hyperthyroidism in susceptible groups
urinary iodine excretion (UIE): ? ug/L
200-299 ug/dL
epidemiological criteria for assessment of iodine nutrition in a population based on median or range of urinary iodine concentrations in school-aged children (>6 y/o)
iodine intake: excessive
iodine status: risk of adverse health consequences
urinary iodine excretion (UIE): ? ug/L
> 300 ug/dL
guidelines for interpretation of serum 25-hydroxy vitamin D
deficient
<50 mmol/mL
guidelines for interpretation of serum 25-hydroxy vitamin D
insufficient
50 - <75 mmol/mL
guidelines for interpretation of serum 25-hydroxy vitamin D
sufficient
> 75 mmol/mL
suggested guidelines for public health concern for zinc deficiency
low
<5%
suggested guidelines for public health concern for zinc deficiency
moderate
5 - <10%
suggested guidelines for public health concern for zinc deficiency
moderately high
9 - 20%
suggested guidelines for public health concern for zinc deficiency
high
> 20%
condition:
nutrient: protein and energy
protein-energy malnutrition (kwashiorkor, nutritional marasmus)
condition:
nutrient: vitamin a
xerophthalmia
condition:
nutrient: thiamine (vitamin b1)
beriberi, wernicke’s encelopathy
condition:
nutrient: riboflavin
ariboflavinosis
condition:
nutrient: niacin
pellagra
condition:
nutrient: ascorbic acid (vitamin c)
scurvy
condition:
nutrient: folate, vitamin b12
megaloblastic anemia
condition:
nutrient: vitamin d
rickets, osteomalacia
condition:
nutrient: iodine
iodine deficiency disorders, goiter, cretinism
condition:
nutrient: zinc
zinc deficiency
condition:
nutrient: iron
microcytic anemia
condition:
nutrient: fluoride
dental caries
lab test: low total serum protein and very low serum albumin levels, low levels of digestive enzymes
kwashiorkor
lab test: low urinary hydroxyproline
marasmus
lab test: low serum vitamin a levels; altered relative dose response, changed cytology of conjunctival cells
xerophthalmia
lab test: low whole blood or erythrocyte transketolase, low urinary thiamine in 24-hr urine collections or per gram of creatinine, low thiamine in whole blood
beriberi, wernicke’s encelopathy
lab test: raised levels of erythrocyte glutathione reductase, low urinary riboflavin levels in 24hr urine collections or per gram of creatinine
ariboflavinosis
lab test: low levels or urinary n-methyl-nicotinamide in 24hr urine collections or per gram of creatinine, low niacin in whole blood
pellagra
lab test: low leucocyte vitamin c; low serum ascorbate levels
scurvy
lab test: low hemoglobin, hyper segmentation of polymorphonuclear leucocytes, megaloblastic red blood cells, macrocytic red blood cells, low levels of serum folate
megaloblastic anemia
lab test: low plasma 25-hydroxycholecalciferol levels; increased plasma alkaline phosphatase
rickets, osteomalacia
lab test: low hemoglobin, low serum ferritin, low transferrin saturation, raised free erythrocyte protoporphyrin, hypochromic macrocytic red blood cells
microcytic anemia
lab test: low urinary iodine levels
goiter, cretinism, iodine disorders
lab test: decreased plasma zinc levels
zinc deficiency
