Biochemical Assessment of Nutritional Status Flashcards

Biochemical Tests

2 general categories of biochemical test

Static Tests

Functional Tests

Biochemical can be used to

Non-nutritional factors may influence test results

Biochemical test must be used in conjunction with

Roles of protein in body:

2 compartment model (Protein Status)

Somatic Protein

Visceral Protein

Protein-energy malnutrition (PEM)

____ more common in developing countries

Assessment of ______ _______ essential to the prevention, diagnosis, and treatment of PEM

Causes of PEM:

Test of Protein Synthesis

Creatinine

Creatinine Excretion

____ expressed as percent of expected value

CHI formula

Creatinine-Heaight Index (CHI)

60-80% CHI

40-60% CHI

< 40% CHI

_____ is a state in which the amount of nitrogen in (consumed as protein) equals the amount of nitrogen excreted by body

______ is expected state in healthy adults

Occurs when nitrogen intake exceeds nitrogen loss

Positive Nitrogen Balance ex..

Negative Nitrogen Balance

Negative Nitrogen Balance ex.

1g Nitrogen =

Nitrogen balance equations =

Useful in
-assessing protein status
-pt. is at risk of medical complication
-pt. response to nutritional support

Measuring serum proteins is usually _____ and _____

Use of serum proteins based on

Limited supply of amino acids or decrease in liver's ability to synthesize _____

Cannot always determine extent to which nutritional status or liver functions affects _____

Factos other than inadequate protein intake affect _____

Most abundant serum protein & synthesized in liver

Maintains fluid/electrolyte balance & transport of substances

indicates depleted protein status and decreased dietary intake

Low concentrations associated with increased morbidity/mortality in hospital pt's.

Limitations for albumin:

DECREASED albumin

Fluid status affects Albumin levels

Synthesized in liver & bind/transports iron in plasma

Better indicator than albumin bc smaller body pool/shorter half-life (8-9 days)

Transferrin levels decreased by

Transferrin levels increased by

______ levels inversely related to iron stores (levels are high in iron deficiency/ low when too much iron)

Also called transthyretin or thyroxine-binding ________

-Synthesized in liver
-trasport protein for thyroxine/carrier for retinol-binding protein
-more sensitive indicator of protein status due to short half/life (2-3 days)
-small body pool

Factors that affect levels of Prealbumin

A liver protein that acts as a carrier for retinol (Vit A). Responds quickly to depletion/repletion of protein and energy

Responds to adequate energy in absence of sufficient protein. Half-life (12hrs) much shorter than prealbumin and body pool very small (complicates measurement)

Levels increased in renal disease
Levels decreased in Vit. A deficiency, surgery, trauma

What is the normal (reference) values for Albumin?

What is the normal (reference) values for Transferrin?

What is the normal (reference) values for Prealbumin?

What is the normal (reference) values for Retinol-Binding protein?

Degree of malnutrition for Albumin? (mild, moderate, severe)

Degree of malnutrition for Prealbumin? (mild, moderate, severe)

Close and complex relationship exists between nutrition and ______

Nutritional deficiencies can lead to impaired ________, infection, and ________.

Immune responses sensitive to impaired nutritional status but often lack ______

Varity of factors other than nutritional status can also affect _______

Immune system's defense mechanisms can be divided into 2 broad categories?

Non-specific:

Specific:

Total number of lymphocytes reduced as protein ______ occurs

Complete blood counts routinely measured in hospitals.... Is total lymphocyte count easily determind?

Factors affecting TLC besides nutritional status inculde?

TLC Interpretation (mild, moderate, severe)

_______ is most common single nutrient deficiency in US

Groups at risk for deficiency include:

_______ results when consumption or absorption of dietary iron is inadequate to meet iron losses or requirement

Heme vs. Non-Heme

Nutrients that promote iron absorption:

Nutrients that inhibit iron absorption:

A deficiency in the :
-size of RBCs
-# of RBCs
-the amount of hemoglobin

Anemia may result from:

Other causes of Iron deficiency:

Types of anemia that are characterized as RBCs:

Microcytic

Macrocytic

Hypochormic

Iron-deficiency anemia leads to decrease in _________ production.

Stages of Iron Depletion

Effects or iron deficiency:

What test at what stage of iron deficiency?

Proteins needed in Iron Absorption?

Mucosal transferrin to

If cells do not need iron where does it go?

Biochemical Tests

____ is primary storage form for iron in body

___ of all iron in body is in the storage form, most as ______

______ occurs before changes are seen in RBCs, other indicators, or before anemia occurs

Once serum stores depleted, _______ levels no longer reflect severity of iron deficiency.

Serum Ferritin levels _____ indicative of iron deficiency

Iron transported in the blood bound to ___

Only ___ of avaible iron-binding sites are occupied

___________ measures amount of iron capable of being bound to serum proteins and provides indirect estimate of serum transferrin

________ is ratio of serum iron to TIBC and is calculated like (TS=Serum Iron/TIBC x 100

____ is percent of transferrin that is saturated with iron

Serum iron levels decrease and TIBC increases, resulting in a decreased TS

TS of _____ is in indicative of iron deficiency

directly proportional to the body's requirement for iron (erythrocyte-producing cells of bone marrow)

begins to increase in early iron deficiency before anemia develops (2nd stage of depletion)

valuble for iron deficiency diagnosis/monitoring erythropoiesis, especially before anemia develops

Not affected by inflammation or infection

_____ began measuring sTfR in 2003

key model used by NHANES to assess iron status in children 1 to 5/ women of childbearing age.

_____ is precursor of heme

_______ accumulates in RBCs when amount of heme that can be produced is limited by iron deficiency

__________ > 1.24 umol/l RBC indicative of iron deficiency

_______ is iron-containing molecule found in RBCs that carries oxygen

grams of hemoglobin per deciliter of blood is an ___ of the bloods oxygen-carrying capacity

measurement of hemoglobin in whole blood is ______ __ _____ _____ ___ for iron-deficiency anemia

amount of hemoglobin in blood depends on number of _____ and ______ of hemoglobin in each RBC

Hemoglobin (normal) values:

Hemoglobin considerations:

Hematocrit (Hct) also known as

Percentage of RBCs making up the entire volume of whole blood

depends larely on the number of RBCs and to a lesser extent on their average size:

Hematocrit (normal) reference range:

What is MCV?

____ is a measure of the size (volume) of the average RBC

How is MCV calculated?

Normal values for MCV

RBCs smaller than average

In folate or vit B12 deficiency, RBCs are larger than averager

Amount of Hbg in RBCs

How to determine if cells are hypochromic? values

Include a variety of test performed on plasme or serum that are useful in diagnosis and management of disease

What do blood chemistry tests test?

When several tests are run at once

Example of blood chemistry test (cororany risk profile)

Increased BUN (blood urea nitrogen) usually indicates

BUN (blood urea nitrogen) is usually _______ with dehydration, gastrointestinal bleeding, congestive heart failure, high protein intake, insufficient renal blood supply, blocked urinary tract

_____ BUN (blood urea nitrogen) results from liver disease, overhydration, malnutrition, or anabolic steriod use

Serum levels of LDH rise 12-24 hours following a _________

Lactate Dehydrogenase is often measure to determine if a ___ has occured

LDH (lactate dehydrogenase) is _______ with hepatitis, cancer, kidney disease, burns, trauma

____ leading cause of death of American males/females. 13 million Americans alive today have CHD

Coronary heart disease is also referred to as

Evidence suggests that CHD begins in ________ - progresses slowly into adulthood

Leading causes of death

4 Modifiable risks!

Strong causual relationship between elevated _____ and _____

Risk of CHD increases proportionally with ______

____ rare in those with low LDL-C, even in the presence of other factors

____ is prime target in attempts to lower blood cholesterol levels

High ____ levels protective against CHD

high _____ levels, risk of CHD is relatively low,

___ HDL-C levels increased CHD risk.

Most clinical labs do not measure ____ directly

Calculations are usually based on ______, _______, _____.

Formula for calculating LDL-C

CHD risk ___ with total cholesterol.

Increase risk is greatest when level rise above

For every __% decrease in TC, CHD risk decreases ____%

Classification of TC
Desirable?
Borderline High?
High?

Classification of LDL Cholesterol
Optimal?
Near or above optimal?
Borderline High?
High?

Classification of HDL Cholesterol
Low HDL?
Protective HDL?

Lipoprotein ratios indicate _______ risk

predictive value of CHD greater than TC, LCL, HDL alone

Ratio TC/HDL primary prevention targets

At risk ratio for TC/HDL

As ___ increases with HDL-C, risk increases to

At risk level LDL/HDL

The ____ ratio is as useful as the TC/HDL ratio

___ is similar to TC/HDL because 2/3 of plasma cholesterol are found in LDL.

Studies of relationship between TG (triglyceride) levels and CHD risk have _____ results

NCEP recognizes elevated ___ as independent risk factor for CHD

Classification for TG
normal
borderline high
high
very high

CHD RISK assessment. Complete lipid profile?

all adults ____ should have a fasting lipoprotein profile performed at least once every 5 yrs.

_______ is required for the accurate measurement of trigylcerides, which is required for calculation of LDL-C

_______ and ________ can be accurately measured in non-fasting state

____ one of most common risk factors for CHD and Renal disease

Blood pressure expressed in millimeters of _____ (mm Hg)

________ = "top number"

___________= "bottom number"

BP Classifications
normal
prehypertension
stage 1 hypertension
stage 2 hypertension

Hypertension (HTN) if often _______.

____% of persons with HTN are aware of condition

_____ of people with HTN are treated

________ have adequate control of BP

What are some risk factors for HTN?

group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both

_________ __________ associated with DM is associated with long-term damage, dysfunction, and failure of various organs, especially the eyes, kidneys, nerves, heart and blood vessels

Symptoms of DM

-abnormal carb/lipid metabolism
-retinopaty w/ potential loss of vision
-nephropathy leading to renal failure
-peripheral neuropathy with risk of foot ulcers and amputation

3 Types of Diabetes

Type 1 diabetes

Type 2 diabetes

Gestational

10-20% of all cases of diabetes

Insulin producing cells in pancreas destroyed >>>>>> no insuiln

possible viral or auto-immune cause

How is type 1 diabetes treated?

80-90% of DM cases

Produces insulin, but not effective
-body resists/ignores it

Rate increases with age/ correlated with obesisty

How is Type 2 DM treated?

Defined as any degree of glucose intolerance with one=set or first recognition during pregnancy

____ weeks post pregnancy, woman should be reclassified

in majority of cases of GDM, glucose regulation will return to normal after _______

GDM complicates _____ of pregnancies

risk assessment for GDM should occur at first ________ visit

High risk characteristics for GDM:

if not found to GDM at initial testing, should be retested at _____ weeks gestation

Women of average risk should have testing at ___ weeks gestaton

Involves having patient drink a beverage containing a known amount of glucose (usually 75 grams for adults)

Blood drawn immediately before the glucose load and then at set intervals. Plasma glucose measured at 1 hr intervals for 2 or 3 hrs.

Diagnosis criteria for OGTT

Diagnosis Criteria for DM

Diagnosis for pre-Dm
1. Impaired glucose tolerance (IGT)
2. Impaired fasting glucose (IFG)
both refer to metabolic stage between normal glucose homeo/diabetes

As many as ____ of people with DM are undiagnosed

_______ recommended screening method

Criteria for testing DM

Testing should be done early is the pt. has a number of risk factors such as

Additional Risk factors for DM

Best screening for DM is the _________

FPG and OGTT are both suitable, but FPG is preferred in a _____ setting.

_____ glycemic status is cornerstone for diabetes care

Results of monitoring used to assess efficacy of therapy and to guide adjustments in _________ ________ _______

Blood glucose monitoring by patients

Recommendations for monitering type 1

Recommendations for Type 2

Data suggest that only a moniority of pts perform

Barriers to increasing use of SMBG

Measurement of glycated proteins, primarily __________ , provide info on average glycemia over weeks and months

Also referred to as glycated hemoglobin, glybohemoglobin, HbA or the AIC test

________ (RBCs) freely permeable to glucose

______ in blood sample provides glycemic history of previous 120 days.
-reflects previous 2-3 months of glycemic control

_____ is preferred standard for assessing glycemic control

Risk factors for Metabolic syndrom