final revision Flashcards
Anthropometric Data: _th and __th percentile suggest nutritional risk
Anthropometric Data: <5th and >95th percentile suggest nutritional risk
How many times should anthropometric measurments be repeated?
3 times
Ways of height measurment
Standing
- using a stadiometer (barefoot, heels and shoulders touching the wall, Frankfurt plane)
Knee Height
- If unable to stand (equations by age, sex and race p.50, Nelms)
Arm span-> not recommended - unable to stand straight
- not for Asians, African Americans, spinal deformities
BMI for Males and Non-Pregnant Female Adults <65 years old
<18.5- Underweight
18.5-24.9- Healthy
25-29.9- Overweight
30-34.9- Obesity - Grade I
35-39.9- Obesity - Grade II
>40- Extreme Obesity - Grade III
BMI: Males and Female Adults >65 years old
<24.0- May be associated with health problems in some elderly
24.0-29.0- Healthy weight for most elderly
>29.0- May be associated with health problems in some elderly
What does skinfold thickness indicate?
How should it be carried out?
Indicative of subcutaneous adipose tissue
Assumes that each site is representative of total body stores
Should ideally use multiple sites:
– Triceps - most commonly used but not fully representative
– Subscapular
– Biceps
– Suprailiac
Describe MAC
- Reflects muscle, bone, subcutaneous fat
- Not sensitive to changes in muscle
Describe MAMC
- Corrects for subcutaneous fat
- Insensitive to small changes in muscle
- Must measure MAC and TSF
Describe MAMA
- Reflects muscle and bone
- More sensitive to changes in muscle than MAMC
- More adequately reflects total body muscle mass
describe cMAMA
- Reflects only muscle without the bone
- Not valid in elderly or obese
- Insensitive to small changes in muscle
Describe MAFA
Mid-upper arm fat area (MAFA)
- Reflects sub-cutaneaous adipose tissue stores
- Better indicator of total body fat than a single skinfold measurement
What are below and above average cut-offs for MAMA and MAFA
15% below average
85% above average
Waist circumference cut-offs
- >102 cm in men; >88 cm women
BMI and WC measures combined as indicators of CVD and type 2 DM
- High BMI Low WC - Low risk
- High BMI High WC - High risk
Limitation of DXA
– Expensive but increasingly accessible in research settings
– Minimal exposure to radiation
– Assumes normal hydration status
Half-lives of serum proteins
- Albumin (most abundant) - 17-21 days
- Transferrin- 8-10 days
- Prealbumin or transthyretin (TTR) - 2-3 days
- Retinol Binding Protein (RBP) - 10-12 hours
Albumin functions
Maintains osmotic pressure
Transport of large insoluble molecules, drugs, calcium, zinc
Transferrin function
iron transport
TTR function
Transport of T3 and T4
Carrier for RBP
RBP function
Retinol transport from liver to periphery
Circulates with TTR
Name negative acute phase proteins
levels decrease by >25% during inflammation, illness or metabolic stress
CRP cut-offs tractation
Used to detect mild or acute inflammation:
Normal <1, mild chronic 1-5, acute >5 mg/L
Albumin cut-off values
Normal: . 35 g/l
Deficit: <35g/L
How to calculate nitrogen balance?
Example: Pt intake of 62.5 g protein/day and excretion of 200 mmol/L UUN in 2.0 L of urine
N Balance (g/day) = (pro intake g/6.25) - (UUN g + 4)]
- Total 24-h UUN (mmol) = (UUN mmol/L)(24h-urine volume L)
- Conversion factor: 1 mmol UUN = 0.028 g UUN
UUN (g) = (200 mmol/L x 0.028) x 2 L = 11.2 g
N balance = 62.5/6.25 - (11.2 + 4) = - 5.2 g
When would creatine excretion increase? Decrease?
- Increase with exercise, meat intake, menstruation, infection, fever, trauma
- Decrease with renal failure and age
Limitations of Creatinine Height Index
- Rely on complete 24h urine collections: errors
- Meat-free diet prior to testing
- not sensitive
- not possible to detect small changes
Laboratory Tests for Anemia: General
When woudl this marjers be increased/decreased?
What are the cut-off values?
-
Hemoglobin (g/L, deficit <120 women; <140 men)
- Total amount in RBC
- Decresed during PEM, hemorrhage and other anemias
-
Hematocrit (%, deficit <37 women; <40 men)
- % of RBC in total blood volume
- Increased during dehydration
- Decreased during hemorrhage and water overload
- RBC count
-
Mean Corpuscular Volume (MCV)
- Size measure to differentiate between micro and macrocytic
-
Mean Corpuscular Hemoglobin (MCH)
- Indicator of colour
-
Hematocrit
- MCHC = Hb/Hct
What is the order of depletion during iron deficiency and the associated markers
1) Storage iron (ferritin)
2) Iron transport (Transferrin)
3) Essential iron (RBC, myoglobin, enzymes)
Laboratory Tests for Anemia: Iron Deficiency
When would each of these markers be affected? What does that mean?
-
Serum Ferritin
- Low in early deficiency state
- Depleted iron stores
-
Serum Iron
- Low in early deficiency state
- Reflects iron bound to transferrin
-
Total Iron Binding Capacity, TIBC
- Measures the saturation ability for transferrin, high in deficiency
-
Transferrin Saturation
- Progressively decreases with diminished transport iron
-
Erythrocyte Protoporphyrin
- Increases in later deficiency state with limited Hb production
Graphs of how iron deficiency anemia markers change as anemia progresses
Components of TEE
TEF (<10%)
Physical Activity (20-30%)
REE or BMR (65-70%)
Protein requirements for healthy adults and elderly
Healthy adults: 1.0 g/kg/day Elderly adults: 1.0-1.2 g/kg/day
Considerations for the Elderly
- Energy- Reduced due to reduced LBM and activity = low appetite
- Protein- 1-1.2 g/kg/day, may be higher if other conditions present
- Fat- Careful evaluation of balancing: too high vs too low
- Calcium- Decreased Ca absorption with age (DRI=1200 mg >50 y)
- Vitamin D- Less efficient synthesis by skin, kidney conversion, and exposure
- Fluids- Decreased sense of thirst, presence of other diseases
How to differentiate types of malnutrition
10-40 is mild inflammation
40-100 is moderate inflammation
100-200 is marked inflammation
Obesity defintion
Progressive chronic disease characterized by excess or abnormal body fat that can impair health
Risk of health problems when analyzing BMI and waist circumference
BMI and waist guidelines for non-whites
• Asian populations
BMI: overweight ≥23, obesity ≥27 kg/m2
Waist (↑ risk): ≥90 cm in men, ≥ 80 cm in women
• African-american, hispanic, native Americans: same as for Caucasians
Health consequences of obesity
Cancer
Breathing problems: sleep apnea and asthma
Arthritis
Hepatobiliary disorders
Reproductive and obstetrical complications
Surgical risk and complications
Psychosocial and emotional consequences
How are BMI and all cause mortality connected?
Obesity and risk of cancer in men and women
Obesity increases cancer risk
Women: Endometrium, Ovary, Cervix, Breast (postmenopausal)
Men: Prostate, Pancreas, Oesophagus
Women & Men: colon, gallbladder, kidney, liver
Obesity and hepatobiliary disorders
Obesity ↑ risk of gallstones (cholelithiasis)
– More related to abdominal obesity, more in women than men
– Risk is also increased with rapid weight loss
Obesity and liver health
Abdominal obesity ↑ risk of non-alcoholic fatty liver disease (NAFLD)
– Steatosis-> steatohepatitis-> cirrhosis-> liver failure
Obesity and reproductive disorders in
• Men:
– Reduced testoterone, increased estrogens levels
– Gynecomastia
• Women:
– Polycystic ovary syndrome (PCOS) in 5-10% of women: -> irregular cycles, acne, excess body hair, infertility
– During pregnancy: ↑ risk gestational diabetes, preeclampsia (high blood pressure), labor and deliveries complications, fetal and maternal death.
Central regulation of food intake
central regulation of food intake takes place in hypothalamus, in arcuate nucleus where there are 2 main pathways of opposing functions:
has 2 pathways of opposing functions
1) NPY- with AgRP stimulates appetite
2) POMC neurones decrease appetite
the balance between the 2 dictates the regulation of appetite