Nutrition Management of - PowerPoint Presentation

Slide1

Nutrition Management of MapleSyrup Urine DiseaseSlide2

Maple syrup urine disease (MSUD) is an

inborn error

of the branched-chain

keto

acid

dehydrogenase (BCKDH

) enzyme complex required for

the catabolism

of the branched-chain amino

acids (BCAA

)

leucine

,

valine

, and isoleucineSlide3
Slide4

Of these,

leucine

and its corresponding

keto

acid, 2-oxo-isocaproic

acid, are the primary toxic

compounds in

this

disorder.

Infants with severe MSUD come to

attention shortly

after birth with symptoms such as

poor feeding

, weak suck, weight loss, and a

high-pitched

cry

progressing to a metabolic

intoxication crisis

characterized by lethargy

,

irritability, vomiting, and

fluctuating

muscle

tone(e.g

.,

floppy

, then rigid).Slide5

If the infant is not

treated, seizures

, metabolic acidosis, coma, and death

may result

.

There

are several

classifications

of

disease severity

, including

:

Classical

thiamine

responsive or intermittent

and

mild or variant

forms.Slide6

BCKDH is a thiamine-dependent enzyme, and

individuals with residual enzyme activity may

benefit

from thiamine supplementation, but

those with

classic MSUD do not.Slide7

Nutrition Management: principles

Restrict

: Branched-chain amino

acids, especially

leucine

Supplement

:

Valine

and isoleucine (if

plasma concentrations

are below target range

), thiamine

Toxic

metabolite

:

Leucine

and its

keto

acid, 2-oxo-isocaproic

acid

a Trial of 100–1,000 mg thiamine is

completed by

some metabolic centers

for patients

with variant forms of MSUDSlide8

Initiating Nutrition Managementof an Infant with MSUD

Goal

: Reduce or normalize plasma

leucine

Step-by-step

:

1. Establish intake goals based on

the

infant’s

diagnostic

blood

leucine,

clinical

status

, and laboratory values

.

2. Determine amount of standard

infant formula

or breast milk required to

meet the

infant’s

leucine

needs.

Determine the

amount of protein and energy

that will

be provided by this amount

of formula

.Slide9

3. Subtract the protein provided by

the standard

infant formula or breast

milk from

the infant’s total protein needs

.

4. Calculate amount of BCAA-free

medical food

required to meet the

remaining protein

needs

.

5. Calculate

valine

and

isoleucine

intake provided

by the infant

formula/breast milk

. Determine the amount of

supplemental

valine

and isoleucine to add

to meet

recommended intakes (Table

).

The

recommended concentration

of

valine

and isoleucine supplements

is

10

mg/mL (1 g amino acid in 100

mL

water

).Slide10

6. Determine the number of calories

provided by

both the

infant formula/breast

milk

and BCAA-free medical food.

If more

energy is required, provide

the remaining

calories from a

BCAA-free medical

food (as long as the

additional medical

food does not cause the

total protein

intake to be excessive).Slide11

7. Determine the amount of

fluid required to

provide a caloric density

of 20–25

kcal/oz.

8. Divide total volume into

appropriate number

of feedings over a 24-h period.Slide12

Suggested daily nutrient intakes for acutelyill or asymptomatic infants with classic MSUDSlide13

Once the diet has been established,

adjustments in

leucine

,

valine

, and isoleucine

prescriptions should

be based on blood

BCAA concentrations

rather than maintaining a

specific mg/kg

intake

goal

The amount of

the BCAA

required per kilogram of body

weight decreases

as the infant matures.Slide14

Recommendations for Adjustingthe MSUD Diet Prescription

1. Determine the estimated increase

or decrease

in

leucine

, isoleucine, and

valine

intake

that will be needed to improve

the blood

concentrations. Changes in 10

% increments

are typical but can be

higher or

lower based on plasma amino

acid concentrations.

2. Adjust the amount of infant formula

or breast

milk to increase or decrease

leucine

in

the diet.Slide15

3. Recalculate the

valine

and

isoleucine content

provided by the infant

formula or

breast milk.

4. Recalculate the amount of

supplemental isoleucine

and

valine

needed to

meet your

intake goals.

5. Recalculate the amount of MSUD

medical food

required to meet the energy goal.

6. Recheck plasma amino

acid

concentrations

.Slide16

Solid foods can be introduced to infants

with MSUD

at the typical age recommended for

all infants

, unless motor delays are present

.

To

allow for

solid food introduction, the volume of

regular infant

formula or breast milk is decreased

and

leucine

from these sources is replaced with

leucine

from

solid foods.Slide17

In MSUD, only the leucine

content of

foods and

beverages need to be

counted. There

is no need for caregivers to calculate

the

valine

and isoleucine content of foods.

Unless

there

is a concern about low energy intake,

caregivers do

not need to count calories from foods

or beverages

; the medical food provides the

majority of

energy for infants.Slide18

Low-protein recipes from cookbooks

designed for

PKU can be useful for MSUD as well.

The

leucine

content can be estimated from the

protein content

of foods (60 mg

leucine

per gram of protein).

For older individuals with MSUD,

counting protein

rather than

leucine

may be

appropriate and

easier for the patient, if metabolic control

can be

maintained with this less accurate method.Slide19

Counting Leucine Intake in theMSUD Diet

Only

dietary

leucine

must be counted

• The

valine

and isoleucine content

of food

is about half that of the

leucine

content

.

• Patients will not get too much

valine

and isoleucine

if they consume the

prescribed amount

of

leucine

.Slide20

In patients with classical

MSUD, medical foods provide up

to 80–90

% of protein needs and a majority

of energy

needs in infancy and beyond.Slide21

Recommended blood BCAA concentrationsin MSUD

a Recommended maximum blood concentration is

200 μmol/L for infants and children <5 years of age and

300 μmol/L for those >5 years of ageSlide22
Slide23

Suggested daily nutrient intakes for acutelyill or asymptomatic infants with classic MSUDSlide24
Slide25

Step 1: Calculate the amount of each nutrient required each day.

Nutrient goal/kg × Infant weight = daily requirement

Leucine

: 90 mg/kg × 4 kg = 360 mg/day

Isoleucine: 50 mg/kg × 4 kg = 200 mg

Valine

: 50 mg/kg × 4 kg = 200 mg

Protein: 3.0 g protein × 4 kg = 12 g total protein requirement

Energy: 110–120 kcal/kg × 4 kg = 440 − 480 kcal/kgSlide26

Step 2: Calculate amount of standard infant formula needed to meet daily LEU

requirement.

Amount of LEU required per day ÷ amount of LEU in 100 g of standard infant formula

360 mg ÷ 1,250 mg = 0.29

0.29 × 100 = 29 g standard infant formula needed to meet daily LEU requirement.Slide27

Step 3: Calculate protein provided from standard infant formula.

Amount of standard infant formula × protein provided in 100 g of standard infant

formula

0.29 × 10.8 g = 3.1 g protein in standard infant formulaSlide28

Step 4: Calculate the amount of protein required to

fill

diet prescription

Daily protein requirement − protein provided in standard infant formula

12 g − 3.1 g = 8.9 g protein needed to

fill

in the diet prescription

Step 5: Calculate amount of BCAA-free medical food required to

fill

diet prescription

Protein needed to

fill

diet prescription ÷ protein provided in 100 g of BCAA-free medical

food

8.9 g ÷ 13.5 g = 0.66

0.66 × 100 = 66 g BCAA-free medical food required in the diet prescriptionSlide29

Step 6: Calculate amount of isoleucine and

valine

provided from standard infant formula

(note: there is no LEU, ILE, or VAL in BCAA-free medical food)

Amount of standard formula × ILE in 100 g of standard formula

0.29 × 640 mg ILE = 186 mg ILE

Amount of standard formula × VAL in 100 g of standard formula

0.29 × 640 mg VAL = 186 mg VALSlide30

Step 7: Calculate the amount of ILE and VAL that needs to be supplemented by an amino

acid solution in order to meet the requirements determined in Step 1.

ILE: 200 mg − 186 mg = 14 mg ILE to be provided by supplement

VAL: 200 mg − 186 mg = 14 mg VAL to be provided by supplement

Amino acid solutions can be made to contain 10 mg/mL by adding 1 g (1,000

mg) of

amino acid (ILE or VAL) powder to 100 mL

14 mg ILE divided by 10 mg/mL = 1.4 mL ILE solution (containing 10 mg/mL)

14 mg VAL divided by 10 mg/mL = 1.4 mL VAL solution (containing 10 mg/mL)Slide31

Step 9: Calculate total energy provided from standard infant formula and BCAA-free

medical food.

Amount of standard infant formula × kcal in 100 g of standard formula.

0.29 × 510 kcal =148 kcal

Amount of BCAA-free medical food × kcal of 100 g of BCAA-free medical food.

0.66 × 473 kcal = 312 kcal

Add standard formula + BCAA-free medical food for total kcal provided in diet

prescription.

148 kcal + 312 kcal = 460 kcalSlide32

Step 10: Calculate the

final

volume of the formula to make a concentration of 20–25 kcal

per ounce.

460 kcal ÷ 20 kcal/

oz

= 23

oz

of formula

(Note: if

final

volume prescribed is 20

oz

, caloric concentration will be 23 kcal/

oz

; if

final

volume prescribed is 25

oz

, caloric concentration will be 18.4 kcal/

oz

)Slide33