DIETARY MANAGEMENT OF ISOVALERIC ACIDAEMIA Carmen Yeung TMH Dietitian (APD) yeungkmc@ha.org.hk

DIETARY MANAGEMENT OF ISOVALERIC ACIDAEMIA

Carmen YeungTMH Dietitian (APD)

yeungkmc@ha.org.hk

Dietary Management

Aim to limit the dietary leucine intake and minimise formation of isovaleric acid.

Sufficient leucine must be given for normal growth requirements

How much protein to give?

Usually a modest protein restriction 2g/kg in infant, then decrease to 1.0 -1.5g/kg in young children, and combined with adequate energy intake is sufficient to limit the production of isovaleric acid.

( Am J Med Genet C Semin Med Genet, 2006, 142C 95-103)

Some reports on treatment with leucine free amino acids and protein intake restricted to below “safe levels”.

Clinical Paediatric Dietetics, 3rd edition

Safe level of protein intake

How much protein to give?

Usually a modest protein restriction 2g/kg in infant, then decrease to 1.0 -1.5g/kg in young children, and combined with adequate energy intake is sufficient to limit the production of isovaleric acid.

Some reports on treatment with leucine free amino acids and protein intake restricted to below “safe levels”.

IMPORTANT: Ensure adequate intake of all vitamins and minerals

Treatment of the newly Dx patient

May be very sick and in intensive care

A protein free feed is given while the infant is stablised, protein is then gradually introduced.

(Clinical Paediatric Dietetics, 3rd edition)

Our case, start with protein free formula (PFD-1), and then support with protein contains formula (Similac), the leucine was given according the Nutrition Support Protocols from Ross Metabolic Formula System

Recommended intake of leucine

Treatment of the newly Dx patient

On discharge, our patient is weight at 3.09kg

Diet order:Similac ≤ 80ml x 4 feeds/dIVA Anamix ≥80ml x 4 feeds/dTotal: 410kcal (= 135kcal/kg/d) 10g protein (=3.23g/kg/d) 444mg leucine (= 148mg/kg/d)

Regular Diet FU is essential to monitor the total calories, protein and leucine intake for normal growth

Sick Day Diet

Aim: reduce production of potentially toxic metabolites from protein catabolism, and provide adequate energy intake (reduced appetite occurs naturally)

Estimated energy requirement (EAR) could up to 30% more than usual requirement during acute illness.

Adequate hydration Requires frequent feeding, usually Q2-3H

Sick Day Diet

Long Term Dietary Management

Adequate protein intake for growth and development, but not excessive.

keep safe level intake of leucine Requirement of ~800mg/d in infancy,

gradually up to ~1000-1500mg for normal growth

Where is the leucine from?

How much of leucine in our food?(Each of the following food contains 50mg leucine)

Food Weight  

Meat/ Poultry    

Fish (cooked) 2.5g 1 oz = 30g Chicken (cooked) 2.5g

Beef (cooked) 2g

Egg yolk (cooked) 3.6g 1 egg yolk = 13g 

Milk/ Dairy    

Cow’s milk 15ml  

Yoghurt 10g ~ 2 teaspoon

Ice-cream 15g

Milk chocolate 5g  1 small cube

Cereals    

Baby Rice cereal (raw) 7g ~ 1 tablespoon

Rice (cooked) 25g ~ 1 tablespoon

Bread 10g 1/3 slide bread

Pasta (cooked) 15g  

Potato (boiled) 60g 1 egg size 

Weighing scale, measuring spoons and cups are required for food preparation

Meal sample18 months old girl, BW 12kg

Food Calories

Protein Leucine

Breakfast

IVA Anamix 240ml

165kcal

4.8g 0

Lunch Noodle ¾ bowl 200kcal

4g 4Ex leucine (200mg)

Cooked meat ½ oz

40kcal 3.5g 5Ex leucine (250mg)

Vegetable ¼ bowl

20kcal 0g 0

Afternoon tea

IVA Anamix 240ml

165kcal

4.8g 0

Dinner Rice ¾ bowl 200kcal

4g 4Ex leucine (200mg)

Cooked meat ½ oz

40kcal 3.5g 5Ex leucine (250mg)

Vegetable ¼ bowl

20kcal 0g 0

Supper IVA Anamix 240ml

165kcal

4.8g 0

TOTAL: 1015kcal

25.4g protein

18Ex Leucine (900mg)

How much of leucine in our food?

The amount of Leucine can be estimated from the protein content of the food, for example

Calculate: 50/ protein in 100g

= 50 / 7.4

= 7g baby cereal contains 50mg leucine (= 1 exchange

of leucine food)

Per 100g baby cereal

Energy 378kcal

Protein 7.4g

Carbohydrate 85g

Fat 0.9g

Summary:

Not to over restricted protein intake Monitor leucine intake Reinforced good diet compliance

Comply with weighting food items Food label reading Basic calculation of diet