 |
III.
Anticatabolic and Anabolic Strategy, (Nutrition)
The
maintenance of optimum nutrition through both the stress
response or catabolic phase and the recovery or anabolic
phase is the most important strategy to decrease lean mass
loss and to regain lost lean mass.
The
remaining strategies are additions to adequate macro
and micronutrient intake.
|
Requirements
- maintain
adequate energy 30-35 cal/kg/day
- maintain
adequate protein 1.5 to 2 g/kg/day
- maintain
adequate micronutrients
|
What
is the Optimum Macronutrient Mix To Meet the Needs?
MEETING
REQUIREMENTS: THE ROLE OF PROTEIN SUPPLEMENTS APPETITE
STIMULANTS AND
INCREASED MICRONUTRIENTS
- Role
of protein supplements
- Appetite
stimulants
- Anticatabolic
micronutrients
|
1.
Protein Supplements
Numerous
studies demonstrate the need for increased protein intake
during both the catabolic and recovery phase after burn
injury. The increased protein demands, especially if
restoration of depleted body lean mass is required, exceed
that which a severe burn injury patient can achieve with
intake of food alone. This concept is particularly well
documented in the management of the burn wound when the
addition of protein supplements to maintain intake at
1.5-2.0 g/kg/day significantly increased healing rate.
As
described, the protein intake correlates best with healing
rate. Nutrient supplements should be selected based on the
following criteria.
NUTRIENT
SUPPLEMENT SELECTION CRITERIA
- Need
for high protein content
- Quality
of the contained nutrients
- Route
of administration, i.e. taken orally or
per feeding tube
- Palatability
(which equates with compliance)
- Complications
|
Most
high protein supplements are non palatable and not for oral
consumption, e.g. Criticare-HN, Jevity, etc. and are really
used only for tube feeding. There are now available more
palatable formulations which have a high protein content in
a palatable form. In addition, all proteins are not equal.
Some proteins and their peptide content have a higher
biologic value, i.e. increased nitrogen retention, based on
their structure and composition. In addition, specific
peptides can act like growth factors or added anabolic
stimuli. In a recent randomized trial in burn patients we
noted the protein composition of a case in hydrolysate
(Met-Rx) doubled lean mass gain when compared to standard
whey hydrolysates, reflecting an added anabolic stimulus
present in the casein hydrolysate.
It
has been demonstrated that bioactive peptides in a
hydrolysate of protein have anabolic activity, wound healing
and immunologic effects in excess of that seen with whole
protein or amino acid intake alone. Bioactive peptides are
absorbed intact by the gastrointestinal tract. A number of
peptides have been identified which have anabolic and
neuroendocrine activity. However, the majority of the active
growth factor-like peptides in protein hydrolysates have not
been identified.
2.
Appetite Stimulating Drugs (Non-anabolic agents)
A
critical component in the process of maintaining and
restoring lost lean mass is to optimize nutrient intake.
Suppression of appetite is a common characteristic of the
stress response during the catabolic phase of injury as well
as during recovery. Adequate energy and protein intake is
essential for any anabolism to occur, especially with the
use of anabolic agents.
The
most widely used non-anabolic agents are megestral
acetate, a synthetic progestational steroid and dronabinol
(delta -9 tetra hydro-cannabinol)
|
Megestral
Acetate
- effective
appetite stimulant
- >
85% of weight gain is fat due to
progestational steroid effect
- can
produce hypogonadism
- decreases
lean mass gain
- not
beneficial for lean mass gain
|
|
Dronabinol
- modest
appetite stimulant
- has
significant CNS effects
- weight
gain mostly fat
|
To
date appetite stimulants which are not anabolic agents,
have not been shown to be beneficial on the burn or trauma
patient to maintain lean mass.
Micronutrient
Support
Delivery
of increased quantities essential micronutrients is required
for the success of any anticatabolic or anabolic strategy as
micronutrient depletion occurs after burns and trauma.
| Micronutrient
Support of the Hypermetabolic State |
| VITAMIN
B COMPLEX |
Energy
Production
|
DAILY
DOSE |
| Thiamine |
Oxidation,
reduction reactions |
10–100
mg |
| Riboflavin |
Oxidative
phosphorylation for ATP production |
10
mg |
| Niacin |
Electron
transfer reactions for energy production |
150
mg |
| Vitamin
B6 |
Transamination
for glucose production and breakdown |
10–15
mg |
| Folate |
One
carbon transfer reaction required for all
macronutrient metabolism |
0.4–1
mg |
| Vitamin
B12 |
Coenzyme
A reactions for all nutrient use |
50
mcg |
| |
|
|
| VITAMIN
C |
Energy
Production
|
Daily
Dose
|
| MINERALS |
Carnitine
production for fatty acid metabolism |
500
mg–2 g |
| Selenium |
Cofactor
for fat metabolism |
100–150
mcg |
| Copper |
Cofactor
for cytochrome oxidase for energy production |
1–2
mg |
| Zinc |
Cofactor
for DNA, RNA, and polymerase for protein
synthesis |
4–10
mcg |
| |
|
|
| AMINO
ACIDS |
Energy
Production |
Daily
Dose |
| Glutamine |
Nitrogen
shuttle for glucose amino acid breakdown, urea
production, direct source of cell energy |
10–20
g |
|
Anticatabolic
and Anabolic Micronutrient Support
|
|
AMINO
ACIDS
|
|
|
Glutamine
|
Decreases
net nitrogen loss
Increases net muscle protein synthesis
Nitrogen carrier
Stimulates HGH release |
|
Arginine
|
Decreases
net nitrogen loss |
|
ANTIOXIDANTS
|
|
Vitamin
A, C,
E, B; Carotene,
Zn, Cu, Se
|
Decreases
net oxidant-induced protein degradation |
|
PROTEIN
SYNTHESIS COFACTORS
|
|
Zn,
Cu, Mg,
Vitamin B
Complex
|
Improve
protein synthesis pathways |
| DAILY
DOSE |
*
See Previous Table |
|
Micronutrient
Support for Wound Healing
|
|
AMINO
ACIDS
|
|
|
Glutamine
|
Primary
fuel for fibroblasts
Preservation of lean mass
Anticatabolic, anabolic properties
Stimulates release of HGH |
|
Arginine
|
Obligatory
precursor for wound protein synthesis
Increases local wound immune system |
|
Cysteine
|
Key
amino acid for new tissue growth
Provider of sulfhydryl bonds |
|
VITAMINS
|
|
|
Vitamin
A
|
Stimulant
for onset of wound-healing process
Stimulant of epithelialization and fibroblast
deposition of collagen |
|
Vitamin
C
|
Necessary
for collagen synthesis |
|
MINERALS
|
|
|
Zinc
|
Cofactor
for collagen and other wound protein synthesis |
|
Copper
|
Cofactor
for connective tissue production
Collagen cross-linking |
| Manganese |
Collagen
and ground substance synthesis |
   |
