Page 66 - Journal of Special Operations Medicine - Winter 2016

glucose molecule. An alternative option to these choices Physiological Importance of Various CHOs
is CeraSport, which contains sodium and potassium but In foods, CHOs make up one of the three categories of
provides an alternative CHO derived from rice. The pro- macromolecules in the diet. Nutrient sources of CHOs
cessing of the rice starch is reported to result in a prod- are important components for energy production in the
uct that contains glucose, maltose (a disaccharide of two human body. One of the main sources of CHO in the

glucose molecules), as well as medium- and long-chain diet is starch (differing types are defined by their three-
maltodextrins (MDs), which have lower osmolality. The dimensional structure), which consists of long chains
MDs in CeraSport may reach the ileum in the distal small of glucose molecules connected through α 1,4 linkages
intestine, in contrast to other CHOs that may be absorbed between the glucose molecules. The straight chains of
in the proximal small intestine (duo denum and jejunum), one type of starch, amylose, allow the CHO to form a
and subsequently may provide sustained-release CHOs tightly coiled α helix whose structure may inhibit effi-
for energy. The greater availability of CHO molecules is cient digestion. A different form of starch, amylopectin,
important, considering a 2% loss of body weight impairs consists of these long-chain molecules but with the addi-
cardiovascular and temperature regulation, which may tion of branches of glucose chains at various points off
result in decrements in physical performance. Addition- the main structure that form through an α 1, –6 link-
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ally, hypohydration (lower than normal volume of water age. This branching prevents the amylopectin molecules
in the body) is known to alter cardiovascular function. from winding tightly into the helix coil, and thus allows
Specifically, it causes the heart rate (HR) to increase in an a more open three-dimensional structure. This open
attempt to maintain cardiac output (CO) as stroke vol- structure enables greater access to the digestive enzymes,
ume (SV; the amount of blood pumped from the heart per allowing amylopectin to be digested more quickly and
contraction) decreases (thus, CO = HR × SV). One of the efficiently than the α helix structure of amylose. This
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primary determinants of blood pressure is CO; therefore, branch-chain feature is reported by the manufacturer to
altered CO affects blood pressure regulation. be a component of the CHO in CeraSport.

Maintaining hydration, energy, and performance is criti- The efficacy of CHOs in drinks is further defined by
cal during war and training, because military person- rates of digestion and absorption in the gastrointestinal
nel are routinely exposed to a variety of environmental tract (GIT), which are determined by anatomic struc-
conditions that can alter judgment and physical per- ture. The surface of the small intestine (where most
formance and even result in death. For instance, when CHO digestion and absorption occurs) facing the lumen
a Servicemember suffers from a heat-related illness of is folded into projections called villi, which increase
any kind, an estimated four members of the platoon are the surface area by about 10-fold. The surface is fur-
needed to carry that member any distance. Therefore, ther increased by the columnar epithelial cells lining the
use of an ORS could help ameliorate heat illness among villi; these form additional projections called microvilli,
military troops, thereby reducing exertional EHI and which make up the brush border. Discrete filaments of
improving field performance. sulfonated proteins are part of the glycocalyx (i.e., the
fuzzy layer over the top of the microvilli). These sulfo-
CeraSport, a spinoff of CeraLyte 70, was specifically nated proteins are structural and hydrophilic, aligned
named in preference to generic glucose-based ORSs as in parallel with each other, and make up part of the un-
a requirement for inclusion in all individual first aid kits stirred layer, so named because it does not move during
and flight jackets in 2005 by Lieutenant General George peristalsis (i.e., the muscular contractions that move the
Peach Taylor Jr, MD, who was the Air Force Surgeon contents along the GIT). Because there is no movement
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General at the time. Before CeraLyte 70 was included within this region, molecules move only by diffusion,
in individual first aid kits, the US Air Force completed and this rate of diffusion plays a distinct role in rates
internal studies comparing CeraLyte 70 with traditional of digestion. The rate of diffusion is a function of the
fluids administered intravenously. Unfortunately, results concentration of the substrate or CHO and the size of
from these internal studies were unavailable to us. Cer- the molecule, with larger molecules moving more slowly
aLyte 70 is reported by the manufacturers to contain than smaller ones. However, the slower rate of diffusion
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70g of long-chain rice CHO combined with a 50:20 of the larger MD molecules may be offset by the faster
sodium and potassium ratio, and has an osmolarity of rate of absorption of glucose from MD as compared
<200mOsm/L compared with other oral rehydration so- with individual glucose molecules because the enzyme
lutions, which may have an osmolarity of ≥275mOsm/L. complexes that hydrolyze CHO are reported to be in
The low osmolar concentration in CeraSport coupled proximity to the CHO transporters. This phenomenon
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with the long-chain CHOs may result in increased has been demonstrated in several studies, which provide
absorption rates in the small intestine and is reported to evidence that glucose from maltose or maltotriose is ab-
reduce the incidence of gastrointestinal distress. 2 sorbed faster than from glucose itself. 9–13

50 Journal of Special Operations Medicine Volume 16, Edition 4/Winter 2016