The impact of the macronutrient composition of a nutritional supplement on postprandial skeletal muscle protein synthesis in elderly

Ageing is accompanied by a progressive decline of skeletal muscle mass and
function which is named sarcopenia. Loss of muscle function is associated with
a decline in mobility and independecy and an increased risk for falling. A
possible cause of sarcopenia is a decreased muscle protein synthesis.
Specifically for elderly Danone Reseach developed an oral nutritional
supplement (ONS) aiming to increase muscle protein synthesis. In this study we
will investigate the macronutrient composition of the ONS on skeletal muscle
protein synthesis in elderly.
This reserach will give more insight in the preferred macronutrient composition
of the ONS.

Obtain more insight in the preferred macronutrient composition of an oral
nutritional supplement.

Randomized, controlled, double-blind, parallel-group, single-centre study in
healthy elderly
Single-arm study in sarcopenic elderly

One single-bolus of one of the three study products

For both visits subjects arrive in a fasted state

During the screening visit an oral glucose tolerance test will be performed.
The subject has to consume a glucose drink (300 ml) and 1x 10 ml and 4 x 5 ml
blood (total volume of 30 mL) is collected. The only risk of blood sampling is
a small hematoma.

Functional test are performed to calculate the SPPB score which is used to
discriminate between healthy and sarcopenic elderly. Body composition is
measured with Dxa. Dxa is a simple, non-invasive procedure which exposes the
subjects to a very low dose of radiation (i.e. <1 µSv). No risks associated
with this procedure are expected.

All subjects are instructed to refrain from alcohol consumption (24 h) and
intense physical activities (72 h) prior to the study visit and keep their
normal dietary habits (except from fasting from 22:00 h the evening preceding
the study visit). All subjects consume a standardized meal the evening prior to
the study visit.

During the study visit we will record medication use during last 3 days prior
to study visit. To be able to meaure muscle protein synthesis we will collect
24 x 8 ml blood (total volume of 192 ml) en 4 muscle biopsies. Both blood
sampling and muscle biopsy collection can cause a small hematoma. Bleedings
and/or infections rarely occur. Muscle biopsy itself can be painfull, but is
generally well tolerated. Later on the day of the muscle biopsy and/or in the 2
days after, the muscle can feel a bit sore. This feels like general
delayed-onset muscle soreness after exercise and will be completely healed
after 2 days.

The subjects will consume 1 single bolus of one the three study products (150
mL). Before and 5 hour after product intake gastrointestinal tolerance will be
assessed with an gastrointestinal tolerance questionaire.