Standardized dietary challenge to monitor effects of rehabilitation program in patients with COPD: a pilot study

Chronic obstructive pulmonary disease (COPD) is primary a chronic respiratory
disease characterized by persistent airflow limitation. However, COPD is today
recognized as a systemic disease with multiple co-morbidities and
extra-pulmonary features. Indeed, patients with COPD suffer more from
alterations in body composition, osteoporosis and hyperglycaemia compared to an
age-matched control group (Triest et al. unpublished data). Furthermore, about
30% of the patients with COPD have continuous low-grade systemic inflammation.
Due to the parallelism between the progression of COPD and the ageing process,
it has been proposed that COPD can be a syndrome of accelerated ageing. Based
on telomere length, a COPD patient has a biological age of on average 8 years
older compared to a control subject with the same age. From this point of view,
it is reasonable to hypothesis that the metabolic flexibility of a patient with
COPD is different compared to an age-matched healthy peer.

In nutrition and health research, there is a growing awareness that health is
determined by the ability to maintain or regain homeostasis after various
physiologic stresses and that this characteristic can be used to study and
quantify the effects of nutrients or nutrition on multiple aspects of health.
In a recent study, the WHO definition of health originating from 1948 is
reconsidered and redefined as *the resilience of homeostatic control*: the
ability to cope with daily challenges without drifting out the regulated
homeostatic/allostatic zone. In short, this concept describes health as *an
ability to adapt* to various day-to-day challenges (e.g. strenuous exercise or
dietary challenge). Pulmonary rehabilitation may change the resilience of
homeostatic control.

In the present pilot study, we intend to test phenotypic flexibility (Phenflex)
in 20 clinically stable patients with COPD by exploring their response to a
dietary challenge test before and after pulmonary rehabilitation. Moreover, the
baseline results of the present pilot study will be compared with the results
of the control subjects obtained in study CHDR1230, in which 100 female and
male subjects within the ranges of a healthy population were measured and with
20 male type 2 diabetic subjects that participated in study CHDR1211. This
pilot study aims also to explore phenotypic flexibility of COPD patients before
and after pulmonary rehabilitation, as pulmonary rehabilitation is expected to
have a positive effect of patients* health.

The study is a single center, explorative observational pilot study with a
dietary challenge test before and after rehabilitation

During the test day before and after pulmonary rehabilitation a high calorie
dietary challenge drink, the so called Phenflex drink will be administered to
all volunteers. This 500 mL drink contains 75 g glucose, 20 g Protifar
(Nutricia), 60 g palm oil, flavour and 345 mL water.

The total engery intake of 900 kcal at once cold cause a feeling of nausea or
abdominal bloating. To reduce the already minimal potential risk, subject with
a reported food allergy or sensitivity for one of the used ingredients will be
excluded from study participation. Due to the long fasting period, the patient
can feel dizzy or have headach. Inserting a cannula can be painful and a bruise
can be a consequence of the cannula.
The health patch may cause irritation of the skin in some individuals. If
participants experience irritation caused by the health patch, the health patch
will be removed but the participants can continue with the study.