1STST and Muscle Weakness in CF Patients
1STST and Muscle Weakness in CF Patients
The investigators know that peripheral muscle weakness and exercise intolerance are prevalent
 (56%) in cystic fibrosis (Trooster et al, 2009). Physical inactivity is likely to be an
 important underlying factor. Those conditions are associated with a poor prognosis (Nixon et
 al, 1992). The effect of intravenous antibiotherapy on peripheral muscle and physical
 activity remains unclear.

 The aim of the study is to evaluate the impact of intravenous antibiotherapy on peripheral
 muscular strength in patients with cystic fibrosis (adults and children) who receive
 intravenous antibiotherapy for an acute exacerbation or electively (decline in lung function
 without exacerbation).
Background Peripheral muscle weakness and exercise intolerance are prevalent (56%) in cystic
 fibrosis (Trooster et al, 2009). Physical inactivity is likely to be an important underlying
 factor. Those conditions are associated with a poor prognosis (Nixon et al, 1992). The effect
 of intravenous antibiotherapy on peripheral muscle and physical activity remains unclear.
 Wieboldt et al showed that quadriceps strength at the hospital admission for an exacerbation
 was lower than before and one month after hospitalisation while Burtin et al showed that
 individual changes in quadriceps force were correlated with daily time spent activities of at
 least moderate intensity (Wieboldt et al, 2012; Burtin et al, 2013). The effect of
 intravenous antibiotherapy itself is poorly known in cystic fibrosis. Moreover, they did not
 study the impact on muscular strength of hospitalisation versus home treatment. In contrast,
 in COPD, it is well known that exacerbations are associated with a decline of muscle mass and
 strength and that repeated exacerbations lead to a more rapid decrease in fat free mass
 (Spruit et al, 2003; Jones et al, 2015; Joppa et al, 2016).

 Hypothesis We think that exacerbations aggravate factors underlying muscle weakness as
 physical inactivity, systemic inflammation and anabolic status. Moreover, hospitalisation
 itself might be a reason of inactivity as patients spent all the day inside their room
 compared to patients who follow their treatment at home and continue their usual life.

 Aim The aim of our study is to evaluate the impact of an intravenous antibiotherapy on
 peripheral muscular strength in patients with cystic fibrosis.

 Methods We would compare patients (adults and children) who receive intravenous
 antibiotherapy for an acute exacerbation, with patients who receive elective intravenous
 antibiotherapy (decline in lung function without exacerbation). We will also compare
 hospitalised patients who receive specific exercise training, with patients who follow their
 antibiotherapy at home without specific exercise training. We will have a stable patients
 group as control. To evaluate muscular strength we plan to measure quadriceps force at the
 beginning of the cure and at the end with a functional test, the 1-minute Sit-to-Stand test
 and a strength (isometric) test, with the Microfet2dynamometer. Those test are not invasive,
 easy to realise and have already been used in other studies (Ozalevli, 2005). We will
 quantify the physical activity level of the patients with an accelerometer that they will
 carry during 72 hours, during the first week of the treatment.
Inclusion Criteria:

 - patients with cystic fibrosis following the definition of Rosentein et al (1997), who
 undergo an intravenous antibiotic cure for an acute exacerbation or electively since we
 notice a decline of respiratory lung function

 Exclusion Criteria:

 -  orthopaedic conditions interfering with mobility or the assessment of skeletal muscle
 force,

 -  a pregnancy,

 -  a pulmonary graft

 -  a negative response for the informed consent.