Page 54 - Physical activity in recipients of solid organ transplantation - Edwin J. van Adrichem

Chapter 3

e results of the present study suggest that, as for maximal exercise capacity,
peripheral muscle function - that is, quadriceps muscle function - seems to be the main
target for intervention in submaximal exercise. However, whether quadriceps training on its
own would contribute to a clinically relevant increase in submaximal exercise capacity is questionable. To achieve the reported minimal clinically important di erence of 54 m,32
increase of 180 N (54/0.3), which is substantial, must be reached.
e
se data suggest that
therapy should not focus solely on quadriceps training but should be more extensive.
health-related quality of life,
the metabolic syndrome,
35 3637
an
Higher grip strength values also were associated with longer 6MWD values in the
linear mixed-model analysis, but this association was not con

rst

rmed by an additional
analysis with data imputation. Grip strength has been associated with general well-being
and prediction of mortality.
33,34
Furthermore, grip strength has been associated with
been proposed as a factor that should be considered in the screening process because it re ects muscle mass (sarcopenia), the immune process, and in ammatory responses.38
Overall, it is not likely that grip strength training would increase walking distance because
grip strength appears to be re

ective of an underlying general construct.

e longitudinal analyses provide a distinctive insight into the change in 6MWD
over time. Relative to the baseline value, a signi
screening and discharge after LTx was followed by a signi
12 months after LTx.

cant decrease that was evident between
e initial decline could be attributed to surgery, intensive care unit

cant increase at 6 months and

and hospital stay, and (relative) immobilization, especially directly after transplantation.
Another contributing factor was the decline in exercise capacity that may have occurred
between screening and transplantation.

e increase in the period after discharge was
expected as a result of recovery from surgery, increased lung function, an increase in daily
activities, and training.
Remarkably, the initial increase in 6MWD between discharge and 6 months did
not persist up to 12 months. A so-called “ceiling e

ect” may have been reached but,
considering the low average values and the amount of interrecipient variation, it is more likely that other factors contributed to this nding. e use of immunosuppressants,13,39 a
lower proportion of type I (oxidative) muscle

bers,
10,12,13
and an early lactate threshold
6,7
likely contributed to the decreased exercise capacity to a certain extent. Other possible
explanatory factors could be a reduction in the frequency of physical therapist treatment, an
insu

cient training load because of a lack of familiarity of the physical therapist, end of
treatment, or relapse into pre-LTx sedentary behavior patterns. Furthermore, it is possible
that patients were satis

ed when improved functioning relative to the pre-LTx situation
was evident and did not strive for optimal functioning.
Future studies into increasing exercise capacity in recipients of LTxs should take the
period between 6 and 12 months after LTx into account and provide insight into physical
activity levels of daily life. Digital monitoring during this period or regular follow-up
therapy or counseling at a lower frequency could provide opportunities. In addition,
whether the focus should be on maximal peripheral muscle strength or maximal exercise
capacity is questionable. In contrast to focusing on the often proposed need to train 2 or 3
times per week, further research into increasing functional exercise capacity by increasing
52.
and frailty.
Frailty, in turn, has