Clinical Trial Details
— Status: Terminated
Administrative data
NCT number |
NCT04106570 |
Other study ID # |
RBHP 2019 BOIRIE 3 (Planeurob) |
Secondary ID |
2019-A00788-49 |
Status |
Terminated |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
December 2, 2019 |
Est. completion date |
June 26, 2023 |
Study information
Verified date |
October 2023 |
Source |
University Hospital, Clermont-Ferrand |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Obese people suffer from significant functional limitations, which affect their quality of
life and limit their physical activity level. Functional abilities are largely determined by
neuromuscular properties, i.e the ability to produce a torque or a power, and fatigability,
i.e the ability to maintain a high level of torque production during repeated contractions.
Our previous studies on "healthy" obese adolescents (i.e without inflammation or metabolic
disorder) suggests that obesity has positive effects on the neural and muscular factors
responsible for torque production, with chronic overload acting as a strength training .
However, this high torque level is associated with higher fatigability. These results are in
contrast with the data obtained on adult obese patients (young and elderly), in whom torque
production and fatigability appear to be more impaired, probably due to the development of
metabolic disorders associated with obesity (inflammation, insulin resistance and lipid
infiltration in muscle) and aging. The respective effects of mechanical overload, metabolic
disorders (insulin resistance and lipid infiltration) and aging on neural and muscular
factors of torque production and neuromuscular fatigue etiology are not currently known in
young adult obese of elderly. Their relationship to the clinical symptoms of mobility
troubles is also unknown. However, this knowledge is crucial for designing physical activity
programs tailored and adapted to the level of metabolic impairment and age of obese patients.
The hypothesis is that mechanical overload associated with obesity has positive effects on
torque production in the absence of metabolic alteration and the effect of aging but negative
effects on fatigability, mainly due to muscular factors; the insulin resistance increases
peripheral fatigue (due to an alteration in the excitability of the sarcolemma during
fatiguing exercise), central fatigue, and slows recovery; the development of inflammation and
lipid infiltration, which are more pronounced in obese subjects, further affect torque
production through inhibition of the nervous control and alteration of contractile properties
and muscle architecture, all these phenomena leading to a decrease in torque production and
increased fatigability, cumulating with the effects of the ageing (sarcopenia).
Description:
The limited data available in the literature suggest that insulin resistance, low-grade
inflammation and muscle lipid infiltration may negatively impact torque production capacity
and promote neuromuscular fatigability. Insulin resistance thus has effects on blood
perfusion of active muscles, via effects on the autonomic nervous system (Petrofsky and al.
2009). Insulin resistance is also associated with a disruption of Na+/K+ pump activity,
excitation-contraction coupling, intracellular ATP concentration (Orlando and al. 2016) and
mitochondrial function (Slattery and al. 2014). All these effects are expected to increase
the development of peripheral fatigue in obese patients with type 2 diabetes and impaired
mitochondrial function is expected to result in impaired post-exercise recovery capacity.
Inflammation can also affect the torque production. Some studies have shown a negative
correlation between muscle torque production and inflammatory status in obese adolescents
(Ruiz and al. 2008) and seniors (Visser and al. 2002). Inflammation is associated with
reduced muscle mass, which may result from inhibition of protein synthesis (Guillet and al.
2012). Inflammation could also have negative effects on the nervous factors of torque
production, via the stimulation of afferences III and IV, as suggested in the healthy subject
(Dousset and al. 2007). However, this has never been demonstrated. Finally, oedema associated
with the inflammatory reaction could modify the architecture and muscle dimensions, as
demonstrated in healthy subjects (Ishikawa and al. 2006) or those suffering from inflammatory
diseases (Kaya and al. 2013). To date, the consequences of low-grade inflammation, combined
or not with aging, on the muscle and nervous factors of force production in obese adults have
yet to be characterized experimentally. Muscle lipid infiltration can also have negative
effects on muscle protein synthesis (Tardif and al. 2014) and especially on strength. This
has been frequently reported in non-obese elderly people (Sipilä and Suominen 1994).
Interestingly, another study reported a negative correlation between intramuscular lipid
content and level of quadriceps voluntary activation in non-obese elderly people (Yoshida and
al. 2012), which may explain the correlation discussed above. To our knowledge, no data are
available for adult obese patients. However, it can be assumed that lipid infiltration would
have inhibitory effects on the level of activation of motor units, and therefore on the
production of force. It is also likely that lipid infiltration limits muscle architectural
adaptations to overweight (contractile and adipose tissues competing to develop in a
restricted muscle volume). Mathematical modelling of the effects of lipid infiltration on
muscle mechanics (Rahemi and al. 2015) suggests that intramuscular lipids could disrupt
contractile activity by limiting the shortening of muscle fascicles, and transverse muscle
deformation during muscle contraction. However, these theoretical predictions have yet to be
confirmed by experimental data.
The PLANEUROB research project is a physiological observational study comparing the
respective effects of mechanical overload, metabolic disorders and age on torque production,
fatigability and functional capacity in obese people. Subjects will have to perform a fatigue
protocol, an adapted Margaria test and a 6 minutes walking test in one session. Blood
samples, muscular ultrasound scanner and physical activity assessment will also be achieved.
Data will be analysed using LabChart 7.3 Pro software (ADInstrument, New South Wales,
Australia), ImageJ (NIH Image, Bethesda, Maryland, USA) and Statistica 8.0 software
(StatSoft, Inc.) and significance will be accepted at a two-sided alpha level of p<.05. The
normality and homogeneity of the variables will be checked respectively from a Shapiro- Wilk
test and a Barlett test. If normality and homogeneity of the variables are verified, absolute
values of variables (Torque, EMG, mean grey, etc.) will be compared using two factors (age x
metabolic disorders) analyses of variance (ANOVA) with repeated measures. If analyses reveal
a significant effect of any factor or interaction of factors, post-hoc Newman-Keuls tests
will be performed to determine differences between the different conditions.