Neuromuscular Plasticity in Response to Obesity: Effects of Mechanical Overload, Metabolic Disorders and Age

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).

Conditions

• Obesity

Interventions

OTHER

fatiguability of the knee extensors

fatiguability of the knee extensors (in N.m) measured with a dynamometer.

Sponsors & Collaborators

• AME2P Laboratory, Clermont Auvergne University

  collaborator UNKNOWN

• University Hospital, Clermont-Ferrand

  lead OTHER

Principal Investigators

• Yves Boirie · University Hospital, Clermont-Ferrand

Study Design

Allocation

NON_RANDOMIZED

Purpose

OTHER

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2019-12-02

Primary Completion

2023-06-26

Completion

2023-06-26

Countries

• France

Study Locations