Background:
Aging leads to an alteration in the immune response, characterized by a chronic
inflammatory state, and a progressive decrease in muscle quantity and quality, a
situation that increases in women and in the presence of obesity. With respect to muscle
quality, intramuscular infiltration of adipose tissue has been considered a relevant
parameter, involved in the relationship between aging-obesity-inflammation. As a
therapeutic strategy, physical training with resistance exercises (or also known as
strength training) has been shown to be effective in increasing skeletal muscle mass in
this age group. However, its role on muscle quality in normal-weight versus obese older
women has not been fully addressed.
Hypothesis:
A 12-week resistance exercise training program is effective in improving muscle quality,
immune response and physical performance in normal weight and obese older women. In
addition to the above, the investigators hypothesize that women with obesity will present
greater baseline alterations, so the percentage of change will be higher compared to
older women with normal weight after the training program.
Goals:
The primary aim of this study is evaluate the effects of a 12-week resistance exercise
training on muscle quality (infiltration of intramuscular adipose tissue), immune
response and physical performance in older women between 60 and 79 years of age with
obesity compared to older women with normal weight of the same age range.
Specific goals:
To evaluate the effects of a 12-week resistance exercise training program in elderly
women between 60 and 79 years of age with obesity, in comparison to older people with
normal weight of the same age range on parameters of:
Muscle architecture (muscle thickness, pennation angle and fascicle length) and
muscle quality functionalities (power and strength).
Immune response through inflammatory cytokines: Tumor necrosis factor a (TNFa)
interleukin-1 (IL-1), IL-6, IL-8 and induction of neutrophil extracellular traps
(NETosis).
Physical performance (SPPB), Body composition (BIA) and quality of life (SF-36).
Methodology:
The present clinical trial will consider 2 study groups of older women between 60 and 79
years old: normal weight (BMI=18.5 to 24.9 kg/m 2 and % fat <25.9) and obese (BMI =30 to
39.9 Kg/m 2 and fat % >32). Participants will perform 12 weeks of training with
resistance exercises 3 times a week. Before and after training, intramuscular
infiltration of adipose tissue (echogenicity) will be measured by ultrasound, followed by
aspects of muscle architecture (muscle thickness, penile angle and fascicle length) and
functional parameters of muscle quality (maximum strength determined by 1 repetition
maximum-1RM, maximum voluntary isometric strength of knee extensors through a lower limb
force and power transducer). Finally, fasting blood samples will be obtained (immune
response) and physical performance, body composition, physical activity level, and
quality of life will be evaluated.
Study parameters/endpoints
The main study endpoint is the decrease in echointensity as a marker of muscle
quality, evaluated through ultrasonography in the quadriceps muscles of the lower
limbs of participants subjected to 12 weeks of resistance training.
Secondary endpoints include: Muscle architecture parameter (morphological aspects of
muscle quality); muscle thickness, pennation angle and fascicle length; Functional
parameters of muscle quality, maximum voluntary isometric strength of knee extensors
and lower limb power; Immune response in blood (TNFa, IL-1, IL-6, IL-8 and NETosis);
Physical performance (SPPB), evaluation of maximum strength (1RM) and handgrip
strength; Body composition (fat mass and total muscle mass and for each lower limb)
and anthropometry (waist - hip, thigh and calf circumference, leg length and knee
height); And Level of physical activity (IPAQ) and Quality of Life (SF-36).
Other study parameters include: Age, body weight, body height, body mass index
(BMI), lipid profile, glucose, insulin, HOMA index, blood pressure, heart rate and
perception of effort using the Borg scale.
Expected results:
The effect of resistance exercise training on muscle quality in normal-weight versus
obese older women is still unclear. The present research project aims to demonstrate the
effectiveness of this training modality in improving muscle quality parameters, as well
as measures of immune response and physical performance in older women. However, the
investigators believe that the impact will be greater in women with obesity, as they
present greater baseline alterations compared to older normal weight women. The possible
findings will define the scientific-practical foundations for the prescription of
physical training in older women with obesity.
