Feasibility and reproducibility of different methods to define muscle mass in obese patients

Obesity is a global health problem. Together with overweight, one third of the
total world population is affected, with numbers expecting to rise further in
the upcoming decades. Obesity increased the risk of comorbidities such as
cardiovascular disease, type 2 diabetes mellitus, sleep apnoea, depression, and
mortality. Obesity is also associated with negative effects on skeletal muscle.
These include an increased risk developing functional disabilities, including
postural, mobility, strength and dynamic balance limitations. Something which
is often overlooked in obese patients is sarcopenic obesity. Sarcopenia is
defined as low muscle mass and either low muscular strength or low physical
performance. Different methods can be used to define muscle mass, where the
golden standard technique are imaging techniques such as magnetic resonance
imaging (MRI) and computed tomography (CT). The problem with these imaging
methods are the weight and radial size limitations. Tools that can be used to
estimate muscle mass and strength indirectly are easy and less costly than the
earlier mentioned methods. Examples of these calculations are limb
circumference, skinfold thickness, bioelectrical impedance analysis, handgrip
strength test, stair stand test, and a 6-minute walking test. Until now, these
tests have not been validated in class II and III obese populations.

Primary Objective: to investigate feasibility and reproducibility of different
methods to define muscle mass in obese patients.
Secondary Objective(s): whether quality of life is linked to muscle mass and
strength in obese individuals.

This study is cross-sectional without intervention. Measurements will take
place on the day of screening of patients who have applied for bariatric
surgery. The main procedures are anthropometric measurements, 6-minute walking
test, hand grip strength test and chair stand test. Urine will be collected
during a period of 24 hours for creatinine levels. Correlation with quality of
life score and blood parameters , which are both already included in standard
patient care will also be investigated.

Both the risks and the benefits are limited for the patients. The various
measurements will take some extra time during the visit. There is also some
physical and mental effort required for the patient, something which they might
not be familiar with. This could result in minor muscle strain the days after.
The results of this study could be helpful for future patients undergoing
bariatric surgery.