Keywords: Obesity - Overweight - Weight loss - Body contouring - Body mass index - Electric
impedance - Bariatric surgery
INTRODUCTION
Obesity is characterized by excess weight resulting from the accumulation of body
fat, characterized by a body mass index (BMI) equal to or above 30
kg/m2 . In Brazil, at the turn of 2002 to 2003, four in ten
Brazilians were overweight. The latest information is that now there are six out
of every ten Brazilians. In other words, around 96 million people are overweight
in the country — that is, the result of their BMI indicates that they are in the
overweight or obese range. If we focus exclusively on the percentage of adults
with obesity, we will see that it more than doubled in the same period, going
from 12.2% to 26.8%. There is no doubt: it is urgent to do something[1 ].
The prevalence of overweight and obesity continues to increase around the world,
and developed countries face a progressive increase in the number of people who
are severely obese (defined as a body mass index of 40kg/m2 )[2 ]. The body mass index used to define
overweight, obesity and morbid obesity is 25.0 to 29.9, 30.0 to 39.9, and above
40 kg/m2 , respectively[3 ].
The prevalence of extreme or grade 3 obesity (BMI>40 kg/m2 ) has
increased threefold in the US over the past four decades, and 3% of adults are
classified as extremely obese. Recent reports also confirm an increase in
prevalence rates in this population. One consequence of this demographic change
is that it is now necessary to assess the body composition of extremely obese
individuals, both in clinical practice and as part of research, to assess the
effectiveness of different treatment programs[4 ].
Body composition and bioimpedance
Some physiological concepts are necessary for general understanding: total
body water is the sum of intracellular and extracellular fluid. Total cell
mass corresponds to intracellular water and visceral proteins. Fat-free mass
corresponds to visceral proteins, total body water, and bone mineral.
Therefore, what remains of this equation is body fat[5 ].
Severe obesity is characterized by large changes in body compartments
compared to overweight or non-obese people. In addition to increased adipose
tissue mass, a general increase in total body hydration, and in particular
an expansion of extracellular water volume (ECW) relative to intracellular
water volume (ICW), generally accompanies this physiological state[6 ]. Bioimpedance analysis (BIA) is easy,
non-invasive, relatively inexpensive, and can be performed on virtually any
individual as it is portable. Data suggest that BIA works well in healthy
individuals and patients with stable water and electrolyte balance with a
validated equation that is age, sex, and race appropriate[7 ].
Inbody Segmental Tetrapolar bioimpedance analysis allows the determination of
fat-free mass (FFM), fat mass (FM), and total body water (TCA) in
individuals without significant changes in fluids and electrolytes, when
using appropriate population equations, age, or pathology and established
procedures. According to the Brazilian Medical Association, segmental
multifrequency bioimpedancemetry equipment that uses 8 electrodes is the
most suitable for assessing body composition and can be considered the most
accurate[8 ].
Treatment
Currently, bariatric surgery is considered the most effective method for
controlling class III obesity (BMI>40kg/m2 ) associated or not
with comorbidities and for class II obesity (BMI>35kg/m2 )
associated with comorbidities. Monitoring body composition is very important
for individuals undergoing bariatric surgery, as the ideal loss of body mass
should be associated with a decrease in body fat mass and the maintenance of
body fat-free mass in the short and long term after surgery[3 ].
Ideally, weight loss should occur primarily due to the reduction in fat mass
(FM), minimizing the loss of fat-free mass (FFM). The assessment of body
composition plays an important role in the clinical assessment and
monitoring of changes in FM and FFM during specific therapeutic regimens in
obese individuals, as a way of determining the effectiveness of
interventions concerning weight loss[9 ].
Post-operative follow-up and plastic surgery
The greatest loss of fat mass occurs in the first 2 years of bariatric
surgery. Patients benefit due to weight loss, improvement in comorbidities,
and increased self-esteem. However, many patients have the disadvantage of
having extensive sagging skin and this has a major impact on their physical
and emotional quality of life. To correct this condition, there are several
procedures that we call body contouring surgery, such as dermolipectomy to
correct an apron abdomen, mammoplasty for sagging breasts; cruroplasty and
brachioplasty to correct excess skin on the thighs and arms,
respectively[10 ].
In the literature, some questionnaires measure the functional effectiveness
of plastic surgery. The BODY-Q proved to be an objective and safe measure to
assess the quality of life of patients after post-bariatric surgery[11 ]. Other studies have proven the
improvement in patients’ quality of life after post-bariatric surgery[12 ].
Patients who underwent body contouring surgery after RYGB surgery maintained
a significantly lower average weight up to 7 years of follow-up than those
who did not have surgery[13 ]. Patients
undergoing body-contouring surgery after laparoscopic adjustable gastric
banding have significant improvement in long-term BMI control[10 ]. Another study showed that body
contouring surgery can help these patients maintain weight loss, in addition
to the proven benefits in quality of life and functionality[14 ], [15 ].
OBJECTIVE
To analyze total body composition before and after plastic surgery in patients
undergoing bariatric surgery, in addition to comparing the percentage of total
body fat before and after plastic surgery in patients undergoing bariatric
surgery.
Check body fat-free mass and visceral fat before and after plastic surgery after
bariatric surgery.
METHOD
The work is an uncontrolled prospective cohort study.
Data collection was carried out at the Obesity and Metabolic Syndrome Surgery
Service of the São Lucas Hospital of the Pontifícia Universidade Católica do Rio
Grande do Sul (HSL/PUCRS), room 801.
Only women were chosen, as the majority of patients undergoing bariatric surgery
are female.
The patients had their body composition assessed by segmental Tetrapolar
Bioimpedance InBody 770 at the Bariatric and Metabolic Surgery and Plastic
Surgery Clinic of the PUCRS Clinical Center (COM-PUCRS) before plastic surgery
and 90 days after the procedure. The exams will be paid for by the COM-PUCRS
service.
The procedure performed was dermolipectomy to correct the apron abdomen. The
volume of the liposuction (if associated with the procedure), the absolute
weight in grams of the tissue removed, which will be transformed into volume to
add to the liposuctioned fat, and its percentage concerning the patient’s weight
was measured.
Sample size
The body fat percentage (BFP) of a normal female person is 18 to 28%. The
average of pre-plastic surgery patients is 34%, in a range of 29 to 40,
which gives a standard deviation of 3.5. For an α=5% and a statistical power
of 90%, 30 patients are needed to evaluate the minimum clinically relevant
difference of 2.2 percentage points of BFP.
Inclusion criteria
As inclusion criteria, the following were defined: Women (18 to 60 years
old), abdominal dermolipectomy as surgery performed, post-bariatric surgery
patients who underwent treatment with Sleeve or gastric bypass,
participation permitted by the attending physician, having read and agreed
to participate voluntarily and have signed the Free and Informed Consent
Form.
Exclusion criteria
Patients with the use of medications that alter body physiology, severe and
decompensated psychiatric illness, and altered preoperative exams (blood
count, TP/KTTP fasting blood glucose, and creatinine) were excluded from the
study.
Data analysis
The data were entered into the Excel program and later exported to the IBM
SPSS statistics version 20.0 program for statistical analysis. The normality
of the variables was checked using the Shapiro-Wilk test. Quantitative
variables were described by mean and standard deviation and compared using
Student’s t-test for paired samples. The mean difference and its 95%
confidence interval were presented. To evaluate the correlation between
measurements, Pearson’s correlation coefficient was used, and simple linear
regression was used to evaluate the variation in visceral fat according to
variations in peripheral fat and percentage of total body fat. A
significance level of 5% was considered for the comparisons established.
Study limitations
Difficulty in having comparative data in previous studies.
Scientific and ethical approvals
This project will be sent to the HSL Research Committee (CPC) and the
Scientific Committee of the PUCRS School of Medicine (ESMED). It was then
submitted and approved on Plataforma Brasil by the PUCRS Research Ethics
Committee. It should be noted that the study is following Resolution No.
466/2012 of the National Health Council, which provides for Ethics in
Research with Human Beings and Terms of Commitment in the Use of Data
(TCUD).
It should be noted that the TCUD foresees the possibility of sharing data in
the future to build an interinstitutional database that allows new analyses
that increase the robustness of research by expanding the sample size.
Furthermore, it includes the use of data by the main researchers for
analysis with Artificial Intelligence for relevant detections on the topic
and the development of new technologies.
RESULTS
Thirty patients were included, of which 6 did not undergo postoperative
bioimpedance analysis, therefore, it was not possible to compare them with the
preoperative period. Data were collected from 24 female participants, with a
mean age of 43.5 years (standard deviation of 10.2 years). The average weight of
the piece was 1696 grams (standard deviation of 929 grams).
When comparing the average percentage of total body fat, total, visceral, and
peripheral fat, there was no statistically significant difference. Weight
dropped significantly (p = 0.024) and, as expected, there was also a
statistically significant decrease in body mass index (p =
0.017) ([Table 1 ]).
Table 1.
Measurements
Pre
Post
Difference (CI 95%)
p*
%
of body fat total
31.4±7.81
30.95±7.86
−0.59 (−1.83 to 0.66)
0.339
Total fat
22.38±6.15
21.57±6.00
−0.80 (−1.94 to 0.33)
0.156
Visceral fat
10.42±3.49
9.96±3.38
−0.46 (−1.03 to 0.11)
0.110
Peripheral fat
21.14±5.93
20.40±5.89
−0.74 (−1.86 to 0.38)
0.183
Weight
70.91±7.19
69.36±7.17
−1.55 (−2.88 to 0.22)
0.024
Body Mass Index
27.00±2.39
26.40±2.60
−0.60 (−1.09 to 0.12)
0.017
Interpretation: For example, the average total body fat percentage was 31.54%
before surgery and decreased to 30.95%. It fell by an average of 0.59, and with
95% confidence, the average difference is a number that goes from −1.83 (the
negative sign shows that it decreased) to an increase of 0.66 (because the upper
limit of the range has a positive sign). So, the average variation could be a
decrease and could even be a small increase. There was no significant difference
(because p is greater than 0.05).
Of 13 patients with visceral fat greater than or equal to 10, 3 (23.1%) had
visceral fat below 10.
In the following mean and error bar graphs, where the circle represents the mean
and the bar represents the standard deviation, the results of the comparison of
measurements before and after surgery are presented ([Figures 1 ] and [2 ]).
Figure 1. % total body fat.
Figure 2. Vιsceral fat.
When evaluating the correlation between the change in peripheral and visceral
fat, this correlation was statistically significant, direct, and strong (r=0.89;
p <0.001). For a variation of 1 unit of peripheral fat,
visceral fat varies by 0.46 units. When evaluating the correlation between the
change in the percentage of total and visceral fat, this correlation was
statistically significant, direct, and strong (r=0.84;
p <0.001). For a variation of 1 unit, the percentage of total
body fat varies by 0.38 units in visceral fat ([Figure 3 ]).
Figure 3. Pre- and post-visceral fat difference x total body fat
percentage.
DISCUSSION
Obesity is currently a globally prevalent disease and its treatments are
increasingly refined and optimized. Bariatric surgery is one of the
fastest-growing procedures today, and even without large studies, post-bariatric
plastic surgery brings excellent aesthetic and restorative benefits to the
health of these patients.
Some studies show that post-obesity surgery plastic surgery helps maintain weight
loss in the long term. The reasons for this are not known, but we believe that
plastic surgery provides reasons for patients to continue taking care of
themselves or that the profile of the patient who undergoes reconstructive
surgery is more prone to postoperative care[15 ]. Concerning quality of life, several studies highlight the
importance that reconstructive surgery has in improving both self-esteem and
health in this group of patients[11 ].
In the present study, we were able to observe that patients who underwent
dermolipectomy lost more weight and, consequently, lowered their muscle mass
indexes, which is compatible with the removal of dermoadipose tissue during the
procedure. This corroborates the initial hypothesis and we know that only the
surgical procedure can perform this correction of excess tissue.
In relation to the percentage of body fat, peripheral fat, visceral fat, and
total fat, although not statistically significant, there was a reduction in
absolute numbers. The reason for not alternating more values may be related to
weight regain, which occurs mainly after 2 years of bariatric surgery[15 ]. Another issue may be stopping physical
activities due to the postoperative period. This issue can be better elucidated
with longer postoperative follow-up or other studies that better evaluate these
parameters.
Finally, we were able to observe that there is a direct, strong, and
statistically significant correlation between the percentage of body fat and
visceral fat, in addition to the same happening with peripheral fat and visceral
fat. This shows that the patient who loses the most peripheral fat loses the
most visceral fat, which is the fat related to various diseases and health
problems. This correlation opens up the possibility of new studies to evaluate
another benefit of reconstructive plastic surgery, which is its clinical impact
on bariatric patients.
CONCLUSION
In the present study, we can conclude that the percentage of body fat did not
change significantly before and after plastic surgery. However, there is a
decrease in this percentage of fat, and even though it is not statistically
significant, it is directly proportional to the decrease in visceral fat, which
is the fat that most impacts our health. With this, we can say that
post-bariatric plastic surgery, among many benefits, has a positive impact on
the body composition of patients.
Bibliographical Record
