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 something1.
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, respectively3.
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 programs4.
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
fat5.
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 state6. 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 appropriate7.
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 accurate8.
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 surgery3.
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 loss9.
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, respectively10.
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 surgery11. Other studies have proven the improvement in patients’ quality of life after post-bariatric
surgery12.
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 surgery13. Patients undergoing body-contouring surgery after laparoscopic adjustable gastric
banding have significant improvement in long-term BMI control10. 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 functionality14, 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 - Patient measurements at different assessment times.
| 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 |
Table 1 - Patient measurements at different assessment times.
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 1 - % total body 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.
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
care15. Concerning quality of life, several studies highlight the importance that reconstructive
surgery has in improving both self-esteem and health in this group of patients11.
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 surgery15. 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.
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1. Hospital São Lucas da PUCRS, Division of Obesity and Metabolic Syndrome, Porto
Alegre, RS, Brazil
2. Hospital São Lucas da PUCRS, Division of Plastic Surgery, Porto Alegre, RS, Brazil
3. Hospital Geral, Division of Surgery, Caxias do Sul, RS, Brazil
Corresponding author: Matheus Piccoli Martini Av. Ipiranga, 6690 - Partenon, Porto Alegre, RS, Brazil. Zip Code: 90610-001. E-mail:
martini_matheus@hotmail.com
