Prospective study of inflammatory response in patients submitted to abdominoplasty after bariatric surgery

the inflammatory response, variations in interleukins and in patients undergoing abdominoplasty. Fourteen patients underwent abdominoplasty after weight loss achieved through bariatric surgery to maintain weight loss for at least18 months. Il4, IL6, IL10 and PCR levels were verified at times: preoperative, during surgery, 24 hours after surgery, 7th postoperative day and 14th postoperative day. Results: IL4 increased in the 24 hours postoperatively and continued on the rise until the 14th day. IL10 went up during surgery and began to fall in the 24 hours postoperatively to levels lower than the initial ones. IL6 began to rise during surgery, being more expressive in the 24 hours postoperatively, followed by a fall until the 14th day. CRP increased 24 hours postoperatively and remained discharged until the 14th day. Conclusion: Abdominoplasty reduced the chronic inflammatory systemic condition. surgery and maintaining the new weight for at least 18 months; being followed up in the body contouring surgery group at the Hospital de Clínicas of FMUSP during the period of the work, the first semester of 2018; in multidisciplinary follow-up, composed of an endocrinologist, digestive tract surgeon, psychologist and plastic surgeon. Exclusion criteria were: patients who were smokers, used contraceptive or replacement hormones, recreational drugs, or that could affect behavior.The average age at the time of plastic surgery was 45.92 years, with extremes ranging from 29 to 60. The average interval between bariatric surgery and abdominoplasty was 5.8 years, ranging from 2 to 12 years. The mean BMI (body mass index) before bariatric surgery was 45.63 kg/m 2, and before abdominoplasty, it was 29.62 kg/m 2 , with extremes of 21.3 to 36.7 kg /m 2 . The average weight of the resected surgical pieces was 2,068kg, varying between 1,000 and 3,600kg (Tables 1 and 2).


INTRODUCTION
O b e s i t y i s a n i n f l a m m a t o r y d i s e a s e 1 , characterized by the production of cytokines, concerning inflammatory responses [2][3][4] . These cytokines are interleukins (IL) produced in fatty tissue thanks to their endocrine properties. Thus, the inflammatory response of obesity causes increased production of inflammatory interleukins and reduces interleukins with anti-inflammatory properties 5 . The variation of these interleukins promotes a change in glycemic and insulinemic profile, characterizing a concomitant metabolic syndrome 6,7 .

OBJECTIVE
This study analyzes the variations in the inflammatory response through changes in interleukin levels and consequent modification of C-reactive protein (CRP) rates of post-bariatric patients submitted to anchor abdominoplasty.

METHODS
The present prospective study was carried out with fourteen female patients who underwent anchor abdominoplasty 8 after weight loss obtained through bariatric surgery. The inclusion criteria were: presenting weight loss at the expense of bariatric Blood samples were collected five times: preoperative, intraoperative, 24 hours after surgery, 7 hours postoperatively and 14 th postoperative day.
Quantitative analyses of interleukins IL4, IL6 and IL10 were performed using the immunoassay method with magnetic beads Milliplex and MagPix System (Merck Millipore, USA). The results were measured in pg/dL (picograms per deciliter).
The C-reactive protein (CRP) was analyzed by C-Reactive Protein Gen. 3. Immunoturbidimetric test for quantitative in vitro determination of PCR in human serum and plasma, using Roche/Hitachi cobas c systems and measured in mg/dL.
The patients signed a free and informed consent form authorizing the study before the procedure.
The project was approved by the hospital's research ethics committee(CAPPesq)under number 48112015.8.0000.0068. It has no support from research funding agencies or private entities, so there is no conflict of interest.

RESULTS
The results obtained were grouped into absolute values and are presented in Table3.

BMI (Kg/m 2 ):
Before bariatric surgery Before abdominoplasty  These results have graphic representation in Figures 1, 2, 3     IL6 increased intraoperatively, being more expressive in the 24 hours after surgery, with a progressive decrease until the 14thpostoperative day.
IL10 increased intraoperatively, followed by a fall lower than the initial levels.
CRP showed a large increase in the first hours after surgery, remaining elevated until the 14th postoperative day.

DISCUSSION
Fatty tissue is responsible for the production of interleukin IL6, considered an inflammatory marker, and IL4 and IL10, anti-inflammatory 2-4 . IL6, in addition to other properties, stimulates the production of inflammatory proteins in the liver, with special emphasis, the object of this study, of C-reactive protein (CRP). The patients in the study, being patients with severe obesity -mean BMI of 45.63 kg/m 2 (35.6 to 56.7 kg/m 2 ) -before bariatric surgery, despite having presented large weight losses, still maintained BMI elevated at the time of abdominoplasty, corresponding to 29.62 kg/m 2 (21.3 to 36.7 kg/m 2 ); therefore, with a basal pattern of inflammatory markers still high, as they are moderately obese. However, it is notorious that the weight loss induced by bariatric surgery, in addition to reducing diseases related to excess weight, minimizes the inflammatory state in morbidly obese patients7-10.
According to the literature 2,11-13 , IL4, with antiinflammatory activity, is produced by interacting the monocyte/macrophage complex with the adipose tissue. In response to the trauma, it begins an upward curve in the first hours of the postoperative period and remains on the rise until the 14th postoperative day.
Patients with compulsions can be considered to have a low degree of chronic inflammation, associated with increased inflammatory markers such as IL6 and CRP 14,15 , which have a considerable increase in the immediate intra and postoperative period, corresponding to the inflammatory response to surgical trauma 16 . CRP, in turn, presents an already high baseline value related to obesity itself, even with surgically achieved weight loss 10 , remaining elevated until the 14th postoperative day in the present study or for up to six months, according to other authors 10,17 .
IL10, an anti-inflammatory cytokine produced by adipocytes, increased intraoperatively, followed by a fall to levels lower than the initial ones. This fact agrees with the bibliography of 12,18 and reveals an anti-inflammatory reaction that accompanies the manifestations of IL6, considered antagonistic and whose inflammatory activity changes in the estimated period.

CONCLUSION
Patients with severe obesity, despite large weight losses at the expense of bariatric surgery, tend to persist with excess dermal fat tissue and, therefore, elevated baseline inflammatory and anti-inflammatory markers that, in response to surgical trauma, change for more time.

COLLABORATIONS NRG
Analysis and/or data interpretation, Conception and design study, Formal Analysis, Methodology, Realization of operations and/or trials, Writing -Review & Editing