The Early Effects of Weight Loss Surgery on Regional Adiposity

Comparative Effects of Medical Versus Surgical Weight Loss on Body Composition: a Pilot Randomized Trial

OBJECTIVE

Bariatric surgery leads to more rapid and greater weight loss (WL) compared to medical weight loss (MWL), but the differences in body composition (BC) changes for these modalities remain unclear. Due to the known health risks associated with central adiposity, we compared the changes in regional distribution of fat mass (FM) and lean mass (LM) after surgical versus MWL.

METHODS

In this 1:1:1 randomized trial among 15 persons with type 2 diabetes and body mass index (BMI) 30-39.9 kg/m², we compared changes in BC, by dual-energy X-ray absorptiometry and abdominal computerized tomography, at time of 10%WL or 9 months after intervention (whichever came first). Participants underwent MWL, adjustable gastric banding (AGB), or Roux-en-Y gastric bypass (RYGB). Non-parametric tests evaluated BC differences (FM, LM, and visceral adipose tissue [VAT]) within and across all three arms and between pair-wise comparisons.

RESULTS

Twelve female participants (75% African American) completed the study. Patient age, BMI, and baseline anthropometric characteristics were similar across study arms. AGB lost more LM (MWL - 5.2%, AGB - 10.3%, p = 0.021) and VAT (MWL + 10.9%, AGB - 28.0%, p = 0.049) than MWL. RYGB tended to lose more VAT (MWL +10.9%, RYGB - 20.2%, p = 0.077) than MWL. AGB tended to lose more LM than RYGB (AGB - 12.38%, RYGB - 7.29%, p = 0.15).

CONCLUSIONS

At similar WL, AGB lost more LM and VAT than MWL; RYGB similarly lost more VAT. Given the metabolic benefits of reducing VAT and retaining LM, larger studies should confirm the changes in BC after surgical versus medical WL.

CLINICAL TRIAL REGISTRATION

NCTDK089557 - ClinicalTrials.gov.

The role of visceral adipose tissue on improvement in insulin sensitivity following Roux-en-Y gastric bypass: a study in Chinese diabetic patients with mild and central obesity

Background

Most Chinese patients with type 2 diabetes mellitus (T2DM) have mild obesity and central obesity. Central obesity is combined with insulin resistance. The aim of this study was to assess the effect of abdominal adipose tissue on insulin-sensitivity improvement after Roux-en-Y gastric bypass (RYGB) in Chinese diabetic patients with mild and central obesity.

Methods

Seventeen T2DM patients with a mean body mass index of 30.3 kg/m² were scheduled for laparoscopic RYGB. A hyperinsulinemic-euglycemic clamp and dual-energy X-ray absorptiometry were performed prior to surgery and 3 months after RYGB. The primary end points were the correlations between insulin sensitivity and abdominal adipose tissue, including visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT), before and 3 months after RYGB.

Results

Indices of peripheral insulin sensitivity, including glucose-disposal rate (M value) and glucose infusion rate, were significantly increased after RYGB. Body-fat mass, VAT and SAT were significantly reduced after RYGB. The pre-operative M value was significantly correlated with VAT mass (r = –0.57, P = 0.02), but not correlated with SAT mass. M value changes after RYGB were highly correlated with changes in VAT mass (r = –0.59, P = 0.01), percentage of VAT mass (r = –0.66, P < 0.01), VAT area (r = –0.56, P = 0.02) and percentage of VAT area (r = –0.57, P = 0.02).

Conclusions

A significant correlation was observed between increased peripheral insulin sensitivity and decreased VAT following RYGB in Chinese patients with mild and central obesity. VAT and SAT were significantly decreased with improved insulin sensitivity after RYGB. VAT mass may be considered as an indication for gastric bypass during patient selection.

Visceral Adipose Tissue Accumulation and Residual Cardiovascular Risk

PURPOSE OF THE REVIEW

Low-grade systemic inflammation increases residual cardiovascular risk. The pathogenesis of low-grade systemic inflammation is not well understood.

RECENT FINDINGS

Visceral adipose tissue accumulates when the subcutaneous adipose tissue can no longer store excess nutrients. Visceral adipose tissue inflammation initially facilitates storage of nutrients but with time become maladaptive and responsible for low-grade systemic inflammation. Control of low-grade systemic inflammation requires reversal of visceral adipose tissue accumulation with intense and sustained aerobic exercise or bariatric surgery. Alternatively, pharmacologic inhibition of the inflammatory signaling pathway may be considered. Reversal visceral adipose tissue accumulation lowers residual cardiovascular risk.

Continued loss in visceral and intermuscular adipose tissue in weight-stable women following bariatric surgery

OBJECTIVE

To assess changes in total (TAT), subcutaneous (SAT), visceral (VAT), and intermuscular (IMAT) adipose tissue by whole-body MRI before surgery and at 12 months and 24 months post-surgery in a subset of participants of the Longitudinal Assessment of Bariatric Surgery-2.

METHODS

From 0 to 12 months, n = 20 females and 3 males; from 12 to 24 months, n = 42 females and 7 males. Paired t-tests and GLM repeated measures examined changes in TAT, SAT, VAT, and IMAT at 12 and 24 months, with sex and age as covariates.

RESULTS

Changes from 0 to 12 months included weight (-41.9 ± 12.1 kg; -36%), TAT (-33.5 ± 9.6 kg; -56%), SAT (-29.2 ± 8.2 kg; -55%), VAT (-3.3 ± 1.6 kg; -73%), and IMAT (-0.99 ± 0.68 kg; -50%), all P < 0.001. In females, from 12 to 24 months, despite relative weight stability (-1.8 ± 6.5 kg, -2%; P = 0.085), VAT (-0.5 ± 0.7 kg; -30%; P < 0.001) and IMAT (-0.2 ± 0.4 kg; -14%; P = 0.012) decreased further. In males, from 12 to 24 months, weight increased (5.1 ± 5.2 kg; 6%; P = 0.04) with no significant changes in TAT or sub-depots.

CONCLUSIONS

Bariatric surgery continues to induce favorable changes in body composition, i.e., persistent adipose tissue loss at 24 months in the absence of further significant weight loss.

Preoperative nutritional interventions in morbid obesity: impact on body weight, energy intake, and eating quality

BACKGROUND

Although the benefits of preoperative weight loss and adequacy of dietary patterns in bariatric surgery is well-recognized, the nutritional strategies in the preoperative period have been scarcely investigated. We aimed to evaluate the impact of intensive and standard nutritional interventions on body weight, energy intake, and eating quality.

METHODS

This is a retrospective study in which 32 patients undergoing intensive nutritional intervention, with low-calorie diet (10 kcal/kg) and biweekly visits, were pair-matched by age, sex, and body mass index with 32 patients under a standard nutritional intervention, based on a general dietary counseling. Twenty-four-hour food recall was used to assess energy intake and to derive healthy eating index (HEI). The follow-up preoperative period varied from 8 to 16 weeks.

RESULTS

Weight loss was observed in 72% of the patients from the intensive intervention group and 75% of the patients from the standard intervention group. According to the mixed model analysis, time effect on weight loss in both groups was significant (P = 0.0002); however, no difference was found between the intervention groups (P = 0.71). The time effect was significant in both groups for energy intake reduction as well (P < 0.0001), but no difference was found between the intervention groups (P = 0.25). Improvement of eating quality was expressed by the nutrient score of the HEI that increased significantly overtime (P = 0.02), also without distinction between the groups (P = 0.61).

CONCLUSION

Both intensive and standard nutritional interventions promoted weight loss, energy intake reduction, and improvement of eating quality in morbidly obese patients during preoperative period.

Macroscopic anatomic changes of subcutaneous fat tissue in massive-weight-loss patients

BACKGROUND

After massive weight loss (MWL), patients are known to experience significant improvement in obesity-associated comorbid conditions and metabolic disturbances, but almost two-thirds of them require reconstructive body-contouring surgery.

METHODS

The authors present an anatomic study of surgical pieces obtained from 28 patients (17 women and 11 men) during torsoplasty and abdominoplasty procedures performed in their department from January 2007 to January 2008. The patients ranged in age from 39 to 52 years (mean, 43.3 years). The patients were divided into three groups. Group A consisted of 9 patients who had a normal body mass index (BMI) and stable weight (±5 kg) over the preceding 3 years. Group B consisted of 10 patients who had followed a nutritional diet over the preceding 3 years, achieving a mean weight loss of 42.2 kg (range, 38-52 kg). Group C consisted of 9 patients who had undergone bariatric surgery and insertion of a gastric band before 2004, achieving a mean weight loss of 47 kg (range, 40-57 kg). The authors evaluated the anatomy of the subcutaneous tissue in four body areas: the epigastric, umbilical, hypogastric, and lumbar regions.

RESULTS

The macroscopic anatomic results of the subcutaneous tissue in the three groups are presented. The patients who underwent bariatric surgery (group C) had significant alterations of the subcutaneous tissue anatomy in all four body areas studied. Plastic surgeons who perform composite body-contouring procedures for this group of patients, combining truncal liposuction and lipoabdominoplasty procedures, should be aware of these anatomic changes. The possibility of a cannula perforating an internal organ during liposuction may have been higher for the group C patients than for the group A and group B patients.

CONCLUSION

Knowledge concerning the anatomy of the subcutaneous fat in post-MWL patients allows a better choice of contouring procedure from an anatomic point of view, performance of a more rational and effective procedure, and differentiation of the technique depending on the area of the body, avoiding major complications.

Visceral obesity is a negative predictor of remission of diabetes 1 year after bariatric surgery

Our aim was to identify preoperative anthropometric and clinical parameters that predict the remission of diabetes after Roux-en-Y gastric bypass (RYGB). Fifty severely obese Korean patients with type 2 diabetes underwent RYGB. Visceral and abdominal subcutaneous fat area (SFA) was assessed using computed tomography before and 6 and 12 months after RYGB. Remission was defined as a glycated hemoglobin (A(1C)) level <6.5% and a fasting glucose concentration <126 mg/dl for 1 year or more without the use of medication. The visceral-to-SFA ratio decreased from 0.60 ± 0.30 to 0.53 ± 0.29 (P = 0.001) after 6 months and decreased further to 0.42 ± 0.24 (P < 0.001) after 12 months. Thirty-four of the 50 patients (68%) had remission of diabetes (remission group). Compared with patients in the nonremission group, patients in the remission group had a shorter duration of diabetes and lower preoperative A(1C) level, and were less likely to use insulin preoperatively. Preoperative BMI did not differ in two groups. However, the preoperative visceral-to-SFA ratio was greater in the nonremission group compared with the remission group (0.79 ± 0.29 vs. 0.53 ± 0.26, P = 0.003). Finally, the preoperative visceral-to-SFA ratio was an independent predictor of the remission of diabetes after RYGB in multiple stepwise logistic regression analysis. In conclusion, our data suggest that visceral adiposity negatively influence the likelihood of the patient experiencing the remission of diabetes after RYGB.

Hepatic steatosis in morbidly obese patients undergoing gastric bypass surgery: assessment with open-system 1H-MR spectroscopy

OBJECTIVE

The purpose of this study was to assess, with histopathologic control, the use of open-system 1-T (1)H MR spectroscopy for the evaluation of hepatic steatosis in morbidly obese patients undergoing gastric bypass surgery.

SUBJECTS AND METHODS

Patients underwent (1)H MR spectroscopy (MRS) for the assessment of steatosis before and 3 months after surgery. Liver biopsy was performed during surgery. Hepatic steatosis was expressed as the ratio of fat peak area to cumulative water and fat peak areas. Histopathologic percentage of steatosis was graded as none (0-5%), mild (5-33%), moderate (33-66%), or severe (> 66%). The accuracy of (1)H-MRS and Spearman correlation coefficient were calculated. Differences between groups were assessed with the Wilcoxon signed rank and Mann-Whitney tests.

RESULTS

The study included 38 patients (median age, 45.5 years; median body mass index, 47.7). Before surgery, median steatosis measured with (1)H-MRS was 5.8%. The accuracy of (1)H-MRS was 89% (32/36), and the (1)H-MRS findings correlated with the histopathologic assessment of steatosis (r = 0.85, p < 0.001). With (1)H-MRS, no steatosis was discriminated from mild steatosis (p = 0.011), mild was discriminated from moderate steatosis (p < 0.001), and moderate was discriminated from severe steatosis (p = 0.021). Three months after surgery, steatosis had decreased to 3.1% (p < 0.001). The prevalence of hepatic steatosis measured with (1)H-MRS decreased from 53% to 32%.

CONCLUSION

In the care of morbidly obese patients undergoing assessment of hepatic steatosis and changes in steatosis after gastric bypass surgery, (1)H-MRS with an open 1-T MRI system is feasible. Measurements of hepatic fat with (1)H-MRS are accurate and correlate with clinical and histopathologic results.

Association of pericardial fat with liver fat and insulin sensitivity after diet-induced weight loss in overweight women

Pericardial adipose tissue (PAT) is positively associated with fatty liver and obesity-related insulin resistance. Because PAT is a well-known marker of visceral adiposity, we investigated the impact of weight loss on PAT and its relationship with liver fat and insulin sensitivity independently of body fat distribution. Thirty overweight nondiabetic women (BMI 28.2-46.8 kg/m(2), 22-41 years) followed a 14.2 ± 4-weeks low-calorie diet. PAT, abdominal subcutaneous (SAT), and visceral fat volumes (VAT) were measured by magnetic resonance imaging (MRI), total fat mass, trunk, and leg fat by dual-energy X-ray absorptiometry and intrahepatocellular lipids (IHCL) by ((1))H-magnetic resonance spectroscopy. Euglycemic hyperinsulinemic clamp (M) and homeostasis model assessment of insulin resistance (HOMA(IR)) were used to assess insulin sensitivity or insulin resistance. At baseline, PAT correlated with VAT (r = 0.82; P < 0.001), IHCL (r = 0.46), HOMA(IR) (r = 0.46), and M value (r = -0.40; all P < 0.05). During intervention, body weight decreased by -8.5%, accompanied by decreases of -12% PAT, -13% VAT, -44% IHCL, -10% HOMA2-%B, and +24% as well as +15% increases in HOMA2-%S and M, respectively. Decreases in PAT were only correlated with baseline PAT and the loss in VAT (r = -0.56; P < 0.01; r = 0.42; P < 0.05) but no associations with liver fat or indexes of insulin sensitivity were observed. Improvements in HOMA(IR) and HOMA2-%B were only related to the decrease in IHCL (r = 0.62, P < 0.01; r = 0.65, P = 0.002) and decreases in IHCL only correlated with the decrease in VAT (r = 0.61, P = 0.004). In conclusion, cross-sectionally PAT is correlated with VAT, liver fat, and insulin resistance. Longitudinally, the association between PAT and insulin resistance was lost suggesting no causal relationship between the two.

Acute effects of gastric bypass versus gastric restrictive surgery on beta-cell function and insulinotropic hormones in severely obese patients with type 2 diabetes

CONTEXT

Hyperglycemia resolves quickly after bariatric surgery, but the underlying mechanism and the most effective type of surgery remains unclear.

OBJECTIVE

To examine glucose metabolism and beta-cell function in patients with type 2 diabetes mellitus (T2DM) after two types of bariatric intervention; Roux-en-Y gastric bypass (RYGB) and gastric restrictive (GR) surgery.

DESIGN

Prospective, nonrandomized, repeated-measures, 4-week, longitudinal clinical trial.

PATIENTS

In all, 16 T2DM patients (9 males and 7 females, 52+/-14 years, 47+/-9 kg m(-2), HbA1c 7.2+/-1.1%) undergoing either RYGB (N=9) or GR (N=7) surgery.

OUTCOME MEASURES

Glucose, insulin secretion, insulin sensitivity at baseline, and 1 and 4 weeks post-surgery, using hyperglycemic clamps and C-peptide modeling kinetics; glucose, insulin secretion and gut-peptide responses to mixed meal tolerance test (MMTT) at baseline and 4 weeks post-surgery.

RESULTS

At 1 week post-surgery, both groups experienced a similar weight loss and reduction in fasting glucose (P<0.01). However, insulin sensitivity increased only after RYGB, (P<0.05). At 4 weeks post-surgery, weight loss remained similar for both groups, but fasting glucose was normalized only after RYGB (95+/-3 mg 100 ml(-1)). Insulin sensitivity improved after RYGB (P<0.01) and did not change with GR, whereas the disposition index remained unchanged after RYGB and increased 30% after GR (P=0.10). The MMTT elicited a robust increase in insulin secretion, glucagon-like peptide-1 (GLP-1) levels and beta-cell sensitivity to glucose only after RYGB (P<0.05).

CONCLUSION

RYGB provides a more rapid improvement in glucose regulation compared with GR. This improvement is accompanied by enhanced insulin sensitivity and beta-cell responsiveness to glucose, in part because of an incretin effect.

Short-term dynamics and metabolic impact of abdominal fat depots after bariatric surgery

OBJECTIVE

Bariatric surgery is gaining acceptance as an efficient treatment modality for obese patients. Mechanistic explanations regarding the effects of bariatric surgery on body composition and fat distribution are still limited.

RESEARCH DESIGN AND METHODS

Intra-abdominal and subcutaneous fat depots were evaluated using computed tomography in 27 obese patients prior to and 6 months following bariatric surgery. Associations with anthropometric and clinical changes were evaluated.

RESULTS

Excess weight loss 6 months following surgery was 47% in male and 42.6% in female subjects. Visceral fat and subcutaneous fat were reduced by 35% and 32%, respectively, in both sexes, thus the visceral-to-subcutaneous fat ratio remained stable. The strongest relation between absolute and relative changes in visceral and subcutaneous fat was demonstrated for the excess weight loss following the operations (r approximately 0.6-0.7), and these relations were strengthened further following adjustments for sex, baseline BMI, and fat mass. Changes in waist circumference and fat mass had no relation to changes in abdominal fat depots. All participants met the criteria of the metabolic syndrome at baseline, and 18 lost the diagnosis on follow-up. A lower baseline visceral-to-subcutaneous fat ratio (0.43 +/- 0.15 vs. 0.61 +/- 0.21, P = 0.02) was associated with clinical resolution of metabolic syndrome parameters.

CONCLUSIONS

The ratio between visceral and subcutaneous abdominal fat remains fairly constant 6 months following bariatric procedures regardless of sex, procedure performed, or presence of metabolic complications. A lower baseline visceral-to-abdominal fat ratio is associated with improvement in metabolic parameters.

Abdominal adiposity and liver fat content 3 and 12 months after gastric banding surgery

Weight loss after laparoscopic adjustable gastric banding surgery (LAGB) is associated with mobilization of adipose tissue from a variety of depots. We sought to evaluate and relate abdominal and hepatic lipid deposition in an obese female population 3 and 12 months after LAGB. We related changes in these depots to markers of insulin sensitivity. Eighteen female obese subjects underwent magnetic resonance imaging and spectroscopy before and 3 and 12 months after LAGB for the quantification of abdominal subcutaneous (ABSAT) and visceral (VAT) adipose tissue areas and liver fat content (LFAT). Fasting blood free fatty acids (FFA) were analyzed. Insulin sensitivity was assessed by the homeostasis model assessment of insulin resistance index (HOMA-R). Mean weight loss 3 and 12 months after LAGB was 9.8 +/- 1.1 kg and 20.0 +/- 2.2 kg, respectively. Postoperatively, VAT area loss exceeded ABSAT area loss in the cohort as a whole and when divided according to preoperative liver fat stores. Three months after LAGB, reductions had occurred in VAT and ABSAT areas (both P < .01) and in FFA (P < .05). Twelve months after LAGB, further significant reductions (P < .01) occurred in VAT and ABSAT areas but not in FFA. No significant reduction occurred in LFAT at either time point in the group as a whole. In those with preoperative hepatic steatosis (LFAT > approximately 5%, n = 7), LFAT fell by 42% (P = .036) 3 months after LAGB, with a total reduction of 50% (P = .027 cf baseline) occurring by 12 months. There was an improvement in HOMA-R at 12 months (1.9 +/- 0.3 cf 2.9 +/- 0.5 at baseline, P = .04) but not 3 months (2.7 +/- 0.4). Preoperatively, LFAT related significantly to VAT area (r = 0.67, P = .003) and HOMA-R (r = 0.497, P = .04) but not ABSAT area. Postoperatively at both 3 and 12 months, LFAT continued to relate to VAT area (r = 0.63, P < .01 at both time points) but not HOMA-R. The changes in LFAT and VAT area were unrelated postoperatively. Abdominal adipose tissue loss was greater from the visceral than subcutaneous depots, suggesting that insulin sensitivity may not be an important determinant of selective lipid depot loss. The lack of a significant change in liver fat in the group as a whole may relate to low preoperative liver fat stores and to high postoperative dietary fat intakes. Preoperative liver fat stores did not influence insulin sensitivity or abdominal lipid changes during weight loss. Liver fat content and VAT area interrelated more closely than either related to ABSAT area, suggesting differing regulatory pathways for fat mobilization from ABSAT and VAT depots but possibly similar pathways for storage and mobilization of fat in the liver and viscerally.

Ghrelin and apolipoprotein AIV levels show opposite trends to leptin levels during weight loss in morbidly obese patients

BACKGROUND

Although bariatric surgery is the most common procedure used to induce weight loss in morbidly obese patients, its effect on plasma satiety factors (leptin, ghrelin, and apolipoprotein (apo)-AIV) is controversial. The aim of this work was to analyze these parameters before and at different times after surgery.

METHODS

Plasma was obtained from 34 patients before undergoing Roux-en-Y gastric bypass and during weight loss in the 12 months following surgery.

RESULTS

Morbidly obese patients had significantly higher values (147%) of leptin than normal-weight (NW) persons, while their ghrelin levels were 46% less than NW. Apo-AIV levels had approximately the same value in both groups (obese and NW). During weight loss, leptin decreased by 75% and ghrelin increased by 78%. Both parameters reached values less than or near NW, respectively, at 1 year after surgery. During the first month after surgery, apo-AIV plasma levels decreased (47%) but later increased and finally returned to preoperative values. Apo-AIV levels were correlated negatively with leptin and positively with ghrelin. High-density lipoprotein (HDL) levels were positively correlated with those of ghrelin and apo-AIV.

CONCLUSIONS

During weight loss, plasma leptin and ghrelin could be good markers of total fat decrease. Ghrelin could also indicate gastric mucous improvement, whereas apo-AIV could indicate the recovery of intestinal function. Changes produced in the HDL levels of morbidly obese patients during weight loss suggest a decreased risk of coronary disease.

Factors associated with percent change in visceral versus subcutaneous abdominal fat during weight loss: findings from a systematic review

BACKGROUND

Visceral adipose tissue (VAT) is associated with greater obesity-related metabolic disturbance. Many studies have reported preferential loss of VAT with weight loss.

OBJECTIVE

This systematic review looks for factors associated with preferential loss of VAT relative to subcutaneous abdominal fat (SAT) during weight loss.

DESIGN

Medline and Embase were searched for imaging-based measurements of VAT and subcutaneous abdominal adipose tissue (SAT) before and after weight loss interventions. We examine for factors that influences the percentage change in VAT versus SAT (%deltaV/%deltaS) with weight loss. Linear regression analyses were performed on the complete data set and on subgroups of studies. Factors examined included percentage weight loss, degree of caloric restriction, exercise, initial body mass index (BMI), gender, time of follow-up and baseline VAT/SAT.

RESULTS

There were 61 studies with a total of 98 cohort time points extracted. Percentage weight loss was the only variable that influenced %deltaV/%deltaS (r=-0.29, P=0.005). Modest weight loss generated preferential loss of VAT, but with greater weight loss this effect was attenuated. The method of weight loss was not an influence with one exception. Very-low-calorie diets (VLCDs) provided exceptional short-term (<4 weeks) preferential VAT loss. But this effect was lost by 12-14 weeks.

CONCLUSIONS

Visceral adipose tissue is lost preferentially with modest weight loss, but the effect is attenuated with greater weight loss. Acute caloric restriction, using VLCD, produces early preferential loss of VAT. These observations may help to explain the metabolic benefits of modest weight loss.

Intragastric balloon reduces liver volume in super-obese patients, facilitating subsequent laparoscopic gastric bypass

BACKGROUND

Surgery in patients with super-obesity (BMI > or = 50) involves technical difficulties that are related, among other factors, to increased liver volume. Although the intragastric balloon is not a definitive alternative to surgery, it has been used in these patients as a primary therapeutic means of reducing excess weight and the risks of subsequent surgery. It has also been reported to considerably diminish liver volume to facilitate technical aspects of the operation. We evaluated preoperative weight loss in patients with super-obesity after placement of an intragastric balloon and its effect on liver volume measured by computed axial tomography (CT) prior to laparoscopic Roux-en-Y gastric bypass (LRYGBP).

METHODS

The balloon was implanted preoperatively under endoscopic guidance and sedation in 31 patients with super-obesity, to reduce weight prior to LRYGBP. Two patients were excluded from the study for intolerance and the balloon was removed 2 weeks after placement. Measurement of liver volume was done with axial images obtained by spiral CT with a section thickness of 10 mm, reconstitution index 10 mm, pitch 1.5 and acquisition delay 60 seconds. Volumes were calculated using the sum of areas technique. Measurement of volume was done in these 29 patients prior to balloon placement and the week before surgery.

RESULTS

After placement of the balloon, 27 patients (93%) had nausea and 25 patients (86%) had vomiting, which abated 1 week after placement. Mean liver volume prior to balloon placement was 2938.53 +/- 853.1 cm3, which at 6 weeks dropped to values of 1918.2 +/- 499.8 cm3, revealing a considerable reduction in liver volume [31.8% +/- 18.16% (range 3.1%-58.5%)]. Percent of excess weight loss was 22.14% +/- 7.39. LRYGBP was performed at 6 months.

CONCLUSIONS

In patients with super-obesity, preoperative treatment with intragastric balloon considerably reduces liver volume to facilitate LRYGBP.

Effects of weight loss after bariatric surgery on epicardial fat measured using echocardiography

Epicardial fat assessed using echocardiography is associated with abdominal visceral adipose tissue and cardiovascular risk factors. Because of its location, epicardial fat may directly affect the coronary vasculature and myocardium through local secretion of bioactive molecules. This study examines the effects of weight loss after bariatric surgery on epicardial adipose tissue in patients with severe obesity. Clinical data and echocardiograms of 23 patients with severe obesity who had echocardiograms recorded before and 8.3 +/- 3.7 months after undergoing bariatric surgery were retrospectively reviewed. Epicardial fat thickness was measured as the hypoechoic space anterior to the right ventricle in both the parasternal long- and short-axis views, and an average was obtained. At baseline, patients had increased epicardial fat compared with normal-weight controls matched for age, gender, and ethnicity (5.3 +/- 2.4 vs 3.0 +/- 1.1 mm, p <0. 001). Epicardial fat thickness was associated with the patient's initial weight in severely obese patients (r = 0.51, p = 0.011). Patients lost an average of 40 +/- 14 kg after surgery. Epicardial fat thickness decreased from 5.3 +/- 2.4 to 4.0 +/-1.6 mm (p = 0.001). Change in epicardial fat correlated with initial epicardial fat thickness measured using echocardiography (r = 0.71, p <0.001). In conclusion, epicardial fat thickness decreases in severely obese patients who have substantial weight loss after bariatric surgery. Measuring epicardial fat thickness using echocardiography may be useful to monitor visceral fat loss with weight reduction therapies.