Biliopancreatic diversion for severe obesity: long-term weight maintenance and occurrence of nutritional complications are two facets of the same coin.

BACKGROUND: Despite the widespread clinical use of hypoabsorptive metabolic bariatric surgery, very long-term outcomes are still lacking. The aim of the study was to assess the long-term safety and efficacy of biliopancreatic diversion at 30 years in patients with class 3 obesity (BMI over 40 kg/m2). METHODS: This retrospective single-centre study used data from a prospectively collected database on a sample of consecutive patients submitted to biliopancreatic diversion with a minimum follow-up of 30 years. Outcomes assessed included overall survival, long-term weight loss and weight maintenance, remission of obesity-related co-morbidities, and short- and long-term surgical and/or nutritional or metabolic complications. RESULTS: Among 199 consecutive patients (136 female, 63 male) who had surgery between November 1992 and April 1994, the mean age at operation was 38 (range 14-69) years and mean preoperative BMI was 48.7 (32.0-74.3) kg/m2. At baseline, 91 of 199 patients (45.7%) had type 2 diabetes. At 20 and 30 years, 122 (61%) and 38 (19%) of the 199 patients respectively were available for follow-up. At 30 years, the overall mortality rate was 12% (23 of 199). Surgical complications were concentrated in the short-term follow-up, whereas nutritional or metabolic complications increased progressively over time. A nutritional complication was diagnosed in 73 of 122 patients (60%) at 20 years and 28 of 38 (74%) at 30 years. Weight loss and glycaemic control were maintained throughout the follow-up; mean % total weight loss was 32.8 (range 14.1-50.0) at 1 year and 37.7 (range 16.7-64.8) at 30 years. One patient presented with recurrence of type 2 diabetes at 20 and 30 years; there were no patients with new-onset type 2 diabetes. CONCLUSION: Biliopancreatic diversion leads to good and sustained weight maintenance up to 30 years with low perioperative risk, but at the cost of a high long-term prevalence of nutritional complications.

Pyrrhic victory? Long-term results of biliopancreatic diversion on patients with type 2 diabetes and severe obesity.

BACKGROUND: The long-term results after biliopancreatic diversion (BPD) in patients with type 2 diabetes (T2D) and severe obesity is still being debated. OBJECTIVE: Retrospective evaluation of the long-term metabolic and clinical conditions of patients with T2D following BPD. SETTING: University hospital. METHODS: A total of 173 patients with T2D and severe obesity were investigated prior to and at 3-5 and 10-20 years after BPD. Anthropometric, biochemical, and clinical findings preoperatively and throughout follow-up were considered. The long-term data were compared with those of a cohort of 173 T2D patients with obesity treated with conventional therapy. RESULTS: T2D resolved within the first postoperative phases in most patients, and in the long and very long term, the fasting blood glucose level remained above the normal range in only 8% of patients. Likewise, a stable improvement of blood lipid pattern was observed (follow-up rate 63%). In contrast, in nonsurgical patients in the long term, the glucose and lipid metabolic parameters remained in the pathologic range in all cases. In the BPD group, a very high number of severe BPD-related complications was recorded, and 27% of the BPD patients died, whereas in the control group, 87% of patients were still alive at the end of the follow-up period (P < .02). CONCLUSION: Despite the high T2D stable resolution rate and the normalization of most metabolic data at 10-20 years following surgery, these results indicate that BPD should be indicated with caution in the surgical treatment of T2D in patients with severe obesity.

Diabetes Resolution at 10 Years After Biliopancreatic Diversion in Overweight and Class 1 Obese Patients with Type 2 Diabetes.

BACKGROUND: Long-term anti-diabetic effects of BPD in overweight or class 1 obese T2DM patients were investigated reporting the results at 10 years after BPD performed in severely non-obese T2DM patients. MATERIAL AND METHODS: Thirty T2DM patients with BMI lower than 35 kg/m2 were investigated at 1, 5, and 10 years after BPD, and the results are compared with those of 30 T2DM patients followed for 10 years on pharmacological and/or behavioral conventional therapy. RESULTS: Mean levels of fasting blood glucose (FBG) and serum glycated hemoglobin (HbA1C) showed a marked reduction 1 year after BPD, values remaining slightly above the diabetic range throughout the entire follow-up. T2DM remission was observed in about 50% of the cases at 5 and 10 years after the operation. In 16 patients (53%), severe BPD-related complications developed, in ten cases requiring a surgical revision of the operation. In the BPD group, one patient died for malignant lymphoma and two patients after surgical revision. Within the control group, during the 10-year follow-up, no changes in the diabetic status were observed, being the FBG and HbA1C mean values higher than those recorded in the BPD patients at any follow-up time. All T2DM subjects of the control group were alive at the end of the 10-year follow-up. CONCLUSION: Despite satisfactory long-term metabolic outcomes, these data indicate that BPD should be used with caution as a metabolic procedure in the treatment of T2DM in overweight or class 1obese patients.

Effects of the Postoepartive Dietetic/Behavioral Counseling on the Weight Loss After Bariatric Surgery.

OBJECTIVE: Weight outcomes after bariatric surgery are due to an adequate adjustment of eating behavior to the new gastrointestinal conditions created by operation. The efficacy of dietary/behavior counseling for promoting weight loss and maintenance in a growing number of bariatric patients was investigated. MATERIAL AND METHODS: One hundred seventy-six non-diabetic obese patients undergoing Roux-en-Y gastric bypass (RYGBP) and sleeve gastrectomy (SG) were investigated. The first group (CO, 88 subjects, 16 male) attended a standard surgical follow-up, while in the second (DIET, 88 subjects, 15 male) the surgeon was supported by a dietitian, and patients received behavioral-dietary sessions on individual request. Data prior to the operation and at 2 years were considered, the weight outcome being regarded as successful when postoperative body mass index (BMI) value was lower than 30 kg/m2. RESULTS: Weight results were better (p < 0.01) in the RYGBP than in the SG patients. In comparison to CO, in the DIET group a greater adherence to the bariatric program was observed (76% vs. 41%, < 0.01), while body weight data and prevalence of successful cases at 2 years (87 ± 23 vs. 83 ± 16 kg and 27% vs.33%, respectively) were similar. CONCLUSIONS: After RYSG and SG, postoperative dietetic/behavioral sessions delivered on patient's request does not influence weight results. The dietetic intervention promotes the adherence to bariatric program and prevents postoperative follow-up loss. In a dietitian/behavioral strategy after RYGBP and SG, a cognitive reinforcement of the compliance to bariatric program and a strengthening of the motivation to changes could promote better weight results.

Disordered eating and weight loss after bariatric surgery.

PURPOSES: Aberrant eating patterns are frequently observed in bariatric patients. Since bariatric operations produce alterations in food transit and in appetite/satiety balance, postoperative eating behavior changes are not surprising. METHODS: 88 consecutive obese patients undergoing Roux-en-Y gastric bypass (RYGBP, 50 cases) and Sleeve Gastrectomy (SG, 38 cases) were retrospectively evaluated. Beside anthropometric data measurement, eating behavior was assessed by direct interview prior to the operation and at the first and second postoperative years: patients were considered as eating disordered (ED) when referred habitual occurrence of binge eating and nibbling/grazing. Weight loss was assessed by percent of BMI loss (% Δ BMI). Together with standard follow-up, patients received additional behavioral/dietetic support upon request. RESULTS: Postoperative ED patients showed lower % Δ BMI than the not ED ones at one (30.7% ± 8,5 vs. 26.8% ± 10, p < 0.02) and two (32% ± 10.3 vs. 27.4% ± 12.9, p < 0.05) years after operation, the follow-up rate being 82% and 76%, respectively, without differences between RYGBP and SG group. After RYGBP, an improvement of eating behavior was observed (ED patients from 75 to 28% at 1 year and to 27% at 2 years), while no changes were observed after SG. In SG patients, the number of additional behavioral/dietetic support sessions throughout the follow-up was positively associated with % Δ BMI. DISCUSSION: The postoperative normalization of eating pattern has a role in weight loss after bariatric surgery. Behavioral/dietetic support is indicated in all SG patient, while after RYGBP is useful only when weight loss is unsatisfactory. LEVEL OF EVIDENCE: III: retrospective cohort study.

Adipose Tissue Composition in Obesity and After Bariatric Surgery.

The adipose tissue is a complex organ that regulates food intake and energy expenditure as well as induces low-grade inflammation. This review deals with changes in the composition and activity of the adipose organ after bariatric surgery, focusing on epicardial and ectopic fat and on relationships between white and brown adipose tissues. Postoperative improvements of ectopic fat and epicardial fat size and composition account for the metabolic recovery and the decreased cardiovascular risk. Following Roux-en-Y gastric bypass or biliopancreatic diversion, a proportional increase in the size and activity of the metabolically active brown adipose tissue was observed, most likely related to the postoperative rearrangement of the entero-hormonal pattern with an increase of GLP-1 production: this aspect would promote the postoperative weight loss and maintenance of post-surgery benefits.

Baseline neutrophil-to-lymphocyte ratio is associated with long-term T2D remission after metabolic surgery.

AIMS: Metabolic surgery is considered as a therapeutic option for obese patients with type 2 diabetes (T2D). In order to identify novel laboratory variables that could improve the selection of patients who might greatly benefit from a surgical approach, we focused on the neutrophil-to-lymphocyte ratio (NLR) as a predictor of long-term T2D remission following metabolic surgery. METHODS: Thirty-one obese patients with T2D included in this pilot study underwent Roux-en-Y gastric bypass or biliopancreatic diversion (BPD) at the Surgical Department of Genoa University, IRCCS Ospedale Policlinico San Martino in Genoa (Italy). Before surgery, serum samples were collected to evaluate blood count, glycemic profile, and circulating neutrophil degranulation products. RESULTS: The median age was 56 years, median body mass index (BMI) was 32.37 kg/m2, and median glycated hemoglobin was 8.4%. White blood cell count was in a range of normality, with a median NLR of 1.97. By a receiver operating characteristic curve analysis, NLR has been found to be significantly associated with T2D remission at 1, 3, and 5 years and the best cutoff of ≤ 1.97 has been identified by Youden index. When comparing study groups according to NLR cutoff, those with NLR ≤ 1.97 were older and underwent more often BPD. By a logistic regression analysis, NLR ≤ 1.97 has been found to predict T2D remission across 5 years, irrespective of baseline BMI. CONCLUSIONS: A baseline low NLR is associated with long-term T2D remission in obese patients undergoing metabolic surgery, suggesting that circulating inflammatory cells (i.e., neutrophils) might negatively impact on T2D remission.

Type 2 Diabetes Remission and Control in Overweight and in Mildly Obese Diabetic Patients at Long-Term Follow-Up After Biliopancreatic Diversion.

BACKGROUND: In severely obese patients with type 2 diabetes (T2DM), the metabolic benefits after biliopancreatic diversion (BPD) are due to mechanisms independent of weight loss. Therefore, the anti-diabetic effect of BPD in overweight or mildly obese T2DM patients was investigated. METHODS: Ninety T2DM patients with BMI 25-35 underwent BPD and were evaluated 1 and 5 years after the operation (follow-up rate 100 and 83%, respectively). RESULTS: T2DM control (Hb1Ac < 7%) and remission (Hb1Ac < 6 without antidiabetics) was observed in 86.6 and 65% of cases at 1 year and 64.0% and 26.5% at 5 years, respectively. The long-term T2DM remission was predicted by baseline BMI value. Both before BPD and throughout the follow-up period, HOMA values were similar in the metabolically successful and unsuccessful subjects, while C-peptide normalized for FBG value as a marker of beta cell mass and insulin secretion increased progressively only in the former from 1.06 ± 0.64 to 1.44 ± 1.08 mcg/l ml/dl-1 * 100 (p < 0.002). CONCLUSIONS: In T2DM patients with BMI of 25-35, a positive metabolic outcome is less frequent than in their counterparts with morbid obesity. In T2DM overweight patients, in spite of a short-term normalization of FBG and HbA1c levels and a well-sustained increase of insulin sensitivity, a long-term T2DM relapse occurs in the majority of the cases. While the surgically obtained decrease in insulin resistance leads to T2DM control in half of the patients, the increase in insulin secretion is mandatory for T2DM stable remission.

Long-Term Follow-Up Study of Liver-Related Outcome After Bilio-Pancreatic Diversion in Patients with Initial, Significant Liver Damage.

BACKGROUND: Obesity is associated with NAFLD, and bariatric surgery has significant impact on this liver disease, with reported improvement in hepatic fibrosis. AIMS: To investigate the effects of bariatric surgery on long-term liver disease-related outcome in obese patients with nonalcoholic fatty liver disease (NAFLD) and significant liver damage. METHODS: This study included 56 NAFLD patients who underwent bilio-pancreatic diversion for morbid obesity and who had significant fibrosis at intraoperative liver biopsy. Data were analyzed at 1, 3, and 5 years of follow-up, and at the latest available visit in patients who had longer follow-up. We assessed the incidence of clinically relevant liver events (ascites, hepatic encephalopathy, portal hypertension-related bleeding, and jaundice) as well as modifications of a validated biochemical index such as the NAFLD score. RESULTS: During a median follow-up of 78 months, median weight decreased from 119 to 78 kg (P < 0.0001), and median body mass index decreased from 45.2 to 29.0 kg/m2 (P < 0.0001). None of the patients developed clinical complications of liver disease, and none died due to liver-related causes. Median NAFLD score significantly decreased (P = 0.0005) during follow-up from - 0.929 (- 1.543 to - 0.561) to - 1.609 (- 2.056 to - 1.102). The NAFLD score category was unchanged in 32 patients (57%), improved in 18 (32%), and worsened in 6 (11%). CONCLUSIONS: Patients with NAFLD and proven histological liver damage at surgery do not develop complications of liver disease in long term after bilio-pancreatic diversion. Moreover, noninvasive parameters of liver damage improve. Thus, preexisting liver damage does not seem to be a contraindication to bilio-pancreatic diversion.

Management of malabsorptive bariatric surgery after cancer surgery for malignancies of the digestive apparatus.

BACKGROUND: Data regarding management of former bariatric operations after onset of a malignancy are still lacking and there is no consensus whether bariatric surgery negatively influences the oncologic management of patients. OBJECTIVES: To investigate the strategy by which patients previously submitted to bariatric surgery were managed after diagnosis of malignancy of the digestive apparatus, whether a revision was performed or not, to assess the incidence of nutritional complications, and the effect of revision versus no revision of bariatric surgery on the outcome of cancer treatment. SETTING: University Hospital, Italy. METHODS: Occurrence of a malignancy of the digestive apparatus in patients submitted to biliopancreatic diversion was investigated retrospectively. Patients' data were collected preoperatively, at 2 and 3 years after the operation, at oncologic diagnosis, and at the longest available postoncologic follow-up. RESULTS: From May 1976 to January 2017, 3341 morbidly obese patients were submitted to biliopancreatic diversion. Sixteen patients were diagnosed with a malignancy involving the digestive apparatus 5 to 28 years after bariatric surgery. Of 10 patients diagnosed with colorectal cancer, 6 were revised. At 2 years after biliopancreatic diversion, body mass index, hemoglobin, and iron levels were significantly lower than preoperatively. Serum transferrin and total protein were unchanged. There was no difference between body mass index, hemoglobin, transferrin, and total protein levels at 2 years and at oncologic diagnosis, or between revised and unrevised patients. CONCLUSION: Revision of a preexisting bariatric operation after digestive cancer surgery is common, although selected, unrevised cases do not seem to be associated with worse outcome.

Surgery to Treat Symptomatic Mobile Cecum Syndrome Is Safe and Associated with Good Recovery Outcomes.

The mobile cecum syndrome includes a spectrum of conditions. The cecal volvulus represents the acute form, with typical feature of a bowel obstruction that needs immediate operative treatment. On the other hand, a chronic form of mobile cecum syndrome which is the most common form reported a history of intermittent crampy abdominal pain, distension, and constipation. In this study, five patients came to our attention during the last ten years, presenting different symptoms due to a mobile cecum. All patients were investigated by several diagnostic techniques according to the specific clinical setting. All patients were found to have the cecum and ascending colon unattached to the posterior peritoneum. Surgery was the treatment of choice. In our experience, the best diagnostic technique was computed tomography scan, especially if performed in the Trendelenburg position. We also propose virtual colonoscopy as a good option for diagnosis (in patients with chronic syndrome) and follow-up after surgery. In conclusion, laparoscopic approach guaranteed a good result, with no symptoms of recurrence, in both acute and elective treatments. The diagnosis of mobile cecum needs a high index of suspicion and a targeted radiological investigation. Surgery, especially laparoscopic cecopexy and appendectomy, is the recommended treatment.

Early reduction of matrix metalloproteinase-8 serum levels is associated with leptin drop and predicts diabetes remission after bariatric surgery.

BACKGROUND: We aimed at investigating whether the acute abrogation of leptin after bariatric surgery is able to reduce neutrophil activation and potentially affect type 2 diabetes mellitus (T2DM) remission. METHODS: Metabolic and inflammatory parameters (i.e. leptin, IL-6 and neutrophil products) were compared at baseline (before bariatric surgery), one month, one and three years after surgery in morbid obese (MOB) T2DM patients (n=12) and non-MOB controls (n=32). In vitro, the effects of leptin on Il-6-induced human neutrophil degranulation and integrin upregulation were assessed. RESULTS: At baseline, MOB T2DM patients had a similar demographic, lipid and glycemic profiles than non-MOB T2DM controls, but higher levels of inflammatory mediators, such as CRP, fibrinogen, neutrophil-to-lymphocyte ratio (NLR), matrix metalloproteinase (MMP)-8 and leptin. One month after surgery, CRP, fibrinogen and MMP-8 were reduced only in MOB T2DM patients, while serum leptin was reduced in both groups. In the overall cohort, leptin and MMP-8 drops from baseline to one month post-surgery were positively correlated (Δleptin vs. ΔMMP8: r=0.391, p=0.025). Moreover, ΔMMP8 inversely correlated with fasting glucose levels at one-year follow-up and with glycated hemoglobin at both one- and three-year. At the cut-off point identified by ROC curve analysis (>0ng/mL), ΔMMP8 predicted complete T2DM remission at 3-year follow-up. In vitro, leptin increased IL-6-induced MMP-8 release and abrogated CD18 up-regulation. CONCLUSION: Bariatric surgery is associated to an acute abrogation of leptin that could affect MMP-8 levels, particularly in MOB T2DM patients. This beneficial event is associated with T2DM remission at 3-year follow-up.

Long-term clinical and functional impact of biliopancreatic diversion on type 2 diabetes in morbidly and non-morbidly obese patients.

SETTING: Obesity surgery has been proposed as a treatment option for diabetic patients with body mass index (BMI)<35 kg/m(2), but the efficacy of metabolic surgery has not been conclusively determined. OBJECTIVES: To evaluate the long-term metabolic outcome of non-morbidly obese (NMO) patients with type 2 diabetes (T2D) after biliopancreatic diversion (BPD). MATERIAL AND METHODS: Two groups of T2D patients with different degree of obesity (NMO, 17 cases, BMI 25-35 kg/m(2); and morbidly obese [MO], 13 cases, BMI>35 kg/m(2)) were studied before and at 1 and 5 years after BPD in a university hospital setting. Insulin secretion was assessed by acute insulin response (AIR) to intravenous glucose and by insulinogenic index (IGI). RESULTS: In all MO patients, T2D was remitted or controlled (1 case) at 1 year and results were maintained at 5 years; AIR (µU/mL) and IGI (µU/mg) improved (P<.001) at 1 year (from .1±3.1 to 18.52±21.9, and from 6.0±8.5 to 9.1±22.8, respectively) with a further increase (to 24.8±25.5 and to 14.3±13.8, respectively) at 5 years. Within the NMO group, T2D was remitted in 1/17 and controlled in 14/17 patients at 1 year, and in 2/17 and in 4/17 patients at 5 years, respectively; AIR (µU/mL) and IGI (µU/mg) remained unchanged throughout the postoperative period (from .31±9.26 to 1.5±2.8 at 1 yr and to .4±3.29 at 5 yr for AIR, and from 2.2±4.9 to 1.3±9.0 at 1 yr and to 2.3±3.3 at 5 yr for IGI). CONCLUSIONS: After BPD, restoration of ß-cell secretion/production plays a pivotal role in determining postoperative T2D remission.

The long-term impact of biliopancreatic diversion on glycemic control in the severely obese with type 2 diabetes mellitus in relation to preoperative duration of diabetes.

BACKGROUND: Bariatric surgery has been shown to be effective in severely obese patients with type 2 diabetes mellitus (T2DM). OBJECTIVE: Evaluate the long-term efficacy of biliopancreatic diversion (BPD) for the treatment of T2DM depending on the preoperative duration of T2DM. SETTING: University Hospital. METHODS: Retrospective analysis investigating 2 subsets of severely obese patients who had undergone BPD from 1984 to 1995. The first included 52 patients with a preoperative T2DM duration of ~1 year (SD group - 49 on oral agents and 3 on insulin), and the second included 68 patients who had been diabetic for>5 years before BPD (LD group - 52 on oral agents and 16 on insulin). Postoperatively, T2DM was regarded as in remission when fasting serum glucose (FSG) was lower than 100 mg/dL on regular diet and without antidiabetic therapy. RESULTS: In the SD patients, the number of individuals without T2DM remission were lower both at 5-10 (0/31, 0% of patients, versus 8/54, 15% of patients, p<.04) and at>15 years (1/28, 3% of patients, versus 10/41, 24% of patients, p<.0012). Furthermore, after BPD, the number of patients with dyslipidemia strongly reduced (p<.001) in both groups, values at 5-10 years remaining very similar to those observed at>15 years. CONCLUSION: These results indicate that severely obese patients with longer T2DM duration have a worse metabolic outcome maintained at long and very long term following BPD.

Effects of gastric bypass on type 2 diabetes in patients with BMI 30 to 35.

BACKGROUND: This study aims to investigate if the benefits on glycemic control following Roux-en-Y gastric bypass (RYGB) in morbidly obese type 2 diabetes (T2DM) patients are maintained in the 30-35 kg/m(2) BMI (body mass index) range, comparing results with those in literature. METHODS: The study participants were twenty T2DM patients aging 35-70 years, BMI 30.0-34.9 kg/m(2), minimum diabetes duration 3 years, glycosylated haemoglobin (HbA1c) ≥7.5% despite good clinical practice medical therapy, submitted to laparoscopic RYGB, and monitored during 36 months. Twenty-seven matched diabetic patients as controls. RESULTS: Five females, mean age 57 (42-69) years, weight 96.0 (70-111) kg, BMI 32.9 (30.3-34.9) kg/m(2), waist circumference 112 (100-128) cm, diabetes duration 14 (3-28) years, HbA1c 9.5 (7.5-14.2) %, and C-peptide 3.2 (1,6-9.1) mcg/l. Ten patients were on insulin. There was no mortality, and there were two major late complications. BMI and waist decreased stabilizing around 25 kg/m(2) and 92 cm. Fasting serum glucose and HbA1c reached values around 150 mg/dl and 7%, which subsequently maintained. There was remission in 25% of cases, control 45%, and all the others improved. HOMA-IR and insulin sensitivity index normalized at 1 month, then maintained. AIR and insulinogenic index showed no postoperative changes. Diabetes remission correlated negatively with duration (p < 0.05; r (2) = 0.61), while control positively with C-peptide (p < 0.05; r (2) = 0.19). In the control group, FSG, HbA1c, serum triglyceride, and cholesterol significantly decreased with considerable progressive increase of antidiabetic/antihyperlipemic therapy. All patients had HbA1c >7% at 2-3 years. CONCLUSIONS: Glycemic control obtained by RYGB in this study was less good than that reported by others, apparently due to different patient selection criteria. Our results do not support RYGB weight loss-independent effect on beta-cell function in the T2DM patients with BMI 30-35 kg/m(2).

Physical activity after surgically obtained weight loss: study with a SenseWear armband in subjects undergoing biliopancreatic diversion.

BACKGROUND: This study aimed to understand the role of the extra load of body mass in limiting physical activity and in preventing an active lifestyle in severely obese patients. MATERIALS AND METHODS: The study was carried out in a University Hospital setting, and investigates severely obese patients, having undergone biliopancreatic diversion (BPD) for obesity and control subjects with a body weight closely similar to that of the BPD subjects; energy intake was evaluated by alimentary interview and energy expenditure was assessed with the Body Media SenseWear® Pro armband (SWA). RESULTS: SWA metabolic efficiency (MET) was negatively associated with body mass index values (ρ = -0.464, p < 0.01), and the SWA overall energy expenditure was very similar to the energy alimentary intake in the obese patients and in the control subjects. Among the controls, the MET mean value was higher (p < 0.05) than that observed both in obese and in BPD subjects (1.392 ± 0.211 vs. 1.149 ± 0.181 and 1.252 ± 0.284, respectively); furthermore, in comparison with the obese and the BPD groups, among the control individuals a greater number of active persons (27% vs. 0 and 7%, respectively) and a lower number of sedentary persons (27% vs. 70 and 43%, respectively) was found (p < 0.01). CONCLUSIONS: These preliminary results suggest the reliability of SWA data in assessing energy expenditure and tend to rule out the hypothesis that in severely obese patients the extra load of body mass by itself is a main factor limiting physical activity and leading to a sedentary lifestyle.