Prevalence and Severity of Sleep Apnea in a Group of Morbidly Obese Patients

Background Obesity is the most important risk factor for obstructive sleep apnea. It is estimated that 70% of sleep apnea patients are obese. In the morbidly obese, the prevalence may reach 80% in men and 50% in women. The aim of this study was to determine the prevalence and severity of sleep apnea in a group of morbidly obese patients, leading to bariatric surgery. Methods In a cross-sectional study developed in Bahia, northeastern Brazil. 108 patients (78 women and 30 men) from the Obesity Treatment and Surgery Center - “Núcleo de Tratamento e Cirurgia da Obesidade” underwent standard polysomnography. Patients with an apnea-hypopnea index (AHI) ≥ 5 events/hour were considered apneic. Results Mean ± SD for age and BMI were 37.1 ± 10.2 years and 45.2 ± 5.4 kg/m2, respectively. The calculated AHI ranged widely from 2.5 to 128.9 events/hour. Sleep apnea was detected in 93.6% of the sample, wherein 35.2% had mild, 30.6% moderate and 27.8% severe apnea. Oxyhemoglobin desaturation was directly related to the AHI and was more severe in men. Conclusion There was a high frequency of sleep apnea in this group of morbidly obese patients, for whom it was very important to request polysomnography, thus enabling therapeutic management and prognostication.     

Gastroesophageal Reflux in Patients with Morbid Obesity: A Role of Obstructive Sleep Apnea Syndrome?

Background  Obesity is a risk factor for gastroesophageal reflux disease (GERD) and for obstructive sleep apnea (OSA). Our aim was to evaluate in morbidly obese patients the prevalence of OSA and GERD and their possible relationship. Methods  Morbidly obese patients [body mass index (BMI) >40 or >35 kg/m² in association with comorbidities] selected for bariatric surgery were prospectively included. Every patient underwent a 24-h pH monitoring, esophageal manometry, and nocturnal polysomnographic recording. Results  Sixty-eight patients [59 women and 9 men, age 39.1 ± 11.1 years; BMI 46.5 ± 6.4 kg/m² (mean ± SD)] were included. Fifty-six percent of patients had an abnormal Demester score, 44% had abnormal time spent at pH <4, and 80.9% had OSA [apnea hypopnea index (AHI) >10] and 39.7% had both conditions. The lower esophageal sphincter (LES) pressure was lower in patients with GERD (11.6 ± 3.4 vs 13.4 ± 3.6 mm Hg, respectively; P = 0.039). There was a relationship between AHI and BMI (r = 0.337; P = 0.005). Patients with OSA were older (40.5 ± 10.9 vs 33.5 ± 10.4 years; P = 0.039). GERD tended to be more frequent in patients with OSA (49.1% vs 23.1%, respectively; P = 0.089). There was no significant relationship between pH-metric data and AHI in either the 24-h total recording time or the nocturnal recording time. In multivariate analysis, GERD was significantly associated with a low LES pressure (P = 0.031) and with OSA (P = 0.045) but not with gender, age, and BMI. Conclusion  In this population of morbidly obese patients, OSA and GERD were frequent, associated in about 40% of patients. GERD was significantly associated with LES hypotonia and OSA independently of BMI.     

Relationship between Obstructive Sleep Apnea and Liver Abnormalities in Morbidly Obese Patients: A Prospective Study

Background Morbid obesity is a risk factor of nonalcoholic steatohepatitis (NASH). Obstructive sleep apnea (OSA) could also be an independent risk factor for elevated liver enzymes and NASH. The relationships between liver injuries and OSA in morbidly obese patients requiring bariatric surgery were studied prospectively. Methods Every consecutive morbidly obese patient (BMI ≥40 kg/m² or ≥35 kg/m² with severe comorbidities) requiring bariatric surgery was included between January 2003 and October 2004. Polygraphic recording, serum aminotransferases (ALT, AST), γ-glutamyltransferase (GGT) and liver biopsy were systematically performed. OSA was present when the apnea–hypopnea index (AHI) was >10/h. Results 62 patients (54 F; age 38.5 ± 11.0 (SD) yrs; BMI 47.8 ± 8.4 kg/m²) were included. Liver enzymes (AST, ALT or GGT) were increased in 46.6%. NASH was present in 34.4% and OSA in 84.7%. Patients with OSA were significantly older (P = 0.015) and had a higher BMI (P = 0.003). In multivariate analysis, risk factors for elevated liver enzymes were the presence of OSA and male sex.The presence of NASH was similar in patients with or without OSA (32.7% vs 44.4% of patients, P = 0.76). Conclusion In this cohort of morbidly obese patients requiring bariatric surgery, one-third of patients had NASH, a prevalence similar to previous studies. OSA was found to be a risk factor for elevated liver enzymes but not for NASH.     

Peptide YY and Glucagon-like Peptide-1 in Morbidly Obese Patients Before and After Surgically Induced Weight Loss

Background Peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) are cosecreted in the same enteroendocrine L-cells of the gut and reported to inhibit food intake additively. However, findings in human studies regarding these peptides are controversial. The aim of this study was to analyze the relationships between fasting PYY, GLP-1, and weight status in morbidly obese patients before and after surgically induced weight loss. Methods Fasting GLP-1, PYY, glucose, and insulin concentrations; blood pressure; and body-mass index (BMI) were determined in 30 morbidly obese adults (mean BMI 45.8, mean age 40 years) before bariatric surgery [Roux-en-Y gastric bypass (RYGB): n = 19; gastric banding (GB): n = 11] and after weight loss (mean 50% excess weight loss) in the course of mean 2 years. Results GLP-1 concentrations decreased (mean −20 pg/ml; mean −38%; p = 0.001) and PYY concentrations increased (mean +19 pg/ml; mean +19%, p = 0.036) after bariatric surgery. The weight loss and changes of GLP-1 were significantly (p < 0.05) more pronounced after RYGB as compared to GB, whereas the changes of PYY did not differ significantly between the patients who had undergone RYGB or GB. Conclusions In morbidly obese adults reducing their weight by bariatric surgery, fasting PYY levels increased and GLP-1 concentrations decreased independently of each other. Therefore, the relationship between PYY and GLP-1 seems more complicated than might be anticipated from animal and in vitro studies. T. Reinehr and C. L. Roth contributed equally to this work.     

Relationship among Adiponectin, Adiponectin Gene Expression and Fatty Acids Composition in Morbidly Obese Patients

Background he aim of this study was to examine the relationship between adiponectin plasma circulating levels and its gene expression in two abdominal fat depots (subcutaneous and visceral) with the fatty acid composition of plasma and adipose tissue in morbidly obese subjects. Methods 20 patients (10 women and 10 men) were selected. All were morbidly obese (BMI ≥40 kg/m²) and admitted for gastric surgery. Plasma samples and adipose tissue from both subcutaneous and visceral regions were obtained. Plasma adiponectin and adipose adiponectin expression were analyzed. Results Adiponectin mRNA expression in the subcutaneous tissue was significantly higher (P = 0.048) than in visceral tissue. Circulating adiponectin values, were positively associated with the proportion of n-3 polyunsaturated fatty acids in plasma (r = 0.62, P = 0.002). The visceral depot showed greater statistical associations between adiponectin gene expression and fatty acids profile, being saturated fatty acids associated with a decrease (r = −0.68, P = 0.015), whereas monounsaturated were related to an increase in this adipose region (r = 0.67, P = 0.017). Conclusions e demonstrated significant associations between adipose tissue adiponectin gene expression and fatty acid composition. These associations were more evident in relation to the visceral depot, an adipose tissue region highly implicated in the metabolic syndrome.     

Ghrelin and Obestatin Levels in Severely Obese Women Before and After Weight Loss After Roux-en-Y Gastric Bypass Surgery

Background  Ghrelin and obestatin are derived from the same gene but have different effects: Ghrelin stimulates appetite, and previous—albeit inconsistent—data show that obestatin may be involved in satiety. The present study was designed to test the hypothesis that Roux-en-Y gastric bypass (RYGB) surgery and/or the weight loss that reliably results from this procedure would alter levels of ghrelin and obestatin and ghrelin/obestatin ratios in a cohort of morbidly obese women. Methods  This is a longitudinal follow-up study in 18 morbidly obese women (mean weight 131.2 kg, mean body mass index [BMI] 47.4). Clinical parameters and fasting serum concentrations of ghrelin, obestatin, triglycerides, low-density lipoprotein cholesterol, glucose, and insulin were measured before and 2 years after RYGB surgery, which was associated with body weight reductions of 41.5 ± 11.6 kg (mean 62.5% excess weight loss). Results  Ghrelin concentrations (−12%, p = 0.022) and ghrelin/obestatin ratios (−14%, p = 0.017) were lower after surgery than before, while obestatin levels did not change. Changes in ghrelin concentrations correlated with changes in insulin levels (r = 0.45, p = 0.011). Most cardiovascular risk factors studied improved postsurgically (p < 0.01). Conclusion  In contrast to previous weight loss studies involving gastric banding, ghrelin levels decreased and obestatin levels remained stable after massive weight loss in long-term follow-up. The favorable gastrointestinal hormone profiles observed are likely to contribute to the long-term weight loss success rate attributed to RYGB. C.L. Roth and T. Reinehr contributed equally to this work.     

Gastric Emptying of Solids and Semi-solids in Morbidly Obese and Non-obese Subjects: An Assessment Using the <Superscript>13</Superscript>C-Octanoic Acid and <Superscript>13</Superscript>C-Acetic Acid Breath Tests

Background It has been suggested that obesity is associated with an altered rate of gastric emptying. The objective of the present study was to determine whether the rates of solid and semi-solid gastric emptying differ between morbidly obese patients and lean subjects. Methods The Gastric-emptying time (GET) of solid and semi-solid meals were compared between lean healthy subjects and morbidly obese patients enrolled in two previously published studies. GET of solid and semi-solid meals was measured using the ¹³C-octanoic acid breath test and ¹³C-acetic acid breath test, respectively, in 24 lean and 14 morbidly obese individuals of both sexes. Student t-test was used to compare the mean data between the lean and morbidly obese groups. The influence of sex, gender, BMI and morbid obesity on the GET of solid meals was verified by linear regression analysis. Results Mean t(1/2) values of solid GET (± standard deviation) were 203.6 ±  76.0 min and 143.5 ± 19.1 min for lean and obese subjects, respectively (P = 0.0010). Mean t(lag) values of solid GET were 127.3 ± 42.7 min and 98.4 ± 13.0 min for lean and obese subjects, respectively (P = 0.0044). No significant difference in semi-solid GET was observed between the lean and morbidly obese groups. Conclusion The present study demonstrated a significantly enhanced gastric emptying of the solid meal test in morbidly obese patients when compared to lean subjects. This finding is compatible with the hypothesis that rapid gastric emptying in morbidly obese subjects increases caloric intake due to a more rapid loss of satiety.     

Who Benefits from Gastric Banding?

Background In the present study, criteria were investigated to predict major benefit after laparoscopic adjustable gastric banding (LAGB). Materials and Methods 85 morbidly obese patients were operated with LAGB between 1999 and 2005. Seventy-one of these patients were analyzed according to several possible predictive characteristics for success as the primary endpoint. Success was defined as excess body weight loss (EBWL) >50% and no band removal. Median follow-up was 27 months (range 8–90 months). Results In total, median EBWL was 43% (−41 to 171.5%) with a decrease in BMI of 8.0 kg/m² (−9 to 35 kg/m²). Success rate was 37% (n = 26). These patients were compared to all other patients (n = 45). Significant success predictors were baseline absolute BW, EBW, BMI (p < 0.01), BMI with a threshold value of 50 kg/m² (p = 0.02), and female sex (p = 0.02) as well as postoperative vomiting (p = 0.02), eating behavior and physical activity after LAGB (p < 0.01). Baseline EBW and change in eating behavior after surgery were identified as independent predictors in multivariate analysis. Conclusion Patients with a lower excess body weight who improve especially their eating behavior after surgery have the highest chance of success after LAGB.     

Surgical Caloric Restriction Ameliorates Mitochondrial Electron Transport Dysfunction in Obese Females

Background The authors examine the mitochondrial electron transport system (ETS) with regard to caloric restriction and body size in humans. Methods The study population included 59 morbidly obese (MO) female subjects with mean body mass index (BMI) 49.6 ± 1.7 and 40 age-matched previously morbidly obese patients with surgically-induced caloric restriction (SCR) and mean BMI 28.9 ± 1.1. ETS function in the 2 study groups were made by measuring their lymphocyte mitochondrial ETS complexes IIV activities and complex III binding kinetics. Linear regression analyses were used to analyze the interactions between ETS function and BMI, energy intake, and metabolic status. Results The MO, as compared to SCR, subjects had significantly (P < 0.01) higher ETS complexes II-IV activities (complex II = 20.4 ± 1.9 vs 15.3 ± 1.1, complex III = 129.4 ± 10.1 vs 72.3 ± 4.9, complex IV = 3.1 ± 0.3 vs 1.4 ± 0.1 nmol/mg/min for the MO vs SCR, respectively). ETS complexes activities were positively and significantly correlated with subjects’ BMI, carbohydrate caloric intake, and fasting plasma insulin levels. Michaelis-Menten kinetic analysis showed that the Km for ubiquinol-2 in complex III of MO patients was 2-fold greater than SCR values, reflecting an apparent reduction in substrate binding capacities producing a resistance to electron flow in the MO population. Caloric consumption, carbohydrate calories, insulin levels, and BMI were also each significantly (P < 0.05) and positively correlated with the Km of Complex III. Conclusions ETS function and efficiency are compromised by increasing BMI and caloric consumption in morbidly obese women, and caloric restriction may reduce the potential for excessive oxidative free radical generation via the ETS.     

Ultrasonic Value is Not Useful to Detect Bone Changes Following a Biliopancreatic Diversion

To study the evolution of the bone mass by ultrasonic transmission after biliopancreatic diversion. Forty eight morbid obese patients were prospectively studied during 36 months following the Larrad biliopancreatic diversion. The bone metabolism was studied by PTHi and the urinary pirydinolines. The bone mass by echography and bone densitometry, which correlate to the levels of PTHi and pyridinolines. After 3 years the bone mass decreased from 50.15 +/− 7.31 kg/m², preoperatively, to 34.03 +/− 4.53 kg/m2 (p < 0.001). There was an increase of the PTHi value (from 71.4 +/− 79.6 to 91.65 +/− 43.06 pg/ml) (p = 0.01), and the urinary pirydinolines (from 7.93 +/− 4.06 an 11.4 +/− 10.12 nM/mM) (p < 0.05). The ultrasonic transmission speed increased (from 1,990.93 +/− 62.38 to 2,035.25 +/− 53.98 m/s). However, the bone mineral content (BMC) did not show changes (from 3,016.5 +/− 562.8 to 2,909.6 +/− 304.2 g), as well as the Bone Mineral Density (BMD) (of 1,174.2 +/− 98.8 g/cm2). Neither correlation was found between the BMD (r = 0.212; p = 0.6), the BMC (r =−0.125; p = 0.768), and the T-score (r = 0.592, p = 0.093). The study of the bone mass through ultrasonic transmission speed revealed low sensitivity during the assessment of the morbid obese patients. A percentage of cases of osteopenia were observed despite the fact that they are not reflected in the bone content or in the bone mass. Ultrasonic evaluation of bone mass has no value in the morbidly obese, by the clear negative correlation between ultrasound velocity and thickness of soft tissue.     

Gastro-Esophageal Reflux and Esophageal Motility Disorders in Morbidly Obese Patients before and after Bariatric Surgery

Background Obesity is a predisposing factor to gastro- esophageal reflux disease (GERD), but esophageal function remains poorly studied in morbidly obese patients and could be modified by bariatric surgery. Methods Every morbidly obese patient (BMI ≥40 kg/m² or ≥35 in association with co-morbidity) was prospectively included with an evaluation of GERD symptoms, endoscopy, 24-hour pH monitoring and esophageal manometry before and after adjustable gastric banding (AGB) or Roux-en-Y gastric bypass (RYGBP). Results Before surgery, 100 patients were included (84 F, age 38.4 ± 10.9 years, BMI 45.1 ± 6.02 kg/m2), of whom 73% reported GERD symptoms. Endoscopy evidenced hiatus hernia in 39.4% and esophagitis in 6.4%. The DeMeester score was pathological in 53.3%; 69% of patients had lower esophageal sphincter (LES) pressure <15 mmHg and 7 had esophageal dyskinesia. BMI was significantly related to the DeMeester score (P = 0.018) but not to LES tone or esophageal dyskinesia. Postoperative data were available in 27 patients (AGB n = 12/60, RYGBP n = 15/36). The DeMeester score (normal <14.72) was significantly decreased after RYGBP (24.8 ± 13.7 before vs 5.8 ± 4.9 after; P < 0.001) but tended to increase after AGB (11.5 ± 5.1 before vs 51.7 ± 70.7 after; P = 0.09), with severe dyskinesia in 2 cases. Conclusion: GERD and LES incompetence are highly prevalent in morbidly obese patients. Preliminary postoperative data show different effects of RYGBP and AGB on esophageal function, with worsening of pH-metric data with occasional severe dyskinesia after AGB.     

Serum Magnesium Status After Gastric Bypass Surgery in Obesity

Background  Roux-en-Y gastric bypass (RYGBP) has become a common surgical procedure to treat morbid obesity. Furthermore, it strongly reduces the incidence of type 2 diabetes and mortality. However, there is scant information on how magnesium status is affected by RYGBP surgery. Previous bariatric surgery methods, like jejunoileal bypass, are associated with hypomagnesemia. Methods  Twenty-one non-diabetic morbidly obese patients who underwent RYGBP were evaluated before and 1 year after surgery and compared to a matched morbidly obese control group regarding serum magnesium. Groups were matched regarding weight, BMI, abdominal sagittal diameter and fasting glucose, blood pressure, and serum magnesium concentrations before surgery in the RYGBP group. Results  The serum magnesium concentrations increased by 6% from 0.80 to 0.85 mmol/l (p = 0.019) in the RYGBP group while a decrease by 4% (p = 0.132) was observed in the control group. The increase in magnesium concentration at the 1-year follow-up in the RYGBP group was accompanied by a decreased abdominal sagittal diameter (r ² = 0.32, p = 0.009), a lowered BMI (r ² = 0.28, p = 0.0214), a lowered glucose concentration (r ² = 0.28, p = 0.027) but not by a lowered insulin concentration (p = 0.242), a lowered systolic (p = 0.789) or a lowered diastolic (p = 0.785) blood pressure. Conclusion  RYGBP surgery in morbidly obese subjects is characterized by reduced visceral adiposity, lowered plasma glucose, and increased circulating magnesium concentrations. The inverse association between lowered central obesity, lowered plasma glucose and increased magnesium concentrations, needs further detailed studies to identify underlying mechanisms.     

Plasma Adhesion and Inflammation Markers: Asymmetrical Dimethyl-L-Arginine and Secretory Phospholipase A<Subscript>2</Subscript> Concentrations before and after Laparoscopic Gastric Banding in Morbidly Obese Patients

Background The aim of this study was to examine the relationship between subclinical inflammation and weight loss by laparoscopic adjustable gastric banding (LAGB). Methods Plasma concentrations of intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1), sensitive C-Reactive Protein (sCRP), asymmetrical dimethyl-L-arginine (ADMA), Secretory Phospholipase A2 (sPLA2), and metabolic markers, such as homeostatic model assessment – insulin resistance (HOMA-IR) and body mass index (BMI) were determined in morbidly obese patients (n = 18, BMI 48.6 ± 1.7 kg/m²) at baseline and 1 month after operations. Baseline levels in patients were also compared with age-matched controls (n = 20, BMI 21.3 ± 1.8 kg/m²). Plasma ICAM-1,VCAM, sCRP and ADMA, and sPLA₂ concentrations were determined by enzyme-linked immunoassay methods and colorimetric method, respectively. Results Plasma sCRP, ICAM-1, ADMA and sPLA₂ concentrations and HOMA-IR were significantly higher in morbidly obese patients than in controls (for each, P < 0.01). Plasma VCAM-1 concentration was not changed in obese patients. HOMA-IR was significantly correlated with ICAM-1, ADMA and sPLA₂ in the obese group at baseline (for each, P < 0.01). There was a significant correlation between plasma sCRP and plasma glucose,VCAM-1, ICAM-1, ADMA and sPLA₂ concentrations (for each, P < 0.01). 1 month after LAGB, mean body weight loss was 13.2 ± 6.3 kg, and plasma sCRP and ADMA concentrations and HOMA-IR and BMI were significantly decreased (for each, P < 0.01). However, these levels cannot be decreased to the levels of the controls. Conclusion Obesity and insulin resistance appear to be associated with low-grade inflammation and endothelial dysfunction. Insulin resistance and endothelial dysfunction were improved by weight loss after LAGB.     

High Prevalence of Small Intestinal Bacterial Overgrowth in Patients with Morbid Obesity: A Contributor to Severe Hepatic Steatosis

Background With the increasing prevalence of obesity, non-alcoholic fatty liver disease (NAFLD) has become a major cause of liver diseases. Small intestinal bacterial overgrowth (SIBO) could be related to NAFLD. Our aim was to determine the prevalence of SIBO and its relationship with liver lesions in morbidly obese patients. Methods A glucose hydrogen (H₂) breath test (positive if fasting breath H₂ concentration > 20 ppm and/or an increase of > 10 ppm over baseline within the first 2 h) was performed in obese patients referred for bariatric surgery (body mass index [BMI] >  40 kg/m² or >  35 in association with comorbidities) and in healthy non-obese subjects. In obese patients, a surgical liver biopsy was performed. Results One hundred and forty-six patients (129 women, age [mean±SE]: 40.7 ± 11.4 years) were prospectively included in the study. The mean BMI was 46.1±6.4 kg/m². A liver biopsy was available in 137 patients and a breath test in 136. The frequency of positive breath tests was higher in obese patients (24/136, 17.1%) than in healthy subjects (1/40, 2.5%; P=0.031). In the univariate analysis, SIBO was not associated with clinical variables, but tended to be associated with more frequent severe hepatic steatosis (26.3 vs. 10.3%, P=0.127), whereas the frequency of sinusoidal or portal fibrosis, lobular necrosis and non-alcoholic steatohepatitis (NASH) were not different. In the multivariate analysis, SIBO (P=0.005) and the presence of a metabolic syndrome (P=0.006) were independent factors of severe hepatic steatosis. Conclusion In morbidly obese patients, bacterial overgrowth prevalence is higher than in healthy subjects and is associated with severe hepatic steatosis.     

Prevalence of Obesity Among Children and/or Grandchildren of Adult Bariatric Surgery Patients

Background  Clinical experience suggests that some adults who undergo bariatric surgery have children who are obese. Childhood obesity is associated with increased morbidity and mortality in later life. This study examined the prevalence of obesity among children and grandchildren (≤12 years of age) of adult bariatric surgery patients. Methods  Patients in a prospective database of morbidly obese patients who underwent bariatric surgery between January 2004 and May 2007 were recruited by phone and in clinic. Patient demographics, body mass index (BMI) at surgery, and survey data were collected. The survey included questions regarding their child/grandchild's body habitus, weight, and height. Child obesity was defined as BMI percentile ≥95. Statistical significance was set at p < 0.05. Results  One hundred twenty-two patients were enrolled in this study (77% women, mean BMI 49 kg/m²). One hundred thirty-four out of 233 children/grandchildren identified had complete data; 41% had a BMI percentile ≥95. Only 29% of these obese children were so identified by the adult respondents. Significantly more biological children/grandchildren were obese than nonbiological (p = 0.013), and significantly more biological children were obese than biological grandchildren (p = 0.027). Conclusions  This sample of bariatric surgery patients had a high proportion of obese preteen children/grandchildren. Obesity was most prevalent among biological children (vs. biological grandchildren and nonbiological children). Patients often did not recognize the degree of overweight in their children/grandchildren. Because families of bariatric surgery patients often include obese children, interventions aimed at all family members merit consideration.     

Plasma Protein Carbonyl and Thiol Stress Before and After Laparoscopic Gastric Banding in Morbidly Obese Patients

Background The aim of this study is to examine the relationship between oxidative plasma protein and thiol stress and weight loss after laparoscopic adjustable gastric banding (LAGB). Methods Plasma protein carbonyl (PCO) concentration as a marker of protein oxidation, plasma thiol (PSH) and erythrocyte glutathione concentration (GSH, major intracellular thiol), as an antioxidant and metabolic markers, such as Homeostatic Model Assessment – Insulin resistance (HOMA-IR), BMI and plasma lipids were determined in morbidly obese patients (n 22, mean age 34.7 ± 11 years, BMI 48.4 ± 6.4 kg/m²) at baseline and 1 and 6 months after operation. Baseline levels in patients were also compared with the levels in agematched controls (n 20, BMI 21.3 ± 1.8 kg/m²). Plasma PCO and thiols and erythrocyte GSH concentrations were determined spectrophotometrically. Results Plasma PCO were significantly higher and plasma and erythrocyte thiol concentrations were significantly lower in morbidly obese patients than in controls (for each comparison, P < 0.01). BMI, plasma triglycerides and HOMA-IR were positively correlated with plasma PCO and negatively correlated with plasma P-SH and erythrocyte GSH (for each comparison, P < 0.01). Plasma HDL-cholesterol levels were positively correlated with plasma erythrocyte GSH (r = 0.405, P < 0.01) and negative correlated with plasma PCO (r = −0.273, P < 0.01). One and 6 months after the LAGB operation, total weight loss was 13.2 ± 6.3 and 35.5 ± 7.5 kg, respectively. Plasma PCO concentrations were decreased and P-SH and erythrocyte GSH concentrations were elevated following weight loss (for each, P < 0.01). Only plasma P-SH levels were restored to the control levels 6 months after LAGB. Conclusions Obesity and insulin resistance appear to be associated with plasma protein oxidation and thiol concentrations. Protein and thiol oxidative stress was improved by weight loss after LAGB in the short-term.     

Is Lean Body Mass Decreased after Obesity Treatment by Adjustable Gastric Banding?

Background There is concern that surgically-induced weight loss in obese subjects is associated with a disproportionate decrease in lean body mass (LBM) and in skeletal muscle mass (SMM), a major constituent of LBM. To address this issue, 1) we measured total and regional body composition following gastric banding in a group of obese subjects, and 2) we compared these data to those of a non-surgical control group of similar age and body size. Methods Body composition was assessed by dualenergy X-ray absorptiometry (DEXA) before and after laparoscopic adjustable silicone gastric banding (LAGB) in 32 women (after 1 year: age 43.7 ± 8.4 years, BMI 36.4 ± 5.9 kg/m², mean ± SD), and in 117 control women (age 44.5 ± 7.5 years; BMI 36.7 ± 5.5 kg/m²) referred for non-surgical weight management, prior to weight loss. SMM was estimated using a published equation based on LBM of the extremities (appendicular LBM). Results 1 year after LAGB, body weight loss (−23.7 ± 11.6 kg, P < 10⁻⁶) was mainly due to decreased fat mass (−21.2 ± 11.2 kg, P < 10⁻⁶), and total LBM was modestly, although significantly, decreased (−2.1 ± 4.2 kg, P = 0.01). Appendicular LBM (−0.7 ± 2.7 kg) and total SMM (−0.9 ± 3.0 kg) were not significantly modified. None of the body composition variables was significantly decreased in weight-reduced subjects compared to the control group, especially appendicular LBM and total SMM. Conclusions Results provide no evidence for a decrease in appendicular LBM and total SMM with weight loss following LAGB. Follow-up of these obese patients revealed a very favorable pattern of change in total and regional body composition, with preservation of muscle mass.     

Respiratory Sleep Disturbances in Patients Undergoing Gastric Bypass Surgery and Their Relation to Metabolic Syndrome

Background  The prevalence of obstructive sleep apnea syndrome (OSAS) is high in obese patients. Certain components of metabolic syndrome are linked to OSAS, but there is no information on their association in morbidly obese patients. Our aim was to ascertain the prevalence of respiratory disturbances during sleep in candidates for bariatric surgery and to study their association with metabolic syndrome. Methods  We examined the preoperative records (history, physical examination and laboratory findings, spirometry, and overnight pulse oximetry [arterial oxygen saturation by pulse oximetry, [SpO₂]]) of patients scheduled for gastric bypass surgery for 1 year in our hospital; an overnight sleep study was performed if SpO₂ readings or symptoms suggested sleep disturbance. Metabolic syndrome was defined according to the criteria of the National Cholesterol Education Program’s Adult Treatment Panel III. Results  Of the 31 patients studied, 19 (61.3%) had OSAS, including 15 newly diagnosed cases with a mean ± standard deviation apnea–hypopnea index of 49 ± 36. OSAS patients had higher fasting plasma glucose and triglyceride levels and a higher prevalence of diabetes. Metabolic syndrome was also more frequent in subjects with previously untreated OSAS (13/14, 92%) than in those without sleep disturbance (six of 11, 55%; p = 0.033). Conversely, the prevalence of OSAS in patients with metabolic syndrome was higher (13/19, 68%) than in subjects without metabolic syndrome (one of six, 17%; p = 0.026) even though the two groups had similar body mass index. Conclusions  Sleep disordered breathing is very prevalent in obese patients who are candidates for bariatric surgery and its presence is related to metabolic syndrome. An erratum to this article can be found at     

Changes in Depression Following Gastric Banding: A 5- to 7-year Prospective Study

Background Long-term outcomes of gastric banding regarding depression and predictors of change in depression are still unclear. This prospective, controlled study investigated depression and self-acceptance in morbidly obese patients before and after gastric banding. Methods A total of 248 morbidly obese patients (mean body mass index [BMI] = 46.4, SD = 6.9) seeking gastric banding completed questionnaires for symptoms of depression (Beck Depression Inventory) and self-acceptance. One hundred twenty-eight patients were treated with gastric banding and 120 patients were not. After 5 to 7 years, patients who either had (n = 40) or had not (n = 42) received gastric banding were reassessed. Results In the preoperative assessment, 35% of all obese patients suffered from clinically relevant depressive symptoms (BDI score ≥18). The mean depression score was higher and the mean self-acceptance score was lower than those of the normal population. Higher preoperative depression scores were observed among patients living alone and who had obtained low levels of education. After 5 to 7 years, patients with gastric banding had lost significantly more weight than patients without gastric banding (mean BMI loss 10.0 vs. 3.3). Gastric banding patients improved significantly in depression and self-acceptance, whereas no change was found in patients without gastric banding. Symptoms of depression were more reduced in patients who lost more weight, lived together with a partner, and had a high preoperative depression score. Conclusion Morbid obesity is associated with depressive symptoms and low self-acceptance. Gastric banding results in both long-term weight loss and improvement in depression and self-acceptance.