Improvement of associated respiratory problems in morbidly obese patients after open Roux-en-Y gastric bypass.

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is present in 44% of patients scheduled for bariatric surgery. Respiratory dysfunction associated with this syndrome is attributable to chronic obstructive pulmonary disease (COPD) and/or obesity hypoventilation syndrome (OHS). We studied the long-term effect of bariatric surgery on weight loss, on the respiratory comorbidities associated with obesity, and on the need for non-invasive positive pressure ventilation. METHODS: We followed a sample of patients with respiratory co-morbidity scheduled for open Capella Roux-en-Y gastric bypass (RYGBP) over 5-years. Patients who were positive for polysomnographic studies and required continous positive airway pressure (CPAP) before surgery were included. All patients were subjected to the same anesthetic and surgical protocols. At 1 year after surgery, polysomnographic studies were performed and arterial blood gases and pulmonary function were tested. RESULTS: Of the 209 patients scheduled for bariatric surgery during the study period, 105 had respiratory co-morbidity. Of these, 30 required CPAP-BiPAP treatment before surgery and were included in our study. Surgery took 128 minutes (range 70 to 210 minutes). Tracheal extubation in the operating theater was possible for 26 patients (86.7%). During the early postoperative period, 7 patients (23.3%) presented respiratory complications. Length of hospitalization was 6.87 days (range 4 to 11 days). At 1 year after RYGBP, patients presented significant weight loss and improvement of hypoxemia (from 73.3 +/- 10.6 to 90.5 +/- 11.5, P = 0.000), hypercarbia (from 44.5 +/- 5.7 to 40.6 +/- 4.9, P = 0.005), and in spirometric (P = 0.004) and polysomnographic results (P = 0.001). CPAP-BiPAP treatment after weight loss was necessary in only 14% of patients (P = 0.001). CONCLUSIONS: Weight loss after RYGBP improved arterial blood gases, respiratory tests and polysomnographic studies. CPAP treatment can be withdrawn in most patients.

Low 25-hydroxyvitamin D concentrations in obese women: their clinical significance and relationship with anthropometric and body composition variables.

UNLABELLED: Obesity is associated with low concentrations of 25-hydroxyvitamin D [25(OH) D]. However, conflicting results have been found regarding the relationship of 25(OH) D with anthropometric and adiposity parameters. The aim of our study was to analyze the association between 25(OH) D and body fat (BF) in a homogeneous cohort of non-obese, obese, and morbidly obese Caucasian women. The study was performed in L'Hospitalet de Llobregat, a city adjacent to Barcelona with a latitude of 41 degrees, 22 minutes, and 5 seconds north. MATERIALS AND METHODS: Plasma concentrations of 25(OH) D were determined and body composition was evaluated by bioelectrical impedance in a group of 43 women with morbid obesity, 28 non-morbidly obese, and 50 non-obese women matched for age. RESULTS: Morbidly obese women showed lower 25(OH) D concentrations compared to non-morbidly and non-obese women (37.9+/-16 vs 40.2+/-13 vs 56.7+/-21 nmol/l, p=0.001). Fifty-one percent of morbidly obese women had vitamin D deficiency [25(OH) D<38 nmol/l] compared to 22% of non-obese patients, (p=0.004). In the bivariate correlation analysis 25(OH) D was inversely associated with weight (r=-0.41, p=0.001), body mass index (BMI) (r=-0.432, p=0.001), waist to hip ratio (WHR)(r=-0.40, p=0.001), BF (r=-0.53, p=0001), fat mass (r=-0.44, p=0.0001), fat-free mass (r=-0.35, p=0.001). In the multivariate general linear model analysis, 25(OH) D was associated with season of examination (p=0.001) and was negatively associated with BF (beta=-0.75, p=0.001), after adjusting for age, BMI, and WHR. CONCLUSIONS: 25(OH) D concentrations are associated with body composition variables especially by BF, independently of seasonal variability. Therefore, body adiposity should be considered when assessing vitamin D requirements in obese patients.

Effect of weight loss induced by gastric bypass on proinflammatory interleukin-18, soluble tumour necrosis factor-alpha receptors, C-reactive protein and adiponectin in morbidly obese patients.

OBJECTIVE: Interleukin-18 (IL-18) is a potent proinflammatory cytokine whose role in human obesity has recently been suggested. The aim of our study was to analyse in morbidly obese patients undergoing gastric bypass, the relationship of IL-18 with insulin resistance and with proinflammatory cytokines (tumour necrosis factor-alpha receptors, sTNFR), C-reactive protein (CRP) and with adiponectin. DESIGN: Observational and prospective study. PATIENTS: Sixty-five morbidly obese patients, aged 45 +/- 8.9 years, were studied before and 12 months after gastric bypass. MEASUREMENTS: We analysed plasma concentrations of IL-18, sTNFR, CRP and adiponectin. RESULTS: Plasma concentrations of sTNFR2, IL-18 and CRP were decreased and adiponectin significantly increased after bypass surgery. In the multiple regression analysis, preoperative values of IL-18 remained significantly associated with preoperative triglycerides (beta = 0.47, P = 0.005) and TNFR2 (beta = 0.47, P = 0.004). R(2) for the model = 0.38. Postoperative IL-18 concentrations in the multiple regression analysis were significantly associated with postoperative homeostasis model assessment of insulin resistance (HOMA-IR) (beta = 0.092, P = 0.019) and triglycerides (beta = 0.40, P = 0.036). R(2) for the model = 0.46. IL-18 did not correlate with body mass index, fat mass, fat-free mass or body fat. No relationship was either found between adiponectin and IL-18, TNFR1 and -2 and CRP. CONCLUSIONS: Massive weight loss induced by gastric bypass reduces IL-18, TNFR2 and CRP. IL-18 might be a marker of the chronic inflammatory process underlying insulin resistance but its lack of association with anthropometric and body composition parameters does not support a major secretion by human adipocytes. IL-18 and sTNFR1 and -2 do not play a main role in the inhibition of the secretion of adiponectin.

Expression of TWEAK and its receptor Fn14 in human subcutaneous adipose tissue. Relationship with other inflammatory cytokines in obesity.

TWEAK, a cytokine of the TNF family, has been found to be expressed under different inflammatory conditions but no data is available concerning the expression of this cytokine and its receptor (Fn14) in human obesity. In the present work we have evaluated the expression of many pro-inflammatory TNF system cytokines (TNF-alpha, TWEAK and their respective receptors, TNFR1, TNFR2 and Fn14) in human adipose tissue of 84 subjects some with different degree of obesity and type 2 diabetes, and its relation with inflammation by also measuring the expression of macrophage marker CD68. We detected expression of TWEAK and Fn14 in isolated mature adipocytes and in the stromovascular fraction. Additionally, we found that LPS upregulates the expression of both genes on THP-1 human monocytic cell line. TWEAK was expressed in adipose tissue of all studied subjects with no differences between obesity group, and was associated with Fn14 expression in morbid obese, mainly in women with type 2 diabetes. The data obtained here also showed that TNF-alpha and TNFR2 mRNAs were significantly more expressed in subcutaneous adipose tissue of subjects with morbid obesity compared to obese and non-obese subjects. In contrast, TNFR1 gene expression was negatively associated with BMI. Our results suggest that the expression of TNF-derived pro-inflammatory cytokines are increased in severe obesity, where macrophage infiltrate could modulate the inflammatory environment through activation of its receptors.

[Influence of the severity of obesity on morbidity and mortality after gastric bypass surgery]. / Influencia del grado de obesidad en la morbimortalidad operatoria de la cirugia bariátrica.

OBJECTIVE: To determine the influence of severity of obesity on morbidity and mortality following Roux-en-Y gastric bypass and vertical ringed gastroplasty, with severity classified as morbid obesity (MO) defined by a body mass index (BMI) between 35 and 55 Kg/m2 and super-morbid obesity (SMO) defined by a BMI exceeding 55 Kg/m2. METHOD: A series of patients who underwent the aforementioned type of gastric bypass surgery were followed for 5 years. The patients were classified as to whether they had associated sleep apnea syndrome, alveolar hypoventilation, or "overlap syndrome". RESULTS: A total of 105 patients were enrolled: 70 (66.7%) classified as having MO and 35 (33.3%) classified as having SMO. Distribution by sex was significantly different in the 2 groups, but respiratory diseases were similar. PaO2 was higher in the MO group, PaCO2 was lower, and the alveolar-arterial gradient was smaller. Duration of surgery was shorter in the MO group (120.43 +/- 32.97 vs. 136.76 +/- 28.28 minutes). The percentage of complications was similar in the 2 groups (32.86% and 45.7% in the MO and SMO groups, respectively), although the incidence of respiratory complications was higher in SMO patients (8.57% vs. 20% in the MO and SMO groups, respectively). No differences were observed in the rates of surgical, hemodynamic, or infectious complications. Length of hospital stay was similar (6.44 vs. 6.69 for MO and SMO patients, respectively). CONCLUSIONS: More severe obesity can be associated with preoperative arterial blood gas alterations in patients with concomitant respiratory disease and a higher incidence of respiratory complications in the early phase of recovery from gastric bypass surgery.

Insulin resistance, leptin and TNF-alpha system in morbidly obese women after gastric bypass.

UNLABELLED: Obesity is a complex disease associated with insulin resistance. Leptin and the TNF-alpha system could be involved in the pathogenesis of obesity and insulin resistance. Gastric bypass (GBP) is a surgical treatment for morbidly obese patients. We conducted a study after GBP to analyze the pattern of variation of anthropometric and body composition variables, leptin and sTNFR1 and 2. METHODS: 29 morbidly obese women were studied, at baseline and throughout 6 months after gastric bypass. RESULTS: At baseline, the BMI was 49 +/- 6 kg/m(2) and patients showed a higher fasting insulin resistance index (FIRI), leptin, leptin/fat mass and sTNFR1 and 2 than did controls. 6 months after GBP, BMI was 35+/-4, and FIRI, leptin and leptin/fat mass decreased significantly in the first months and throughout the follow-up. sTNFR1 and 2 showed an initial increase, but at 6 months their concentrations were similar to baseline (2.6+/-0.8 vs 3.1+/-0.95 ng/ml, P < 0.05; 4.6+/-1.4 vs 7+/-2.5 ng/ml, P < 0.05). At baseline, there was no correlation between leptin and BMI and body composition variables but there was a correlation with fat mass (r=0.42, P=0.004) and sTNFR1 (r=0.58, P=0.001). At 6 months, there was a correlation between leptin and BMI (r=0.53, P=0.004) and sTNFR1 (r=0.46, P=0.013). CONCLUSIONS: Morbidly obese women after GBP became less insulin resistant with lower leptin concentrations, but showed an initial increase of sTNFR1 and 2. This pattern of variation of the leptin TNF-alpha axis suggests a disregulation of the system after dramatic weight loss and also that insulin and leptin up-regulate TNF-alpha production irrespective of insulin resistance status.