Bypass of the duodenum improves insulin resistance much more rapidly than sleeve gastrectomy

BackgroundObesity is very often accompanied by other diseases, with the most common type 2 diabetes mellitus and cardiovascular complications. Bariatric surgery is the most effective strategy for treating morbidly obese patients. We evaluated the metabolic changes that occur in the early stage after 2 types of bariatric surgery, biliopancreatic diversion of Scopinaro (BPD) and sleeve gastrectomy (SG), in morbidly obese patients.MethodsThe study was undertaken in 31 nondiabetic morbidly obese patients (7 men and 24 women). Of the 31 patients, 18 underwent BPD and 13 underwent SG. All patients were examined before bariatric surgery (baseline) and at 15, 30, 45, and 90 days postoperatively.ResultsSignificant improvement occurred in the anthropometric variables after the 2 types of bariatric surgery, without significant differences between the 2 types of interventions. In patients undergoing BPD, the serum glucose, cholesterol, triglycerides, high-density lipoprotein cholesterol, and free fatty acids were significantly reduced. The changes that occurred in these biochemical variables after SG were not significant. Insulin resistance decreased significantly during the 90 days after surgery, with the greatest decrease at 15 days. However, in the patients who underwent SG, insulin resistance worsened at 15 days and later diminished.ConclusionThe results of the present study have shown that the surgical technique that excludes the duodenum (i.e., BPD) has immediate postoperative changes in the degree of insulin resistance in morbidly obese patients compared to those techniques that do not exclude the duodenum (i.e., SG).     

Early insulin sensitivity after restrictive bariatric surgery,inconsistency between HOMA-IR and steady-state plasma glucose levels

BackgroundThe low-grade inflammatory condition present in morbid obesity is thought to play a causative role in the pathophysiology of insulin resistance (IR). Bariatric surgery fails to improve this inflammatory condition during the first months after surgery. Considering the close relation between inflammation and IR, we conducted a study in which insulin sensitivity was measured during the first months after bariatric surgery. Different methods to measure IR shortly after bariatric surgery have given inconsistent data. For example, the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels have been reported to decrease rapidly after bariatric surgery, although clamp techniques have shown sustained insulin resistance. In the present study, we evaluated the use of steady-state plasma glucose (SSPG) levels to assess insulin sensitivity 2 months after bariatric surgery.MethodsInsulin sensitivity was measured using HOMA-IR and SSPG levels in 11 subjects before surgery and at 26% excess weight loss (approximately 2 months after restrictive bariatric surgery).ResultsThe SSPG levels after 26% excess weight loss did not differ from the SSPG levels before surgery (14.3 ± 5.4 versus 14.4 ± 2.7 mmol/L). In contrast, the HOMA-IR values had decreased significantly (3.59 ± 1.99 versus 2.09 ± 1.02).ConclusionDuring the first months after restrictive bariatric surgery, we observed a discrepancy between the HOMA-IR and SSPG levels. In contrast to the HOMA-IR values, the SSPG levels had not improved, which could be explained by the ongoing inflammatory state after bariatric surgery. These results suggest that during the first months after restrictive bariatric surgery, HOMA-IR might not be an adequate marker of insulin sensitivity.     

The role of laparoscopic sleeve gastrectomy on inflammatory parameters in morbidly obese patients

BackgroundObesity is an excessive increase in body fat mass and triggers chronic inflammation which causes increased fat accumulation in the visceral fat tissue. The aim of this study was to analyze serum zinc (Zn), Zn-alpha 2 glycoprotein (ZAG), peroxisome proliferator-activated receptor-γ (PPAR-γ) and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) levels in morbidly obese patients before and after laparoscopic sleeve gastrectomy (LSG) and determine the association between alteration in body mass index (BMI), the % Excess Weight Loss (% EWL) and the biochemical parameters.MethodsThirty healthy individuals as a control group and 30 morbidly obese patients who had undergone LSG were enrolled in this study. Routine anthropometric and laboratory biochemical parameters in venous blood samples of groups at baseline and 1 and 12 months after LSG were recorded.ResultsSignificant weight loss was achieved at 1 and 12 months after LSG. At baseline serum ZAG and PPAR-γ levels were lower, while NF-кB levels were higher in morbidly obese patients compared with the control group. Serum ZAG and PPAR-γ levels increased while NF-кB levels decreased 1 month and 12 months after LSG. Decreased %EWL was negatively correlated with changes in NF-кB, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), fasting plasma glucose and insulin at 12 months after LSG in morbidly obese patients. However, %EWL was positively correlated with changes in ZAG.ConclusionsObesity was associated with down-regulated serum ZAG and PPAR-γ levels while up-regulated serum NF-кB. Our findings suggest that LSG ameliorates upregulating PPAR-γ expression, thereby inhibiting NF-κB-mediated inflammation by weight loss.     

Does Homeostasis Model Assessment of Insulin Resistance have a predictive value for post-coronary artery bypass grafting surgery outcomes?

Objective

This study aims to investigate whether pre-operative Homeostasis Model Assessment Insulin Resistance (HOMA-IR) value is a predictor in non-diabetic coronary artery bypass grafting patients in combination with hemoglobin A1c, fasting blood glucose and insulin levels.

Methods

Eighty one patients who were admitted to Cardiovascular Surgery Clinic at our hospital between August 2012 and January 2013 with a coronary artery bypass grafting indication were included. Patients were non-diabetic with <6.3% hemoglobin A1c and were divided into two groups including treatment and control groups according to normal insulin resistance (HOMA-IR<2.5, Group A; n=41) and high insulin resistance (HOMA-IR>2.5, Group B; n=40), respectively. Pre-operative fasting blood glucose and insulin were measured and serum chemistry tests were performed. The Homeostasis Model Assessment Insulin Resistance values were calculated. Statistical analysis was performed.

Results

There was a statistically significant difference in fasting blood glucose and HOMA-IR values between the groups. Cross-clamping time, and cardiopulmonary bypass time were longer in Group B, compared to Group A (P=0.043 and P=0.031, respectively). Logistic regression analysis revealed that hemoglobin A1c was not a reliable determinant factor alone for pre-operative glucometabolic evaluation of non-diabetic patients. The risk factors of fasting blood glucose and cardiopulmonary bypass time were more associated with high Homeostasis Model Assessment Insulin Resistance levels.

Conclusion

Our study results suggest that preoperative screening of non-diabetic patients with Homeostasis Model Assessment Insulin Resistance may improve both follow-up visit schedule and short-term outcomes, and may be useful in risk stratification of the high-risk population for impending health problems.     

Can bariatric surgery improve cardiovascular risk factors in the metabolically healthy but morbidly obese patient?

BackgroundBariatric surgery has been shown to be effective in resolving co-morbid conditions even in patients with a body mass index (BMI)<35 kg/m². A question arises regarding the metabolic benefits of bariatric surgery in metabolically healthy but morbidly obese (MHMO) patients, characterized by a low cardiometabolic risk. The objective of this study was to assess the effects of bariatric surgery on cardiometabolic risk factors among MHMO and metabolically unhealthy morbidly obese (MUMO) adults.MethodsA nonrandomized, prospective cohort study was conducted on 222 severely obese patients (BMI>40 kg/m²) undergoing either laparoscopic roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy. Patients were classified as MHMO if only 1 or no cardiometabolic factors were present: high blood pressure, triglycerides, blood glucose (or use of medication for any of these conditions), decreased high-density lipoprotein-cholesterol (HDL-C) levels, and insulin resistance defined as homeostasis model assessment for insulin-resistance (HOMA-IR)> 3.29.ResultsForty-two (18.9%) patients fulfilled the criteria for MHMO. They were younger and more frequently female than MUMO patients. No differences between groups were observed for weight, BMI, waist and hip circumference, total and LDL-C. MHMO patients showed a significant decrease in blood pressure, plasma glucose, HOMA-IR, total cholesterol, LDL-C and triglycerides and an increase in HDL-C 1 year after bariatric surgery. Weight loss 1 year after bariatric surgery was similar in both groups.ConclusionEighteen percent of patients with morbid obesity fulfilled the criteria for MHMO. Although cardiovascular risk factors in these patients were within normal range, an improvement in all these factors was observed 1 year after bariatric surgery. Thus, from a metabolic point of view, MHMO patients benefited from bariatric surgery.     

Gastric bariatric operation in insulin-treated adults

Gastric bariatric operation has been advocated to ameliorate adult-onset diabetes mellitus in the morbidly obese patient. However, there are few data to support this. In this clinical study we report the cases of 23 insulin-treated, morbidly obese, adult-onset diabetes (type II) patients who underwent gastric bariatric operations for weight reduction. Preoperative insulin requirements ranged from 10 to 230 U/day (mean 74 U/day). After operation, 14 patients discontinued insulin, and seven patients decreased their insulin requirement by 72% (100 to 28 U/day). Two patients were lost to follow-up. Six patients were admitted to the Clinical Research Unit before and after operation to evaluate the effects of surgically induced weight loss on fasting blood glucose levels, hemoglobin A1C insulin resistance, and glucose tolerance. Weight loss at the time of postoperative studies ranged between 22.5 and 49.1 kg (mean 30.6 kg). Fasting blood glucose levels decreased 48% (mean 321 mg/dl before operation to 166 mg/dl after operation). Hemoglobin A1C levels improved from a mean of 11.8% to 7.9%. Insulin resistance assessed in four patients by measurement of glucose clearance during insulin and glucose infusion improved from a mean of 77 ml/min before operation to 228 ml/min after operation. Glucose tolerance was quantitated by determination of glucose disappearance during intravenous glucose tolerance test. The mean glucose disappearance improved from 0.176% to 0.385%/min following operation. This study provides clinical and laboratory evidence indicating significant improvement of insulin-treated diabetes mellitus in morbidly obese patients who have lost weight following gastric bariatric operation.     

Relationship between bone mineral density, leptin and insulin concentration in Brazilian obese adolescents

Despite the epidemic of adolescent obesity, the effect of obesity and hormones on bone mineral accrual during growth is poorly understood. Studies using dual-energy X-ray to examine the effect of obesity on bone mass in children and adolescents have yielded conflicting results. The aim of this study was to explore the combined and independent contributions of body mass index, body composition, leptin, insulin, glucose levels and Homeostasis Model Assessment Insulin Resistance (HOMA-IR) to bone mineral density (BMD) and bone mineral content in a group of Brazilian obese adolescents. This study included 109 post-pubescent obese adolescents. A whole-body dual-energy X-ray absorptiometry scan was performed,using a HOLOGIC QDR4200, to determine whole-body BMD and body composition. Blood samples were collected in the outpatient clinic after an overnight fast, and evaluated for fasting blood glucose and immunoreactive insulin. Leptin levels were assessed with a radioimmunoassay kit. Insulin resistance was assessed by HOMA-IR and the quantitative insulin sensitivity check index. Our results showed that insulin levels and HOMA-IR correlated negatively with BMD and a linear regression analysis showed that serum leptin is inversely associated to BMD adjusted for body mass. In conclusion, our data support the hypothesis that leptin, insulin and HOMA-IR are inversely associated with BMD and play a significant direct role in bone metabolism.     

Effect of bariatric surgery on glycemic profiles in multiethnic obese nondiabetic Asians

BackgroundThe effect of bariatric surgery on improvement and remission of type 2 diabetes (T2D) is well studied. The effect of surgery on glycemic profiles of obese, but nondiabetic individuals is unknown.ObjectivesWe aimed to study changes in glycemic indices in obese nondiabetics undergoing bariatric surgery and correlate fat mass loss with changes in glycemic profiles.SettingUniversity Hospital, Singapore.MethodsA prospective database of nonT2D patients who underwent bariatric surgery between April 2009 and December 2014 was analyzed. Changes in weight, fat mass, and glycemic profiles, including glycated hemoglobin, C-peptide levels, and the homeostasis model assessment of insulin resistance were studied at 1- and 3-year follow-up.ResultsOne hundred thirty-three nondiabetics underwent bariatric surgery in the study period. Twenty-nine (21.8%) patients were found to have impaired fasting glycemia. We observed reductions in mean fat mass from 47.4 ± 12.2 kg preoperatively to 27.8 ± 11.6 kg at 1 year. Despite mean fat mass regain to 33.9 ± 19.6 kg at 3 years, homeostasis model assessment of insulin resistance improved from severe insulin resistant state of >5.00 (7.13 ± 11.5) preoperatively to normal ranges of <3.00 (1.55 ± .91) at 3 years.ConclusionBariatric surgery results in significant sustained weight loss in obese nondiabetics and normalizes glycated hemoglobin and homeostasis model assessment of insulin resistance after surgery. It is a promising modality to prevent or delay the onset of T2D in obese nondiabetic patients. Further studies should be conducted in nondiabetics to assess the efficacy of bariatric surgery in prevention of T2D onset in the longer term.     

The impact of metabolic parameters on the change of pulmonary function in obese patients

BackgroundEthnic differences exist in the function and distribution of adipose tissue, which influences whole body metabolism, including pulmonary function. The object of this study was to examine the relationships between serum metabolic parameters and pulmonary function in a morbidly obese Asia-Pacific population.MethodsOne-hundred thirty-seven morbidly obese Chinese patients, aged≥18 years with a body mass index (BMI)>32 kg/m² who were being evaluated for bariatric surgery between July 2007 and December 2008, were studied. Cross-sectional associations between serum metabolic parameters, including lipids, glucose, insulin, leptin, and adiponectin levels with forced vital capacity (FVC) and forced expiratory volume in the first second (FEV₁) assessed by spirometry, were analyzed. Multiple regression analyses also were conducted, with age, gender, smoking history, and various anthropometric measurements of obesity as confounders.ResultsSerum adiponectin and HDL cholesterol had a positive correlation with FVC and FEV₁. In addition, insulin resistance, determined by the homeostatic model assessment method (HOMA), was negatively correlated with FVC. In the multiple linear regression analysis, only serum adiponectin was significantly correlated with FVC and FEV₁, independent of obesity level.ConclusionsSerum adiponectin level was positively and independently associated with pulmonary function in morbidly obese Chinese adults.     

Severe Obesity and P-Wave Dispersion: The Effect of Surgically Induced Weight Loss

Background Recent data have shown that obesity is an important potential risk factor for atrial fibrillation (AF). The mechanism of development of AF in obesity patients is still unclear and may be related to atrial refractoriness heterogeneity. The aim of our study was to determine the influence of bariatric surgery with a consequent substantial weight loss on P-wave dispersion in morbidly obese population. Methods We enrolled in this study 40 severe obese patients, and 40 age-matched non-obese healthy subjects were also recruited as controls. All subjects underwent conventional 12-lead electrocardiography for the analysis of P-wave dispersion. All subjects underwent bariatric surgery and were resubmitted to electrocardiography, biochemical, and anthropometric examination within 12 months after intervention. Results Severe obese patients had greater values in P-wave duration and dispersion than the normal weight controls. Bariatric surgery reduced significantly P-wave dispersion. There was a significant correlation between decrease of atrial refractoriness heterogeneity and bariatric-surgery-induced weight loss. Conclusions In severe obese patients, surgically induced weight loss reduction is associated with significant decreased in P-wave dispersion. The reduction of the atrial refractoriness heterogeneity may be of clinical significance by reducing the risk of atrial fibrillation in morbidly obese subjects.     

Predictors of psychological symptoms in morbidly obese patients after gastric bypass surgery

BackgroundMorbid obesity is associated with debilitating psychosocial consequences, such as depression, anxiety, and low self-esteem. One of the main goals of bariatric surgery should not only be reducing weight and counteracting co-morbid conditions, but also improving postoperative psychosocial functioning. The objective of our study was to determine the preoperative variables that could predict the psychological symptoms 6 and 12 months after surgery to improve the clinical outcome of morbidly obese patients undergoing bariatric surgery. The setting was a university hospital in Spain.MethodsThe study group consisted of 60 morbidly obese patients (46 women and 14 men) who had undergone gastric bypass surgery for weight reduction and had ≥1 year of follow-up. The patients were evaluated using different questionnaires (Symptom Checklist-90-Revised, Body Shape Questionnaire, Rosenberg Self-Esteem Questionnaire, COPE, Medical Outcomes Study Social Support Survey) at 3 points: before surgery, at 6 months postoperatively, and at 1 year postoperatively. To determine the influence of preoperative variables on long-term psychological status, a step-by-step multivariate linear regression analysis was performed, taking P < .05 as statistically significant.ResultsThe variables of self-esteem, instrumental support, and coping focused in the emotions were the main preoperative predictors for psychological symptoms 6 months after surgery. Preoperative drug abuse as a strategy of problem solving and mainly body image significantly predicted most of the psychological disorders 1 year after surgery.ConclusionThe study of different psychosocial variables in patients before bariatric surgery is an important aid to predict postoperative psychological functioning. Self-esteem and body image were the most influential factors in the postoperative psychological outcome of morbidly obese patients in our study.     

Serum Fetuin-A: A Novel Potential Link Between Post-adolescent Acne and Insulin Resistance

BackgroundPost-adolescent acne is acne in patients aged older than 25 years. It is more common in women, suggesting an underlying hormonal imbalance. It has been postulated that insulin resistance (IR) may play a role in pathogenesis.ObjectiveTo explore the relationship between fetuin-A, IR, and post-adolescent acne.MethodsSerum fetuin-A levels were assessed using an ELISA technique in 50 female patients with post-adolescent acne and 50 healthy controls, and IR was calculated using the Homeostasis Model Assessment of Insulin Resistance Index (HOMA-IR).ResultsStudied patients had significantly higher HOMA-IR indices and serum fetuin-A levels than control subjects (P=0.001 and <0.001, respectively) and they were significantly increased in patients with severe lesions (P<0.001).ConclusionWe found that IR was more significantly prevalent among studied patients, especially those with more severe acne grades, and that could be attributed to higher serum fetuin-A levels. Fetuin -A might be a predictor for acne severity and associated metabolic comorbid conditions, such as IR. However, further large-scale studies will be needed.     

Serologic predictors of nonalcoholic steatohepatitis in a population undergoing bariatric surgery

BackgroundNonalcoholic steatohepatitis (NASH) is common in the morbidly obese. It is a condition that can lead to progressive fibrosis and cirrhosis. We determined the prevalence in a population undergoing bariatric surgery and evaluated the possible serologic predictors before the development of fibrosis.MethodsLiver biopsies were taken from 370 consecutive patients who were undergoing laparoscopic bariatric surgery. The clinical and biochemical parameters were then assessed for correlation with the histologic features of nonalcoholic steatohepatitis.ResultsOf the 370 patients, 68 (18%) were found to have NASH. Increased insulin resistance, alanine transaminase, and total bilirubin were independently associated with the presence of NASH. The presence of ≥2 of the 3 provided the best combination of sensitivity (.71) and specificity (.71) for predicting NASH.ConclusionIncreased insulin resistance, alanine transaminase, and total bilirubin are serologic predictors for the presence of NASH before the development of fibrosis.     

Impact of Laparoscopic Roux-en-Y Gastric Bypass on Metabolic Syndrome, Inflammation, and Insulin Resistance in Super Versus Morbidly Obese Women

Background  Although Roux-en-Y gastric bypass (RYGBP) is one of the preferred bariatric procedures in obese individuals, the efficacy of this procedure in the setting of super-obesity [body mass index (BMI) ≥50] is unclear. The aim of this study was to compare the efficacy of laparoscopic (L) RYGBP to reverse metabolic syndrome, inflammation, and insulin resistance in super-obese women compared to morbidly obese women. Methods  Seventy-three consecutive women were enrolled in this prospective study. Anthropometric, metabolic, and inflammatory biological parameters were assessed in 18 super-obese and 55 morbidly obese women before LRYGBP and 1 year after surgery. Metabolic syndrome was diagnosed according to the International Diabetes Federation definition. Results  Before surgery, super-obese women had a higher BMI, fat mass, blood insulin, and HOMA1-IR than morbidly obese women. Both groups had similar serum levels of C-reactive protein and orosomucoid. The incidence of metabolic syndrome, type 2 diabetes, and increased liver enzymes was comparable in the two groups. One year after LRYGBP, metabolic syndrome, type 2 diabetes, metabolic and inflammatory biological parameters were improved in the whole study population. A similar degree of improvement was observed in super-obese and morbidly obese women, although BMI and fat mass were persistently higher in super-obese patients. Conclusions  One year after surgery, LRYGBP was equally effective at reversing metabolic syndrome, inflammation, and insulin resistance in morbidly obese and super-obese women.     

Change in serum polyamine metabolome pattern after bariatric surgery in obese patients with metabolic syndrome

BackgroundRecent works have reported that bariatric surgery has remarkable effects on the metabolome, which might be potentially associated to the metabolic improvement of this procedure in patients with obesity. Serum polyamines, metabolites derived from amino acid metabolism, have been recently related to the metabolic status in obese individuals. However, the impact of bariatric surgery on the circulating levels of polyamines remains elusive.ObjectiveTo evaluate the effect of bariatric surgery on serum polyamine levels and to evaluate the association of changes in these molecules with metabolic improvement in patients with morbid obesity.SettingVirgen de la Victoria University Hospital, Malaga, Spain.MethodsThis study included 32 morbidly obese patients (weight index ≥40 kg/m²) with metabolic syndrome, who underwent sleeve gastrectomy. Serum levels of polyamines (putrescine, spermidine, and spermine), acetylpolyamines, and polyamine-related amino acids (arginine and ornithine) were assessed at baseline and 6 months after bariatric surgery, and were analyzed in an ultraperformance liquid chromatography–mass spectrometry platform.ResultsOur metabolomic analysis revealed a significant rise in several metabolites related to the polyamine metabolism, such as putrescine and acetyl derivatives of spermidine and spermine in serum samples from morbidly obese patients after bariatric surgery. Changes in serum levels of both putrescine and acetylputrescine were associated to the resolution of metabolic syndrome after surgery.ConclusionOur study indicates that bariatric surgery affects the serum polyamine pattern and the resolution of metabolic syndrome after bariatric surgery is associated to specific changes in the serum polyamine metabolome.     

The effect of bariatric surgery on gout: a comparative study

BackgroundObesity is a risk factor for the development of gout. An increased incidence of early gouty attacks after bariatric surgery has been reported, but the data is sparse. The effect of weight loss surgery on the behavior of gout beyond the immediate postoperative phase remains unclear. The objective of this study was to evaluate the pre- and postoperative frequency and features of gouty attacks in bariatric surgery patients.MethodsCharts were reviewed to identify patients who had gout before bariatric surgery. Demographic and gout-related parameters were recorded. The comparison group consisted of obese individuals with gout who underwent nonbariatric upper abdominal procedures.ResultsNinety-nine morbidly obese patients who underwent bariatric surgery had gout. The comparison group consisted of 56 patients. The incidence of early gouty attack in the first month after surgery was significantly higher in the bariatric group than the nonbariatric group (17.5% versus 1.8%, P = .003). In the bariatric group, 23.8% of patients had at least one gouty attack during the 12-month period before surgery, which dropped to 8.0% during postoperative months 1–13 (P = .005). There was no significant difference in the number of gouty attacks in the comparison group before and after surgery (18.2% versus 11.1%, P = .33). There was a significant reduction in uric acid levels 13-months after bariatric surgery compared with baseline values (9.1±2.0 versus 5.6±2.5 mg/dL, P = .007).ConclusionThe frequency of early postoperative gout attacks after bariatric surgery is significantly higher than that of patients undergoing other procedures. However, the incidence decreases significantly after the first postoperative month up to 1 year.     

Does Gastric Restriction Surgery Reduce the Risks of Metabolic Diseases?

Background: Certain risk factors for arteriosclerosis are associated with obesity, e.g. hypertension, insulin resistance, the high triglyceride - low HDL pattern. One aim in treating morbid obesity is to reduce these risk factors. This study was designed to follow metabolic risk factors after weight loss in 165 morbidly obese patients who underwent a gastric restriction operation. Methods and Patients: Lipid and hormone levels were analyzed before surgery and after 25, 50, 75 and 100% loss of excess weight. Mean cholesterol and triglyceride levels were normal or slightly elevated. HDL cholesterol was also normal (41 mg/dl). Thirty eight percent of the patients had elevated cholesterol and triglyceride levels. Insulin levels were measured as an indicator of potential insulin resistance, and with a mean of 21 μU/ml it was at the upper normal level. Results: After reaching 75% reduction of overweight in a mean time of 10 months, serum cholesterol levels were unchanged. Serum triglycerides, however, decreased by 35% (P < 0.0001) and HDL cholesterol increased by 24% (P < 0.0001). Insulin levels decreased to 8 μU/ml (P < 0.0001). Conclusion: We found an amelioration in the metabolic parameters in 75% of the patients. Nevertheless morbidly obese patients were found to have fewer abnormalities in lipid and glucose metabolism than expected from data of overweight patients with metabolic syndrome. Further long-term studies with careful evaluation of the metabolic parameters as risk factors in patients with morbid obesity need to be performed. ? 1998 Rapid Science Ltd.     

Bariatric surgery rapidly improves mitochondrial respiration in morbidly obese patients

Background

Obesity and its attendant comorbidities are an emerging epidemic. Chronic metabolic inflammation (metainflammation) is thought to precipitate obesity-associated morbidities; however, its mechanistic progression is poorly understood. Moreover, although interventions such as diet, exercise, and bariatric surgery can control body weight, their effects on metainflammation are also poorly understood. Recently, metainflammation and the pathobiology of obesity have been linked to mitochondrial dysfunction. Herein we examined the effects of bariatric surgery on mitochondrial respiration as an index of resolving metainflammation in morbidly obese patients.

Methods

This institutional review board-approved study involved morbidly obese patients (body mass index > 35 kg/m²) undergoing sleeve gastrectomy or Roux-en-Y gastric bypass. Mitochondrial respiration was assessed in peripheral blood monocytes and in skeletal muscle samples before surgery and at 12 weeks after surgery. Patient biometrics, homeostasis model assessment-estimated insulin resistance (HOMA-IR) score, C-reactive protein, and lipid profile were analyzed.

Results

Twenty patients were enrolled and showed an average percent excess body weight loss of 30.3 % weight loss at 12 weeks after surgery. Average HOMA-IR score decreased from 3.0 to 1.2 in insulin-resistant patients. C-reactive protein, an index of metainflammation, showed a modest decrease. Lipid profile remained stable. Intriguingly, mitochondrial basal and maximal respiration rates in peripheral blood monocytes increased after surgery. Basal rates of skeletal muscle mitochondrial respiration were unchanged, but the maximal respiration rate trended toward an increase after surgery.

Conclusions

Cellular and tissue mitochondrial respiration increased in a morbidly obese patient cohort after laparoscopic bariatric surgery. These changes were consistent in patients with postsurgical weight loss. Importantly, no significant changes or improvements occurred in canonical indices used to assess recovery after bariatric surgery over this short time course. Thus, increased mitochondrial respiration may represent a novel biomarker of early improvement and positive outcome after surgery in morbidly obese patients.     

Insulin Resistance, Serum Adipokines and Risk of Fibrosis Progression in Patients Transplanted for Hepatitis C

In the nontransplant setting diabetes mellitus is a risk factor for disease progression in patients with chronic hepatitis C virus (HCV) infection. The impact of early insulin resistance on the development of advanced fibrosis, even in the absence of clinically apparent diabetes mellitus, is not known.
Our aim was to determine whether the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) can be used to identify insulin-resistant patients at risk for rapid fibrosis progression.
Cohort study including patients transplanted for chronic HCV between January 1, 1995 and January 1, 2005.
One hundred sixty patients were included; 25 patients (16%) were treated for diabetes mellitus and 36 patients (23%) were prediabetic, defined as HOMA-IR >2.5.
Multivariate Cox regression analysis showed that insulin resistance (hazard ratio (HR) 2.07; confidence interval (CI) 1.10–3.91, p = 0.024), donor age (HR 1.33;CI 1.08–1.63, p = 0.007) and aspartate aminotransferase (HR 1.03;CI 1.01–1.05, p < 0.001) were significantly associated with a higher probability of developing advanced fibrosis, i.e. Knodell fibrosis stage 3 or 4, whereas steatosis (HR 0.94;CI 0.46–1.92, p = 0.87) and acute cellular rejection (HR 1.72;CI 0.88–3.36, p = 0.111) were not.
In conclusion, posttransplant insulin resistance is strongly associated with more severe recurrence of HCV infection. HOMA-IR is an important tool for the identification of insulin resistance among patients at risk for rapid fibrosis progression after liver transplantation for HCV.     

Gene Expression of Leptin, Resistin, and Adiponectin in the White Adipose Tissue of Obese Patients with Non-Alcoholic Fatty Liver Disease and Insulin Resistance

Background: Adipose tissue is an active endocrine organ that secretes a variety of metabolically important substances including adipokines. These factors affect insulin sensitivity and may represent a link between obesity, insulin resistance, type 2 diabetes (DM), and nonalcoholic fatty liver disease (NAFLD). This study uses real-time polymerase chain reaction (PCR) quantification of mRNAs encoding adiponectin, leptin, and resistin on snap-frozen samples of intra-abdominal adipose tissue of morbidly obese patients undergoing bariatric surgery. Methods: Morbidly obese patients undergoing bariatric surgery were studied. Patients were classified into two groups: Group A (with insulin resistance) (N=11; glucose 149.84 ± 40.56 mg/dL; serum insulin 8.28 ± 3.52 μU/mL), and Group B (without insulin resistance) (N=10; glucose 102.2 ± 8.43 mg/dL; serum insulin 3.431 ± 1.162 μU/mL). Results: Adiponectin mRNA in intra-abdominal adipose tissue and serum adiponectin levels were significantly lower in Group A compared to Group B patients (P<0.016 and P<0.03, respectively). Although serum resistin was higher in Group A than in Group B patients (P<0.005), resistin gene expression was not different between the two groups. Finally, for leptin, neither serum level nor gene expression was different between the two groups. Serum adiponectin level was the only predictor of nonalcoholic steatohepatitis (NASH) in this study (P=0.024). Conclusions: Obese patients with insulin resistance have decreased serum adiponectin and increased serum resistin. Additionally, adiponectin gene expression is also decreased in the adipose tissue of these patients. This low level of adiponectin expression may predispose patients to the progressive form of NAFLD or NASH.