Platelet counts and liver enzymes after bariatric surgery

Reducing Dietary Polyunsaturated to Saturated Fatty Acids Ratio Improves Lipid and Glucose Metabolism in Obese Zucker Rats

We investigated the influence of varying dietary polyunsaturated fatty acid (PUFA)/saturated fatty acids (SFA) ratios on insulin resistance (IR), fatty acid metabolism, N-acylethanolamine (NAE) bioactive metabolite levels, and mitochondrial function in lean and obese Zucker rats in a model designed to study obesity and IR from overnutrition. We provided diets with 7% fat (w/w), with either a low PUFA/SFA ratio of 0.48, predominantly comprising palmitic acid (PA), (diet-PA), or the standard AIN-93G diet with a high PUFA/SFA ratio of 3.66 (control, diet-C) over eight weeks. In obese rats on diet-PA versus diet-C, there were reductions in plasma triglycerides, cholesterol, glucose, insulin concentrations and improved muscle mitochondrial function, inflammatory markers and increased muscle N-oleoylethanolamine (OEA), a bioactive lipid that modulates lipid metabolism and metabolic flexibility. Elevated palmitic acid levels were found exclusively in obese rats, regardless of their diet, implying an endogenous production through de novo lipogenesis rather than from a dietary origin. In conclusion, a reduced dietary PUFA/SFA ratio positively influenced glucose and lipid metabolism without affecting long-term PA tissue concentrations. This likely occurs due to an increase in OEA biosynthesis, improving metabolic flexibility in obese rats. Our results hint at a pivotal role for balanced dietary PA in countering the effects of overnutrition-induced obesity.

Analysis of time-dependent changes in the FIB4 index in patients with obesity receiving weight reduction therapy

Weight reduction therapy represents a fundamental strategy to prevent nonalcoholic fatty liver disease (NAFLD) in patients with obesity, which may result in liver fibrosis. Histological findings previously demonstrated that weight reduction therapy attenuated NAFLD. The FIB4 index is widely used to assess the status of NAFLD. The present study investigated whether the FIB4 index improved during weight reduction therapy. We used cohort data of the Japan Obesity and Metabolic syndrome Study and examined the correlation between body weight (BW) loss (BW loss) and changes in the FIB4 index (ΔFIB4 index) in patients who successfully reduced their BW by more than 5% from baseline BW after 3, 6, and 12 months (M) of weight reduction therapy. A negative correlation (r = −0.342, p = 0.029) was observed between BW loss and FIB4 index after 3 M, but not after 6 M, whereas a positive correlation (r = 0.298, p = 0.03) was noted after 12 M. These results revealed changes in the correlation between ΔBW loss and ΔFIB4 index during the therapy, mainly due to time-dependent changes in components of the FIB4 index formula. Thus, we concluded that the FIB4 index is useful and reliable to assess liver fibrosis until 3 M during weight reduction therapy. However, after 3 M, we should recognize that the FIB4 index may not reflect liver status. Therefore, it is important to consider this characteristic of the FIB4 index as a limitation when assessing liver fibrosis in obese patients receiving weight reduction therapy.

Fatty Acid Metabolism and Derived-Mediators Distinctive of PPAR-α Activation in Obese Subjects Post Bariatric Surgery

Bariatric surger (BS) is characterized by lipid metabolic changes as a response to the massive release of non-esterified fatty acids (NEFA) from adipose depots. The study aimed at evaluating changes in polyunsaturated fatty acids (PUFA) metabolism and biosynthesis of the lipid mediators N-acylethanolamines (NAE), as indices of nuclear peroxisome proliferator-activated receptor (PPAR)-α activation. The observational study was performed on 35 subjects (27 female, 8 male) with obesity, undergoing bariatric surgery. We assessed plasma FA and NAE profiles by LC-MS/MS, clinical parameters and anthropometric measures before and 1 and 6 months after bariatric surgery. One month after bariatric surgery, as body weight and clinical parameters improved significantly, we found higher plasma levels of N-oleoylethanolamine, arachidonic and a 22:6-n3/20:5-n3 ratio as evidence of PPAR-α activation. These changes corresponded to higher circulating levels of NEFA and a steep reduction of the fat mass. After 6 months 22:6-n3/20:5-n3 remained elevated and fat mass was further reduced. Our data suggest that the massive release of NEFA from adipose tissue at 1-Post, possibly by inducing PPAR-α, may enhance FA metabolism contributing to fat depot reduction and improved metabolic parameters in the early stage. However, PUFA metabolic changes favor n6 PUFA biosynthesis, requiring a nutritional strategy aimed at reducing the n6/n3 PUFA ratio.

Anthropometric Measurements and Correlations to Glucometabolic and Cardiovascular Risk in Obese Patients Undergoing Gastric Bypass Surgery

Abdominal obesity is associated with hypertension, increased fasting glucose, HbA1c, and cholesterol. Body mass index (BMI) is frequently used to measure and define obesity and as inclusion criteria for bariatric surgery. Sagittal abdominal diameter (SAD) has been suggested to predict the amount of visceral fat, metabolic traits, and cardiometabolic risk superior to BMI. The aim was to test whether SAD has stronger correlations to glucometabolic traits compared to BMI. One hundred and fifty-five (108 women, 47 men) morbidly obese patients undergoing bariatric surgery were evaluated before (baseline), 6 and 12 months after Roux-en-Y gastric bypass (RYGBP). BMI was reduced from 43.7 kg/m2 (baseline) to 31.3 kg/m2 (12 months) and SAD from 32.6 to 23.2 cm (both p<0.001). SAD correlated with CRP (p=0.04), fasting glucose (p=0.008), HbA1c (p=0.016), triglycerides (p=0.017), systolic blood pressure (p=0.032), and vitamin D (p=0.027). BMI correlated with CRP (p=0.006), triglycerides (p=0.016), vitamin D (p=0.002), and magnesium (p=0.037). Despite RYGBP surgery, vitamin D was significantly increased. Liver enzymes were significantly lowered after RYGBP and the change over time in SAD correlated with gamma-glutamyltransferase. SAD was superior to BMI to predict glucose disturbance and dyslipidemia implying increased use of SAD as it is cost effective and simple to perform in the clinic and could be of value when considering patients for bariatric surgery.

Laparoscopic Sleeve Gastrectomy on the Horizon as a Promising Treatment Modality for NAFLD

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) is viewed as the hepatic manifestation of the metabolic syndrome with hepatic fatty infiltration is the common liver pathology. NAFLD can lead to nonalcoholic steatohepatitis (NASH), liver cirrhosis, liver cell failure, and liver malignancy.The present work aims to prospectively study the histological changes that occur in NAFLD obese patients 1-year post-laparoscopic sleeve gastrectomy (LSG) based on standardized NAS (NAFLD activity score).

PATIENTS

This prospective study included 94 obese patients who underwent laparoscopic sleeve gastrectomy. Intraoperative wedge liver biopsy was taken from all patients with a follow-up liver biopsy at 12 months after the operation.

RESULTS

LSG produced a marked reduction in body weight with a mean reduction in BMI from 44.54 + 5.45 to 34.23 + 2.66 kg/m² at 12 months. There were statistically highly significant improvements regarding metabolic comorbidities, blood pressure, lipid profile, and HbA1C at 12-month post-LSG (P < 0.001). The current study showed a highly statistically significant improvement at 1-year post LSG regarding steatosis grade, hepatocyte ballooning, lobular inflammation as well as fibrosis stage (P < 0.001). Moreover, the present study showed that NAS score significantly decreased from 5.20 + 1.96 at baseline to 2.63 + 1.55 at 1-year follow-up (P < 0.001).

CONCLUSION

Our relatively large patient cohort shows a significant improvement of steatosis, steatohepatitis, and fibrosis at a 1-year follow-up. LSG can lead to resolution of NAFLD, and it may be in the near future another routine indication for bariatric surgery.

The immune remodel: Weight loss-mediated inflammatory changes to obesity

Obesity is an escalating world problem that contributes to the complexity and cost of treatment of metabolic disorders. Obesity is the result of increased storage of energy in the form of adipose tissue, reducing the quality of daily life, and interfering with longevity. Obesity is also a chronic, low-grade inflammatory disorder. The inflammatory processes affect many organ systems with expanded numbers of immune cells and increased cytokine production. Long-term weight loss is difficult to achieve and maintain. Lifestyle modifications, pharmacologic treatments, and surgical methods are increasingly utilized to ameliorate excess body weight and the comorbidities of obesity, such as diabetes, cardiovascular disease, dyslipidemia, and cancers. Weight loss is also touted to reduce inflammation. Here we review the current literature on human obesity-related systemic and local changes to the immune system and circulating inflammatory mediators. Further, we consider the impact of weight loss to reduce the burden of inflammation, bearing in mind the different methods of weight loss—behavioral change vs. surgical intervention.

Platelet Counts and Liver Enzymes After Gastric Bypass Surgery

Background

Obesity is associated with chronic inflammation, liver steatosis and increased liver enzymes such as gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT), markers for non-alcoholic fatty liver disease (NAFLD) and liver fat content. Increased platelet counts (PCs) are a biomarker reflecting inflammation and the degree of fibrosis in NAFLD. We investigated alterations in PCs, GGT, ALT, C-reactive protein (CRP) and ferritin after Roux-en-Y gastric bypass (RYGBP).

Methods

One hundred twenty-four morbidly obese non-diabetic patients were evaluated before (baseline) and 12 months after (follow-up) RYGBP.

Results

Body mass index (BMI) was reduced from 43.5 kg/m² (baseline) to 31.1 kg/m² (follow-up), and p < 0.001 and weight declined from 126.2 to 89.0 kg. PCs decreased from 303 × 10⁹ to 260 × 10⁹/l, p < 0.001. GGT was reduced from 0.63 to 0.38 μkat/l, p < 0.001. ALT decreased from 0.69 to 0.59 μkat/l, p = 0.006. CRP was lowered from 7.3 to 5.4 mg/l p < 0.001 and ferritin from 106 to 84 μg/l p < 0.001. The alterations in PCs correlated with the changes in CRP (r = 0.38, p = 0.001), BMI (r = 0.25, p = 0.012), weight (r = 0.24, p = 0.015) and inversely correlated with ferritin (r = 21, p = 0.036).

Conclusions

PCs, GGT and ALT (markers for NAFLD), and CRP and ferritin (markers for inflammation) decreased in morbidly obese after RYGBP. The decrease in PCs correlated with alterations in CRP, BMI, weight and ferritin. The lowering of liver enzymes may reflect a lowered liver fat content and decreased general inflammation.

Systematic review and meta-analysis of Roux-en-Y gastric bypass against laparoscopic sleeve gastrectomy for amelioration of NAFLD using four criteria

Nonalcoholic fatty liver disease (NAFLD) prevalence is rising worldwide, as a direct consequence of the obesity epidemic. Bariatric surgery provides proven NAFLD amelioration, although questions remain regarding whether Roux-en-Y gastric bypass (RYGB) or laparoscopic sleeve gastrectomy (LSG) is more effective. To answer this question, we conducted a systematic review and meta-analysis exclusively comparing RYGB and LSG for amelioration of NAFLD using 4 separate criteria: alanine transaminase, aspartate transaminase, NAFLD activity score, and NAFLD fibrosis score. Our search included 1290 initial studies, which were narrowed to 20 final studies in the meta-analysis. Overall, both RYGB and LSG significantly improved alanine transaminase, aspartate transaminase, NAFLD activity score, and NAFLD fibrosis score postoperatively. Direct comparisons of RYGB to LSG in any of the 4 criteria failed to demonstrate superiority. Our findings corroborate the current literature showing that bariatric surgery significantly improves biochemical and histologic parameters in patients with NAFLD. The novel individual comparisons of 4 criteria failed to show superiority between RYGB and LSG in ameliorating NAFLD. Despite several limitations, our study can assist clinicians by supporting the notion that RYGB and LSG may be equally efficacious in ameliorating NAFLD.

Evolution of Liver Steatosis Quantified by MR Imaging and MR Spectroscopy, in Morbidly Obese Patients Undergoing Sleeve Gastrectomy: Short-Term Outcomes

BACKGROUND

Currently, the standard procedure used to evaluate hepatic steatosis is the liver biopsy. This is an invasive practice that presents inherent risks. Increasing evidence suggests that magnetic resonance imaging (MRI) and MR spectroscopy (MRS) may represent an accurate method to determine the hepatic lipid content. The aim of this study was to evaluate the effect of sleeve gastrectomy on liver steatosis, quantified by MRI and MRS.

PATIENTS AND METHODS

A prospective observational study of patients undergoing laparoscopic sleeve gastrectomy was performed. All patients underwent a MRI and a MRS study 2 weeks before the intervention and 6 months after the surgery. Anthropometric, biochemical, and radiological parameters were analyzed.

RESULTS

Twenty-three patients were included, 21 females and 2 males, with a mean age of 47.6 ± 10.6 years and mean pre-op BMI 47.6 ± 6.7 Kg/m². Six months after surgery, mean BMI was 32.2 ± 5.1 Kg/m², with a mean excess weight loss of 68.2 ± 18.6%. Mean preoperative hepatic volume was 1999.9 ± 436.2 ml and 6 months after surgery it decreased to 1568 ± 170.3 ml (p = 0.005). Mean preoperative percentage of lipid content was 14.2 ± 15.4% and 6 months after surgery, it decreased to 4.3 ± 3.2% (p = 0.007). A significant reduction of steatosis grade was observed, with disappearance of preoperative steatosis in 54.9% of the patients.

CONCLUSION

Six months after sleeve gastrectomy, a significant reduction of liver steatosis is observed, as demonstrated by reduction in the percentage of intrahepatocitary lipids and liver volume, determined by MRS and MRI. These imaging techniques can be considered as noninvasive, accurate methods for monitoring liver steatosis in morbidly obese patients undergoing bariatric surgery.

Effect of Bariatric Surgery-Induced Weight Loss on Platelet Count and Mean Platelet Volume: a 12-Month Follow-Up Study

BACKGROUND

Abdominal obesity is strongly correlated with cardiovascular risk and associated with platelet hyperactivity. This hyperactivity is associated with an increase in mean platelet volume (MPV). Few data are available about changes in platelet counts and MPV in obese patients after bariatric surgery (BS). The purpose of this study was to describe quantitative and qualitative changes in the platelet lineage after BS.

METHODS

One hundred twenty-eight consecutive patients were included. The mean age was 43 ± 12 years, 77 % of patients were female, and the mean preoperative BMI was 44 ± 6 kg/m². Ninety patients (71 %) had a Roux-en-Y gastric bypass (RYGBP), and 38 (29 %) had a sleeve gastrectomy (SG). Patients were evaluated preoperatively, and postoperative follow-up was performed at 3, 6, and 12 months. The postoperative evaluation included blood samples for full blood count (FBC), including measure of mean platelet volume (MPV).

RESULTS

At the 12-month follow-up, the reduction in preoperative weight was 29 ± 9 %. We showed a significant decrease in platelet count (245 ± 62 vs. 234 ± 54 G/L; p = 0.0015) found in parallel with a non-significant decrease in MPV (9.27 ± 1.1 vs. 9.22 ± 1.05; p = 0.34). With regard to the intervention type, SG caused a more significant decrease in platelet count than RYGBP (p = 0.02). There was no significant difference in MPV variations between the two groups (p = 0.08).

CONCLUSIONS

Our results suggest that BS has a positive impact on platelet metabolism, possibly mediated by weight loss. These data need to be confirmed to understand the multifactorial benefits of BS on cardiovascular risk in obese patients.

Nonalcoholic fatty liver disease and bariatric surgery: a comprehensive review

CONTEXT AND OBJECTIVE:

Nonalcoholic fatty liver disease (NAFLD) has been increasingly diagnosed worldwide and is now recognized as a source of public health concern. It comprises a wide spectrum of histological features that range from simple steatosis to severe forms of fibrosis, steatohepatitis and even cirrhosis. The impact of bariatric surgery on the course of NAFLD in individuals with obesity has been extensively studied.

DESIGN AND SETTING:

Narrative review; public university hospital.

METHODS:

A comprehensive review was conducted based on an online search on the electronic databases MEDLINE and LILACS using the MeSH terms "fatty liver" and "bariatric surgery".

RESULTS:

The exact mechanisms that lead to improvement in NAFLD following bariatric surgery are not completely understood. Since Roux-en-Y gastric bypass (RYGB) is the bariatric surgical procedure most performed worldwide, it is also the one from which the effects on NAFLD have been most studied, although there is also consistent evidence regarding the effects from gastric banding, sleeve gastrectomy and biliopancreatic diversions.

CONCLUSION:

According to the currently available evidence, bariatric surgery leads to significant improvement in NAFLD. Further research, especially by means of randomized controlled trials enrolling larger cohorts of individuals, is needed to determine the optimal procedure for this group of subjects.

Acylated and desacyl ghrelin are associated with hepatic lipogenesis, β-oxidation and autophagy: role in NAFLD amelioration after sleeve gastrectomy in obese rats

Bariatric surgery improves non-alcoholic fatty liver disease (NAFLD). Our aim was to investigate the potential role of ghrelin isoforms in the resolution of hepatic steatosis after sleeve gastrectomy, a restrictive bariatric surgery procedure, in diet-induced obese rats. Male Wistar rats (n = 161) were subjected to surgical (sham operation and sleeve gastrectomy) or dietary interventions [fed ad libitum a normal (ND) or a high-fat (HFD) diet or pair-fed]. Obese rats developed hepatosteatosis and showed decreased circulating desacyl ghrelin without changes in acylated ghrelin. Sleeve gastrectomy induced a dramatic decrease of desacyl ghrelin, but increased the acylated/desacyl ghrelin ratio. Moreover, sleeve gastrectomy reduced hepatic triglyceride content and lipogenic enzymes Mogat2 and Dgat1, increased mitochondrial DNA amount and induced AMPK-activated mitochondrial FFA β-oxidation and autophagy to a higher extent than caloric restriction. In primary rat hepatocytes, the incubation with both acylated and desacyl ghrelin (10, 100 and 1,000 pmol/L) significantly increased TG content, triggered AMPK-activated mitochondrial FFA β-oxidation and autophagy. Our data suggest that the decrease in the most abundant isoform, desacyl ghrelin, after sleeve gastrectomy contributes to the reduction of lipogenesis, whereas the increased relative acylated ghrelin levels activate factors involved in mitochondrial FFA β-oxidation and autophagy in obese rats, thereby ameliorating NAFLD.

Laparoscopic Adjustable Gastric Banding In Patients with Unexpected Cirrhosis: Safety and Outcomes

BACKGROUND

The safety and efficacy of laparoscopic adjustable gastric banding (LAGB) in the context of cirrhosis have not been established. We hypothesized that LAGB in cirrhotic patients is a safe procedure that may offer positive long-term benefits, both in terms of obesity and avoiding progression of liver disease.

METHODS

Data were gathered from a prospectively maintained database of 8402 patients who had undergone LAGB from November 1993 and April 2014.

RESULTS

Fourteen patients with biopsy-proven cirrhosis were identified in the database. In all cases, cirrhosis was an unexpected macroscopic finding at the time of surgery, confirmed with intraoperative biopsy. All patients were either Child-Pugh A or B. No patients had preoperative clinical evidence of decompensated liver disease. The mean initial weight was 116.6 kg and BMI 38.9. There was no operative mortality. Two patients experienced a surgical complication (Clavien-Dindo grade II and grade IIIa). At 12 months, the mean excess weight loss was 61.3% giving a mean BMI 31.7. Repeat biopsies were available in three patients. All demonstrated improvement in inflammation and two had fibrosis regression. Baseline liver biochemistry was compared in nine patients who had repeat biochemistry studies after 12 months. There was a significant improvement in alanine transaminase (ALT) (p = 0.04) and aspartate transaminase (AST) (p = 0.02). Two patients developed hepatocellular carcinoma (HCC). One has died as a result of this disease 11 years after LAGB surgery.

CONCLUSION

LAGB may be a safe and effective bariatric intervention in patients with compensated cirrhosis. Our findings support the need for a prospective study with paired liver biopsies.

Association between platelet count as a noninvasive marker and ultrasonographic grading in patients with nonalcoholic Fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease has become a worldwide challenge. Liver biopsy remains the single most reliable approach to determine the severity of this disease. As patients with nonalcoholic fatty liver disease require close follow-up, performing this invasive method repeatedly seems impractical; therefore, designing a noninvasive system to follow up patients has become a common interest.

OBJECTIVES

We intended to investigate the association between platelet counts of patients with nonalcoholic fatty liver disease and the severity of their disease based on serum levels of liver enzymes and grade of fatty liver on ultrasonography.

PATIENTS AND METHODS

One thousand, three hundred and five patients with nonalcoholic fatty liver disease were included in this descriptive study. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and platelet counts of patients were measured. The grade of fatty liver was determined by abdominal ultrasonography.

RESULTS

Of our study population, 54.3% (n = 708) were women. Patients with mild fatty liver on ultrasonography had lower platelet counts than those with moderate and severe fatty liver. However, no cutoff value of platelet count could reliably distinguish different grades of fatty liver. We found no significant association between platelet counts and serum levels of AST, ALT or ALP. However, we showed that male patients with abnormal levels of ALT had higher platelet counts.

CONCLUSIONS

Platelet count in nonalcoholic fatty liver disease can serve as a clue to the severity of disease, but it cannot be considered as a sole test to follow up patients.