Effect of orlistat on the total ghrelin and leptin levels in obese patients

Increased Leptin Levels in Plasma and Serum in Patients with Metabolic Disorders: A Systematic Review and Meta-Analysis

A large number of studies have reported the relationships between leptin levels and diabetes or obesity. However, the results are still controversial, and no consensus has been reached. Therefore, the purpose of the study was to collect data from various databases to perform a meta-analysis and address the inconsistencies in these studies. A systematic literature search was conducted on PubMed, Web of Science, and EBSCO for relevant available articles. The pooled standard mean difference (SMD) with 95% confidence interval (CI) was used to estimate the association by a meta-analysis. Fifteen reports with 1,388 cases and 3,536 controls were chosen for the meta-analysis. First, an increase in leptin levels in serum (SMD 0.69; 95% CI 0.36-1.02 ng/mL) and plasma (SMD 0.46; 95% CI 0.18-0.74 ng/mL) was observed in individuals with diabetes compared to controls. This increased level was also observed by gender and population. Second, statistical analysis showed that leptin levels in serum were significantly increased in individuals with obesity (SMD 1.03; 95% CI 0.72-1.34 ng/mL). This meta-analysis analyzed leptin in individuals with diabetes or obesity and emphasized the importance of monitoring serum/plasma leptin levels in patients with these diseases. However, more comprehensive studies are necessary in order to draw firm conclusions.

Differences in gastrointestinal hormones and appetite ratings between individuals with and without obesity-A systematic review and meta-analysis

Determining if gastrointestinal (GI) hormone response to food intake differs between individuals with, and without, obesity may improve our understanding of obesity pathophysiology. A systematic review and meta-analysis of studies assessing the concentrations of GI hormones, as well as appetite ratings, following a test meal, in individuals with and without obesity was undertaken. Systematic searches were conducted in the databases MEDLINE, Embase, Cochrane Library, PsycINFO, Web of Science, and ClinicalTrials.gov. A total of 7514 unique articles were retrieved, 115 included in the systematic review, and 70 in the meta-analysis. The meta-analysis compared estimated standardized mean difference in GI hormones' concentration, as well as appetite ratings, between individuals with and without obesity. Basal and postprandial total ghrelin concentrations were lower in individuals with obesity compared with controls, and this was reflected by lower postprandial hunger ratings in the former. Individuals with obesity had a lower postprandial concentration of total peptide YY compared with controls, but no significant differences were found for glucagon-like peptide 1, cholecystokinin, or other appetite ratings. A large methodological and statistical heterogeneity among studies was found. More comprehensive studies are needed to understand if the differences observed are a cause or a consequence of obesity.

The effect of orlistat and weight loss diet on plasma ghrelin and obestatin

BACKGROUND

The objective of this study was to evaluate the effect of weight loss with hypocaloric diet and orlistat treatment in addition to hypocaloric diet on gut-derived hormones ghrelin and obestatin.

MATERIALS AND METHODS

A total of 52, euglycemic and euthyroid, obese female patients were involved in the study. The patients were assigned to two groups: Group 1 (n = 26) received hypocaloric diet alone and Group 2 (n = 26) received orlistat in addition to hypocaloric diet for 12 weeks. Anthropometric measurements, serum lipid, insulin levels, and obestatin and ghrelin values were assessed at the beginning of the study and after 12 weeks of therapy.

RESULTS

Baseline clinical characteristics and laboratory parameters including serum ghrelin and obestatin concentrations and ghrelin/obestatin ratio were similar between the two groups. After 12 weeks, mean change in BMI, fat mass, and fat-free mass (FFM) were -1.97 ± 1.56 kg/m2 (P = 0.003), -2.63% ±2.11% (P = 0.003), and -1.06 ± 0.82 kg (P = 0.003), respectively, in Group 1. In Group 2, mean change in BMI was -2.11 ± 1.24 kg/m2 (P = 0.001), fat mass was -3.09% ±2.28% (P = 0.002), and FFM was -1.26 ± 0.54 kg (P = 0.001). However, fasting glucose, lipid, and insulin levels did not change in Group 1. Furthermore, except serum high-density lipoprotein cholesterol and triglyceride levels, no significant change was observed in Group 2. Although serum ghrelin and obestatin concentrations increased significantly in both groups (Group 1: pGhrelin: 0.047, pobestatin: 0.001 and Group 2: pGhrelin: 0.028, pobestatin: 0.006), ghrelin/obestatin ratio did not change significantly. When the changes in anthropometric assessments and laboratory parameters were compared, no significant difference was observed between the two groups. Furthermore, no correlation was observed between ghrelin or obestatin and any other hormonal and metabolic parameters.

CONCLUSION

Weight loss with diet and diet plus orlistat is both associated with increased ghrelin and obestatin concentrations.

Antiobesity Activities of Methanolic Extracts of Amaranthus dubius, Cucurbita pepo, and Vigna unguiculata in Progesterone-Induced Obese Mice

Amaranthus dubius, Vigna unguiculata, and Cucurbita pepo are traditionally used to manage obesity in Kenya but lack scientific validation to support their use. The aim of this study was to determine the antiobesity activity of methanolic leaf extracts of these plants in progesterone-induced obese mice. The activity of the methanolic leaf extracts was orally bioscreened in progesterone-induced obese mice at 200 mg/kg/bw and 400 mg/kg/bw. Body mass index was calculated once per week for four weeks and blood samples were obtained at the end of the experiment for lipid profile analysis. Antiobesity activities of the extracts were compared with the controls. Leaf extracts of A. dubius, C. pepo, and V. unguiculata, at dose concentrations of 200 mg/kgbw and 400 mg/kgbw, showed significant effects on body mass index (p < 0.05). There was no significant difference between the three extracts on lipid parameter profiles (p > 0.05). The present study showed high food intake in the negative control group as compared with normal control, positive control, and treatment groups. These extracts contained various phytochemicals such as saponins, flavonoids, alkaloids, and steroids and therefore validate use of aforementioned plants in the suppression of obesity and their use for management of obesity is recommended.

Improvement of plasma adiponectin, leptin and C-reactive protein concentrations by orlistat: a systematic review and meta-analysis

AIMS

To conduct a systematic review and meta-analysis of relevant randomized clinical trials (RCTs) to ascertain the effect size of orlistat in modulating plasma levels of adipokines, ghrelin and C-reactive protein (CRP).

METHODS

Medline, SCOPUS, Web of Science and Google Scholar databases were searched. A random-effects model and the generic inverse variance method were used for quantitative data synthesis. Heterogeneity was quantitatively assessed using I(2) index. Sensitivity analyses were conducted using the one-study remove approach. Random-effects meta-regression was performed using unrestricted maximum likelihood method to evaluate the impact of duration of treatment, percentage change in body mass index (BMI) and baseline BMI values as potential confounders of the estimated effect size.

RESULTS

Meta-analysis suggested a significant increase in plasma levels of adiponectin [weighted mean difference (WMD): 19.18%, 95% confidence interval (CI): 5.80, 32.57, p = 0.005] and significant reductions in plasma levels of leptin (WMD: -13.24%, 95% CI: -20.69, -5.78, p = 0.001) and CRP (WMD: -11.52%, 95% CI: -16.55, -6.49, p < 0.001) following treatment with orlistat. In meta-regression, changes in plasma concentrations of adiponectin, leptin and CRP were associated with duration of treatment, but not with either change in BMI or baseline BMI values.

CONCLUSION

Orlistat is effective in increasing plasma concentrations of adiponectin and decreasing those of leptin and CRP.

Helicobacter pylori infection and diabetes mellitus

The rate of Helicobacter pylori (H. pylori) infection increases significantly in patients with diabetes mellitus. H. pylori infection as an independent factor can promote insulin resistance. H. pylori eradication rate is much lower in diabetic patients than in normal controls. Blood glucose levels tend to fluctuate more widely, and is not easy to be controlled in diabetic patients with H. pylori infection. Eradication of H. pylori can help to improve diabetic progression. H. pylori infection is related to the occurrence of diabetic complications, such as diabetic nephropathy, atherosclerosis, and gastroparesis. The mechanism of H. pylori infection affecting diabetes mellitus may be related to systemic inflammatory response, vascular endothelial damage and changes of hormone levels such as leptin and ghrelin.

Associations of ghrelin with eating behaviors, stress, metabolic factors, and telomere length among overweight and obese women: preliminary evidence of attenuated ghrelin effects in obesity?

Ghrelin regulates homeostatic food intake, hedonic eating, and is a mediator in the stress response. In addition, ghrelin has metabolic, cardiovascular, and anti-aging effects. This cross-sectional study examined associations between total plasma ghrelin, caloric intake based on 3day diet diaries, hedonic eating attitudes, stress-related and metabolic factors, and leukocyte telomere length in overweight (n=25) and obese women (n=22). We hypothesized associations between total plasma ghrelin and eating behaviors, stress, metabolic, cardiovascular, and cell aging factors among overweight women, but not among obese women due to lower circulating ghrelin levels and/or central resistance to ghrelin. Confirming previous studies demonstrating lowered plasma ghrelin in obesity, ghrelin levels were lower in the obese compared with overweight women. Among the overweight, ghrelin was positively correlated with caloric intake, giving in to cravings for highly palatable foods, and a flatter diurnal cortisol slope across 3days. These relationships were non-significant among the obese group. Among overweight women, ghrelin was negatively correlated with insulin resistance, systolic blood pressure, and heart rate, and positively correlated with telomere length. Among the obese subjects, plasma ghrelin concentrations were negatively correlated with insulin resistance, but were not significantly correlated with blood pressure, heart rate or telomere length. Total plasma ghrelin and its associations with food intake, hedonic eating, and stress are decreased in obesity, providing evidence consistent with the theory that central resistance to ghrelin develops in obesity and ghrelin's function in appetite regulation may have evolved to prevent starvation in food scarcity rather than cope with modern food excess. Furthermore, ghrelin is associated with metabolic and cardiovascular health, and may have anti-aging effects, but these effects may be attenuated in obesity.

A practical guide for the stabilization of acylghrelin in human blood collections

OBJECTIVE AND METHODS

To better understand acylghrelin plasma stability, human synthetic acylghrelin was spiked into plasma and tracked by liquid chromatography tandem mass spectrometry. To investigate the best method for quantifying clinical plasma acylghrelin levels, pre- and postprandial human blood was collected from healthy volunteers (n=6) using various sample collections and treatments. Plasma ghrelin levels from human blood collections were analysed by enzyme-linked immunosorbant assay (ELISA).

RESULTS

Acylghrelin's half-life in plasma was approximately 45 min with the formation of des-acylghrelin approaching 50% before the end of the 60-min incubation. Loss of acylghrelin inversely correlated with an increase in des-acylghrelin (P<0.008; r(2) =0.870). Plasma pretreated with 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride (AEBSF) or protease inhibitor cocktail without acidification resulted in no detectible acylghrelin losses. Acylghrelin measurements with AEBSF-treated blood were minimally 40% higher than sodium citrate/citric acid, K(2) EDTA, aprotinin/HCl and P800 collections. HCl addition to AEBSF-treated plasma did not provide enhanced acylghrelin stability and induced deacylation at and above the 100 mM final concentration. Pre- and postprandial ghrelin attenuation was investigated using aprotinin/HCl, AEBSF, protease inhibitor cocktail and no treatment for blood and plasma preparations. Fasting samples treated with AEBSF and protease inhibitor cocktail were approximately threefold higher than aprotinin/HCl and control treatments (P<0.03). Pre- and postprandial ghrelin attenuation was approximately twofold different (P<0.04) with significant counterintuitive trends in aprotinin/HCl and K(2) EDTA groups.

CONCLUSIONS

Our data suggest that AEBSF addition to K(2) EDTA blood immediately after collection without plasma acidification, processing on ice and 14-day 70 °C storage is the best treatment for accurately quantifying acylghrelin in human plasma.