Impact of Helicobacter pylori infection on ghrelin and various neuroendocrine hormones in plasma

Circulating ghrelin levels in patients with gastric cancer: a systematic review and meta-analysis

Background

Ghrelin plays a critical role in regulating energy metabolism and homeostasis. The association between circulating ghrelin levels and gastric cancer has not been systematically analyzed.

Objective

This work explored the association between circulating ghrelin levels and gastric cancer.

Methods

The literature search for relevant articles published until November 2022 was performed using PubMed, Cochrane Library, EMBASE, and Web of Science with the keywords "ghrelin" and "gastric cancer". Standardized mean differences (SMD) with 95% confidence intervals were used to measure the effectiveness. We assessed pooled data by use of a random-effects model.

Results

Of 5,302 identified studies, nine were included (N=3,196 participants). Circulating ghrelin levels were lower in gastric cancer patients (SMD=-0.255, 95%CI: -0.528 to 0.017, P < 0.00001), but with high heterogeneity (I2 = 88.8%).

Conclusion

The circulating ghrelin levels in patients with gastric cancer were lower than in controls. However, there was heterogeneity among results; therefore, studies with larger sample sizes are recommended.

Is Diabetes Mellitus a Predisposing Factor for Helicobacter pylori Infections?

PURPOSE OF REVIEW

This review aims to analyse the consistency of reports suggesting the role of Diabetes Mellitus in the pathogenesis of Helicobacter pylori (H. pylori).

RECENT FINDINGS

There have been numerous controversies citing the prevalence of H. pylori infections in patients suffering from type 2 diabetes mellitus (T2DM). This review investigates the possible crosstalk between H. pylori infections and T2DM and also designs a meta-analysis to quantify the association. Subgroup analyses have also been conducted to deduce factors like geography and testing techniques, in playing a role in stratification analysis. Based on a scientific literature survey and meta-analysis of databases from 1996 to 2022, a trend towards more frequent H. pylori infections in patients with diabetes mellitus was observed. The highly diversified nature of H. pylori infections across age, gender, and geographical regions requires large interventional studies to evaluate its long-term association with diabetes mellitus. Further possible linkage of the prevalence of diabetes mellitus concomitant with that of H. pylori infected patients has also been delineated in the review.

The impact of prebiotic fructooligosaccharides on gut dysbiosis and inflammation in obesity and diabetes related kidney disease

Obesity is an extensive health problem worldwide that is frequently associated with diabetes. It is a risk factor for the development of several diseases including diabetic nephropathy. Recent studies have reported that gut dysbiosis aggravates the progression of obesity and diabetes by increasing the production of uremic toxins in conjunction with gut barrier dysfunction which then leads to increased passage of lipopolysaccharides (LPS) into the blood circulatory system eventually causing systemic inflammation. Therefore, the modification of gut microbiota using a prebiotic supplement may assist in the restoration of gut barrier function and reduce any disturbance of the inflammatory response. In this review information has been compiled concerning the possible mechanisms involved in an increase in obesity, diabetes and kidney dysfunction via the exacerbation of the inflammatory response and its association with gut dysbiosis. In addition, the role of fructooligosaccharides (FOS), a source of prebiotic widely available commercially, on the improvement of gut dysbiosis and attenuation of inflammation on obese and diabetic conditions has been reviewed. The evidence confirms that FOS supplementation could improve the pathological changes associated with obesity and diabetes related kidney disease, however, knowledge concerning the mechanisms involved is still limited and needs further elucidation.

Factors associated with gastro-duodenal ulcer in compensated type 2 diabetic patients: a Romanian single-center study

INTRODUCTION

Helicobacter pylori infection is accepted as the leading cause of chronic gastritis, ulcer disease and gastric cancer, with an important impact on health care burden, especially in countries with a high prevalence of infection. The aim of the study was to investigate the influence of H. pylori infection, medication, associated medical conditions or social habits on endoscopic ulcer occurrence in the compensated type 2 diabetic population.

MATERIAL AND METHODS

Two hundred and sixty type 2 diabetic patients investigated on endoscopy (57 patients with peptic ulcer and 203 controls) with a complete set of biopsies, demographic and medical data were enrolled.

RESULTS

On univariate regression analysis, H. pylori infection (42.1% vs. 35.5%, p = 0.359) or a history of peptic ulcer (61.4% vs. 61.6%, p = 0.981) was not a predictor for ulcer on endoscopy in the diabetic population, and heartburn was more frequent in diabetics without ulcer (21.2% vs. 8.8%, p = 0.033). Anemia was the best predictor for ulcer on endoscopy in both diabetics with (p < 0.001, OR = 4.77, 95% CI: 2.02-11.28) and without (p = 0.027, OR = 2.76, 95% CI: 1.10-6.91) chronic proton pump inhibitor (PPI) therapy. In diabetic patients on PPI more than 1 month anticoagulants - acenocoumarol or low-weight molecular heparin (p = 0.038, OR = 2.37, 95% CI: 1.04-5.40), low-dose aspirin 75-125 mg/day (p = 0.029, OR = 2.61, 95% CI: 1.08-6.28) and alcohol consumption (p = 0.015, OR = 2.70, 95% CI: 1.19-6.13) were predictors for ulcer on endoscopy.

CONCLUSIONS

In diabetic patients, anemia is the most important predictor for ulcer on endoscopy, but not H. pylori or digestive symptoms, while low-dose aspirin or anticoagulant therapy and alcohol consumption are the most important predictors for ulcer in diabetics on chronic proton pump inhibitor therapy.

Anti-diabetics and antimicrobials: Harmony of mutual interplay

Diabetes is one of the four major non-communicable diseases, and appointed by the world health organization as the seventh leading cause of death worldwide. The scientists have turned over every rock in the corners of medical sciences in order to come up with better understanding and hence more effective treatments of diabetes. The continuous research on the subject has elucidated the role of immune disorders and inflammation as definitive factors in the trajectory of diabetes, assuring that blood glucose adjustments would result in a relief in the systemic stress leading to minimizing inflammation. On a parallel basis, microbial infections usually take advantage of immunity disorders and propagate creating a pro-inflammatory environment, all of which can be reversed by antimicrobial treatment. Standing at the crossroads between diabetes, immunity and infection, we aim in this review at projecting the interplay between immunity and diabetes, shedding the light on the overlapping playgrounds for the activity of some antimicrobial and anti-diabetic agents. Furthermore, we focused on the anti-diabetic drugs that can confer antimicrobial or anti-virulence activities.

H. pylori effects on ghrelin axis: Preliminary change in gastric pathogenesis

Ghrelin and its receptors are present in the stomach, suggesting that the ghrelin axis plays an essential role in gastrointestinal complications. This investigation aimed to explore the effects of H. pylori infection and gastritis on serum ghrelin and ghrelin axis gene expression. In this study, we enrolled 68 adult ambulatory people referred for upper gastrointestinal endoscopy. The individuals were classified into three groups based on H. pylori infection and gastritis. Total serum ghrelin and tissue gene expression were tested with ELISA and quantitative RT-PCR, respectively. Serum ghrelin and mRNA expression were significantly lower in H. pylori-positive with gastritis subjects compared with both H. pylori-negative with and without gastritis. Growth hormone secretagogue receptor1a mRNA expression was not different between groups while GHSR1b expression was significantly higher in patients with H. pylori infection and gastritis. We propose the ghrelin axis intermediaries, such as GHSR1b, as a potential clinical target for gastric disorders.

Chronic stress accelerates the process of gastric precancerous lesions in rats

Background: Gastrointestinal cancers account for 20% of all deaths worldwide. Gastric cancer (GC) patients are susceptible to psychological change, especially depression which is commonly induced by chronic stress. Gastric precancerous lesions (GPL) is an important prodromal stage in the occurrence of gastric cancer. Chronic stress influences the prognosis of GC and may influence the process of GPL as well. Methods: Sixty SD rats were randomly divided into a control group, GPL group, and GPL+CUMS group. In the GPL group, 200μg/mL N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) free drinking method combined with intermittent fasting was applied to establish the GPL animal model. Based on this, we combined the GPL rats with chronic unpredicted mild stress (CUMS) to establish a comprehensive model. We then evaluated their behavior by open field tests and sucrose preference tests. We tested the IL-6, IL-10, TNF-α, Ghrelin, Leptin and Somatostatin (SS) levels in serum and observed the expression of Ghrelin and Gastrokine 2(GKN2) in the gastric mucosa of rats with tumors by immunofluorescence. Results: Our results showed that GPL and GPL+CUMS rats all displayed a significantly decreased total distance and mean velocity traveled in the open field test. The percentages of sucrose preference were significantly decreased in the GPL+CUMS group compared to the control group. In addition, IL-6 and TNF-α were significantly increased in both the GPL and GPL+CUMS groups. Furthermore, the GPL+CUMS group showed significantly increased TNF-α levels in serum compared to the GPL rats. Our results showed that the expression of NF-κB, p53, and BCL-2 were significantly increased while BAX was reduced in the GPL and GPL+CUMS groups. Moreover, Ghrelin and Leptin levels in serum were significantly decreased in the GPL and GPL+CUMS groups. SS levels in serum were significantly increased in the GPL+CUMS group. Additionally, we found that the GPL+CUMS rats with tumors not only had strong expression of GKN2 on the luminal side and the lamina propria of the gastric mucosa and tumor, but also had expression of Ghrelin on the luminal side of the gastric mucosa. The areas that showed strong expression of GKN2 and Ghrelin, are all located around the blood vessels in the tumor. Conclusions: GPL rats under chronic stress would aggravate the conditions of GPL, shorten the process of GPL, and increase the risk of tumorigenesis. In addition, the close monitoring of the mental health of cancer survivors and precancerous lesion patients is suggested to be of great significance in the prevention and treatment of cancer.

Helicobacter pylori infection and prevalence of stroke

BACKGROUND

Helicobacter pylori causes peptic ulcer disease; however, conflicting evidence exists regarding its role in extragastric conditions. We aimed to examine associations of H pylori infection and peptic ulcer disease with stroke.

METHODS

A cross-sectional study was undertaken using data of 147 936 individuals aged 25-95 years who underwent the urea breath test during 2002-2012, based on the computerized database of the second largest health maintenance organization in Israel. Logistic regression models were fitted to control for potential confounders.

RESULTS

Overall, 1397 (0.9%) patients had stroke and 76 965 (52.0%) had a H pylori positive test. The likelihood of prevalent stroke increased in relation to H pylori infection: adjusted odds ratio (aOR) 1.16 (95% confidence intervals [CI]: 1.04-1.29), gastric ulcer: aOR 1.50 (95% CI: 1.18-1.91), and duodenal ulcer: aOR 1.25 (95% CI: 1.07-1.46).

CONCLUSIONS

The results support the premise that stroke may be associated with a history of H pylori infection.

Potential risk factors and prevalence of Helicobacter pylori infection among adult patients with dyspepsia symptoms in Cameroon

BACKGROUND

Helicobacter pylori is a Gram negative bacterium that colonizes the stomach of approximately two-thirds of the human population and it is involved in the pathogenesis of gastroduodenal diseases. This study sought to determine potential risk factors associated with seroprevalence of H. pylori among dyspepsia patients in Cameroon for a better management of the disease.

METHODS

The study was carried out from August to December 2014 at Laquintinie Hospital and District Hospital of Bonassama in Douala metropolis. 205 patients (127 women and 78 men; mean age, 53.79 ± 11.11 years; range, 35-75 years) were enrolled. Each subject gave a written consent. The study was approved by the local Ethical Committee of Medical Sciences. A structured questionnaire was used to collect information on sociodemographic parameters and predisposing risk factors for Helicobacter pylori infection. For each patient, body mass index (BMI) and direct inquiry about dyspeptic symptoms were done. Blood samples were tested for H. pylori antibodies, and ABO/Rhesus blood group antigen typing was performed.

RESULTS

The overall prevalence was 64.39%. All patients with upper abdominal pains and frequent burping were H. pylori seropositive. We found that infection takes place early in childhood and adolescence, and reaches its peak at adulthood at 35 to 44 years. Sixty-two percent of women over 68 of men were infected. 80.39% of patients with family history of gastric cancer were seropositive, while 19.60% were seronegative (p = 0.001). Prevalence of 79.09 and 47.4% was recorded respectively for subjects with low, middle and high income levels (p = 0.001). H. pylori infection rate was 60.48% in blood group O patients compared with 70.37% in other blood groups (p = 0.203). 73% of infected subjects over 59% of uninfected ones currently take NSAIDs (p = 0.0509). Overcrowded households have a higher rate of 65.32% seropositivity in contrast with a lower rate of 33.33% from norm household (p = 0.197). 69.29% of obese and overweight patients versus 58.24% of subjects with normal weight were seropositive (P = 0.215).

CONCLUSION

The results of this study demonstrate that low income, family history of gastric cancer, clinical symptoms of nausea/vomiting and flatulence/bloating were risk factors of H. pylori infection in this population.

Relationships of H. pylori infection and its related gastroduodenal morbidity with metabolic syndrome: a large cross-sectional study

The few published studies on the relationship between Helicobacter pylori infection and metabolic homeostasis were relatively small and yielded inconsistent results. We examined the prevalence of metabolic syndrome in relation to H. pylori infection and its symptoms in a large and unselected population. Coded data from the computerised database of a large health maintenance organisation in Israel were accessed for 147,936 individuals 25–95 years of age who performed the urea breath test during 2002–2012. The classification of metabolic syndrome followed a modified definition of the international diabetes federation. Prevalences of H. pylori infection and metabolic syndrome were 52.0% and 11.4% respectively. H. pylori infected patients had increased likelihood of metabolic syndrome: adjusted odds ratio (aOR) 1.15 (95% confidence intervals (CI) 1.10–1.19), as did patients with gastric ulcer: aOR 1.15 (95% CI 1.03–1.28) vs patients without these conditions. Duodenal ulcer was associated with metabolic syndrome only in persons aged 25–34 years: aOR 1.59 (95% CI 1.19-2.13), but not in older persons (P = 0.001 for heterogeneity). In conclusion, the likelihood of metabolic syndrome appeared significantly increased in relation to H. pylori infection and gastric and duodenal ulcers. These findings suggest that H. pylori long-term gastric inflammation might play a role in metabolic homeostasis.

Resistance and tolerance defenses in cancer: Lessons from infectious diseases

Infectious disease and cancer are two maladies with multiple similarities. Both types of disease induce activation of the host immune response and induce pathologies that compromise host heath and survival. In infection biology, defense against pathogens can be broken down into two distinct components called resistance and tolerance. Resistance protects the host by killing pathogens. Tolerance protects the host by alleviating the pathology caused by the infection. The conceptual framework of resistance and tolerance, concepts explored during infectious disease, is applicable to cancer, a condition for which patient survival is dependent on tumor eradication (resistance) and the mitigation of pathologies that occur during disease (tolerance). Here, we propose that integration of the concept of disease tolerance into cancer studies will result in new therapies to complement current resistance-based treatment strategies to increase the likelihood of patient survival and to improve quality of life. Furthermore, by drawing parallels between infectious disease and cancer, we propose that host interactions with microbes could provide therapeutic insight for promoting tolerance defense and focus our discussion on cachexia, a pathology resulting in significant morbidity in cancer patients.

Helicobacter pylori Infection in Children: Nutritional Status and Associations with Serum Leptin, Ghrelin, and IGF-1 Levels

BACKGROUND

Helicobacter pylori is associated with gastrointestinal diseases such as gastritis, peptic ulcers, malignancy and lymphoma, and extra-gastrointestinal conditions. H. pylori infection is negatively associated with children's growth. Chronic inflammation of the stomach that results in the loss of appetite and, dysregulation of neuroendocrine hormones such as leptin, and ghrelin are the probable reasons of this negative association. The objective of this study is to determine the serum levels of leptin, ghrelin, and IGF-1 in H. pylori-infected children and their relations with growth.

MATERIALS AND METHODS

A hundred and sixty-one school children aged between 6 and 14 years were selected randomly from five primary schools representing a cross section of population. Demographic and sociocultural characteristics, and anthropometric measurements were recorded. Serum H. pylori IgG, insulin-like growth factor-1, leptin, and ghrelin levels were measured in all children. The children were grouped according to the nutritional status and Helicobacter pylori seropositivity. Nutritional indices were compared among groups in association with serum leptin, ghrelin, and insulin-like growth factor-1 levels.

RESULTS

H. pylori IgG positivity was found in 34.2%, and 14.9% of children were malnourished. H. pylori seropositivity was significantly higher in older ages (10.32 ± 2.26 vs 9.53 ± 2.36 years, p = .036), and body weight and height Z scores were significantly lower in H. pylori-seropositive children (-0.33 ± 1.08 vs 0.04 ± 1.26, p = .044 and 0.13 ± 0.92 vs 0.23 ± 0.91, p = .018 respectively). H. pylori seropositivity was found to be an independent risk factor for shorter body height (p = .01). Serum leptin, ghrelin, and IGF-1 levels were not associated with H. pylori IgG seropositivity (0.35 vs 0.55 ng/mL, p = .3; 3267.4 ± 753.0 vs 2808.3 ± 911.4 pg/mL, p = .06; 470 ± 176 vs 521 ± 179 ng/mL, p = .32, respectively).

CONCLUSIONS

Children infected with H. pylori are prone to short stature. This effect seems to be independent of neuroendocrine hormones.

Helicobacter pylori infection is associated with type 2 diabetes among a middle- and old-age Chinese population

BACKGROUND

Although the association of Helicobacter pylori (H. pylori) infection with diabetes mellitus has been evaluated, findings are controversial. This study investigated the association in a Chinese population.

METHODS

A cross-sectional study, including a total of 30 810 subjects from the Dongfeng-Tongji Cohort study, was conducted. H. pylori status was measured via (14) C urea breath test. Association analysis was performed by logistic regression, with multivariable adjustment for sex, age, body mass index, smoking, alcohol consumption, family history of diabetes, physical activity and the use of antibiotics.

RESULTS

Among a middle-age and old-age Chinese population, individuals with H. pylori infection also had a higher prevalence of type 2 diabetes (21.3% versus 20.2%, p = 0.026). H. pylori infection was associated with higher risk of type 2 diabetes [odds ratio, 1.08 (95% confidence interval: 1.02-1.14); p = 0.008] after adjustment for other confounders. The association was significant among women, those who were above 65 years old, not overweight or obese, and those who did not smoke, did not consume alcohol and without family history of diabetes. However, there was no interaction between H. pylori infection and other traditional risk factors on type 2 diabetes risk. Subjects with H. pylori infection had a lower level of high-density lipoprotein cholesterol (p < 0.0001) and higher levels of blood pressure (p < 0.001), total cholesterol, HbA1c and fasting blood glucose (p < 0.0001) than those who did not.

CONCLUSIONS

These findings suggested that H. pylori infection was associated with the risk of type 2 diabetes in a middle-age and old-age Chinese population. Copyright © 2015 John Wiley & Sons, Ltd.

Influence of Helicobacter pylori infection on ghrelin levels in children

AIM: To compare ghrelin levels in plasma and gastric mucosa before and after Helicobacter pylori (H. pylori) treatment in children with H. pylori-associated functional dyspepsia.

METHODS: Children with H. pylori-associated functional dyspepsia were enrolled in this study. H. pylori infection was confirmed by positive bacterial culture results. All of the children received triple H. pylori eradication therapy (a 2 wk course of omeprazole, amoxicillin, and clarithromycin). The children were divided into two groups based on the success of the H. pylori treatment: group 1 (eradicated) - patients who had a negative 13C-urea breath test 2 mo after the end of therapy; and group 2 (non-eradicated) - patients who had a positive 13C-urea breath test. Plasma ghrelin, gastric ghrelin mRNA, and the body mass index were evaluated in both groups before and after the H. pylori treatment. The plasma ghrelin levels were measured by a radioimmunoassay. The expression of gastric ghrelin mRNA was determined by real-time reverse transcription polymerase chain reaction.

RESULTS: A total of 50 children with H. pylori-associated functional dyspepsia were treated with triple H. pylori eradication therapy. The mean age of the children was 5.52 ± 0.83 years, and there were 28 males and 22 females. Among the 50 H. pylori-positive children, 30 successfully achieved eradication, and 20 did not. The mean plasma ghrelin levels of group 1 were 22.17 ± 1.73 ng/L and 26.59 ± 2.05 ng/L before and after the treatment, respectively, which was a significant increase (P = 0.001). However, the mean plasma ghrelin level of group 2 before and after the H. pylori treatment was 21.34 ± 2.40 ng/L and 22.24 ± 2.10 ng/L (P = 0.785). The plasma ghrelin levels increased substantially after treatment in group 1 but showed only minor changes in group 2. Similarly, the gastric ghrelin mRNA expression in group 1 before treatment was 2.84 ± 0.08. After treatment, the level was 3.11 ± 0.65, which was significantly different (P = 0.023). The gastric ghrelin mRNA expression in group 2 did not change significantly during the treatment (2.82 ± 0.44 vs 2.79 ± 0.31, P = 0.875). The plasma ghrelin and gastric ghrelin mRNA levels in group 1 increased substantially after the treatment but did not do so in group 2. In addition, the body mass index the two groups did not differ significantly 2 mo before and after the H. pylori treatment.

CONCLUSION: H. pylori eradication increases the plasma and tissue ghrelin levels in children with H. pylori-associated functional dyspepsia.

Association between gastric Helicobacter pylori colonization and glycated hemoglobin levels

BACKGROUND

Few studies have evaluated the potential influence of Helicobacter pylori on biomarkers for diabetes.

METHODS

We conducted cross-sectional analyses using data from 7417 participants in the National Health and Nutrition Examination Survey (NHANES) III (aged ≥18 years) and 6072 participants in NHANES 1999-2000 (aged ≥3 years) to assess the association between H. pylori and levels of glycosylated hemoglobin (HbA1c).

RESULTS

There was no association between H. pylori and history of self-reported diabetes. Helicobacter pylori seropositivity, especially H. pylori cagA positivity, was positively associated (P < .01, NHANES III; P = .02, NHANES 1999-2000) with HbA1c levels after excluding individuals with history of diabetes and controlling for potential confounders. There was also a synergistic interaction between H. pylori and higher body mass index (BMI), such that increased levels of HbA1c associated with having both H. pylori and higher BMI were greater than the sum of their individual effects (P for interaction < .01). This interaction was observed consistently in both NHANES III and NHANES 1999-2000 and for H. pylori cagA positivity in NHANES III.

CONCLUSIONS

The findings indicate a role of H. pylori in impaired glucose tolerance in adults that may be potentiated by higher BMI level.

The effect of H. pylori eradication on meal-associated changes in plasma ghrelin and leptin

Background

Appetite and energy expenditure are regulated in part by ghrelin and leptin produced in the gastric mucosa, which may be modified by H. pylori colonization. We prospectively evaluated the effect of H. pylori eradication on meal-associated changes in serum ghrelin and leptin levels, and body weight.

Methods

Veterans referred for upper GI endoscopy were evaluated at baseline and ≥8 weeks after endoscopy, and H. pylori status and body weight were ascertained. During the first visit in all subjects, and during subsequent visits in the initially H. pylori-positive subjects and controls, blood was collected after an overnight fast and 1 h after a standard high protein meal, and levels of eight hormones determined.

Results

Of 92 enrolled subjects, 38 were H. pylori-negative, 44 H. pylori-positive, and 10 were indeterminate. Among 23 H. pylori-positive subjects who completed evaluation after treatment, 21 were eradicated, and 2 failed eradication. After a median of seven months following eradication, six hormones related to energy homeostasis showed no significant differences, but post-prandial acylated ghrelin levels were nearly six-fold higher than pre-eradication (p = 0.005), and median integrated leptin levels also increased (20%) significantly (p < 0.001). BMI significantly increased (5 ± 2%; p = 0.008) over 18 months in the initially H. pylori-positive individuals, but was not significantly changed in those who were H. pylori-negative or indeterminant at baseline.

Conclusions

Circulating meal-associated leptin and ghrelin levels and BMI changed significantly after H. pylori eradication, providing direct evidence that H. pylori colonization is involved in ghrelin and leptin regulation, with consequent effects on body morphometry.

Randomised clinical trial: Helicobacter pylori eradication is associated with a significantly increased body mass index in a placebo-controlled study

BACKGROUND

Body mass index (BMI) increased following Helicobacter pylori eradication in several Japanese cohorts, which requires further investigation.

AIM

To determine the impact of H. pylori eradication on BMI in a European population.

METHODS

A total of 10,537 unselected people aged 20-59 years were screened for H. pylori; 1558 of the 1634 infected participants were randomised to intervention (eradication therapy: ranitidine bismuth citrate 400 mg and clarithromycin 500 mg twice daily) or placebo for 2 weeks with follow-up at 6 months (92%) for weight and dyspepsia symptoms (epigastric pain).

RESULTS

The mean weight of participants in the intervention group increased from 77.7 kg at baseline to 78.4 kg at 6 months (unadjusted increase of 0.7 kg) and from 76.8 to 77.2 kg (0.5 kg) in the placebo group. The adjusted difference between randomised groups was statistically significant at 0.6 kg [95% confidence interval (CI) 0.31, 0.88]. Significantly, more participants gained ≥3 kg in the intervention group (138/720, 19%) compared with the placebo group (92/706, 13%) [odds ratio (OR) 1.57 (95% CI: 1.17, 2.12)]. The mean BMI increased from 27.5 to 27.8 kg/m(2) at 6 months in the intervention group compared with the increase from 27.0 to 27.2 kg/m(2) in the placebo group [adjusted difference between groups was statistically significant at 0.2 kg/m(2) (95% CI: 0.11, 0.31)]. Dyspepsia was less frequently reported by intervention group participants (168/736, 23%, placebo group 209/711, 29%), OR 0.71 (95% CI: 0.55, 0.93).

CONCLUSION

Body mass index increased significantly following randomisation to H. pylori eradication therapy, possibly due to resolution of dyspepsia.

Endocrine impact of Helicobacter pylori: Focus on ghrelin and ghrelin o-acyltransferase

Ghrelin is predominantly produced by the gastric enteroendocrine cell compartment and is octanoylated by the recently discovered ghrelin o-acyltransferase (GOAT) before secretion into the bloodstream. This octanoylation is essential for many of the biological properties of ghrelin including appetite stimulation and anti-inflammatory properties as only the acylated form of ghrelin binds to the ghrelin receptor, the growth hormone secretagogue receptor (GHS-R). Given the gastric location of ghrelin production, it is perhaps not surprising that insult to the gastric mucosa affects circulating ghrelin levels in humans. Helicobacter pylori (H. pylori) infects more than fifty percent of the world’s population and once established within the gastric mucosa, can persist for life. Infection is associated with chronic gastritis, gastric atrophy and ulceration, reduced appetite and a lower body mass index (BMI). The large majority of studies investigating levels of circulating ghrelin and ghrelin expression in the stomach in patients with H. pylori infection indicate that the bacterium has a negative impact on ghrelin production and/or secretion. Eradication of infection restores ghrelin, improves appetite and increases BMI in some studies, however, a causative relationship between H. pylori-associated serum ghrelin decline and food intake and obesity has not been established. Most studies measure total ghrelin in the circulation although the measurement of the ratio of acyl/total ghrelin gives a clearer indication that the ghrelin acylation process is altered during infection and atrophy. GOAT is essential for the production of biologically-active, acyl ghrelin and the impact of H. pylori on GOAT expression and activity will be highly informative in the future.

Helicobacter pylori infection and circulating ghrelin levels - a systematic review

BACKGROUND

The nature of the association between ghrelin, an orexigenic hormone produced mainly in the stomach, and Helicobacter pylori (H pylori), a bacterium that colonises the stomach, is still controversial. We examined available evidence to determine whether an association exists between the two; and if one exists, in what direction.

METHODS

We reviewed original English language studies on humans reporting circulating ghrelin levels in H pylori infected and un-infected participants; and circulating ghrelin levels before and after H pylori eradication. Meta-analyses were conducted for eligible studies by combining study specific estimates using the inverse variance method with weighted average for continuous outcomes in a random effects model.

RESULTS

Seventeen out of 27 papers that reported ghrelin levels in H pylori positive and negative subjects found lower circulating ghrelin levels in H pylori positive subjects; while 10 found no difference. A meta-analysis of 19 studies with a total of 1801 participants showed a significantly higher circulating ghrelin concentration in H pylori negative participants than in H pylori positive participants (Effect estimate (95%CI) = -0.48 (-0.60, -0.36)). However, eradicating H pylori did not have any significant effect on circulating ghrelin levels (Effect estimate (95% CI) = 0.08 (-0.33, 0.16); Test for overall effect: Z = 0.67 (P = 0.5)).

CONCLUSIONS

We conclude that circulating ghrelin levels are lower in H pylori infected people compared to those not infected; but the relationship between circulating ghrelin and eradication of H pylori is more complex.

Helicobacter pylori infection and circulating ghrelin levels - a systematic review

Background

The nature of the association between ghrelin, an orexigenic hormone produced mainly in the stomach, and Helicobacter pylori (H pylori), a bacterium that colonises the stomach, is still controversial. We examined available evidence to determine whether an association exists between the two; and if one exists, in what direction.

Methods

We reviewed original English language studies on humans reporting circulating ghrelin levels in H pylori infected and un-infected participants; and circulating ghrelin levels before and after H pylori eradication. Meta-analyses were conducted for eligible studies by combining study specific estimates using the inverse variance method with weighted average for continuous outcomes in a random effects model.

Results

Seventeen out of 27 papers that reported ghrelin levels in H pylori positive and negative subjects found lower circulating ghrelin levels in H pylori positive subjects; while 10 found no difference. A meta-analysis of 19 studies with a total of 1801 participants showed a significantly higher circulating ghrelin concentration in H pylori negative participants than in H pylori positive participants (Effect estimate (95%CI) = -0.48 (-0.60, -0.36)). However, eradicating H pylori did not have any significant effect on circulating ghrelin levels (Effect estimate (95% CI) = 0.08 (-0.33, 0.16); Test for overall effect: Z = 0.67 (P = 0.5)).

Conclusions

We conclude that circulating ghrelin levels are lower in H pylori infected people compared to those not infected; but the relationship between circulating ghrelin and eradication of H pylori is more complex.

Eradication of Helicobacter pylori increases ghrelin mRNA expression in the gastric mucosa

It has been suggested that Helicobacter pylori eradication may influence production of some peptides in the stomach, which can affect appetite. This hypothesis is controversial. To verify the hypothesis, we conducted this randomized controlled trial using H. pylori infected subjects without any gastrointestinal symptoms. The treatment group received triple H. pylori eradication therapy for 7 days and the control group received no medication. We measured ghrelin, obestatin and the tumor necrosis factor-alpha (TNF-alpha) mRNA levels in endoscopic biopsy specimens and the changes from baseline to follow-up. The plasma active n-octanoyl ghrelin and obestatin levels were measured in both groups. The ghrelin/obestatin ratios in plasma and gastric mRNA expression were calculated at baseline and follow-up. Ghrelin mRNA expression in the fundic mucosa after H. pylori eradication increased significantly compared to the control group (4.47+/-2.14 vs. 1.79+/-0.96, P=0.009), independent of inflammatory changes. However, obestatin mRNA expression decreased in the antral mucosa (-0.57+/-1.06 vs. 0.41+/-0.72, P=0.028). The treatment group showed a marginal increase (P=0.060) in plasma ghrelin/obestatin ratio. The TNF-alpha mRNA expression also decreased significantly with treatment. This randomized controlled trial demonstrates that H. pylori eradication increases ghrelin mRNA expression, independent of inflammatory cell changes.

Is stomach spontaneously ageing? Pathophysiology of the ageing stomach

During ageing, histological and physiological modifications occur in the stomach leading to a confirmed state of gastric frailty defined by a decreased capacity of tissue repairing after mucosa gastric aggression. The process of intrinsic gastric ageing may play a role in inducing abnormalities of gastric epithelial proliferation against injury but, most of the time, pathophysiological modifications observed in older people are the consequences of chronic insults, such as chronic Helicobacter pylori infection, polymedication, especially Proton-pump inhibitors (PPI) and Non-steroidal Anti-inflammatory Drugs (NSAID), and co morbidities. One of the major clinical consequences of the gastric frailty is the higher vulnerability to the occurrence of peptic ulcer disease during ageing. In this review recent data on gastric changes during ageing, focussing especially on histological modifications and motility disorders are summarized.

Helicobacter pylori infection and endocrine disorders: Is there a link?

Helicobacter pylori (H pylori) infection is a leading world-wide infectious disease as it affects more than half of the world population and causes chronic gastritis, peptic ulcer disease and gastric malignancies. The infection elicits a chronic cellular inflammatory response in the gastric mucosa. However, the effects of this local inflammation may not be confined solely to the digestive tract but may spread to involve extra-intestinal tissues and/or organs. Indeed, H pylori infection has been epidemiologically linked to extra-digestive conditions and diseases. In this context, it has been speculated that H pylori infection may be responsible for various endocrine disorders, such as autoimmune thyroid diseases, diabetes mellitus, dyslipidemia, obesity, osteoporosis and primary hyperparathyroidism. This is a review of the relationship between H pylori infection and these endocrine disorders.

Helicobacter pylori, helminth infections and growth: a cross-sectional study in a high prevalence population

AIM

Helicobacter pylori (H. pylori) infection is usually acquired in childhood and may adversely affect growth, although data are inconsistent. This study investigated growth parameters in a paediatric cohort with a high prevalence of H. pylori and helminth infection.

METHODS

A cross-sectional study of African refugee children (<16 years) recruited at their initial health assessment following resettlement in Australia. Detailed demographic, infection and anthropometric data were obtained. H. pylori infection was diagnosed by monoclonal faecal antigen enzyme immunoassay testing (MFAT). Growth restriction was defined as children with any anthropometric measures below the fifth centile for age and gender.

RESULTS

H. pylori infection was detected in 149/182 (81.9%). Children with H. pylori infection were older (mean 8.5 years, standard deviation (SD) 4.2 years vs. 5.8 years, SD 4.5 years, p < 0.001). No gender differences were observed. After adjustment for age, H. pylori did not adversely affect body mass index or other anthropometric measurements. Helminth infections were common (41.8%) but not associated with reduced growth or with H. pylori infection.

CONCLUSION

H. pylori and helminth infections are prevalent in African refugee children but neither is associated with growth restriction. Longitudinal growth velocity studies are necessary to identify any long-term consequences of H. pylori on childhood growth.

Serum ghrelin as a marker of atrophic body gastritis in patients with parietal cell antibodies

AIM

Autoimmune gastritis is frequently associated with autoimmune thyroiditis and other organ-specific autoimmune diseases, and may lead to atrophic body gastritis (ABG). We studied the diagnostic use of the measurement of serum ghrelin compared with other markers of gastric damage in predicting the presence of ABG in patients with autoimmune gastritis.

METHODS

We studied 233 patients with autoimmune gastritis and 211 control subjects. All patients and control subjects were screened for circulating parietal cell antibodies (PCAs) and were tested for serum ghrelin, gastrin, pepsinogen I and II, and anti-Helicobacter pylori antibody levels. A total of 52 patients and 28 control subjects underwent a gastric endoscopy.

RESULTS

In PCA/positive patients, mean (+/-sd) serum ghrelin levels were significantly lower (238 +/- 107 pmol/liter), and mean (+/-sd) serum gastrin levels were significantly higher (81.2 +/- 128.3 ng/ml), with respect to PCA/negative patients (282 +/- 104 pmol/liter and 20.7 +/- 13.3 ng/ml, respectively; P < 0.0001). Serum ghrelin and gastrin levels were inversely correlated (P = 0.004). A total of 40 patients had ABG documented by the gastric biopsy (90% in PCA/positive patients and 10% in PCA/negative patients). The receiver operating characteristic curve analysis revealed that a cutoff value for serum ghrelin of 188 pmol/liter was associated with the highest sensitivity and specificity (97.3 and 100%, respectively) in detecting gastric atrophy and was superior to gastrin (P = 0.012), PCA (P = 0.002), and the pepsinogen I/II ratio (P = 0.016) measurements.

CONCLUSIONS

Our study demonstrates that ghrelin secretion is negatively affected by autoimmune gastritis, and its serum level represents the most sensitive and specific noninvasive marker for selecting patients at high risk for ABG.

Correlation between gastrointestinal symptoms and gastric leptin and ghrelin expression in patients with gastritis

The purpose of this study was to examine the changes in gastric ghrelin and leptin with respect to Helicobacter pylori infection and whether such changes affect the plasma levels of leptin and ghrelin. In addition, we examined the relationship between changes in gastric mucosal ghrelin and leptin levels and gastrointestinal symptoms. Sixty-three patients diagnosed with chronic gastritis were enrolled in the study. Twenty-nine patients were Helicobacter pylori negative and 34 were Helicobacter pylori positive. Expression of ghrelin and leptin mRNA in the gastric mucosa was measured using endoscopic biopsies from the fundus. Plasma levels of ghrelin and leptin were measured by radioimmunoassay. Expression of leptin mRNA in the gastric mucosa was significantly higher in Helicobacter pylori-positive patients than in negative patients (0.38 +/- 0.17 vs. 0.24 +/- 0.12, p = 0.039). The expression of ghrelin was lower in positive patients than in the negative group, although this difference was not significant (p = 0.07). However, there was no significant difference in plasma leptin and ghrelin levels. Gastric mucosal ghrelin mRNA expression was significantly lower in patients with dyspepsia than in those without (0.15 +/- 0.11 vs. 0.23 +/- 0.20, p = 0.05). Helicobacter pylori infection and gastrointestinal symptoms could be associated with leptin and ghrelin expression in the gastric mucosa.

Prevalence of Helicobacter pylori infection among Egyptian children: impact of social background and effect on growth

OBJECTIVE

The study aim was to assess the prevalence of Helicobacter pylori infection in Egyptian schoolchildren and its effect on growth parameters.

DESIGN

A cross-sectional population-based study was conducted among 286 schoolchildren (168 boys and 118 girls), with a mean age of 11.04 +/- 0.19 years, to determine the prevalence of H. pylori. The presence of the bacterium was assessed using the [13C]urea breath test. Relevant personal and socio-economic data on risk factors for infection were collected. Height and weight were analysed in relation to H. pylori infection.

RESULTS

The overall prevalence of H. pylori infection was 72.38%. Attending school in a socially deprived area and residing in an overcrowded home were the major risk factors for infection. Differences between infected and non-infected children were significant with regard to body weight and height (weight: 39.5 +/- 1.0 vs. 44.6 +/- 1.8 kg, P = 0.05; height: 139.9 +/- 1.3 vs. 144.2 +/- 2.1 cm; P = 0.009). The number of children (both boys and girls) falling below the 5th percentile of height-for-age was significantly higher in infected than non-infected children (P = 001), similarly for Z-scores for height-for-age below -2.0 (P = 0.003).

CONCLUSION

The results demonstrate not only that the prevalence of H. pylori infection is extremely high among Egyptian schoolchildren, but also that the adverse effects of the infection reach far beyond the stomach. Evidence of the burden of infection on growth failure is presented.

Serum ghrelin levels are higher in Caucasian men than Japanese men aged 40-49 years

BACKGROUND

Ghrelin, a 28-amino-acid gastric peptide hormone, has an appetite-stimulating effect and controls the energy balance. Serum ghrelin levels inversely correlate with body mass index. Recently, several papers reported the ethnic difference in the ghrelin levels. To our knowledge, however, no studies have compared the serum ghrelin levels between Caucasians in the USA and the Japanese in Japan.

METHODS

We conducted a cross-sectional study of 189 men 40-49 years of age (91 US Caucasians in the U.S. and 98 Japanese in Japan) to examine serum ghrelin levels and metabolic and other factors.

RESULTS

Serum ghrelin levels correlated with waist circumferences and lipid profiles among Caucasian Americans and the Japanese. Serum ghrelin levels were significantly higher among Caucasian Americans than among the Japanese (904.5 (632.0, 1132.0) pg/mL, 508.0 (399.0, 1378.3) pg/mL (median and 95% confidence interval), respectively, P < 0.01), although Caucasian Americans were much more obese (BMI: 26.9 +/- 3.3 kg/m(2) versus 23.3 +/- 3.1 kg/m(2) respectively, P < 0.01). The ethnic difference remained after adjusting for metabolic factors, smoking status, and other factors (P < 0.01).

CONCLUSIONS

We have shown in our population-based study that serum ghrelin levels among men aged 40-49 are significantly higher in Caucasian Americans than in the Japanese in Japan. Reasons for the ethnic difference in the ghrelin levels are largely unknown and warrant further investigation.

Effects of Helicobacter pylori infection on gut appetite peptide (leptin, ghrelin) expression in elderly inpatients

The aim of the study was to investigate the relationship between gastritis and leptin and ghrelin in elderly patients. Patients older than 75 years undergoing an endoscopy were included. We reported data on nutritional status and Helicobacter pylori infection diagnosis (serology, 13C-urea breath test, culture, histology, and polymerase chain reaction on gastric biopsies). Gastric messenger RNA expression of leptin and ghrelin were quantified by real-time polymerase chain reaction. Sixty-two patients were included (84.7 +/- 5.2 years). H. pylori infection was associated with decreased gastric expression of leptin (p = .021), ghrelin (p =.002), and plasma ghrelin levels (p = .018). Atrophy was associated with decreased gastric leptin (p = .007) and ghrelin (p = .02). H. pylori infection correlated negatively with patient energy intake (r = -0.36; p = .001) and body mass index (r = -0.34; p = .018). The negative association between ghrelin and H. pylori infection may be related to a higher prevalence of atrophy and raises the possibility that H. pylori may be contributing to undernutrition in some older people.

Gastroduodenal mucosal defense

PURPOSE OF REVIEW

The duodenum absorbs nearly all secreted gastric acid. Carbonic anhydrases facilitate transmucosal acid movement. The upper gastrointestinal tract must resist a variety of injuries, including those caused by ingested noxious substances, acid, ischemia/reperfusion, and infections such as Helicobacter pylori. The results are similar, however, regardless of insult: inflammation, ulceration, or metaplasia/dysplasia. In the past year, there have been prominent findings suggesting that oxidative stress and the formation of reactive oxygen species may play a pivotal role in all forms of injury, and that antioxidants may be the key to injury prevention and healing.

RECENT FINDINGS

Oxidative injury may be a common mechanism by which the upper gastrointestinal mucosa responds to noxious insults. Endogenous antioxidants, such as ghrelin, L-carnitine, and annexin-1 attenuate the oxidative-stress response. Similarly, exogenous antioxidants have also been shown to decrease inflammation, upregulate free radical scavengers, and prevent the formation of reactive oxygen species.

SUMMARY

Many studies published in the past year have linked oxidative stress to a variety of upper gastrointestinal insults. Exogenous and endogenous antioxidant compounds prevent the oxidative stress response. The future holds great promise for the development of pharmaceuticals with antioxidant properties that are safe, efficacious, and inexpensive.

Extragastric manifestations of Helicobacter pylori infection--other Helicobacter species

Recent studies have indicated a strong link between Helicobacter pylori and idiopathic thrombocytopenic purpura and iron deficiency anemia. Interesting results have also been obtained for ischemic heart disease, though most putative associations between H. pylori infection and extragastric disease remain speculative. With regard to other Helicobacter species, Helicobacter felis has been shown to play a role in gastric carcinogenesis in mouse models. An increased susceptibility to cholesterol gallstone formation has been described in animals fed a lithogenic diet and infected with Helicobacter bilis, or co-infected with Helicobacter hepaticus and Helicobacter rodentium. Finally, enterohepatic Helicobacter species have also been exploited to better understand inflammatory bowel disease.

Spurious associations in oral epidemiological research: the case of dental flossing and obesity

BACKGROUND

Individuals with increased oral health awareness may also have increased general health awareness, and vice versa. Such associations between oral and general health awareness has the potential to induce spurious associations in oral epidemiological research.

OBJECTIVE

To assess the extent to which oral self-care patterns and general health awareness are confounded, we investigated the association between flossing and obesity, two lifestyle factors that are unlikely to be causally related.

METHODS

A cross-sectional study of 1497 individuals presenting for an initial periodontal exam by the specialist. Self-reported flossing behaviors and body mass index (BMI) categories were related using logistic regression models.

RESULTS

After adjustment for confounding variables, lack of daily flossing was associated in a dose-dependent way with morbid obesity (odds ratio (OR), 20.3; 95% confidence interval (CI), 2.7-154.0), obesity (OR, 2.1; 95% CI, 1.5-2.9), and being overweight (OR, 1.7; 95% CI, 1.3-2.2). When restricting to never smokers, a significant relationship between obesity and lack of flossing remained.

CONCLUSION

The strong associations between two causally unrelated oral and general lifestyle characteristics indicate that simplistic epidemiologic methodology is unlikely to provide insights into causal mechanisms of oral diseases or oral-systemic relationships.