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

The role of leptin in indirectly mediating "somatic anxiety" symptoms in major depressive disorder

BACKGROUND

Leptin is a multifunctional hormone secreted from adipose tissue, which plays a core role in regulating energy intake and expenditure. Evidence has demonstrated that leptin receptors are located in brain areas involved in emotional processing, and major depressive disorder (MDD) is characterized by dysfunction of emotional processing. Taken together, these features suggest that leptin may play a potential role in the pathophysiology of MDD. However, the precise roles of leptin in modulating depressive symptoms in MDD remain unclear.

METHODS

Participants [18 drug-naïve MDD patients, 15 unaffected first-degree relatives of MDD patients (FDR-MDD), and 40 healthy controls] completed clinical assessments and provided blood samples for measurement of leptin levels. We evaluated the effect of leptin on clinical status (MDD or FDR-MDD) and symptomatic dimensionalities of MDD using mediation analysis.

RESULTS

We found that leptin was increased in MDD patients and this only predicted "somatic anxiety" symptoms. Furthermore, leptin was a significant and indirect mediator of the association between clinical status (MDD or FDR-MDD) and "somatic anxiety" symptoms.

CONCLUSION

Our finding that leptin was a significant and indirect mediator of clinical status (MDD or FDR-MDD) and "somatic anxiety" symptoms suggests that leptin may indirectly affect somatic depressive symptoms in MDD. Our findings may provide a theoretical basis for novel clinical interventions in MDD.

Body Mass Index and Risk of Intestinal Metaplasia: A Cohort Study

BACKGROUND

We examined the association between body mass index (BMI) and development of endoscopic intestinal metaplasia.

METHODS

This retrospective cohort study included 142,832 Korean adults free of endoscopic intestinal metaplasia and atrophic gastritis who underwent upper endoscopy at baseline and subsequent visits and were followed for up to 5 years. A parametric proportional hazards model was used to estimate the adjusted HR with 95% confidence interval (CI) for incident intestinal metaplasia.

RESULTS

In more than 444,719.1 person-years of follow-up, 2,281 participants developed endoscopic intestinal metaplasia (incidence rate, 5.1 per 1,000 person-years). Increased BMI categories were associated with increased risk of new-onset intestinal metaplasia in a dose-response manner. After adjustment for age, sex, center, year of screening exam, smoking status, alcohol intake, exercise, total calorie intake, history of diabetes and hypertension, and history of Helicobacter pylori infection, the multivariable adjusted HRs (95% CIs) for incident intestinal metaplasia comparing BMIs of <18.5, 23-24.9, 25.0-29.9, and >30 kg/m² with a BMI of 18.5-22.9 kg/m² were 0.84 (0.64-1.09), 1.03 (0.93-1.16), 1.07 (0.96-1.20), and 1.48 (1.20-1.83), respectively. These associations did not differ by clinically relevant subgroups. Risk of endoscopic atrophic gastritis also increased as the baseline BMI category increased.

CONCLUSIONS

In a large cohort of Korean men and women, obesity was independently associated with increased incidence of endoscopic atrophic gastritis and intestinal metaplasia.

IMPACT

Excessive adiposity appears to play a role in development of stomach precursor lesions of stomach cancer, requiring further studies to determine whether strategies to reduce obesity will also help reduce precancerous lesions and, in turn, gastric cancer.

[Associations between Body Mass Index and Chronic Atrophic Gastritis and Intestinal Metaplasia]

Background/Aims

Chronic atrophic gastritis (AG) and intestinal metaplasia (IM) of the stomach are premalignant lesions. The present study aimed to examine the associations between obesity and these lesions.

Methods

A total of 2,997 patients, who underwent gastroscopy, participated in this study, excluding those who had been diagnosed with gastric cancer. Participants were divided into four groups based on their body mass index (BMI). The risk of AG and IM with increasing BMI was analyzed in men and women, separately.

Results

The association between BMI and AG was not significant. After adjusting for age, smoking, alcohol, and AG, the odds ratios for IM in the overweight, obesity, and severe obesity groups were 2.25 (95% confidence interval [CI], 1.50-3.37), 2.32 (95% CI, 1.58-3.42), and 4.86 (95% CI, 2.04-11.5) in men, and 2.66 (95% CI, 1.29-5.47), 4.46 (95% CI, 2.28-8.75), and 9.57 (95% CI, 3.26-28.12) in women, compared with the normal BMI group.

Conclusions

Gastric IM was significantly associated with increased BMI.

Polymorphisms at Locus 4p14 of Toll-Like Receptors TLR-1 and TLR-10 Confer Susceptibility to Gastric Carcinoma in Helicobacter pylori Infection

Helicobacter pylori (H. pylori) -induced gastric inflammation impacts the functions of leptin- and ghrelin-producing cells in the gastroduodenum. Inflammation resulting from H. pylori sensing via Toll-like receptors (TLRs) and the associated downstream signaling largely remain ambiguous. Here, we investigated the role of gut hormones, pro-inflammatory cytokines and single nucleotide polymorphisms (SNPs) associated with TLR 4p14 in H. pylori disease in 30 subjects with non-ulcer dyspepsia (NUD), 40 with peptic ulcer disease (PUD) and 15 with gastric cancer (GC) subjects positive and negative for H. pylori infection. The level of pro-inflammatory cytokines was directly proportional to the severity of gastritis, and disease status influenced the levels of gut hormones and pro-inflammatory cytokines. TLR-1 SNPs rs4833095 and TLR-10 SNPs rs10004195 and were directly associated with H. pylori disease, and were up-regulated in the presence of H. pylori in a genotype-independent manner. We concluded that TLR-1 rs4833095 and TLR10 rs10004195 confer susceptibility to development of gastroduodenal disease, especially GC in H.pylori disease.

Impairment of ghrelin synthesis in Helicobacter pylori-colonized stomach: New clues for the pathogenesis of H. pylori-related gastric inflammation

Ghrelin, the ligand of growth hormone secretagogue receptor 1a, takes part in several functions of the digestive system, including regulation of appetite, energy homeostasis, gastric acid secretion and motility. Ghrelin has also immunoregulatory properties and is supposed to inhibit some inflammatory pathways that can mediate gastric damage. Interestingly, ghrelin synthesis is reduced in the gastric mucosa of patients with Helicobacter pylori (H. pylori) infection, a worldwide condition inducing a T helper (Th)1/Th17 cell response-driven gastritis, which may evolve towards gastric atrophy and cancer. In this article, we review the available data on the expression of ghrelin in H. pylori infection and discuss how the defective ghrelin synthesis may contribute to sustain the ongoing inflammatory response in this disease.

Augmenting Effect of DA-9601 on Ghrelin in an Acute Gastric Injury Model

BACKGROUND/AIMS

Acute gastric injury by alcohol or indomethacin has been reported to be prevented by DA-9601, an extract of the herb Artemisia asiatica. Ghrelin, an endogenously produced gastrointestinal peptide hormone, has also been demonstrated to play a role in gastric mucosal defense. The aim of this study was to investigate the effects of DA-9601 on ghrelin in an acute gastric injury model induced by alcohol or indomethacin.

METHODS

A total of 140 Sprague-Dawley rats were divided into two groups, a placebo group and a DA-9601-pretreated group. Thirty minutes later, half of the rats in each group received ethanol injury and the other half received indomethacin injury. Levels of serum ghrelin and gastric mucosal ghrelin mRNA were measured by ELISA and RT-PCR, respectively.

RESULTS

Immediately after ethanol administration, ghrelin increased in both groups pretreated with DA-9601 and placebo. However, the increase occurred more rapidly and was higher in the DA-9601-pretreated rats than in the controls that did not receive DA-9601-pretreatment. Similarly, from 30 minutes to 2 hours after indomethacin administration, the DA-9601-pretreated rats showed a significant increase in serum and gastric mucosal ghrelin concentrations, whereas placebo-pretreated rats showed only a mild increase.

CONCLUSIONS

DA-9601 potentiates the endogenous production and secretion of ghrelin in acute gastric injury models induced by ethanol or indomethacin.

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.

The effect of Helicobacter pylori and economic status on growth parameters and leptin, ghrelin, and insulin-like growth factor (IGF)-I concentrations in children

BACKGROUND

It was suggested that gastric colonization with Helicobacter pylori (H. pylori) was associated with suboptimal nutrition and growth in childhood. Furthermore, several studies indicated a relationship between H. pylori colonization and alterations in the circulating levels of growth-related molecules (GRM). Accordingly, in this study, we investigate the effect of H. pylori infection on GRMs and on the growth of healthy school children, taking into consideration the effect of their economic status (ES) and anthropometric indices of their parents.

METHODS

To acquire sociodemographic and anthropometric nutritional parameters and to detect H. pylori-specific serum IgG antibodies and growth-related molecules, we evaluated a total of 473 children attending four different primary and secondary schools in Istanbul. Subsequently, we assessed the effect of H. pylori on growth-related parameters (weight for age SDS, height for age SDS, BMI SDS, TSF, and waist-to-hip ratio) and on GRMs (leptin, ghrelin, and insulin-like growth factor-1 (IGF-1)), controlling for age, gender, family income, household crowding (HC), breastfeeding, maternal and paternal BMI SDS, and midparental height SDS with complex statistical models.

RESULTS

Of the 473 children (275 F/198 M, age 6-15 years; mean: 10.3 ± 0.1 years), 161 (34%) were H. pylori-positive. The prevalence of H. pylori was significantly higher in lower economic status (ES) groups, in children living in crowded houses, and in older age groups. Using simple statistical models, we did not find any significant associations between H. pylori infection and the growth parameters. However, in complex models for height for age SDS and for weight for age SDS, there was a significant interaction between H. pylori infection status and ES. Whereas in H. pylori-positive subjects, mid-income family children were both taller and heavier than the low-income group, there was no such an association in H. pylori-negative subjects. Among biochemical parameters, only ghrelin levels were associated with H. pylori infection in all models. Leptin levels were associated with HC in girls, whereas none of the parameters was significantly associated with leptin levels in boys. For IGF-1 levels, for boys, age and maternal BMI, and for girls, age and HC were significantly associated with IGF-1 levels.

CONCLUSION

We suggest that H. pylori may impair growth significantly only in susceptible children where unfavorable socioeconomic conditions facilitate its action, probably through mechanisms, at least in part, involving growth-related molecules.

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.

Serum levels of leptin as marker for patients at high risk of gastric cancer

BACKGROUND

Serological screening for gastric cancer (GC) may reduce mortality. However, optimal serum markers for advanced gastric precursor lesions are lacking.

AIM

To evaluate in a case-control study whether serum leptin levels correlate with intestinal metaplasia (IM) and can serve as a tool to identify patients at high risk for GC.

MATERIALS AND METHODS

Cases were patients with a previous diagnosis of IM or dysplasia, controls were patients without such a diagnosis. All patients underwent endoscopy. Fasting serum was collected for the measurement of leptin, pepsinogens I/II, gastrin, and Helicobacter pylori. Receiver operating characteristic (ROC) curves and their area under the curve (AUC) were provided to compare serum leptin levels with other serological markers.

RESULTS

One hundred nineteen cases and 98 controls were included. In cases, the median leptin levels were 116.6 pg/mL versus 81.9 pg/mL in controls (p = .01). After adjustment for age, sex and BMI, leptin levels remained higher in cases than in controls (p < .005). In multivariate analysis, male sex (p = .002), age (<0.001), low pepsinogen levels (p = .004) and high leptin levels (p = .04) were independent markers for the presence of IM. In addition, a ROC curve including age, sex and pepsinogen I levels had an AUC of 0.79 (95% CI (0.73-0.85)). Adding serum leptin levels increased the AUC to 0.81 (95% CI (0.75-0.86)).

CONCLUSIONS

High leptin levels are associated with an increased risk of IM. Moreover, serum leptin levels are a significant independent marker for the presence of IM. However, in combination with the serological test for pepsinogen I the additional value of serum leptin levels is rather limited.

Leptin and ghrelin in relation to Helicobacter pylori status in adult males

CONTEXT

Leptin and ghrelin, hormones involved in human energy homeostasis, are both produced in the stomach.

OBJECTIVE

We sought to determine whether the presence of Helicobacter pylori affects gastric and systemic levels of leptin and ghrelin.

DESIGN, SETTING, AND PATIENTS

We consecutively enrolled 256 patients referred for upper endoscopy at a Veterans Affairs outpatient endoscopy center.

OUTCOMES

We obtained fasting serum, fundic and antral biopsies, and gastric juice. Based on histological, biochemical, and serological assays, patients were categorized as H. pylori+ or H. pylori-. Leptin and total ghrelin levels in serum, gastric biopsies, and gastric juice were determined by specific ELISAs.

RESULTS

Of the 256 subjects, 120 were H. pylori+ and 96 were H. pylori-; 40 patients of indeterminate status were excluded. Serum and fundic leptin levels correlated with body mass index in the H. pylori+ (r = 0.35; P < 0.0001 and r = 0.35; P < 0.0001, respectively) and H. pylori- (r = 0.65; P < 0.0001 and r = 0.41; P < 0.0001, respectively) groups, but H. pylori+ subjects had significantly lower serum leptin levels [median 2.2 ng/ml (interquartile range 0.9-4.6) vs. 4.0 ng/ml (1.7-7.2); P = 0.0003]. Serum ghrelin levels were similar in the H. pylori+ and H. pylori- groups [median 1651 pg/ml (interquartile range 845-2247) vs. 1629 pg/ml (992-2886); P = 0.23]. H. pylori status did not significantly affect gastric biopsy leptin and ghrelin levels. Ghrelin levels in gastric juice varied over 4 log(10) (<80-776,000 pg/ml) and correlated with gastric juice pH in the H. pylori+ group (r = 0.68; P < 0.0001).

CONCLUSIONS

These findings provide evidence that H. pylori status affects leptin and ghrelin homeostasis, presumably via intragastric interactions.

The effect of laparoscopic gastric banding surgery on plasma levels of appetite-control, insulinotropic, and digestive hormones

BACKGROUND

We hypothesized that laparoscopic adjustable gastric banding (LAGB) reduces weight and modulates ghrelin production, but largely spares gastrointestinal endocrine function. To examine this hypothesis, we determined plasma concentrations of appetite-control, insulinotropic, and digestive hormones in relation to LAGB.

METHODS

Twenty-four patients undergoing LAGB were prospectively enrolled. Body mass index (BMI) was measured and blood samples obtained at baseline and 6 and 12 months post-surgery. Plasma concentrations of leptin, acylated and total ghrelin, pancreatic polypeptide (PP), insulin, glucose-dependent insulinotropic peptide (GIP), active glucagon-like peptide-1 (GLP-1), gastrin, and pepsinogens I and II were measured using enzyme-linked immunoassays.

RESULTS

Median percent excess weight loss (%EWL) over 12 months was 45.7% with median BMI decreasing from 43.2 at baseline to 33.8 at 12 months post-surgery (p < 0.001). Median leptin levels decreased from 19.7 ng/ml at baseline to 6.9 ng/ml at 12 months post-surgery (p < 0.001). In contrast, plasma levels of acylated and total ghrelin, PP, insulin, GIP, GLP-1, gastrin, and pepsinogen I did not change in relation to surgery (p > 0.05). Pepsinogen II levels were significantly lower 6 months after LAGB but returned to baseline levels by 12 months.

CONCLUSIONS

LAGB yielded substantial %EWL and a proportional decrease in plasma leptin. Our results support the hypothesis that LAGB works in part by suppressing the rise in ghrelin that normally accompanies weight loss. Unchanged concentrations of insulinotropic and digestive hormones suggest that gastrointestinal endocrine function is largely maintained in the long term.