Plasma ghrelin concentrations in type 1 diabetic patients with autoimmune atrophic gastritis

Relationship between atrophic gastritis, serum ghrelin and body mass index

OBJECTIVE

Atrophic gastritis may affect circulating ghrelin levels and, indirectly, body mass index. The aim of this study was to investigate the relationship between atrophic gastritis, focusing on autoimmune atrophic gastritis and advanced stages of atrophic gastritis, serum ghrelin levels and BMI.

METHODS

Sixty-three patients, of whom 18 had autoimmune atrophic gastritis, 27 non-autoimmune antrum and corpus atrophic gastritis, and 18 non-atrophic gastritis or antrum-limited atrophic gastritis (control group) were assessed. All participants underwent endoscopy with multiple gastric biopsies. Atrophic gastritis was diagnosed by histology, classified according to the Updated Sydney System and staged by the Operative Link on Gastritis Assessment (OLGA) Classification. Total serum ghrelin, body weight and height were measured.

RESULTS

Compared with control patients (144.6 ± 111 pg/ml), mean serum level of total ghrelin was higher in patients with autoimmune atrophic gastritis (226.08 ± 243.03 pg/ml, P = 0.65) and lower in those with both antrum and corpus atrophic gastritis (74.51 ± 37.38 pg/ml, P = 0.12), although differences were not statistically significant. Serum ghrelin decreased in patients with advanced OLGA stages of atrophic gastritis. In non-obese patients BMI was significantly lower in those with both antrum and corpus atrophic gastritis than in control patients (23.1 ± 1.8 vs. 24.5 ± 1.6, P = 0.01), also after adjustment for age and sex (P = 0.02); BMI was positively correlated with serum total ghrelin (r = 0.51, P < 0.001).

CONCLUSION

Advanced stages of atrophic gastritis, but not autoimmune atrophic gastritis, seem to be associated with lower serum levels of ghrelin and lower BMI. In non-obese patients, BMI was positively correlated with total serum ghrelin.

Helicobacter pylori and nutrition: a bidirectional communication

Helicobacter pylori (HP) is a gram-negative flagellated pathogen acid-resistant bacterium; it belongs to the order Campylobacterales that is wide spread all over the world, infecting more than 50% of the world population. HP infection is etiologically associated with non-atrophic and atrophic gastritis, peptic ulcer and with 3 to 6-fold increased relative risk for developing gastric adenocarcinoma and mucosa-associated lymphoid tissue (MA LT) lymphoma. For this reason HP is recognized by the World Health Organization as a Class I human carcinogen. In the last years a lot of studies clarified the role of this pathogen in nutrition and metabolism; particularly, it has been shown that it is able to induce malabsorption of several nutrients like iron, cobalamin, vitamin C and vitamin E, with strong consequences on nutritional status. Interesting, this bacterium is able to produce different biological effects on hormones like ghrelin and leptin controlling both appetite and growth, mostly depending on the time of acquisition of the infection and of its treatment. In this review, the authors focused their attention on nutritional effects of HP infection and particularly on the role that diet, food, plants and specific nutrients can play in its treatment, considering that HP eradication rates, with standard triple-therapy, have fallen to a low level in the last years.

The Relations Among Serum Ghrelin, Motilin and Gastric Emptying and Autonomic Function in Autoimmune Gastritis

BACKGROUND

Gastric emptying (GE) of solids is delayed and autonomic dysfunction is detected in autoimmune gastritis (AIG). The goals of this study were to: (1) compare serum levels of ghrelin and motilin in subjects with delayed and normal GE and (2) investigate whether circulating antimyenteric antibodies (CAA), serum ghrelin levels and motilin levels have any effect on autonomic function.

MATERIALS AND METHODS

Noninvasive cardiovascular reflex tests were used in order to evaluate the autonomic function. GE was evaluated by a standard 2-hour scintigraphic test. Serum ghrelin and motilin levels were tested by enzyme-linked immunosorbent assay and CAA were tested by immunofluorescence.

RESULTS

The serum ghrelin and motilin levels in the patients with delayed GE (n = 22) were significantly decreased compared to the normal GE patients (n = 19), (67.55 ± 8.81 versus 126.79 ± 25.81pg/mL, P < 0.001 and 279.59 ± 111.12 versus 500.42 ± 155.95pg/mL, respectively, P < 0.001). Whereas, the serum ghrelin and motilin levels in the patients with deranged autonomic function (n = 26) were significantly decreased compared to the patients with normal autonomic function (n = 15), (80.73 ± 28.46 versus 127.79 ± 28.06pg/mL, P < 0.001 and 316.92 ± 160.47 versus 490.20 ± 141.02pg/mL, P < 0.001, respectively).  None of the patients were positive for CAA.

CONCLUSIONS

Ghrelin and motilin levels in AIG subjects with delayed GE and deranged autonomic function were significantly decreased. The decrease in serum ghrelin and plasma motilin levels in AIG suggest their potential role in the delayed GE observed in these subjects.

Ghrelin gene products in acute and chronic inflammation

Ghrelin gene products--the peptides ghrelin, unacylated ghrelin, and obestatin--have several actions on the immune system, opening new perspectives within neuroendocrinology, metabolism and inflammation. The aim of this review is to summarize the available evidence regarding the less known role of these peptides in the machinery of inflammation and autoimmunity, outlining some of their most promising therapeutic applications.

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.

Ghrelin in neuroendocrine tumors

Ghrelin is a 28 amino acid peptide, primarily produced by the oxyntic mucosa X/A like neuroendocrine cells in the stomach. It is also found in the small intestine, hypothalamus, pituitary gland, pancreas, heart, adipose tissue, and immune system. In gastrointestinal neuroendocrine tumors (NETs) ghrelin release has been well documented. Ghrelin is a brain-gut circuit peptide with an important role in the physiological regulation of appetite, response to hunger and starvation, metabolic and endocrine functions as energy expenditure, gastric motility and acid secretion, insulin secretion and glucose homeostasis, as well as in the potential connection to the central nervous system. Recently, there has been a significant interest in the biological effects of ghrelin in NETs. In this article, we present a comprehensive review of ghrelin's expression and a brief summary of ghrelin's physiological role in NETs patients with carcinoids, type A chronic atrophic gastritis (CAG), with or without MEN-1, and with and without liver metastases. We hope, with the research reviewed here, to offer compelling evidence of the potential significance of ghrelin in NETs, as well as to provide a useful guide to the future work in this area.

Serum autoimmune gastritis markers, pepsinogen I and parietal cell antibodies, in patients with type 1 diabetes mellitus: a 5-year prospective study

BACKGROUND AND AIM

To determine the temporal evolution of serum markers of autoimmune gastritis, mainly pepsinogen I (PI) and parietal cell antibodies (PCA), in patients with Type 1 diabetes mellitus (DM1).

MATERIALS AND METHODS

A 5-yr prospective follow-up study of 168 DM1 patients (87 men, aged 31 ± 9.3 yr) attending the endocrinology outpatient clinic of a university hospital evaluated in 2001 and 2006. Serum PI, gastrin, hemoglobin, cobalamin concentrations, PCA and antibodies to intrinsic factor were measured.

RESULTS

In 2001, 11 patients had low PI concentrations and positive PCA (group I), 11 had only low PI concentrations (group II), and 33 had only positive PCA (group III). After 5 yr, PI remained low and PCA positive in all patients from group I. In group II, PI remained low in 4 and normalized in 7. In group III, 4 patients presented low PI concentrations after 5 yr, which remained normal in the other 29 subjects. PCA became negative in 17 patients from group III. In 2001, 3 of the 11 patients of group I had low cobalamin concentrations. In 2006, 2 additional patients from this group presented low cobalamin concentrations.

CONCLUSIONS

These results show the importance of determining PI together with PCA, since the presence of abnormal results in both tests, that is low PI and positive PCA, is the association that best identifies patients with a higher risk to decrease cobalamin concentrations during follow-up.

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.

Regulatory T cells in type 1 diabetic patients with autoimmune chronic atrophic gastritis

Type A chronic atrophic gastritis (CAG) is increased in type 1 diabetic patients (DM1). To address this issue, we determined and analyzed the number of peripheral blood regulatory T cells (Tregs) in 15 DM1-CAG patients, 15 DM1 patients without associated autoantibodies (DM1) and 15 healthy controls by flow cytometry and compared gastric Tregs expression (CD4+Foxp3+/CD4+) in DM1-CAG patients with that observed in 10 control Helicobacter pylori CAG-infected biopsies. The percentage of peripheral Tregs was higher in DM1-CAG patients compared to DM1 and controls (CD4+Foxp3+: 7.67 +/- 1.91% vs. 5.38 +/- 1.57% and 5.65 +/- 1.76%, P < 0.001, respectively), with no differences between DM1 and controls. Gastric mucosal Tregs were higher in H. pylori CAG than in DM1-CAG patients (31.31 +/- 5.52% vs. 7.68 +/- 3.70%; P < 0.001). Data suggest that Tregs are stimulated in patients with more than one autoimmune disease (DM1 + CAG) in an ineffectual attempt to control autoimmune response and that the number of Tregs in gastric mucosa implicated in the chronification of gastritis differs according to the etiology.

Regulatory T cells in diabetes and gastritis

Patients with Type 1 diabetes mellitus (T1D) have an increased prevalence of associated organ-specific autoimmune diseases such as pernicious anemia whose histological substrate is a chronic atrophic gastritis (CAG). Latent pernicious anemia precedes clinically-manifest pernicious anemia and may be difficult to detect solely on simple analytical grounds. We recently described an increased prevalence of clinically-latent pernicious anemia in T1D using low concentrations of pepsinogen I, a zymogen of pepsin present in gastric mucosa, as a useful additional diagnostic marker, besides parietal cell antibodies, for screening latent pernicious anemia in T1D. The failure of peripheral tolerance mechanisms such as regulatory T cells (Treg) might be involved in CAG development in T1D patients. Indeed, functional defects in Tregs have been described in T1D patients. To this end, the percentage of Tregs in peripheral blood of T1D-CAG patients was analyzed and compared with those of a group of T1D without associated autoantibodies and a healthy control group. Tregs levels were also analyzed in gastric biopsies of T1D-CAG patients. The results obtained have led to new questions regarding the pathogenic mechanisms implicated in the development of associated autoimmune diseases in T1D.