Appetite and Gastrointestinal Hormone Response to a Gluten-Free Meal in Patients with Coeliac Disease

Circulating anti-hypothalamus antibodies in celiac patients: tissue transglutaminase friend or foe?

Celiac disease (CD) is an autoimmune disease with inflammatory characteristics, having a condition of chronic malabsorption, affecting approximately 1% of the population at any age. In recent years, a concrete correlation between eating disorders and CD has emerged. Hypothalamus plays a central role in determining eating behaviour, regulating appetite and, consequently, food intake. One hundred and ten sera from celiac patients (40 active and 70 following a gluten-free diet) were tested for the presence of autoantibodies against primate hypothalamic periventricular neurons by immunofluorescence and by a home-made ELISA assay. In addition, ghrelin was measured by ELISA. As control, 45 blood serums from healthy age matched were analysed. Among active CD, all patients resulted positive for anti-hypothalamus autoantibodies and sera showed significantly higher levels of ghrelin. All of the free-gluten CD were negative for anti-hypothalamus autoantibodies and had low levels of ghrelin, as well as healthy controls. Of interest, anti-hypothalamic autoantibodies directly correlate with anti-tTG amounts and with mucosal damage. In addition, competition assays with recombinant tTG showed a drastically reduction of anti-hypothalamic serum reactivity. Finally, ghrelin levels are increased in CD patients and correlated with anti-tTG autoantibodies and anti-hypothalamus autoantibodies. This study demonstrates for the first time the presence of anti-hypothalamus antibodies and their correlation with the severity of the CD. It also allows us to hypothesize the role of tTG as a putative autoantigen expressed by hypothalamic neurons.

Celiac Disease and Pregnancy Outcomes in Patients with Gestational Diabetes Mellitus

AIM

Gestational diabetes mellitus (GDM) and celiac disease, if not diagnosed and properly treated, are associated with adverse outcomes of pregnancy. The aim of our study was to examine pregnancies complicated by GDM in celiac and nonceliac women in terms of their metabolic parameters and maternal and fetal outcomes.

METHODS

The study involved 60 women with GDM, 20 with and 40 without celiac disease. Maternal clinical and metabolic parameters (glucose and insulin levels in the oral glucose tolerance test (OGTT), fasting plasma glucose, HbA1c, lipid profile, prepregnancy BMI, gestational weight gain, and chronic diseases), pregnancy outcomes (gestational hypertension, pre-eclampsia, eclampsia, time, and mode of delivery), and fetal parameters (weight and length at birth, and neonatal complications) were recorded.

RESULTS

The two groups did not differ significantly in maternal parameters other than blood glucose levels at 120' in the diagnostic OGTT (141.2 ± 35.2 vs 161.2 ± 35.4, mg/dl, p=0.047), prepartum cLDL (127.2 ± 43.5 vs 179.6 ± 31.7 mg/dl, p ≤ 0.001), and total cholesterol (229.0 ± 45.9 vs 292.5 ± 42.1 mg/dl, p ≤ 0.001), which were significantly lower in celiac women than in nonceliac controls. Children born from celiac women had a significantly higher birth weight (3458.1 ± 409.8 vs 3209.0 ± 432.7 g, p=0.044) and ponderal index (2.89 ± 0.32 vs 2.66 ± 0.25 g/cm3, p=0.006) and were more likely to be large for gestational age (27.8% vs 2.5%, p=0.012). Analyzing the composition of the celiac and nonceliac women's diet showed that, for the same amount of kilocalories, the gluten-free diet was associated with a slight increase in the amount of carbohydrates (49.75% vs 48.54%) and a reduction in the amount of protein (21.10% vs 23.31%) and especially of fiber (9.84% vs 12.71%).

CONCLUSIONS

Celiac women with GDM have much the same pregnancy outcomes as nonceliac women with GDM, except for fetal overgrowth. Gluten-free food, being richer in carbohydrates and less rich in fiber and protein, could have a role in fetal growth in celiac women.

Appetite, the enteroendocrine system, gastrointestinal disease and obesity

The enteroendocrine system is located in the gastrointestinal (GI) tract, and makes up the largest endocrine system in the human body. Despite that, its roles and functions remain incompletely understood. Gut regulatory peptides are the main products of enteroendocrine cells, and play an integral role in the digestion and absorption of nutrients through their effect on intestinal secretions and gut motility. Several peptides, such as cholecystokinin, polypeptide YY and glucagon-like peptide-1, have traditionally been reported to suppress appetite following food intake, so-called satiety hormones. In this review, we propose that, in the healthy individual, this system to regulate appetite does not play a dominant role in normal food intake regulation, and that there is insufficient evidence to wholly link postprandial endogenous gut peptides with appetite-related behaviours. Instead, or additionally, top-down, hedonic drive and neurocognitive factors may have more of an impact on food intake. In GI disease however, supraphysiological levels of these hormones may have more of an impact on appetite regulation as well as contributing to other unpleasant abdominal symptoms, potentially as part of an innate response to injury. Further work is required to better understand the mechanisms involved in appetite control and unlock the therapeutic potential offered by the enteroendocrine system in GI disease and obesity.