Sporadic and MEN1-related gastrinoma and Zollinger-Ellison syndrome: differences in clinical characteristics and survival outcomes

PURPOSE

Gastrinoma with Zollinger-Ellison syndrome (ZES) may occur sporadically (Sp) or as part of the inherited syndrome of multiple endocrine neoplasia 1 (MEN-1). Data comparing Sp and MEN-1/ZES are scanty. We aimed to identify and compare their clinical features.

METHODS

Consecutive patients with ZES were evaluated between 1992 and 2020 among a monocentric Italian patient cohort.

RESULTS

Of 76 MEN-1 patients, 41 had gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN), 18 of whom had ZES; of 320 Sp-GEP-NEN, 19 had Sp-ZES. MEN-1/ZES patients were younger (p = 0.035) and the primary MEN-1/ZES gastrinoma was smaller than Sp-ZES (p = 0.030). Liver metastases occurred in both groups, but only Sp-ZES developed extrahepatic metastases. 13 Sp-ZES and 8 MEN-1/ZES underwent surgery. 8 Sp-ZES and 7 MEN-1/ZES received somatostatin analogs (SSAs). Median overall survival (OS) was higher in MEN-1/ZES than in Sp-ZES (310 vs 168 months, p = 0.034). At univariate-logistic regression, age at diagnosis (p = 0.01, OR = 1.1), G3 grading (p = 0.003, OR = 21.3), Sp-ZES (p = 0.02, OR = 0.3) and presence of extrahepatic metastases (p = 0.001, OR = 7.2) showed a significant association with OS. At multivariate-COX-analysis, none of the variables resulted significantly related to OS. At univariate-logistic regression, age (p = 0.04, OR = 1.0), size (p = 0.039, OR = 1.0), G3 grade (p = 0.008, OR = 14.6) and extrahepatic metastases (p = 0.005, OR = 4.6) were independently associated with progression-free survival (PFS). In multivariate-COX-analysis, only extrahepatic metastases (p = 0.05, OR = 3.4) showed a significant association with PFS. Among SSAs-treated patients, MEN-1/ZES showed better PFS (p = 0.0227). After surgery, the median PFS was 126 and 96 months in MEN-1 and Sp, respectively.

CONCLUSION

MEN-1/ZES patients generally show better OS and PFS than Sp-ZES as well as better SSAs response.

Relevance of vitamin D deficiency in patients with chronic autoimmune atrophic gastritis: a prospective study

Background

Chronic autoimmune atrophic gastritis (CAAG) is an autoimmune disease characterized by hypo/achlorhydria. A role of CAAG in the pathogenesis of nutritional deficiencies has been reported, therefore we hypothesized a possible association between CAAG and 25-OH-Vitamin D [25(OH)D] deficiency. Aim of the present study is to evaluate the prevalence of 25(OH)D deficiency in CAAG patients. Methods: 87 CAAG patients (71 females; mean age 63.5 ± 12.8 years) followed at our Centre from January 2012 to July 2015 were consecutively evaluated. 25(OH)D, vitamin B₁₂, parathormone, and calcium were measured in all the CAAG patients. The results were compared with a control group of 1232 healthy subjects.

Results

In the CAAG group the mean 25(OH)D levels were significantly lower than in the control group (18.8 vs. 27.0 ng/ml, p < 0.0001). 25(OH)D levels < 20 ng/ml was observed in 57 patients, while levels < 12.5 ng/ml in 27 patients. A significant correlation between vitamin B₁₂ values at diagnosis and 25(OH)D levels was observed (r_s = 0.25, p = 0.01). Interestingly, the CAAG patients with moderate/severe gastric atrophy had lower 25(OH)D values as compared to those with mild atrophy (11.8 vs. 20 ng/ml; p = 0.0047). Moreover, the 25(OH)D levels were significantly lower in CAAG patients with gastric carcinoid as compared to those without gastric carcinoid (11.8 vs. 19.8 ng/ml; p = 0,0041).

Conclusion

Data from the present study showed a significant reduction of 25(OH)D levels in CAAG patients and a possible impairment of vitamin D absorption in CAAG may be postulated. Any implication to the genesis of gastric carcinoids remains to be elucidated.

Chromogranin A and other enteroendocrine markers in inflammatory bowel disease

Changes in the distribution and products of enteroendocrine cells may play a role in immune activation and regulation of gut inflammation. This review aims at critically evaluating the main enteroendocrine markers in inflammatory bowel diseases (IBD). A narrative review was performed by searching inflammatory bowel diseases and enteroendocrine biomarkers in PubMed. Relevant modifications of some enteroendocrine markers, such as Chromogranin A, and their correlation with disease activity have been reported in patients with inflammatory bowel diseases. Even if data about neuroendocrine markers are sometimes contrasting, they may be potentially useful for the diagnosis and clinical management of these patients.

Intermittent treatment of recurrent type-1 gastric carcinoids with somatostatin analogues in patients with chronic autoimmune atrophic gastritis

BACKGROUND

Optimal management and treatment of type-1 gastric carcinoids is under debate.

AIMS

This prospective study evaluates the outcome of patients with recurrent type-1 gastric carcinoids treated with somatostatin analogues.

METHODS

From 2000 to 2013, among a population of 107 chronic atrophic gastritis patients, 25 (20% males, median age 62 years) developed type-1 gastric carcinoids and underwent regular clinical and endoscopic follow-up (median 77 months, range 6-165) after the initial treatment. Those patients showing recurrent disease were treated with somatostatin analogues until carcinoid disappearance.

RESULTS

12/25 patients (33% males, median age 65 years) showed recurrent gastric carcinoids and were treated with somatostatin analogues for a median duration of 12 months. Median gastrin and chromogranin A levels, which were 802 pg/mL and 33 U/L, respectively, decreased to 299 pg/mL (p=0.002) and 15.6 U/L (p=0.001) at the end of the treatment. Gastric carcinoids disappeared after a median length of treatment of 12 months. After a median time of 19.5 months from somatostatin analogues discontinuation, 4/12 patients (25% males, median age 56 years) showed a further recurrence. A new cycle of treatment was performed successfully.

CONCLUSIONS

This study confirms that type-1 gastric carcinoids are a recurring disease and somatostatin analogues, administered on 12-month cycles, represent an effective treatment.

Therapy for metastatic pancreatic neuroendocrine tumors

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs) are frequently malignant (50-80%, except for insulinoma) and may show an aggressive course with metastases to the liver as well as more distant sites. These heterogeneous neoplasms include functioning tumors, which secrete a variety of peptide hormones, and non-functioning tumors (up to 90% of pNETs), which often show metastases at the time of diagnosis.

METHODS

A PubMed search was performed for English-language publications from 1995 through December 2012. Reference lists from studies selected were manually searched to identify further relevant reports. Manuscripts comparing different therapeutic options and advances for metastatic pNETs were selected.

RESULTS

The therapeutic options for metastatic pNETs are expanding and include surgery, which remains the only curative approach, liver-directed therapies, and medical therapy. In selected cases also liver transplantation (OLT) may be considered. The option of OLT for metastatic disease is unique to neuroendocrine tumors. Recently, novel promising targeted therapies have been proposed for progressive well-differentiated pNETs.

CONCLUSIONS

The best therapeutic approach for pNETs is still matter of debating. However, since pNETs often show a more indolent behavior compared to other malignancies, the preservation of the quality of life of the patient and the personalization of the therapy according to tumor's and patient's features are mandatory.

Chromogranin A in diagnosing and monitoring patients with gastroenteropancreatic neuroendocrine neoplasms: a large series from a single institution

BACKGROUND/AIMS

Plasma chromogranin A (CgA) is the most widely used biochemical biomarker in the diagnostic workup and follow-up of gastroenteropancreatic neuroendo- crine neoplasms (GEP-NENs). Herein, we assessed the clinical utility of CgA in diagnosing and monitoring a large series of GEP-NENs.

PATIENTS AND METHODS

A total of 181 GEP-NEN patients (87 males, 94 females) with pancreatic (n = 81) and gastrointestinal neoplasms (n = 100) were included; 99 patients had grade (G)1 NENs (Ki-67 ≤2%), 57 G2 NENs (Ki-67 3-20%) and 25 G3 NENs (Ki-67 >20%); 81 patients had tumor-node-metastasis (TNM) stage I, 14 stage II, 17 stage III and 69 stage IV cancer. For every patient, CgA values were assessed at diagnosis and during follow-up.

RESULTS

At diagnosis, the CgA values were above the upper reference limit in 148 patients (82%); the median CgA levels were significantly higher in functioning than in nonfunctioning tumors (295 vs. 43 U/l; p = 0.0001) as well as significantly higher in patients with metastases than in those without metastases (324.5 vs. 42 U/l; p = 0.0001). In logistic regression analysis, baseline CgA levels were significantly associated with Ki-67 index (p < 0.0001) and TNM stage (p < 0.0001) independently of the age and sex of the patient and the primary site of the tumor. The overall 5- and 10-year survival rates were 74 and 64.5%, respectively. A low Ki-67 index, the type of treatment and an early CgA decrease after treatment were positively correlated with the survival rate. After radical surgery, 15/95 patients relapsed, and an increase in CgA values anticipated the clinical and objective disease recurrence after a period of 9-12 months.

CONCLUSIONS

In GEP-NENs, plasma CgA has a significant prognostic relevance.

Chronic autoimmune atrophic gastritis associated with primary hyperparathyroidism: a transversal prospective study

DESIGN

The coexistence of chronic autoimmune atrophic gastritis (CAAG) and primary hyperparathyroidism (PHPT) has been described previously, even if its extent and underlying mechanisms remain poorly understood. We therefore prospectively evaluated this association in two series of patients, one with CAAG and the other with sporadic PHPT.

METHODS

From January 2005 to March 2012, 107 histologically confirmed CAAG patients and 149 PHPT patients were consecutively enrolled. Routine laboratory assays included serum calcium, parathyroid hormone (PTH), plasma gastrin and chromogranin A (CgA). In CAAG patients with high PTH levels, ionized calcium and 25(OH)-vitamin D were evaluated. All CAAG and hypergastrinemic PHPT patients received an upper gastrointestinal endoscopy. Exclusion criteria were familial PHPT, MEN1 syndrome, treatment with proton pump inhibitor drugs, Helicobacter pylori infection and renal failure.

RESULTS

Of the 107 CAAG patients, nine (8.4%) had PHPT and 13 (12.1%) had secondary hyperparathyroidism stemming from vitamin D deficiency. Among the 149 PHPT patients, 11 (7.4%) had CAAG. Gastrin and CgA levels were similar in the CAAG patients with vs those without hyperparathyroidism (either primary or secondary), and calcium and PTH levels were similar in the PHPT patients with vs those without CAAG.

CONCLUSIONS

This study confirms a non-casual association between PHPT and CAAG. The prevalence of PHPT in CAAG patients is threefold that of the general population (8.4 vs 1-3%), and the prevalence of CAAG in PHPT patients is fourfold that of the general population (7.4 vs 2%). The mechanisms underlying this association remain unknown, but a potential role for autoimmunity is suggested.

Contrast-enhanced ultrasonography in evaluating hepatic metastases from neuroendocrine tumours

OBJECTIVES

At presentation, gastroenteropancreatic neuroendocrine tumours (GEP NETs) frequently show prognostically negative hepatic involvement. The aim of this study was to characterise hepatic metastases of GEP NETs as revealed by contrast-enhanced ultrasonography (CEUS), which allows the fine definition of the microvascular system, and to correlate these findings to the biological behaviour of the tumour.

METHODS

Eighteen out of 62 GEP NET patients examined between January 2007 and September 2008 had histologically proven hepatic metastases from primary ileal (#6), gastric (#1) or rectal (#1) carcinoids, pancreatic tumours (#7), or primary duodenal (#2) or occult gastrinomas (#1), and all underwent low mechanical index real-time CEUS with SonoVue injection.

RESULTS

Strong early enhancement in the arterial phase was observed in 15 cases (83%), and a rapid wash-out in the portal venous phase in 14 (78%). In the late venous phase, the lesions were hypoechoic in 12 cases (67%), isoechoic in five (28%), and hyperechoic in one (0.05%). The time of arterial enhancement correlated with the Ki-67 proliferative index (r(s)=0.516; p=0.028).

CONCLUSIONS

Most of the neuroendocrine liver metastases showed increased arterial enhancement at CEUS, a behaviour that is similar to that of hepatocellular carcinomas and the opposite of that of other metastases. CEUS can be a useful diagnostic means of characterising such metastases.

Plasma chromogranin a in patients with inflammatory bowel disease

BACKGROUND

Circulating chromogranin A (CgA) levels, a marker for neuroendocrine tumors including carcinoids, have recently been found elevated in some patients with inflammatory bowel disease (IBD), although their significance is unclear. Therefore, we aimed to evaluate CgA levels and their possible relationship with clinical and biochemical disease activity indexes in 119 IBD patients.

METHODS

The study groups comprised 75 patients with ulcerative colitis, 44 with Crohn's disease, in both active and quiescent phases, and 85 controls.

RESULTS

Mean CgA levels were significantly higher in IBD patients than in controls (20.4 +/- 14.0 [SD] versus 11.3 +/- 4.3 U/L, P < 0.001), without any statistical significant difference among the IBD subgroups. However, CgA levels were above the normal range (20 U/L) in 25/45 patients with active IBD (55%; 95% confidence interval [CI]: 40%-70%) and in 18/74 patients with remission IBD (24%; 95% CI: 15%-36%) (P < 0.001, Fisher's test). Among biochemical parameters, CgA correlated with serum TNF-alpha levels (r(s) = 0.398, P < 0.001).

CONCLUSIONS

High CgA levels can occur in IBD. The disease activity and TNF-alpha levels seem to influence the CgA pattern, which could reflect the neuroendocrine system activation in response to inflammation. From a clinical point of view, the possibility of high CgA levels in IBD should be taken into consideration when a carcinoid is suspected in such patients, since this event seems to be more frequent than previously considered. Indeed, revision of our 83 patients with gastrointestinal carcinoids, studied between 1997 and 2006, showed that 4 patients had IBD, with a prevalence of 4.8%, which is markedly higher than that of the general population.

Gastric carcinoids: Between underestimation and overtreatment

Gastric carcinoids (GCs), which originate from gastric enterochromaffin-like (ECL) mucosal cells and account for 2.4% of all carcinoids, are found increasingly in the course of upper gastrointestinal tract endoscopy. Current nosography includes those occurring in chronic conditions with hypergastrinemia, as the type 1 associated with chronic atrophic gastritis, and the type 2 associated with Zollinger-Ellison syndrome in multiple endocrine neoplasia type 1, and type 3, which is unrelated to hypergastrinemia and is frequently malignant, with distant metastases. The optimal clinical approach to GCs remains to be elucidated, depending upon type, size and number of carcinoids. While there is agreement concerning the treatment of type 3 carcinoids, for types 1 and 2, current possibilities include simple surveillance, endoscopic polypectomy, surgical excision, associated or not with surgical antrectomy, or total gastrectomy. Moreover, the recent introduction of somatostatin analogues represents a therapeutic option of possibly outstanding relevance.

Neuroendocrine tumors of the gastro-entero-pancreatic system

Gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs) are rare neoplasms, although their prevalence has increased substantially over the past three decades. Moreover, there has been an increased clinical recognition and characterization of these neoplasms. They show extremely variable biological behavior and clinical course. Most NETs have endocrine function and secrete peptides and neuroamines that cause distinct clinical syndromes, including carcinoid syndrome; however, many are clinically silent until late presentation with mass effects. Investigation and management should be individualized for each patient, taking into account the likely natural history of the tumor and general health of the patient. Management strategies include surgery for cure or palliation, and a variety of other cytoreductive techniques, and medical treatment including chemotherapy, and biotherapy to control symptoms due to hormone release and tumor growth, with somatostatin analogues (SSAs) and alpha-interferon. New biological agents and somatostatin-tagged radionuclides are under investigation. Advances in the therapy and development of centers of excellence which coordinate multicenter studies, are needed to improve diagnosis, treatment and therefore survival of patients with GEP NETs.

Evaluation of IGF-I levels during long-term somatostatin analogs treatment in patients with gastroenteropancreatic endocrine tumors

Previous experiments reported desensitization to SS action in rat anterior pituitary cells and cell lines. The aim of the study was to verify whether the lack of desensitization to SS analogs (SSa) observed in acromegalic patients was also present in subjects with normal hypothalamic-pituitary function. The effect of chronic treatment with octreotide long-acting release (o-LAR, 10-30 mg/28 days) on IGF-I levels was then evaluated in 23 patients with gastroenteropancreatic (GEP) endocrine tumors (8 gastrinomas, 6 carcinoids, and 9 functioning pancreatic tumors). Serum IGF-I, clinical symptoms, plasma chromogranin-A (CgA) and markers of hepatic synthesis were evaluated before and after a short-term period in all the patients (median 4.5 months), after a medium-term period in 12 (median 18 months) and after a long-term follow-up period in 9 of them (median 48 months). Mean IGF-I levels decreased from 17.3+/-7.0 to 12.8+/-6.2 nmol/l in the short-term (p<0.005) being reduced from baseline concentrations in 87% and under the normal range for age in 35% of patients. Afterwards, they always remained stable both in the medium- and long-term periods, still being low in 3/12 and 2/9 patients, respectively. No alterations in biochemical markers of liver function were found either before or during therapy. No correlation between IGF-I levels, CgA concentrations and/or clinical definitive outcome was observed. In conclusion, the study demonstrated that: a) similarly to that observed in acromegalic patients, chronic o-LAR treatment did not induce desensitization of pituitary SS receptors (SSR) in humans with intact hypothalamic-pituitary axis, and b) in patients with GEP endocrine tumors, GH/IGF-I inhibition did not contribute to SSa efficacy.

New insights into the pathophysiology of cobalamin deficiency

Cobalamin-deficient (Cbl-D) central neuropathy in the rat is associated with a locally increased expression of neurotoxic tumour necrosis factor-alpha (TNF-alpha) and a locally decreased expression of neurotrophic epidermal growth factor (EGF). These recent findings suggest that cobalamin oppositely regulates the expression of TNF-alpha and EGF, and raise the possibility that these effects might be independent of its coenzyme function. Furthermore, adult Cbl-D patients have high levels of TNF-alpha and low levels of EGF in the serum and cerebrospinal fluid. Serum levels of TNF-alpha and EGF of cobalamin-treated patients normalize concomitantly with haematological disease remission. These observations suggest that cobalamin deficiency induces an imbalance in TNF-alpha and EGF levels in biological fluids that might have a role in the pathogenesis of the damage caused by pernicious anaemia.

Hypokalemic rhabdomyolysis without watery diarrhea: an unexpected presentation of a pancreatic neuro-endocrine tumor

Pancreatic polypeptide (PP) islet cell tumors are usually not associated with a distinct clinical syndrome, although some reports suggest that they can cause a watery diarrhea syndrome similar to vasoactive intestinal polypeptide (VIP) cell tumors. We report the case of a young woman with an unusual presentation of a pancreatic neuroendocrine tumor mainly secreting PP. The patient developed a reversible hypokalemic rhabdomyolysis very likely secondary to the presence of the tumor. The myopathy resolved following the restoration of normokaliemia using potassium supplementation and a partial laparoscopic pancreasectomy. Isolated cases of hypokalemic rhabdomyolysis induced by intestinal diseases have been described in literature but these did not include gastroenteropancreatic neoplasms. We suggest that pancreatic neuroendocrine tumors should be added to the list of intestinal diseases capable of producing hypokalemic myopathy.

A follow-up study of patients with Zollinger-Ellison syndrome in the period 1966-2002: effects of surgical and medical treatments on long-term survival

AIM

To evaluate the clinical history of a series of patients with Zollinger-Ellison syndrome (ZES) in the period 1966 to 2002, before and after the introduction of the current antisecretive H2 receptor antagonists and proton pump inhibitors into clinical practice.

PATIENTS AND METHODS

The study involved 18 ZES patients (9 males; mean age, 43 years; range, 12-70 years), 8 with Type 1 multiple endocrine neoplasia (MEN-1), diagnosed on the basis of standard criteria. We considered the type, number and effectiveness of surgical interventions before and after appropriate treatment, the localization of the gastrinoma, the presence of associated diseases, the causes of death, and the duration of survival.

RESULTS

Total gastrectomy (but not antrectomy and vagotomy) and full compliance to antisecretory treatment reduced the number of operations from 29 to 9. One patient was cured (5.5%), whereas relapsing gastrinomas occurred in 4 patients and associated diseases or complications in ten. Death was related to ZES in 5 patients and to other causes in 4.

CONCLUSIONS

Curing gastrinoma or appropriately inhibiting gastric acid hypersecretion in ZES patients prevent death and favors long-term survival, regardless of gastrin levels and the size or number of tumors.

Cerebellar degeneration and hearing loss in a patient with idiopathic myenteric ganglionitis

A 35-year-old male with an 11-year history of intestinal pseudo-obstruction associated with an idiopathic inflammatory insult of the myenteric plexus and the presence of circulating anti-Hu antibodies developed a neurological syndrome characterized by bilateral hearing loss, deteriorating balance, an unsteady gait and difficulty in estimating distances. A similar neurological syndrome has previously been described in older patients among the paraneoplasic syndromes associated with small-cell lung carcinoma and the presence of circulating anti-Hu antibodies, but never in the rare cancer-free patients with anti-Hu-associated chronic idiopathic intestinal pseudo-obstruction. The patient underwent a steroid treatment. No further episodes of functional intestinal obstruction were observed and, after an initial improvement, the neurological symptoms stabilized, leaving a permanent reduction in hearing function and an unsteady gait. The case shows that an idiopathic inflammatory insult of the myenteric plexus may precede (and perhaps lead to) central nervous system impairment in patients with anti-Hu-associated chronic idiopathic intestinal pseudo-obstruction.

Plasma chromogranin A in patients with autoimmune chronic atrophic gastritis, enterochromaffin-like cell lesions and gastric carcinoids

OBJECTIVE

In atrophic body gastritis (ABG) chronic hypergastrinaemia stimulates enterochromaffin-like (ECL) cell proliferation with development of cell hyperplasia, dysplasia and possibly type-1 gastric carcinoids. As circulating chromogranin A (CgA) levels are a marker of neuroendocrine tumours, we evaluated the clinical usefulness of CgA assay in ABG patients to detect those with carcinoids.

DESIGN AND METHODS

Plasma CgA levels were measured using a commercial ELISA in 45 healthy volunteers, nine patients with type-1 gastric carcinoids and 43 consecutive ABG patients (21 without and 22 with ECL cell hyperplasia/dysplasia).

RESULTS

CgA levels were significantly higher in ABG patients with and without gastric carcinoids than in healthy subjects (P < 0.001). The highest values occurred in patients with carcinoids (median (interquartile range): 58.1 (44.5-65.3) U/l) and with ECL cell hyperplasia/dysplasia (35.5 (31.8-48.65) U/l) but there were no significant differences in CgA among the various subgroups of ABG patients classified according to ECL cell status. Nevertheless, in ABG patients without carcinoids CgA values correlated with the presence and severity of ECL cell lesions (r(s) = 0.428, P < 0.01). The sensitivity and specificity of the CgA assay in identifying patients with carcinoids were 100 and 23% respectively.

CONCLUSIONS

CgA plasma levels reflect the histological degree of ECL cell lesions in patients with ABG but the assay specificity is too low to detect among these patients those with gastric carcinoids.

Searching for coeliac disease in patients with non-alcoholic fatty liver disease

BACKGROUND

A non-negligible percentage of patients with non-alcoholic fatty liver disease, a leading cause of hepatic progressive disorder related to insulin resistance, have no metabolic risk factors, and abnormal intestinal permeability has been suggested to be involved in the pathogenesis of the liver damage. Coeliac disease, a curable disorder characterised by inflammatory mucosal damage, may show hepatic histological features similar to steatohepatitis. Conflicting data have been reported on the prevalence of coeliac disease in non-alcoholic steatohepatitis.

AIM

To search for coeliac disease in a series of patients with non-alcoholic fatty liver disease by screening with anti-tissue transglutaminase and anti-endomysium antibodies.

PATIENTS AND METHODS

Fifty-nine consecutive patients with hypertransaminasemia and non-alcoholic fatty liver disease, 38 (64%) with steatohepatitis. Anti-endomysium antibodies were assayed by indirect immunofluorescence, IgA anti-tissue transglutaminase by ELISA. Patients who tested positive underwent HLA DQ typing and endoscopy.

RESULTS

Tissue transglutaminase antibodies were positive in six (10%) patients and anti-endomysium in two (3.4%); only two (3.4%), positive for both anti-endomysium positive and anti-transglutaminase, resulted to have coeliac disease based on histological findings. After 6 months of gluten-free diet, liver enzymes normalised.

CONCLUSIONS

The prevalence of silent coeliac disease is 3.4% in patients with non-alcoholic fatty liver. The inclusion of anti-endomysium antibodies test in studying patients with non-alcoholic fatty liver and persistent biochemical abnormalities has to be taken into account, since positivity for tissue transglutaminase antibodies, in the absence of confirmatory anti-endomysium antibodies, is not sufficient to perform diagnostic endoscopy.

Gallstone disease and related risk factors in a large cohort of diabetic patients

BACKGROUND AND AIM

The aim of this study of a large cohort of consecutive patients with diabetes mellitus was to investigate the still controversial questions concerning the prevalence and possible risk factors of gallstone disease in diabetics.

PATIENTS AND METHODS

We enrolled 1337 consecutive patients (710 males aged 63 +/- 11 years and 627 females aged 65 +/- 11 years), of whom 1235 (92%) had type 2 and 102 (8%) had type 1 diabetes mellitus. The data were statistically analysed using multiple logistic regression analysis.

RESULTS

The prevalence of gallstone disease was significantly higher in diabetics than in the general population with comparable characteristics (MICOL study) (332/1337 (24.8%) versus 4083/29684 (13.8%); z = 11.208, P = 0.0001) and this difference maintained its statistical significance even when only the North Italian centers involved in this nation-wide survey were considered (332/1337 (24.8%) versus 2469/18091 (13.6%); z = 11.225, P = 0.0001). A total of 332 diabetics (25%) had gallstone disease: 261 had stone(s) and 71 had previously undergone cholecystectomy for gallstone disease after a diagnosis of diabetes mellitus. The prevalence of gallstone disease was higher in the females (29% versus 22%, P = 0.003), and increased with age (13, 20 and 30% in patients aged < or = 40, 41-65 and > 65 years, respectively; P = 0.001), body mass index (24% in patients with a body mass index of < or = 30 and 30% in those with a body mass index of > 30 kg/m2; P = 0.001) and a positive family history of gallstone disease (31% versus 23%; P = 0.001). Gallstone disease was not significantly related to the type of diabetes, plasma total and HDL cholesterol and triglyceride levels, alcohol intake, smoking habits, physical activity, weight reduction in the last year, the use of oral contraceptives, parity or menopause. At multivariate analysis, increasing age, a higher body mass index and a positive family history maintained their statistical significance.

CONCLUSIONS

In patients with type 1 or type 2 diabetes mellitus, the prevalence of gallstone disease was significantly related to age, body mass index and a family history of gallstone disease.

High tumor necrosis factor-? in levels in cerebrospinal fluid of cobalamin-deficient patients

We studied 14 patients with neurological manifestations of subacute combined degeneration (SCD) and 40 control patients not cobalamin (Cbl)-deficient. The cerebrospinal fluid (CSF) markers of Cbl deficiency (Cbl and total homocysteine [tHCYS] levels) and the CSF levels of tumor necrosis factor (TNF)-alpha and epidermal growth factor (EGF) were measured. Significantly higher levels of tHCYS and TNF-alpha, and significantly lower levels of Cbl and EGF were found in the SCD patients. In human CSF, as in human serum and the rat central nervous system, decreased Cbl concentrations are concomitant with an increase in TNF-alpha and a decrease in EGF-levels. Ann Neurol 2004;56:886-890.

Ghrelin administration affects circulating pituitary and gastro-entero-pancreatic hormones in acromegaly

OBJECTIVE

Ghrelin, a gut-brain peptide involved in the control of energy homeostasis, affects antero-pituitary and gastro-entero-pancreatic (GEP) hormone secretion in healthy subjects. We aimed to verify whether such hormonal responses are retained in acromegaly, a disease characterized by high GH, subnormal ghrelin and abnormal GEP hormone levels.

DESIGN AND METHODS

The effect of ghrelin (3.3 microg/kg given after overnight fasting as an i.v. bolus) on GH, prolactin (PRL), adrenocorticotropin (ACTH), cortisol, insulin, glucose, total somatostatin (SS) and pancreatic polypeptide (PP) circulating levels were evaluated in seven non-diabetic patients with newly diagnosed acromegaly and in nine healthy controls.

RESULTS

Ghrelin elicited a prompt, marked increase of serum GH and PRL levels in all normal (from 1.6+/-0.6 to 52.9+/-7.8 and from 9.7+/-0.8 to 24.2+/-4.8 microg/l (means+/-S.E.M.), respectively) and acromegalic subjects (from 11.2+/-4.9 to 91.6+/-21.0 and from 42.9+/-26.1 to 113.8+/-79.0 microg/l, respectively). Both plasma ACTH and serum cortisol levels rose significantly in the controls, whereas the cortisol response was blunted in the acromegalic patients. Glucose levels rose earlier and insulin levels fell later in all subjects, with a significantly greater net insulin decrease in acromegalic than in healthy subjects (-80+/-21 vs -17+/-4 pmol/l, P<0.01). A prompt PP rise and a biphasic SS response occurred in all controls, whereas in the acromegalic group the PP response (from 26.1+/-5.0 to 92.2+/-39.0 pmol/l) and the SS response (from 11.9+/-3.0 to 19.7+/-4.0 ng/l) were quite variable.

CONCLUSIONS

Ghrelin affects both pituitary and GEP hormones in acromegalic patients as in normal subjects. These findings suggest that ghrelin actions on the energy balance are mediated by complex interactive endocrine loops that involve also the gut and pancreas.

Circulating ghrelin levels in celiac patients

OBJECTIVE

Ghrelin, the gut-brain peptide, recently identified as the natural endogenous ligand for growth hormone secretagogue receptors, exerts various endocrine and nonendocrine effects, including the control of energy homeostasis and food intake, but its possible relevance in malabsorption syndromes is unknown. Therefore, the aim of this study was to evaluate circulating ghrelin levels in adults with untreated and treated celiac disease (CD) and, for comparison, in healthy subjects.

METHODS

Fasting serum ghrelin levels were measured in 30 consecutive patients with newly diagnosed CD, 13 celiac patients successfully treated with a gluten-free diet (GFD), and 30 healthy controls.

RESULTS

Ghrelin levels were abnormally high in patients with active CD compared with controls (297 +/- 17.6 vs 218 +/- 15.2 pmol/L, p<0.01) and correlated positively with intestinal mucosal lesion severity (rs=0.444, p<0.02). In the successfully GFD-treated patients, ghrelin values were normal compared with controls (233 +/- 22.0 vs 218 +/- 15.2 pmol/L, ns) and, moreover, correlated negatively with body mass index (r=-0.632, p=0.02), unlike in the untreated patient group (r=-0.263, ns).

CONCLUSION

High ghrelin levels characterized our series of adult patients with newly diagnosed CD and correlated significantly with the degree of severity of intestinal mucosal lesions. This is the first evidence of a relationship between ghrelin and inflammatory processes, but the mechanisms involved are still unclear. Furthermore, our findings suggest that an interplay of hormonal, metabolic, and nutritional factors could influence ghrelin secretion under pathophysiological circumstances.

Circulating ghrelin levels in patients with pancreatic and gastrointestinal neuroendocrine tumors: identification of one pancreatic ghrelinoma

Ghrelin is a novel gastrointestinal hormone involved in several metabolic functions. Although the expression of ghrelin has been demonstrated in most gastrointestinal carcinoids and pancreatic tumors, the circulating levels of this peptide have been marginally assessed in patients with these disorders. We measured plasma ghrelin levels in 16 patients with gastrointestinal carcinoid (10 with midgut and 6 with gastric carcinoid), 24 patients with pancreatic tumor (8 with gastrinoma, 2 with insulinoma, 2 with vipoma, 1 with glucagonoma, and 11 with nonfunctioning tumor), and 35 healthy controls. Plasma ghrelin levels recorded in patients with gastroenteropancreatic tumors were similar to controls (mean +/- SE, 182.7 +/- 66.5 pM in patients vs. 329 +/- 32 pM in controls, P = not significant), and no significant difference between gastrointestinal and pancreatic, functioning and nonfunctioning, and metastatic and nonmetastatic tumors was observed. One patient with metastatic nonfunctioning pancreatic tumor had circulating ghrelin levels of 12,000 pM that were slightly reduced during chemotherapy and interferon therapy. Immunohistochemistry performed on peritoneal lesions showed an intense, focal cytoplasmic positivity for ghrelin. Despite the 50-fold increase in ghrelin concentrations, the patient had normal serum GH and IGF-I levels. In conclusion, the study showed that carcinoids and pancreatic tumors rarely cause ghrelin hypersecretion. However, in this series, 1 pancreatic ghrelinoma not associated with clinical features of acromegaly was identified.

Elevated circulating somatostatin levels in acromegaly

GH increases hypothalamic somatostatin (SS) synthesis and secretion but it is unknown if chronic GH excess, as found in acromegaly, may influence circulating SS levels, that are mainly of enteropancreatic source and affect several gastrointestinal functions, including motility. Circulating SS occurs in several post-translational forms including somatostatin-14 (SS-14), somatostatin-28 (SS-28) and other small peptides. The aim of the present study was to characterize the fasting and postprandial pattern of plasma circulating somatostatin in normal subjects and patients with acromegaly. Fasting total SS and SS-28 levels were measured in 32 subjects, 16 acromegalic patients with a new diagnosis (A) (8 F, 8 M, median age 48) and 16 matched healthy volunteers (C) (8 F, 8 M, median age 45). SS was also determined after a standard solid-liquid meal (550 kCal) in 24 of the subjects (12 C and 12 A). Fasting SS and SS-28 were significantly higher in acromegalic patients as compared to healthy subjects. In the former, a positive correlation was found between IGF-I and SS levels (r = 0.525 p < 0.05). Furthermore, the ratio between SS (as pmol equivalent SS-14/I) and SS-28 was higher in the acromegalic patients than in the controls (3.4 +/- 2.1 vs 2.0 +/- 1.6, p < 0.05). The postprandial SS peak, as well as the incremental area above baseline values, was similar in the patients and controls. In conclusion, fasting but not postprandial hypersomatostatinemia, mainly due to an increase in SS-14, characterizes acromegaly. Excess GH/IGF-I could be a causal factor in somatostatin hypersecretion. Conceivably this abnormality might play a role in some alterations of gastrointestinal function of acromegalic patients such as prolonged bowel transit.

Stimulatory effects of ghrelin on circulating somatostatin and pancreatic polypeptide levels

Ghrelin, the recently identified endogenous ligand of the GH secretagogue receptor, is a gut-brain peptide with endocrine, orexigenic, and gastrointestinal effects. In rodents it increases circulating gastrin and insulin levels, whereas in man it appears to decrease insulin secretion despite a rise in blood glucose levels. The aim of the present study was to evaluate the effects of ghrelin administration on total circulating somatostatin (SS), pancreatic polypeptide (PP), and gastrin levels compared with those elicited on insulin, glucose, and GH. Eight healthy volunteers of normal weight (four women and four men) were injected with 3.3 microg/kg ghrelin or saline after an overnight fast on 2 different days. Blood was taken every 15 min for 1 h and then every 30 min for 2 h. As expected, ghrelin injection elicited a prompt GH and glucose increase with a peak at 30 min and an insulin decrease with a nadir at 60 min. Gastrin concentrations were not modified, whereas significant rises were observed in both SS (in a biphasic pattern with peaks at 15 and 120 min) and PP (which increased promptly with a peak at 15 min). A significant negative correlation was found between SS (first peak) and insulin changes (r = -0.86; P < 0.01). In conclusion, this study clearly demonstrates that ghrelin stimulates SS and PP release in man. Although the underlying mechanisms and biological significance of these pharmacological effects remain to be elucidated, a causal relationship between the SS increase and the insulin changes may be hypothesized. Finally, these findings strongly support ghrelin's postulated role in linking the endocrine control of energy balance and growth with the regulation of gastrointestinal functions.

Plasma chromogranin A in patients with sporadic gastro-entero-pancreatic neuroendocrine tumors or multiple endocrine neoplasia type 1

OBJECTIVE

As circulating chromogranin A (CgA) has been claimed to be the best general neuroendocrine marker so far available, we evaluated the usefulness of CgA determination in the clinical assessment of patients with sporadic gastro-entero-pancreatic neuroendocrine tumors (GEP NETs) or multiple endocrine neoplasia type 1 (MEN 1).

DESIGN AND METHODS

Plasma CgA levels were measured using a commercial enzyme-linked immunosorbent assay in 61 patients with sporadic GEP NET and in 25 with MEN 1 including 16 with GEP NET. Controls were 50 healthy volunteers, 46 patients with pituitary adenoma and 35 patients with primary hyperparathyroidism.

RESULTS

The cutoff value for CgA established in our healthy subjects (as mean+2 s.d.) was 20 U/l. CgA levels were above the normal range in 71/77 patients with sporadic or MEN 1-related GEP NETs (92%), in four out of nine MEN 1 patients without GEP NETs (44%), and only in 22/81 control patients with pituitary or parathyroid disease (27%). Furthermore, CgA levels of over 100 U/l occurred in 36/77 patients with GEP NETs (47%) and only in one patient with a non-functioning pituitary adenoma. In the patients with GEP NETs, both tumor burden and secretory activity affected CgA levels, and successful surgical resection was associated with markedly decreased CgA values.

CONCLUSIONS

Plasma CgA was confirmed to be a reliable marker for GEP NETs. Moreover, in MEN 1 patients the finding of very high CgA levels strongly suggests the presence of a GEP NET, as both primary hyperparathyroidism and pituitary adenomas rarely cause marked CgA increases.

Tissue transglutaminase antibodies in patients with end-stage heart failure

OBJECTIVE

For celiac disease (CD), screening a trend has recently emerged to measure tissue transglutaminase antibodies (tTGA) by immunoassays instead of the more laborious endomysial antibodies (EmA), as they recognize the same target, tissue transglutaminase (tTG). However, a high rate of false-positive results has been reported in some patient series with diseases known to be associated with CD. Moreover, tTG is a ubiquitous, multifunctional enzyme, overexpressed in experimental models of heart failure. Therefore, we assessed the specificity of tTGA assays in a large series of EmA-negative patients with end-stage heart failure.

METHODS

We studied 288 patients with end-stage heart failure and 60 blood donors. No subject had clinical evidence of CD or IgA deficiency, and all were EmA negative. Serum IgA and IgG tTGA were measured by means of commercial kits using as substrate, either guinea pig or recombinant human tTG. Blocking studies and Western blots were also performed using recombinant human tTG.

RESULTS

All blood donor sera were IgA tTGA negative. IgA tTGA positivity was observed in 47.6% and 49.1% of patients with heart failure using, respectively, guinea pig tTG and recombinant human tTG as substrates. Preincubation of positive sera with recombinant human tTG resulted in 81% blocking of IgA tTGA in immunoassay. Western blot analysis confirmed the presence of antibodies against recombinant human tTG. IgA tTGA-positive sera were also IgG tTGA positive.

CONCLUSIONS

IgA and IgG tTGA occur in a large number of EmA-negative patients with end-stage heart failure, and their presence is unlikely to be caused by concomitant CD.

High frequency of anti-endomysial reactivity in candidates to heart transplant

BACKGROUND

A possible link between coeliac disease and dilated cardiomyopathy has recently been suggested.

AIMS

. To assess the frequency of anti-endomysial antibodies, the marker for coeliac disease, in patients with different forms of heart failure, and to establish the clinical features of those endomysial antibody positive.

SUBJECTS AND METHODS

. A total of 642 consecutive patients entering the waiting list for heart transplantation from 1995 through 1997 were studied. The prevalence of endomysial IgA antibodies, determined by indirect immunofluorescence, was compared to that observed in three surveys conducted in the Italian general population.

RESULTS

Of the 642 patients, 12 (1.9%; 95% confidence interval 0.97-3.2) resulted endomysial antibody positive, versus 34/9,720 healthy controls (0.35%; 95% confidence interval, 0.23-0.47), accounting for a relative risk of 5.3 (95% confidence interval, 2.8-10.3). Anti-endomysial antibodies were found in 6/275 patients with dilated cardiomyopathy and 6/367 with other forms of heart failure (2.2% versus 1.6%; 95% confidence interval 0.8-4.7 and 0.6-3.5), with no statistical difference. The 12 endomysial antibody positive patients were leaner (body mass index, 22.0 +/- 1.9 vs 24.2 +/- 3. 1, p<0. 05) than 36 seronegative patients matched for baseline demographics and aetiology of cardiomyopathy No differences were observed as regards clinical, biochemical and echocardiographic features, mortality in waiting list and 2-year post-transplant survival.

CONCLUSIONS

Patients with end-stage heart failure are at increased risk for coeliac disease as compared to the general population.

Human cobalamin deficiency: alterations in serum tumour necrosis factor-alpha and epidermal growth factor

OBJECTIVES

We have previously demonstrated that vitamin B12 (cobalamin)-deficient central neuropathy in the rat is associated with local overexpression of neurotoxic tumour necrosis factor (TNF)-alpha combined with locally decreased synthesis of neurotrophic epidermal growth factor (EGF). The aims of this study were to investigate whether a similar imbalance also occurs in the serum of adult patients with clinically confirmed cobalamin deficiency and whether it can be corrected by vitamin B12 replacement therapy.

PATIENTS AND METHODS

We studied 34 adult patients with severe cobalamin deficiency, 12 patients with pure iron deficiency anaemia and 34 control subjects. Haematological markers of cobalamin deficiency and serum TNF-alpha and EGF levels were measured using commercial kits. Thirteen cobalamin-deficient patients were re-evaluated after 3 and 6 months of parenteral vitamin B12 treatment.

RESULTS

TNF-alpha was significantly higher (p < 0.01) and EGF significantly lower (p < 0.01) in the patients with cobalamin deficiency, but both were unchanged in patients with pure iron deficiency anaemia. In cobalamin-deficient patients the serum TNF-alpha levels correlated significantly with plasma total homocysteine levels (r = 0.425; p < 0.02). In the treated patients TNF-alpha and EGF levels normalised concomitantly with clinical and haematological disease remission.

CONCLUSIONS

In humans, as in rats, cobalamin concentration appears to be correlated with the synthesis and release of TNF-alpha and EGF in a reciprocal manner, because cobalamin deficiency is accompanied by overproduction of TNF-alpha and underproduction of EGF.

Increased glucose-dependent insulinotropic polypeptide (GIP) secretion in acromegaly

OBJECTIVE

Acromegaly is often associated with fasting and postprandial hyperinsulinemia, and the mechanisms involved are only partly understood. Hypersecretion of incretins such as glucose-dependent insulinotropic polypeptide (GIP) could play a role in determining hyperinsulinemia in acromegaly, but the available data are inconsistent. The aim of this study was to characterize the fasting and postprandial pattern of plasma GIP and insulin in a group of acromegalic patients.

DESIGN AND METHODS

Eleven non-diabetic patients with newly diagnosed acromegaly and 11 sex- and age-matched healthy subjects were studied. Blood samples were taken at regular intervals in fasting conditions and for 3 h after a standard solid-liquid meal for growth hormone (GH), GIP and insulin measurements.

RESULTS

Not only insulin, but also fasting and postprandial GIP levels were significantly higher in the patients with acromegaly than the healthy subjects (P<0.01). In the former group fasting GIP levels and the integrated GIP response to the meal correlated significantly with GH basal levels (r=0.83, P<0.01 and r=0.65, P<0.05, respectively). Moreover, multivariate linear regression analysis showed that the presence of acromegalic status was associated with higher fasting and postprandial GIP levels independently of sex, age, fasting and postprandial plasma glucose and insulin levels, and the occurrence of normal or impaired glucose tolerance.

CONCLUSION

This study provides evidence that in patients with acromegaly fasting and postprandial GIP levels are abnormally high. GIP hypersecretion in turn might play a role in the pathogenesis of hyperinsulinemia that characterizes acromegaly.

Serological markers for coeliac disease: is it time to change?

BACKGROUND

Anti-gliadin and anti-endomysium antibodies are useful markers in the screening and follow-up of coeliac disease. The recent finding that tissue transglutaminase is the main auto-antigen of anti-endomysium has led to the discovery of anti-tissue transglutaminase antibodies.

AIM

To compare, in a prospective study, the diagnostic accuracy of anti-tissue transglutaminase, anti-gliadin and anti-endomysium antibodies in a large series of adult patients.

METHODS

The study involved 80 consecutive subjects undergoing upper gastrointestinal tract endoscopy for suspected coeliac disease (subsequently confirmed in 40 cases), 195 coeliac patients on a gluten-free diet, and 70 patients with different gastrointestinal disor ders and normal duodenal histology. Anti-gliadin, anti-endomysium and anti-tissue transglutaminase antibodies levels were measured using commercial kits.

RESULTS

The diagnostic sensitivity and specificity of anti-gliadin, anti-endomysium and anti-tissue transglutaminase antibodies were, respectively, 95% and 89.1%, 100% and 97.3%, and 100% and 98.2%: the agreement between the markers was substantial or almost perfect. In terms of follow-up, the positivity of the markers varied according to the strict adherence to, and duration of the gluten-free diet; the agreement between antiendomysium and anti-tissue transglutaminase antibodies was almost perfect.

CONCLUSIONS

Anti-endomysium and anti-tissue transglutaminase antibodies are both highly efficient for routine laboratory screening: the choice of one or the other will depend on the available facilities. However, neither can replace intestinal biopsy for general population screening because, in this case, their respective positive predictive values are only 15.7% and 21.8%. During follow-up, anti-gliadin retain their value as an early predictor of gluten ingestion.

Influence of caloric intake on gastric emptying of solids assessed by 13C-octanoic acid breath test

BACKGROUND

The 13C-octanoic breath test (13C-OBT), a recently developed technique to evaluate gastric emptying of solids, has been validated in comparison to scintigraphy with low caloric meals (250 kcal). However, there is consensus that for clinical studies total caloric load should be in excess of 300 kcal, but studies comparing 13C-OBT results after low and medium caloric meals are lacking.

METHODS

Ten healthy subjects were given a 250-kcal and a 550-kcal meal in randomized order. Gastric emptying was assessed simultaneously by ultrasonography and 13C-OBT. Breath samples were taken according to both classic (21 samples over 5 h) and simplified (11 samples) schedules.

RESULTS

Increasing the meal energy content resulted in significantly longer half emptying time (T(1/2)) estimates by both ultrasonography (P < 0.01, Wilcoxon test) and 13C-OBT (P < 0.05). T(1/2) estimates by the two methods significantly correlated for both the 250 (r(s) = 0.733, P = 0.018) and the 550 (r(s) = 0.637, P = 0.035) kcal meal. However, differences between T(1/2) estimates by 13C-OBT and ultrasonography were greater after the 550- than the 250-kcal meal (median 172.5 versus 76.5 min, P < 0.05). Interindividual variability was also 2-fold greater for indexes estimated by 13C-OBT with the 550-kcal meal compared with the 250-kcal meal. For both meals 13C-OBT yielded similar results with the classic and simplified schedules.

CONCLUSIONS

In healthy subjects caloric intake is a major determinant of gastric emptying rate. However, after a medium caloric meal 13C-OBT shows some inaccuracy, which raises questions about its routine clinical application. Nevertheless, when using 13C-OBT one must take into account that the simplified schedule is just as effective as the classic one, and is far lower in cost.

The physical state of a meal affects hormone release and postprandial thermogenesis

There is evidence that food consistency may influence postprandial physiological responses. Recently we found that homogenization of a vegetable-rich meal significantly delayed the gastric emptying rate and was more satiating than the same meal in solid-liquid form. In this present study we investigated whether homogenization also influences endocrine and metabolic responses to the meal. Eight healthy men, aged 21-28 (mean 24.5) years, were given the meal (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, with water 300 ml; total energy 2.6 MJ) in both solid-liquid (SM) and homogenized (HM) form, in random order, at 1-week intervals. Variables assayed were plasma glucose, insulin and glucose-dependent insulinotropic peptide (GIP) levels for 2 h and diet-induced thermogenesis (DIT) for 5 h. Plasma glucose pattern was similar after both meals. However, HM induced significantly greater insulin, GIP and DIT responses than SM. Mean integrated areas under the curves (AUC) were 1.7 (SEM 0.38) v. 1.2 (SEM 0.33) U/l per 120 min (P = 0.005) for insulin, 19.9 (SEM 2.44) v. 16 (SEM 1.92) nmol/l per 120 min (P = 0.042) for GIP, and 237.7 (SEM 16.32) v. 126.4 (SEM 23.48) kJ/300 min (P = 0.0029) for DIT respectively. Differences between GIP-AUC after HM and SM correlated significantly with differences between insulin-AUC after HM and SM (r2 0.62, P = 0.021). These findings demonstrate that homogenization of a meal results in a coordinated series of changes of physiological gastroentero-pancreatic functions and confirm that the physical state of the meal plays an important role in modulating endocrine and metabolic responses to food.

Gastric emptying and plasma neurotensin levels in untreated celiac patients

BACKGROUND

Upper gastrointestinal motor abnormalities could account for some of the dyspeptic symptoms of celiac patients. However, the data on gastric emptying time are conflicting, and the pathophysiology of motor disturbances is still unclear. Neurotensin modulates upper gastrointestinal motor activity, and its postprandial increase is a reliable index of nutrient delivery to the ileum. We therefore assessed both plasma neurotensin levels and gastric emptying in untreated celiacs.

METHODS

The gastric antral area of nine untreated celiac patients and nine controls was measured with ultrasound at base line and every 30 min after a fatty meal (227 kcal, 45% fat); the base-line and postprandial neurotensin plasma levels were determined by means of radioimmunoassay. The data are mean values +/- standard deviation and were analyzed by using non-parametric tests.

RESULTS

The overall and half gastric emptying time were significantly longer in the patients (203+/-32 versus 133+/-15 min, P = 0.0117, and 137+/-32 versus 78+/-11 min, P = 0.0001). The pattern of the changes in antral area was similar in both groups during the observation period as a whole but differed significantly in the first 120 min (P = 0.0343). Base-line neurotensin levels were significantly higher in the patients (41.6+/-23.9 versus 18.2+/-5.5 pg/ml, P = 0.0214) and their net postprandial increase was lower than in controls (15.0+/-15.9 versus 29.8+/-13.0 pg/ml, P = 0.046). In both groups the base-line neurotensin levels were related to the half gastric emptying time (P = 0.023).

CONCLUSIONS

In untreated celiac patients gastric emptying time is longer than in controls and is concomitant with an increase in base-line plasma neurotensin levels.

Sensations induced by medium and long chain triglycerides: role of gastric tone and hormones

BACKGROUND

The relative roles of gastric relaxation and the neuroendocrine signals released by the small intestine in the perception of nutrient induced sensations are controversial. The different effects of long chain (LCT) and medium chain (MCT) triglyceride ingestion on perception, gastric relaxation, and hormonal release may help to elucidate the mechanisms underlying nutrient induced sensations.

AIMS

To compare the effects of intraduodenal LCT and MCT infusions on perception, gastric tone, and plasma gut hormone levels in healthy subjects.

SUBJECTS

Nine fasting healthy volunteers.

METHODS

The subjects received duodenal infusions of saline followed by LCTs and MCTs in a randomised order on two different days. The sensations were rated on a visual analogue scale. Gastric tone was measured using a barostat, and plasma gut hormone levels by radioimmunoassay.

RESULTS

LCT infusion increased satiation scores, reduced gastric tone, and increased the levels of plasma cholecystokinin, gastric inhibitory polypeptide, neurotensin, and pancreatic polypeptide. MCT infusion reduced gastric tone but did not significantly affect perception or plasma gut hormone levels. LCTs produced greater gastric relaxation than MCTs.

CONCLUSIONS

The satiation induced by intraduodenal LCT infusion seems to involve changes in gastric tone and plasma gut hormone levels. The gastric relaxation induced by MCT infusion, together with the absence of any significant change in satiation scores and plasma hormone levels, suggests that, at least up to a certain level, gastric relaxation is not sufficient to induce satiation and that nutrient induced gastric relaxation may occur through cholecystokinin independent mechanisms.

Epidermal growth factor as a local mediator of the neurotrophic action of vitamin B(12) (cobalamin) in the rat central nervous system

We have recently demonstrated that the myelinolytic lesions in the spinal cord (SC) of rats made deficient in vitamin B(12) (cobalamin) (Cbl) through total gastrectomy (TG) are tumor necrosis factor-alpha (TNF-alpha)-mediated. We investigate whether or not permanent Cbl deficiency, induced in the rat either through TG or by chronic feeding of a Cbl-deficient diet, might modify the levels of three physiological neurotrophic factors-epidermal growth factor (EGF), vasoactive intestinal peptide (VIP), and somatostatin (SS)-in the cerebrospinal fluid (CSF) of these rats. We also investigated the ability of the central nervous system (CNS) in these Cbl-deficient rats to synthesize EGF mRNA and of the SC to take up labeled Cbl in vivo. Cbl-deficient rats, however the vitamin deficiency is induced, show a selective decrease in EGF CSF levels and an absence of EGF mRNA in neurons and glia in various CNS areas. In contrast, radiolabeled Cbl is almost exclusively taken up by the SC white matter, but to a much higher degree in totally gastrectomized (TGX) rats. Chronic administration of Cbl to TGX rats restores to normal both the EGF CSF level and EGF mRNA expression in the various CNS areas examined. This in vivo study presents the first evidence that the neurotrophic action of Cbl in the CNS of TGX rats is mediated by stimulation of the EGF synthesis in the CNS itself. It thus appears that Cbl inversely regulates the expression of EGF and TNF-alpha genes in the CNS of TGX rats.

Gallbladder emptying and somatostatin and cholecystokinin plasma levels in celiac disease

OBJECTIVE

Gallbladder hypomotility in celiac disease has been attributed to decreased cholecystokinin secretion. The possible influence of somatostatin, which inhibits gallbladder motility, however, has never been evaluated. In this study gallbladder emptying and cholecystokinin and somatostatin plasma levels were evaluated in response to a fatty meal in patients with celiac disease at diagnosis and after long-term gluten-free diet and in controls.

METHODS

Gallbladder volume and plasma levels of cholecystokinin and somatostatin were measured by ultrasonography and radioimmunoassay, respectively, at 0 time and 30, 60, 75, and 90 min after an oral fatty meal (227 kcal, 45% fat) in 10 celiac patients at diagnosis and after 18 months of successful gluten-free diet and in 10 healthy subjects. The pattern of gallbladder emptying was evaluated by mixed factorial analysis of variance and the curve fitting by multiple regression analysis.

RESULTS

Patients at diagnosis had significantly greater fasting gallbladder volume and higher somatostatin plasma levels than controls (25.7 +/- SD 9.7 ml vs 16.8 +/- 7.0 ml, p = 0.021 and 9.3 +/- 4.6 vs 4.8 +/- 3.4 pmol/L, p = 0.023, respectively), significantly lower fatty meal-induced gallbladder ejection fraction (55 +/- 11.2% vs 76 +/- 7.2%, p = 0.005), and cholecystokinin peak and smaller area under the cholecystokinin secretion curve (3.1 +/- 2.3 pmol/L vs 10.5 +/- 6.9 pmol/L, p = 0.028 and 157 +/- 142 pmol/L/90 min vs 453 +/- 229 pmol/L/90 min, p = 0.028, respectively). The two groups had a similar emptying pattern (p = 0.8913) expressed by a significant quadratic term of the emptying function (p = 0.0001). The mean overall emptying volume was significantly greater in patients than in controls (p = 0.0007). Gluten-free diet normalized these findings.

CONCLUSIONS

In patients at diagnosis, elevated somatostatin levels were associated with increased gallbladder fasting volume, whereas decreased cholecystokinin secretion was responsible for the reduced gallbladder emptying. Gluten-free diet reversed these abnormalities.

Plasma pancreatic polypeptide response to secretin

OBJECTIVE

Intravenously administered secretin stimulates pancreatic polypeptide (PP) release in patients with endocrine enteropancreatic tumors, but data in patients with nontumorous disorders are controversial. Therefore, we aimed to evaluate the plasma PP pattern after secretin administration in healthy subjects and in patients with gastroduodenal diseases investigated for recurrent ulcer disease and/or hypergastrinemia.

METHODS

Synthetic secretin was given as an intravenous bolus (2U/kg) in ten patients with Zollinger Ellison syndrome, ten with duodenal ulcer, ten with atropic gastritis and ten healthy volunteers. Blood samples were taken before and at regular intervals for 30min after secretin injection. Plasma PP and gastrin levels were measured by radioimmunoassay.

RESULTS

Secretin promptly and significantly (P<0.01) increased PP plasma levels in all groups of subjects without any differences in peak values. There were no significant correlations between PP and gastrin plasma levels.

CONCLUSIONS

Secretin at pharmacological doses is a powerful stimulus for PP release.

Postprandial gut peptide plasma levels in women with idiopathic slow-transit constipation

BACKGROUND

As abnormalities of circulating gut regulatory peptides may have pathogenetic relevance in chronic idiopathic slow-transit constipation, we measured fasting and postprandial levels of plasma pancreatic polypeptide, motilin, cholecystokinin, neurotensin, and somatostatin in women with the disease. Results were compared with those of women with normal bowel habits.

METHODS

Eight women with slow-transit constipation and 10 healthy women were studied. Blood samples were taken at regular intervals in fasting conditions and for 3 h after a standard solid-liquid meal (550 kcal). Gut peptide plasma levels were measured with a radioimmunoassay.

RESULTS

Fasting gut peptide levels and postprandial pancreatic polypeptide responses were normal in constipated patients, in whom, however, motilin levels did not increase after the meal, and postprandial concentration-time curves of cholecystokinin, neurotensin, and somatostatin were delayed. Mean +/- standard error of the mean peak times in patients and in controls were, respectively, 99 +/- 14.7 and 46 +/- 4.1 min (P < 0.01, Mann-Whitney test) for cholecystokinin, 135 +/- 9.8 and 60 +/- 3.9 min (P < 0.01) for neurotensin, and 111 +/- 17.7 and 51 +/- 6.0 min (P < 0.05) for somatostatin.

CONCLUSIONS

Patients with slow-transit constipation have abnormal postprandial patterns of motilin, cholecystokinin, neurotensin, and somatostatin.

Physical state of meal affects gastric emptying, cholecystokinin release and satiety

To verify the influence of food consistency on satiety mechanisms we evaluated the effects of the same meal in solid-liquid (SM) and homogenized (HM) form on satiety sensation, gastric emptying rate and plasma cholecystokinin (CCK) concentration. Eight healthy men, aged 21-28 (mean 24.5) years were given two meals (cooked vegetables 250 g, cheese 35 g, croutons 50 g and olive oil 25 g, total energy 2573 kJ, with water 300 ml) differing only in physical state: SM and HM. The subjects consumed the meals in randomized order on non-consecutive days. The sensations of fullness, satiety and desire to eat were evaluated by means of a questionnaire, gastric emptying was assessed by ultrasonographic measurement of antral area, and plasma CCK concentration was measured by radioimmunoassay. The vegetable-rich meal was significantly more satiating (P < 0.05) when in the HM form than when eaten in a SM state. Furthermore, the overall gastric emptying time was significantly slowed (255 (SEM 11) min after HM v. 214 (SEM 12) min after SM; P < 0.05) and CCK peak occurred later (94 (SEM 12) min after HM v. 62 (SEM 11) min after SM; NS) when the food was consumed in the HM form. Independently of the type of meal, antral area was significantly related to fullness sensations (r2 0.46, P = 0.004). These results demonstrate that meal consistency is an important physical food characteristic which influences both gastric emptying rate and satiety sensation. Moreover, the relationship observed between antral area and fullness sensation confirms that antral distension plays a part in the regulation of eating behaviour.

Pattern of plasma cyclic nucleotides and related hormones in liver cirrhosis and hepatocellular carcinoma

To evaluate the pattern of plasma cyclic adenosine 3',5'-monophosphate, cyclic guanosine 3',5'-monophosphate, atrial natriuretic factor and glucagon levels in different stages of chronic liver diseases, we measured these variables in 20 normal subjects, 25 patients with genetic hemochromatosis, associated with liver cirrhosis in 19 cases and not in six, eight patients with compensated and 15 with decompensated alcoholic or posthepatitic cirrhosis, and 12 with hepatocellular carcinoma. All variables were within the normal range in non-cirrhotic hemochromatotic patients. Cyclic adenosine 3',5'-monophosphate levels were within the normal range (9.5-15.7 nmol/l) in hemochromatotic cirrhotics and elevated in other patients. Cyclic guanosine 3',5'-monophosphate, atrial natriuretic factor and glucagon were above the normal ranges (1.92-5.91 nmol/l, 8.8-62.7 ng/l, and 39-165 ng/l, respectively) in most patients with cirrhosis both with and without hemochromatosis and in most individuals with hepatocellular carcinoma. Cyclic guanosine 3',5'-monophosphate correlated with atrial natriuretic factor in the former groups but not in the latter. These findings indicate that glucagon and atrial natriuretic factor hypersecretion is an early event in cirrhosis, regardless of its etiology. In hepatocellular carcinoma, the underlying cirrhosis may account for most hormonal and metabolic changes although cyclic guanosine 3',5'-monophosphate increases could also be due to the neoplastic process per se.

Late-onset idiopathic hypoparathyroidism as a cause of diarrhoea

A 62-year-old man presented with a 20-month history of intermittent watery diarrhoea and hypocalcaemia. At age 43 he had undergone partial gastrectomy with Billroth II anastomosis for perforated peptic ulcer and at age 57 developed megaloblastic anaemia with low serum cobalamin and folate levels. Exhaustive gastrointestinal studies performed to ascertain the cause of the diarrhoea were all negative. Plasma parathyroid hormone levels were undetectable and late-onset idiopathic hypoparathyroidism was diagnosed. Normalization of hypocalcaemia promptly corrected the bowel habit. Idiopathic hypoparathyroidism is an unusual cause of diarrhoea that should, however, be considered in patients with hypocalcaemia and associated diarrhoea without evidence of primary intestinal disease.

Plasma somatostatin-like immunoreactivity and somatostatin-28 levels in obese men

Somatostatin (SS) impairs nutrient absorption. It has been suggested that hyposomatostatinaemia may be involved in the pathogenesis of obesity. However, data on postprandial SS-like immunoreactivity (SLI) levels in obese subjects are controversial and the levels of SS-28, the main molecular form of circulating SLI in healthy subjects, have not been determined. To characterise the fasting and postprandial plasma pattern of SLI and SS-28 in obese men, we studied eight obese men (age 24-32 yr, BMI 33-42 kg/m2), with normal glucose tolerance test and normal gastric emptying of solids, and eight healthy men (age 24-39 yr, BMI 21-24 kg/m2). Blood samples were taken at regular intervals in fasting conditions and for 2 h after a standard solid-liquid meal (2.3 MJ). Plasma SLI and SS-28 were measured by RIA. Our results showed that fasting and postprandial plasma SLI and SS-28 levels were not significantly different in healthy and obese subjects. In conclusion SS-28 is the predominant form of circulating SLI in obese subjects. The normal pattern of fasting and postprandial plasma SLI and SS-28 levels in such subjects suggests that somatostatin does not have a pathogenetic role in obesity.

Multiple endocrine neoplasia type 1 in patients with recognized pituitary tumours of different types

OBJECTIVE

We have investigated the prevalence of MEN 1 in patients with recognized pituitary adenomas. Since hyperparathyroidism is present in nearly 95-100% of patients with MEN 1 and frequently is the first condition to be identified, the study was limited to the identification of patients with hyperparathyroidism while the screening for gastroenteropancreatic (GEP) lesions was carried out in patients with both pituitary and parathyroid lesions.

PATIENTS AND MEASUREMENTS

Serum total and ionized calcium, phosphate and intact PTH 1-84 (EASIA) were measured in 166 patients (68 with non-functioning pituitary adenoma, 42 with prolactinoma, 35 with GH-secreting adenoma, 17-with ACTH-screening adenoma, 1 with TSH-secreting adenoma, 1 with FSH-secreting adenoma and 2 with an only alpha-subunit secreting adenoma) referred to our clinic from 1990 to 1996. Plasma gastrin, somatostatin, pancreatic polypeptide and vasoactive intestinal peptide were measured by RIA in patients with hyperparathyroidism.

RESULTS

Eight of 166 patients (4.8%) were found to have primary hyperparathyroidism and among these 2 also had a gastrinoma while there was no evidence of other GEP tumours. Considering the tumour type, 6 had prolactinoma (14.3%), 1 GH-secreting adenoma (2.8%) and 1 non-functioning adenoma (1.5%). In most patients the diagnosis of pituitary tumour was made several years before that of hyperparathyroidism (from 1 to 15 years) although 6 patients had previously suffered from urolithiasis and one had undergone gastric resections for recurrent peptic ulcers. One patient was identified as a MEN 1 gene carrier and 2 had relatives with signs and symptoms referable to parathyroid or GEP lesions.

CONCLUSIONS

The study shows a prevalence of 4.8% of primary hyperparathyroidism in unselected patients with known pituitary tumours similar to that reported in a previous study. By contrast, the prevalence of MEN 1 in patients with prolactinoma was definitely high (14.3%). In most patients the diagnosis of pituitary tumours was made several years before that of hyperparathyroidism. Although the patients were believed to harbour a sporadic pituitary tumour, most of them had had signs and/or symptoms referable to one or both of the other organs involved in MEN 1, often concomitantly with those of pituitary tumours. These data indicate that the diagnosis of MEN 1 syndrome is missed in a substantial proportion of patients with prolactinomas and therefore the screening of these patients for the syndrome is strongly recommended.