Atrophic gastritis during long-term omeprazole therapy affects serum vitamin B12 levels

Vitamin B12 deficiency and use of proton pump inhibitors: a systematic review and meta-analysis

BACKGROUND

Proton pump inhibitors (PPI) may impact the absorption of vitamin B12. We performed a systematic review to ascertain if PPI use increases risk of vitamin B12 deficiency.

METHODS

Electronic databases (Pubmed, Embase, Scopus) were searched on first of September 2022. We selected studies that compared the frequency of vitamin B12 deficiency in PPI users and non-users. Pooled Odds Ratio (OR) was calculated for the occurrence of vitamin B12 deficiency in PPI users compared to non-users. The risk of bias was assessed using the Newcastle Ottawa scale.

RESULTS

Twenty-five studies were included. The pooled OR of vitamin B12 deficiency among PPI users (2852 participants) was higher than non-users (28070 participants) (OR 1.42, 95% CI: 1.16-1.73; I² = 54%). Overall risk of PPI use among vitamin B12 deficient individuals was higher than those without deficiency (OR 1.49, 1.20-1.85; I² = 68%). Most studies found no difference between serum vitamin B12 levels among PPI users compared to non-users.

CONCLUSION

Although the pooled OR of vitamin B12 deficiency was slightly increased in PPI users, but there was significant heterogeneity, and the pooled OR was too low to imply an association clearly. Better-designed prospective studies in long-term users may clarify the issue.

REGISTRATION

This study was not registered on PROSPERO.

The Effects of Proton Pump Inhibitors in Acid Hypersecretion-Induced Vitamin B12 Deficiency: A Systematic Review (2022)

Gastroesophageal reflux disease (GERD) is the most common disease, for which proton pump inhibitors (PPIs) are a widely used class of drugs. Due to their efficacy and relative safety profile, PPIs are used chronically by GERD patients. Although it is a safe drug, particular attention focuses on the long-term adverse effects of PPI. The association with vitamin deficiencies has received additional focus since chronic PPI treatment increases the incidence of vitamin B12 deficiency, especially in the elderly. However, numerous studies regarding the establishment of an association between PPI and vitamin B12 status revealed conflicting results. In this systematic review, we systematically examined observational studies that focused on the impact of chronic PPI effects on vitamin B12 absorption and diagnostic biomarkers of vitamin B12 deficiency. Our review showed significant changes in diagnostic biomarkers of vitamin B12 status in long-term PPI users, including elevated homocysteine and methylmalonic acid (MMA) concentration levels defining cellular vitamin B12 deficiency. Although there is uncertainty regarding the exact mechanism, it supports the concept that long-term intake of PPI can have clinical implications for vitamins.

Important drug-micronutrient interactions: A selection for clinical practice

Interactions between drugs and micronutrients have received only little or no attention in the medical and pharmaceutical world in the past. Since more and more pharmaceutics are used for the treatment of patients, this topic is increasingly relevant. As such interactions - depending on the duration of treatment and the status of micronutrients - impact the health of the patient and the action of the drugs, physicians and pharmacists should pay more attention to such interactions in the future. This review aims to sensitize physicians and pharmacists on drug micronutrient interactions with selected examples of widely pescribed drugs that can precipitate micronutrient deficiencies. In this context, the pharmacist, as a drug expert, assumes a particular role. Like no other professional in the health care sector, he is particularly predestined and called up to respond to this task. The following article intends to point out the relevance of mutual interactions between micronutrients and various examples of widely used drugs, without claiming to be exhaustive.

A descriptive study of clinico-hematological profile of megaloblastic anemia in a tertiary care hospital

Background

Megaloblastic Anemia (MA) is a relatively common disease, yet the data on prevalence of MA remains scarce. This study was conducted to study the prevalence and clinico-hematological profile of MA.

Methods

This was a cross-sectional study done on 1150 adult anemic patients. All patients diagnosed to have MA were studied for clinico-hematological and etiological profile. Nerve conduction studies (NCS) were done in all.

Results

MA was present in 3.6% cases of anemia. Severe anemia was seen in 9.7% of anemic patients and 75% of MA cases (p < 0.05). Forty five percent of MA patients presented with pancytopenia. Vitamin B12 and folic acid deficiency were documented in 40% and 25% cases respectively while combined deficiency was noted in 35% of all MA cases. There was no co-relation between severity of anemia and deficiency of either of the vitamins (Fischer exact test: 0.530). Among MA patients, 35% were vegetarians while 65% consumed mixed diet. There was no association between vegetarian diet and Vit B12 deficiency (p = 0.3137). An additional etiology was more commonly found in patients on mixed diet [92%; 24/26] as compared to those on vegetarian diet [50%; 7/14] (p = 0.04). NCS was abnormal in 14 patients (35%). Overt clinical neuropathy was present in 12 cases of MA, while subclinical neuropathy was seen in 2 cases.

Conclusion

MA is one of common causes of pancytopenia and severe anemia. Diet plays an important role in causation of MA in vegetarians. An alternative etiology is however, more likely to be found in patients on mixed diet. While overt neurological abnormalities are common in MA, subclinical neuropathy is uncommon.

Evidence of Drug-Nutrient Interactions with Chronic Use of Commonly Prescribed Medications: An Update

The long-term use of prescription and over-the-counter drugs can induce subclinical and clinically relevant micronutrient deficiencies, which may develop gradually over months or even years. Given the large number of medications currently available, the number of research studies examining potential drug-nutrient interactions is quite limited. A comprehensive, updated review of the potential drug-nutrient interactions with chronic use of the most often prescribed medications for commonly diagnosed conditions among the general U.S. adult population is presented. For the majority of the interactions described in this paper, more high-quality intervention trials are needed to better understand their clinical importance and potential consequences. A number of these studies have identified potential risk factors that may make certain populations more susceptible, but guidelines on how to best manage and/or prevent drug-induced nutrient inadequacies are lacking. Although widespread supplementation is not currently recommended, it is important to ensure at-risk patients reach their recommended intakes for vitamins and minerals. In conjunction with an overall healthy diet, appropriate dietary supplementation may be a practical and efficacious way to maintain or improve micronutrient status in patients at risk of deficiencies, such as those taking medications known to compromise nutritional status. The summary evidence presented in this review will help inform future research efforts and, ultimately, guide recommendations for patient care.

Effects of widely used drugs on micronutrients: a story rarely told

Vitamins and trace elements are essential to the body, however, deficiencies are frequently observed in the general population. Diet is mostly responsible for these deficiencies but drugs also may play a significant role by influencing their metabolism. These effects are rarely assessed in clinical practice, in part because of limited data available in the literature. Drug-induced micronutrient depletions, however, may be the origin of otherwise unexplained symptoms that might sometimes influence medication compliance. We present various examples of widely prescribed drugs that can precipitate micronutrient deficiencies. This review aims at sensitizing physicians on drug-micronutrient interactions. High-risk population groups also are presented and supplementation protocols are suggested.

Safety of long-term PPI therapy

Proton pump inhibitors have become the mainstay of medical treatment of acid-related disorders. Long-term use is becoming increasingly common, in some cases without a proper indication. A large number of mainly observational studies on a very wide range of possible associations have been published in the past decade and are critically reviewed in this article and the existing evidence is evaluated and translated into possible clinical consequences. Based on the existing evidence the benefits of PPI treatment seem to outweigh potential risks in the large majority of patients especially if PPI use is based on a relevant indication. The concern for complications should primarily be directed at elderly, malnourished with significant co-morbidity. In this population an increased risk for enteric infections, fractures and nutritional deficiencies might have clinical consequences and should lead to a careful evaluation of the indication for PPI treatment.

Rationale in diagnosis and screening of atrophic gastritis with stomach-specific plasma biomarkers

BACKGROUND AND AIMS

Atrophic gastritis (AG) results most often from Helicobacter pylori (H. pylori) infection. AG is the most important single risk condition for gastric cancer that often leads to an acid-free or hypochlorhydric stomach. In the present paper, we suggest a rationale for noninvasive screening of AG with stomach-specific biomarkers.

METHODS

The paper summarizes a set of data on application of the biomarkers and describes how the test results could be interpreted in practice.

RESULTS

In AG of the gastric corpus and fundus, the plasma levels of pepsinogen I and/or the pepsinogen I/pepsinogen II ratio are always low. The fasting level of gastrin-17 is high in AG limited to the corpus and fundus, but low or non-elevated if the AG occurs in both antrum and corpus. A low fasting level of G-17 is a sign of antral AG or indicates high intragastric acidity. Differentiation between antral AG and high intragastric acidity can be done by assaying the plasma G-17 before and after protein stimulation, or before and after administration of the proton pump inhibitors (PPI). Amidated G-17 will rise if the antral mucosa is normal in structure. H. pylori antibodies are a reliable indicator of helicobacter infection, even in patients with AG and hypochlorhydria.

CONCLUSIONS

Stomach-specific biomarkers provide information about the stomach health and about the function of stomach mucosa and are a noninvasive tool for diagnosis and screening of AG and acid-free stomach.

Long-term acid inhibition: benefits and harms

Proton pump inhibitors (PPIs) are the drugs of choice in the therapy of acid-related disorders. PPIs are as a class remarkably safe. Serious adverse events such as acute interstitial nephritis are extremely rare. Some reports in recent years have placed some concern on the long-term use of PPIs. Long-term therapy with PPIs can cause hypochlorhydria, hypergastrinemia and has interactions on hepatic cytochrome P450 enzymes which might increase the risk of infectious complications, nutritional deficiencies and drug-drug interactions. The vast majority of data came from retrospective case-control or cohort studies which are prone to confounders. At the moment we cannot conclude that long-term PPI use causes anemia, osteoporosis and bone fractures, increases the risk for pulmonary or enteric infections, has an effect on GUT mucosa, polyp or tumor formation, or that PPI use increases the risk of cardiovascular events in patients on PPIs and clopidogrel. We need prospective randomized trials to be able to definitely answer the questions raised in epidemiologic studies. Maintenance therapy with PPIs should be started only if strict indications for that therapy are fulfilled.

Short and long-term PPI treatment for GERD. Do we need more-potent anti-secretory drugs?

Because the reflux of the acidic gastric content into the esophagus plays a major role in the pathogenesis of symptoms of GERD and lesions of erosive esophagitis, acid suppression with a proton pump inhibitor (PPI) is currently the mainstay of anti-reflux therapy. There is a strong correlation between the degree of acid suppression provided by a given drug and its efficacy. The superiority of PPIs over other drugs (antacids, prokinetics and H(2)-receptor antagonists) has now been established beyond doubt, both for short- and long-term treatment. However, there are still some unmet therapeutic needs in GERD; hence, patients with non-erosive reflux disease (NERD) are less responsive to PPIs than those with erosive esophagitis. Moreover, the efficacy of PPIs in patients with atypical symptoms is frequently limited to the relief of associated heartburn or regurgitation. With respect to safety, although most studies on short- and long-term PPI use have provided reassuring data, recent reports have drawn attention to potential side effects or drug-drug interference. Better healing rates in the most severe forms of esophagitis, or a faster onset of symptom relief, may require optimization of acid suppressive therapy with regard to the daily course of acid secretion, especially during the night. Different pharmacological approaches can be considered, with the ultimate goals of achieving faster, stronger and more-sustained acid inhibition. How a better pharmacological profile may translate into clinical benefit should now be tested in appropriate, controlled studies.

Vitamin B(12) deficiency is linked with long-term use of proton pump inhibitors in institutionalized older adults: could a cyanocobalamin nasal spray be beneficial?

The purpose of this study was to determine whether institutionalized older individuals taking proton pump inhibitors (PPI) for more than 12 months were more likely to have vitamin B(12) deficiency than individuals not taking PPI, and whether cyanocobalamin nasal spray would improve their vitamin B(12) status. Participants were long-term care residents aged 60-89 years. PPI users (n = 17) were treated with cyanocobalamin nasal spray for 8 weeks; non-PPI users (n = 19) were not treated but were followed for the same time duration. Serum samples from all subjects were analyzed for vitamin B(12) and serum methylmalonic acid (sMMA) at baseline and the end of the 8-week treatment. There was a significant difference in mean vitamin B(12), sMMA, and frequency of deficiency between control and intervention groups at baseline. After treatment, there was an increase (p = 0.012) in serum vitamin B(12) concentration, and a decrease (p = 0.004) in frequency of deficiency in PPI users. Thus, we found that institutionalized older individuals on PPI for more than 12 months may be more likely to be vitamin B(12) deficient than non-PPI users. Additionally, treatment of PPI users with cyanocobalamin nasal spray for 8 weeks could improve vitamin B(12) status.

Safety of the long-term use of proton pump inhibitors

The proton pump inhibitors (PPIs) as a class are remarkably safe and effective for persons with peptic ulcer disorders. Serious adverse events are extremely rare for PPIs, with case reports of interstitial nephritis with omeprazole, hepatitis with omeprazole and lansoprazole, and disputed visual disturbances with pantoprazole and omeprazole. PPI use is associated with the development of fundic gland polyps (FGP); stopping PPIs is associated with regression of FGP. In the absence of Helicobacter pylori infection, the long-term use of PPIs has not been convincingly proven to cause or be associated with the progression of pre-existing chronic gastritis or gastric atrophy or intestinal metaplasia. Mild/modest hypergastrinemia is a physiological response to the reduction in gastric acid secretion due to any cause. The long-term use of PPIs has not been convincingly proven to cause enterochromaffin-like cell hyperplasia or carcinoid tumors. PPIs increase the risk of community acquired pneumonia, but not of hospital acquired (nosocomial) pneumonia. There is no data to support particular care in prescribing PPI therapy due to concerns about risk of hip fracture with the long-term use of PPIs. Long-term use of PPIs does not lead to vitamin B12 deficiencies, except possibly in the elderly, or in persons with Zollinger-Ellison Syndrome who are on high doses of PPI for prolonged periods of time. There is no convincingly proven data that PPIs increase the risk of Clostridium difficile-associated diarrhea in persons in the community. The discontinuation of PPIs may result in rebound symptoms requiring further and even continuous PPI use for suppression of symptoms. As with all medications, the key is to use PPIs only when clearly indicated, and to reassess continued use so that long-term therapy is used judiciously. Thus, in summary, the PPIs are a safe class of medications to use long-term in persons in whom there is a clear need for the maintenance of extensive acid inhibition.

Influence of gastric mucosal status on success of stepwise acid suppressive therapy for dyspepsia

BACKGROUND

The most effective initial treatment strategy of dyspepsia is still under debate. Individual biological characteristics, such as condition of gastric mucosa, might contribute to selection of the most appropriate acid suppression treatment strategy.

AIM

To assess whether pre-treatment testing of gastric mucosal status is relevant for treatment success in an RCT comparing step-up and step-down therapies in newly diagnosed dyspepsia patients.

METHODS

Baseline serum samples were collected to assess gastric mucosal status using serum levels of pepsinogens-I&II, gastrin-17, and Helicobacter pylori IgA/IgG-antibodies. The 6-month treatment success was compared between step-up and step-down for patients with serum diagnoses: normal; gastritis; corpus atrophy or antrum atrophy.

RESULTS

In all, 519 patients (M/F: 249/270, age: 47 (18-85) years, 29%H. pylori+) were randomized to step-up (n = 293) or step-down (n = 226). Normal mucosa, gastritis and corpus atrophy were diagnosed serologically in 70%, 28% and 2% of the patients, evenly distributed between the strategies (P = 0.65). Treatment success was achieved in respectively, 69%, 70% and 70% for the serum diagnosis groups, and did not differ between the strategies.

CONCLUSIONS

Dyspepsia treatment success could not be predicted by gastric mucosal status. Therefore, serum diagnosis of gastric mucosal status is no useful tool for patient allocation to acid suppressive treatment strategies.

Serum biomarkers provide an accurate method for diagnosis of atrophic gastritis in a general population: The Kalixanda study

OBJECTIVE

Serological biomarkers can be used for non-invasive diagnosis of gastritis and atrophic gastritis. The aim of this study was to compare the validity of serum levels of pepsinogen I (PGI) and II (PGII), gastrin-17 (G-17) and Helicobacter pylori antibodies (Hpab) with that of the gold standard histology for diagnosis of atrophic gastritis in a population sample from Northern Sweden.

MATERIAL AND METHODS

In all, 1000 subjects underwent endoscopies with biopsies. Serum biomarkers were available in 976 subjects for independent diagnosis of gastric mucosal status using a predetermined diagnostic algorithm.

RESULTS

Overall agreement between histology and serological biomarkers in diagnosing corpus atrophy was 96% (CI 95%: 95-97%). Sensitivity and specificity of markers for atrophic gastritis were 71% (CI 68-74%) and 98% (CI 97-99%) respectively, corresponding to 69% (CI 95%: 66-72%) and 98% (95% CI 97-99%) positive and negative predictive values. The positive likelihood ratio was 35.5 (95% CI: 35.0-36.0%). In subgroups with normal stomachs, H. pylori non-atrophic gastritis and H. pylori-negative gastritis by histology, the prevalence of corpus atrophy diagnosed with the biomarkers was 0.8% and 4.9%, respectively. In total, 6.6% of subjects in the study population had corpus atrophy according to the serological biomarkers. CONCLUSIONS. Serological biomarkers show a high degree of accuracy as a non-invasive method to diagnose corpus atrophy, which is common in the general population.

Effect of proton pump inhibitors on vitamins and iron

Vitamin C is actively secreted in human gastric juice. Proton pump inhibitor therapy lowers the concentration of vitamin C in gastric juice and the proportion of the vitamin in its active antioxidant form i.e., ascorbic acid. This has secondary effects on intragastric nitrite chemistry, resulting in a rise in gastric juice nitrite levels. There is also some evidence that proton pump inhibitors may reduce the bioavailability of ingested vitamin C. The effect of proton pump inhibitors on vitamin C and nitrite chemistry is more marked in Helicobacter pylori-infected subjects. Proton pump inhibitors also reduce the absorption of vitamin B(12) probably by inhibiting intragastric proteolysis and, thus, its release from food required prior to binding to R-proteins and gastric intrinsic factor. Under certain circumstances, the treatment may lower serum vitamin B(12) levels. Proton pump inhibitor therapy reduces the absorption of non-heme iron and this effect has been employed in the management of hemochromatosis. It may also retard clinical response to iron supplementation.

Proton pump inhibitors and Helicobacter pylori gastritis: friends or foes?

H. pylori gastritis and gastric acid closely interact. In H. pylori-positive patients, profound acid suppressive therapy induces a corpus-predominant pangastritis, which is associated with accelerated corpus gland loss and development of atrophic gastritis. Both corpus-predominant and atrophic gastritis have been associated with an increased risk of development of gastric cancer. H. pylori eradication leads to resolution of gastritis and may induce partial regression of pre-existent gland loss. H. pylori eradication does not aggravate GERD nor does it impair the efficacy of proton pump inhibitor maintenance therapy for this condition. This is the background of the advise within the European guidelines for the management of H. pylori infection to offer an H. pylori test and treat policy to patients who require proton pump inhibitor maintenance therapy for GERD. As such a policy fully reverses H. pylori pangastritis even in patients who have been treated for years with proton pump inhibitors, there is no need to eradicate H. pylori before the start of proton pump inhibitors. In fact, the somewhat slower initial response of H. pylori-negative GERD patients to proton pump inhibitor therapy and the fact that many GERD patients will only require short-term therapy suggests to first start the proton pump inhibitor, and only test and treat when maintenance therapy needs to be prescribed. Such considerations prevent the persistent presence of active corpus-predominant gastritis in proton pump inhibitor-treated reflux patients without impairing the clinical efficacy of treatment.

Gastric atrophy, diagnosing and staging

H pylori is now accepted as the cause of gastritis and gastritis-associated diseases, such as duodenal ulcer, gastric ulcer, gastric carcinoma, and gastric MALT lymphoma. The natural history of H pylori gastritis includes inflammation progressing from the antrum into the adjacent corpus resulting in an atrophic front of advancing injury leading to a reduction in acid secretion and eventual loss of parietal cells and development of atrophy. Sub-typing intestinal metaplasia has no clinical value to the patient, the pathologist, or the endoscopist. The pattern, extent, and severity of atrophy, with or without intestinal metaplasia, is a far more important predictor than is intestinal metaplasia subtype. The challenge remains to identify a reliable marker that relates to pre-malignant potential.

Consequences of long-term proton pump blockade: insights from studies of patients with gastrinomas

Proton pump inhibitors are being increasingly used and for longer periods of time, especially in patients with gastroesophageal reflux disease. Each of these trends has led to numerous studies and reviews of the potential risk-benefit ratio of the long-term use of proton pump inhibitors. Both long-term effects of hypergastrinaemia due to the profound acid suppression caused by proton pump inhibitors as well as the effects of hypo-/achlorhydria per se have been raised and studied. Potential areas of concern that have been raised in the long-term use of proton pump inhibitors, which could alter this risk-benefit ratio include: gastric carcinoid formation; the development of rebound acid hypersecretion when proton pump inhibitor treatment is stopped; the development of tolerance; increased oxyntic gastritis in H. pylori patients and the possibility of increasing the risk of gastric cancer; the possible stimulation of growth of non-gastric tumours due to hypergastrinaemia; and the possible effect of the hypo/achlorhydria on nutrient absorption, particularly iron and vitamin B12. Because few patients with idiopathic gastro-oesophageal reflux disease/peptic ulcer disease have been treated long-term (i.e., >10 years), there is little known to address the above areas of potential concern. Most patients with gastrinomas with Zollinger-Ellison syndrome have life-long hypergastrinaemia, require continuous proton pump inhibitors treatment and a number of studies report results of >5-10 years of tratment and follow-up. Therefore, an analysis of Zollinger-Ellison syndrome patients can provide important insights into some of the safety concerns raised above. In this paper, results from studies of Zollinger-Ellison syndrome patients and other recent studies dealing with the safety concerns above, are briefly reviewed.

Gastric juice: a barrier against infectious diseases

All vertebrates produce gastric acid. Its main function is inactivation of ingested microorganisms. The majority of microbiological pathogens ingested never reaches the intestine because of the gastric barrier. Although gastric hypochlorhydria is fairly common due to atrophic gastritis, gastric surgery or use of inhibitors of gastric acid secretion, the resulting susceptibility to infection has not been studied extensively. Drug-induced blockade of acid secretion leads to gastrointestinal bacterial overgrowth; the clinical significance of this is still controversial. Gastric acidity is known to protect against non-typhoid salmonellosis and cholera and it is suspected that it protects against several parasitic diseases as giardiasis and strongyloides. There is a lack of studies focusing on the impact of the gastric acidic barrier on viral infections. Concerning prion infections only a single study has been performed, demonstrating a possible role of gastric acidity in the protection against foodborne prion disease in mice. The combination of malnutrition and hypochlorhydria may contribute to the high prevalence of gastrointestinal infections in developing countries. Further studies are needed to evaluate the clinical consequences of impaired gastric acidity with respect to susceptibility to infections.

Indicaciones y consecuencias de la erradicación de Helicobacter pylori en la enfermedad por reflujo gastroesofágico

Several epidemiological data indicate that H. pylori infection prevalence in patients with gastroesophageal reflux disease (GERD) is lower than that reported in respective controls, which would suggest that the organism plays a protective role against this disease. On the other hand, most studies demonstrate that the presence of the infection in patients with GERD does not negatively affect the therapeutic efficacy of proton pump inhibitors (PPIs), and, in case of negatively influencing it, the effects are not clinically relevant and are easily controllable with standard antisecretory treatment. Therefore, the decision to administer H. pylori eradication treatment to a patient should not be influenced by the concomitant presence of GERD. In most cases, H. pylori eradication does not seem to induce GERD development, and it does not seem to worsen GERD when it was already present. Nevertheless, when the gastritis pattern is unknown before the antibiotic administration, the effect of H. pylori eradication on gastric acid secretion and the incidence of GERD is unpredictable. In the exceptional cases in which H. pylori eradication could have negative effects on GERD, its clinical relevance will be limited, and reflux symptoms or endoscopic esophagitis will favourably respond to the standard PPI antisecretory treatment. Therefore, again, when H. pylori eradication is indicated in a particular patient, the concomitant diagnosis of GERD should not change our attitude. Finally, is has recently been recommended to eradicate H. pylori infection in those patients with GERD needing long-term treatment with PPI, as some studies have reported that these drugs induce, in presence of the organism, an atrophic gastritis, with the consequent risk of gastric cancer. However, most of these studies have important methodological defects, and several authors have reported contrary results. In any case, the appearance in the gastric mucosa of clinically relevant lesions, such as intestinal metaplasia, dysplasia or adenocarcinoma, in patients treated with PPI for several years, has not yet been demonstrated, although this could simply be a problem of time. This question seems to be too controversial to be answered with the available data, and we should wait until new studies clarify this topic. In the meantime, as it occurs with any controversial indication, the decision of the doctor facing a patient infected by H. pylori and needing maintenance therapy with PPIs should be assessed on a case by case basis.

Serum vitamin B12 concentrations and atrophic gastritis in older New Zealanders

OBJECTIVE

To determine the serum vitamin B(12) status of older New Zealanders and to assess the impact of atrophic gastritis on vitamin B(12) status.

DESIGN

A cross-sectional nationally representative population-based survey.

METHOD

Serum vitamin B(12) concentrations were used to assess vitamin B(12) status. The presence and severity of atrophic gastritis was classified using serum pepsinogen I and II.

SUBJECTS

A total of 466 noninstitutionalized urban and rural dwelling New Zealanders aged 65 y or older who participated in the 1997 National Nutrition Survey.

RESULTS

The prevalence of deficient (<148 pmol/l) and marginal (148-221 pmol/l) serum vitamin B(12) concentrations was 12 and 28%, respectively. The prevalence of atrophic gastritis was 6.7% (severe 3.1%, mild-moderate 3.6%). While atrophic gastritis increased the relative risk (RR, 95% CI) of having a deficient or marginal serum vitamin B(12) concentration by 21-fold (6-67) and five-fold (1-17), respectively, those who had atrophic gastritis made up only 33 and 6% of the participants with deficient or marginal serum vitamin B(12) concentrations. An intake of vitamin B(12) from food that exceeded the recommended dietary allowance (2.4 mug/day) did not protect against deficient (RR 0.5; 95% CI: 0.2, 1.2) or marginal (RR 0.9; 95% CI: 0.5, 1.7) serum vitamin B(12) status. Vitamin B(12) supplement users had a reduced risk of having deficient and marginal vitamin B(12) status (RR 0.3; 95% CI: 0.1, 0.8).

CONCLUSIONS

There is a relatively high prevalence of deficient and marginal serum vitamin B(12) concentrations among older New Zealanders. However, the prevalence of atrophic gastritis was low in the New Zealand elderly compared with other surveys. Although atrophic gastritis was a risk factor for low vitamin B(12) status, it did not fully explain the prevalence of low serum vitamin B(12).

Double-blind, randomized controlled study to assess the effects of lansoprazole 30 mg and lansoprazole 15 mg on 24-h oesophageal and intragastric pH in Chinese subjects with gastro-oesophageal reflux disease

BACKGROUND

Previous studies have suggested that the acid secretory capacity of the Chinese population is lower than that of the Western population.

AIM

To compare the effect of lansoprazole 30 mg and 15 mg once daily on the 24-h oesophageal and intragastric pH profiles in Chinese patients with gastro-oesophageal reflux disease.

METHODS

Forty-four patients (male to female ratio, 27 : 17; mean age, 53 years; 55% with oesophagitis) with gastro-oesophageal reflux disease were randomized to receive lansoprazole 30 mg or 15 mg once daily for 4 weeks. Measurement of the 24-h oesophageal and intragastric pH, gastro-oesophageal reflux disease symptoms and quality of life was performed at baseline and during the last week of each dosing period.

RESULTS

Lansoprazole 30 mg maintained an intragastric pH > 4 for 10.5 h vs. 9.6 h for lansoprazole 15 mg (P = 0.44). The percentage total time at oesophageal pH < 4 was similar for lansoprazole 30 mg and 15 mg (2.0% vs. 2.3%, P = 0.30). The proportion of patients with complete cure of heartburn and acid regurgitation and the quality of life assessment were similar for lansoprazole 30 mg and 15 mg. Both dosages of lansoprazole were well tolerated and the compliance was 100% in both groups.

CONCLUSION

Lansoprazole dosages of 30 mg and 15 mg once daily provide a satisfactory decrease for oesophageal acid exposure and are equally effective for the treatment of gastro-oesophageal reflux disease in the Chinese population.

False negative urea breath tests with H2-receptor antagonists: interactions between Helicobacter pylori density and pH

BACKGROUND

We studied the effects of famotidine, sodium bicarbonate, and citric acid on the 13C-urea breath test (UBT).

METHODS

Helicobacter pylori-infected volunteers received a UBT, 40 mg of famotidine at bedtime, and a second UBT (pudding test meal, 648 mg NaHCO3 tablet then 125 mg of urea in 200 ml of water containing 650 mg of NaHCO3). Experiment 2 consisted of four UBTs. Two were standard citric acid UBTs with 75 mg of urea and 2 g citric acid and two were sequential bicarbonate-citric acid UBTs. Sequential UBTs consisted of administration of a 648 mg bicarbonate tablet with 50 g of Polycose in 200 ml of water. Five minutes later, 125 mg of 13C-urea was given in 75 ml of water containing 650 mg of NaHCO3. Breath samples were collected after 15 minutes. Then, to acutely acidify the stomach, 4 g of citric acid was given in 200 ml of water. A second breath sample was collected 15 minutes after the citric acid. The standard UBTs were done before and after 6 days of famotidine (40 mg b.i.d.). Sequential UBTs were done after 1 and 6 days of famotidine therapy. Gastric biopsies for histology, culture, and mucosal cytokines were assessed before and after 6 days of famotidine.

RESULTS

Eighteen subjects participated, 10 in each experiment; seven had endoscopy with biopsy. Famotidine/ bicarbonate resulted an approximately 50% fall in UBT values (p = .021) with 10% becoming negative. The gastric pH increased from 5.1 +/- 0.5 to 6.7 +/- 0.2 (p = .03) although no pH value predicted the occurrence of false negative results. Under famotidine acid suppression, NaHCO3 reduced the delta over baseline (DOB) by 63% (p = .021). This was reversed with citric acid. Histology showed a H2-receptor antagonist-associated increase in the depth of gastric corpus inflammation.

CONCLUSIONS

H2-receptor antagonists differ from proton pump inhibitors as high intragastric pH may cause a reduction in urease activity, unrelated to a reduced bacterial load and reversed by citric acid.

Treatment of acid-related diseases in the elderly with emphasis on the use of proton pump inhibitors

Proton pump inhibitors (PPIs) have revolutionised the treatment of acid-related disorders, and they have also made it possible to define the spectrum of acid inhibition required for optimal treatment in each disorder. Five PPIs are now available: the older drugs, omeprazole, lansoprazole and pantoprazole, and the two newest, rabeprazole and esomeprazole. These agents have predominantly been developed in the younger adult population, and data for the elderly population are limited. Subtle differences have emerged between the old and the new PPIs in their pharmacokinetic, pharmacodynamic and efficacy profiles. The degree of clinical relevance of these differences in the adult population is in question. However, according to this review, based on the available data for the elderly and by inference from the adult population, the differences are highly relevant in the elderly population. Studies of the pharmacokinetics of older PPIs demonstrated considerable variation in drug clearance that was reflected in a wide range of efficacy related to acid suppression with standard dosages. The newer PPIs offer several advantages over older agents, particularly in terms of rapid, profound and consistent acid inhibition. Consistent acid inhibition is particularly important in the elderly since clinical response is often difficult to judge in this patient group. An individual's cytochrome P450 (CYP) 2C19 genotype predicts the degree of acid suppression and consequently the clinical efficacy of the PPIs. The older PPIs are predominantly metabolised by CYP2C19, with this being of more importance for omeprazole and lansoprazole than pantoprazole. The hepatic metabolism of rabeprazole is predominantly by nonenzymatic reactions and minimally by CYP-mediated reactions, which therefore confers an advantage over older PPIs in that genetic polymorphisms for CYP2C19 do not significantly influence rabeprazole clearance, clinical efficacy or potential for drug interactions. The metabolism of esomeprazole involves CYP2C19 but to a lesser extent than its predecessor omeprazole. Furthermore, esomeprazole has a more rapid onset of action and less variation in clearance rates than omeprazole. Drug clearance decreases with age independently of CYP2C19 status, exaggerating some of the differences between the PPIs and increasing the risk of drug interactions.

Early events in proton pump inhibitor-associated exacerbation of corpus gastritis

BACKGROUND

Antisecretory therapy may exacerbate Helicobacter pylori corpus gastritis. The rate and mechanism(s) remain unknown.

AIM

To investigate the early events in proton pump inhibitor therapy on antral and corpus H. pylori gastritis.

METHODS

Nine H. pylori-infected volunteers underwent gastric biopsy with jumbo forceps for culture and histology. Histology was scored in the range 0-5 using a visual analogue scale. The depth of inflammation in gastric pits was scored in the range 1-3 (superficial or less than one-third, one-third to two-thirds and greater than two-thirds of the gastric pit, respectively). Tissue interleukin-1 beta and interleukin-8 levels were measured by enzyme-linked immunoabsorbent assay. Omeprazole, 20 mg b.d., was given for 6.5 days and biopsies were repeated on day 7.

RESULTS

Proton pump inhibitor therapy resulted in a fall in H. pylori density in the antrum and corpus. Inflammation and tissue levels of interleukin-8 and interleukin-1 beta decreased in the antrum and increased in the corpus mucosa. There was a significant increase in the depth of inflammation to include the proliferative zone in the corpus.

CONCLUSIONS

Within 1 week of starting proton pump inhibitor therapy, there was a marked extension of corpus inflammation into the gastric pit and an increase in corpus mucosal interleukin-1 beta and interleukin-8 levels. H. pylori eradication should be considered for all patients receiving long-term antisecretory therapy.

Neuromuscular diseases and disorders of the alimentary system

This review outlines the relationship and interaction between neuromuscular diseases and disorders of the alimentary system. Neuromuscular manifestations of gastrointestinal and hepatobiliary diseases are first considered. Such diseases may cause neuromuscular disorders by leading to nutritional deficiency or by more direct mechanisms. The pathogenesis, clinical features, and treatment of these various neuromuscular manifestations are discussed. The impact of disorders of nerve, neuromuscular transmission, and muscle on the alimentary system is then reviewed. The main sequelae are impaired deglutition and gastrointestinal dysmotility. The management of these complications is considered.

Gastric mucosal morphological consequences of acid suppression: a balanced view

In the chapter, an analysis of the literature on the relationship between Helicobacter pylori, the use of proton pump inhibitors and the development of atrophic gastritis is presented, and the difficulties of classifying gastritis and the new possibilities of quantifying chronic inflammation by morphometric analysis are discussed. The issue surrounding the necessity of eradicating H. pylori in H. pylori-positive patients has still not been solved. Most studies have now accepted that proton pump inhibitors indeed accelerate the onset of atrophic gastritis in H. pylori-positive patients, but evidence against such an association was published in one recent (Scandinavian) study; conclusions from this study have, however, been challenged by several groups. Some data are available on the efficacy of H. pylori eradication with regard to the prevention of atrophy. The limited significance of the development of parietal cell protrusions and fundic gland cysts is better understood, but much less is known of the development and long-term consequence of H. pylori-induced autoimmune gastritis. Finally, recent studies in H. pylori-positive patients indicate that treatment with proton pump inhibitors may promote bacterial N-nitrosation formation. These data taken together suggest that the eradication of H. pylori may be based not only on morphological arguments, but also on bacterial alterations in the gastric milieu.

Occurrence and significance of gastric colonization during acid-inhibitory therapy

There are now a wide variety of drugs available that are able profoundly to reduce the production of gastric acid. These drugs are currently widely prescribed for the treatment of peptic ulceration and gastro-oesophageal reflux disease. One of the main functions of gastric acid is to kill ingested bacteria. Colonization of the gastric lumen occurs in patients on anti-secretory medication, the degree of bacterial overgrowth depending upon the degree of elevation of the pH. There have been concerns that these bacteria may produce carcinogenic nitrosamines and increase the risk of gastric cancer, but there is at present no definitive evidence in support of this. A profound suppression of gastric acid may also facilitate the colonization of the upper small intestine, leading to deconjugation of the bile salts and malabsorption. There is some evidence that profound gastric acid suppression may decrease the number of ingested pathogens required to produce enteric disease. This chapter discusses these potential bacterial complications of therapeutic acid suppression and the evidence for them.

Genotypic, clinical, and demographic characteristics of children infected with Helicobacter pylori

Helicobacter pylori isolates vary between geographic regions. Certain H. pylori genotypes may be associated with disease outcome. Thirty-eight children underwent diagnostic upper endoscopy at four medical centers and were retrospectively analyzed to determine if H. pylori virulence genes were associated with endoscopic disease severity, histologic parameters, and host demographics. The H. pylori virulence genotype was analyzed by a reverse hybridization line probe assay and type-specific PCR. Endoscopic ulcers or erosions were found in 17 (45%) patients, with 13 (34%) of these patients having antral nodularity. Histological gastritis, of varying severity, was present in all children. Four patients harbored more than one H. pylori strain: one subject had both cagA(+) and cagA-negative strains, while three patients harbored either two different cagA-negative strains (two children) or two cagA(+) strains (one child). There were 28 (74%) cagA(+) isolates; 19 were associated with the vacA s1b genotype, 7 were associated with the vacA s1a genotype, 1 was associated with the vacA s1c genotype, and 1 was associated with the s2 genotype. Of 14 cagA-negative isolates, 6 were vacA s2 genotype, 4 were vacA s1b, 3 were vacA s1a, and 1 was vacA s1c. Nine of ten (90%) Hispanics had similar H. pylori strains (vacA s1b,m1), and all Asian-Canadian children were infected by strains with vacA s1c genotype. No correlation between H. pylori strain and endoscopic or histopathologic abnormalities was found. This study provides a baseline framework of North American children and their H. pylori strains, serving as a powerful epidemiological tool for prospective investigations to better understand the transmission and evolution of diverse disease outcomes.

The treatment of peptic ulcer disease

There is a continuation of the debate on the management of dyspepsia while the role of Helicobacter pylori in duodenal ulcer disease is being questioned with renewed vigor, specifically in the United States. The interaction of NSAIDs and H. pylori provided some interesting, if at times confusing, literature while the debate on the safety of long-term acid suppression remained unresolved. There were some interesting developments with regard to therapeutic agents during this period. A fourth proton pump inhibitor was introduced to the market while cisapride, a drug previously considered safe, was effectively withdrawn from the North American market because of safety concerns. More data on the COX-1-sparing agents became available, and their impressive gastrointestinal safety profile was confirmed. It was noted, however, that the incidence of dyspepsia, experienced by users of these drugs, may remain a problem.