Impaired skeletal health in patients with chronic atrophic gastritis

Association between gastric polyps and decreased bone mineral density in patients with chronic gastritis

Gastric polyps indicate the disturbance of gastric microecology and inflammatory status, which may affect bone metabolism. We aimed to investigate the association between gastric polyps and bone mineral density (BMD) in patients with chronic gastritis (CG). In this cross-sectional study, we collected the clinical data of 627 inpatients with CG between July 2017 and August 2022. Gastric polyps were diagnosed through gastroscopy. BMD was measured using dual energy X-ray absorptiometry. Osteopenia or osteoporosis was defined as decreased BMD. Linear regression analysis was employed to assess the relationship between BMD with gastric polyps. Logistic regression analysis was conducted to evaluate the correlation between decreased BMD and gastric polyps. In results, the prevalence of gastric polyps in males and females with CG was 17.3% and 18.3%, respectively. The occurrence of decreased BMD was observed in 51.4% and 65.1% of males and females, respectively. Gastric polyps were negatively correlated with lumbar spine, femoral neck, and total femur BMD (β=-0.025, -0.043, -0.029, p ≤ 0.005) in females with CG. Furthermore, gastric polyps significantly elevated the risk of osteoporosis or osteopenia (OR = 2.672, p = 0.010) among females with CG. However, no significant correlation between gastric polyps and BMD was detected in males with CG. In addition, gastric polyps in females were positively correlated with hypertension and high low-density lipoprotein cholesterol levels, while negatively correlated with high phosphorus levels. In conclusion, gastric polyps are negatively correlated with BMD and significantly increase the risk of osteoporosis or osteopenia in females with CG.

Current study of pathogenetic mechanisms and therapeutics of chronic atrophic gastritis: a comprehensive review

Chronic atrophic gastritis (CAG) is a prevalent digestive system disease characterized by atrophy of the gastric mucosa and the disappearance of inherent gastric glands. According to the theory of Correa's cascade, CAG is an important pathological stage in the transformation from normal condition to gastric carcinoma. In recent years, the global incidence of CAG has been increasing due to pathogenic factors, including Helicobacter pylori infection, bile reflux, and the consumption of processed meats. In this review, we comprehensively described the etiology and clinical diagnosis of CAG. We focused on elucidating the regulatory mechanisms and promising therapeutic targets in CAG, with the expectation of providing insights and theoretical support for future research on CAG.

Research on drug treatment and the novel signaling pathway of chronic atrophic gastritis

BACKGROUND

Chronic atrophic gastritis (CAG) is a global digestive system disease and one of the important causes of gastric cancer. The incidence of CAG has been increasing yearly worldwide.

PURPOSE

This article reviews the latest research on the common causes and future therapeutic targets of CAG as well as the pharmacological effects of corresponding clinical drugs. We provide a detailed theoretical basis for further research on possible methods for the treatment of CAG and reversal of the CAG process.

RESULTS

CAG often develops from chronic gastritis, and its main pathological manifestation is atrophy of the gastric mucosa, which can develop into gastric cancer. The drug treatment of CAG can be divided into agents that regulate gastric acid secretion, eradicate Helicobacter. pylori (H. pylori), protect gastric mucous membrane, or inhibit inflammatory factors according to their mechanism of action. Although there are limited specific drugs for the treatment of CAG, progress is being made in defining the pathogenesis and therapeutic targets of the disease. Growing evidence shows that NF-κB, PI3K/AKT, Wnt/ β-catenin, MAPK, Toll-like receptors (TLRs), Hedgehog, and VEGF signaling pathways play an important role in the development of CAG.

Association between Chronic Atrophic Gastritis and Bone Mineral Density among Women Older than 40 Years of Age in Korea

BACKGROUND

Chronic atrophic gastritis causes hypochlorhydria, hypergastrinemia, and malabsorption of nutrients, leading to lower bone mineral density. The few studies that investigated the association between chronic atrophic gastritis and bone mineral density have reported inconsistent findings. As such, the present study assessed the association between chronic atrophic gastritis and bone mineral density among a large sample of women >40 years of age in Korea.

METHODS

Data from 8,748 women >40 years of age who underwent esophagogastroduodenoscopy and bone densitometry were analyzed. Chronic atrophic gastritis was diagnosed using esophagogastroduodenoscopy. Bone mineral density of the lumbar vertebrae (L), femur neck, and femur total, measured using dual-energy X-ray absorptiometry, were the primary outcome variables. Low bone mineral density, which could be diagnosed as osteoporosis or osteopenia, was defined and analyzed as a secondary outcome. Linear regression was used to calculate adjusted mean values of bone mineral density. The association between low bone mineral density and chronic atrophic gastritis was analyzed using multiple logistic regression.

RESULTS

The adjusted mean bone mineral density for L1-L4 was 1.063±0.003, femur neck (0.826±0.002), and femur total (0.890±0.002) were significantly lower in patients with chronic atrophic gastritis than others (1.073±0.002, 0.836±0.001, 0.898±0.002, respectively; all P<0.01). Women with chronic atrophic gastritis exhibited an increased likelihood for osteopenia or osteoporosis, even after adjusting for age and other confounding factors (odds ratio, 1.25; 95% confidence interval, 1.13-1.40; P<0.01). However, subgroup analysis revealed statistical significance only in postmenopausal women (odds ratio, 1.27; P<0.001).

CONCLUSION

Chronic atrophic gastritis was associated with lower bone mineral density and a higher risk for osteopenia or osteoporosis among postmenopausal women.

Clinical features and shared mechanisms of chronic gastritis and osteoporosis

Chronic gastritis (CG) and osteoporosis (OP) are common and occult diseases in the elderly and the relationship of these two diseases have been increasingly exposed. We aimed to explore the clinical characteristics and shared mechanisms of CG patients combined with OP. In the cross-sectional study, all participants were selected from BEYOND study. The CG patients were included and classified into two groups, namely OP group and non-OP group. Univariable and multivariable logistic regression methods were used to evaluate the influencing factors. Furthermore, CG and OP-related genes were obtained from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the GEO2R tool and the Venny platform. Protein-protein interaction information was obtained by inputting the intersection targets into the STRING database. The PPI network was constructed by Cytoscape v3.6.0 software again, and the key genes were screened out according to the degree value. Gene function enrichment of DEGs was performed by Webgestalt online tool. One hundred and thirty CG patients were finally included in this study. Univariate correlation analysis showed that age, gender, BMI and coffee were the potential influencing factors for the comorbidity (P < 0.05). Multivariate Logistic regression model found that smoking history, serum PTH and serum β-CTX were positively correlated with OP in CG patients, while serum P1NP and eating fruit had an negative relationship with OP in CG patients. In studies of the shared mechanisms, a total of 76 intersection genes were identified between CG and OP, including CD163, CD14, CCR1, CYBB, CXCL10, SIGLEC1, LILRB2, IGSF6, MS4A6A and CCL8 as the core genes. The biological processes closely related to the occurrence and development of CG and OP mainly involved Ferroptosis, Toll-like receptor signaling pathway, Legionellosis and Chemokine signaling pathway. Our study firstly identified the possible associated factors with OP in the patients with CG, and mined the core genes and related pathways that could be used as biomarkers or potential therapeutic targets to reveal the shared mechanisms.

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Bone Fragility in Gastrointestinal Disorders

Osteoporosis is a common systemic disease of the skeleton, characterized by compromised bone mass and strength, consequently leading to an increased risk of fragility fractures. In women, the disease mainly occurs due to the menopausal fall in estrogen levels, leading to an imbalance between bone resorption and bone formation and, consequently, to bone loss and bone fragility. Moreover, osteoporosis may affect men and may occur as a sequela to different diseases or even to their treatments. Despite their wide prevalence in the general population, the skeletal implications of many gastrointestinal diseases have been poorly investigated and their potential contribution to bone fragility is often underestimated in clinical practice. However, proper functioning of the gastrointestinal system appears essential for the skeleton, allowing correct absorption of calcium, vitamins, or other nutrients relevant to bone, preserving the gastrointestinal barrier function, and maintaining an optimal endocrine-metabolic balance, so that it is very likely that most chronic diseases of the gastrointestinal tract, and even gastrointestinal dysbiosis, may have profound implications for bone health. In this manuscript, we provide an updated and critical revision of the role of major gastrointestinal disorders in the pathogenesis of osteoporosis and fragility fractures.

Do patients with gastroesophageal reflux disease exhibit compromised bone quality prior to proton pump inhibitor therapy?

Patients with gastroesophageal reflux disease (GERD) are routinely treated with proton pump inhibitors (PPIs), despite many reports of increased fracture risk associated with PPI use. Notably, the skeletal properties in patients with GERD prior to PPI therapy have not been addressed. We hypothesized that PPI-naïve GERD patients have bone impairment, and that short-term treatment with PPI has minimal skeletal effects. To test this, 17 (12 men/5 women) GERD patients age 32–73 years, not previously exposed to PPI, and 17 age- and sex-matched controls were enrolled from September 2010 to December 2012. Bone mineral density (BMD) at lumbar spine, femoral neck, total hip, and trabecular bone score (TBS) at the lumbar spine, a marker of bone microarchitecture, were measured by dual X-ray absorptiometry. Markers of bone turnover and calcium homeostasis, and gastric hormones were analyzed. The same parameters were measured after three months of treatment with the PPI pantoprazole. The GERD patients displayed a significantly lower TBS at baseline than controls (1.31 ± 0.11 vs. 1.43 ± 0.07, p = 0.0006). Total hip and femoral neck BMD were lower in patients compared to controls, however, not significantly (p = 0.09 and 0.12, respectively). CTX was non-significantly higher in GERD patients at baseline (p = 0.11). After three months, changes in BMD, TBS and CTX did not differ between the groups. In conclusion, this is the first report demonstrating compromised bone quality and inferior BMD in PPI-naïve GERD patients. Treatment with pantoprazole did not influence bone parameters, indicating that short-term use with this PPI is safe for the skeleton.

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Previous studies have reported an increased fracture risk in PPI users.

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Patients with GERD had compromised bone quality before starting PPI.

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Three months treatment with pantoprazole did not influence bone parameters.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Normative Data for Impact Microindentation for Australian Men: Cross-Sectional Data From the Geelong Osteoporosis Study

Impact microindentation (IMI) is a novel technique for assessing the bone material strength index (BMSi) in vivo. However, no studies have presented normative data for BMSi. The aim of this study was to develop such normative data using a population-based sample of men, randomly selected from electoral rolls for the Barwon Statistical Division in southeastern Australia to participate in the Geelong Osteoporosis Study. BMSi was measured on the tibial plateau using an OsteoProbe in 405 men (ages 33 to 96 years) during the period 2016 to 2019. Associations between BMSi, age, and anthropometry were examined using linear regression models. BMSi values ranged from 49.0 to 100.5. BMSi was negatively correlated with age (r = -0.152, p = 0.002), weight (r = -0.103, p = 0.039), and BMI (r = -0.187, p < 0.001), and positively correlated with height (r = +0.107, p = 0.032). Mean ± SD BMSi was 82.6 ± 7.0 for the whole group, and ranged from 85.6 ± 6.0 for ages 30 to 39 years to 79.8 ± 6.6 for ages 80+ years. This study provides normative data that can be used to calculate T- and Z-scores for BMSi. These data will be useful for identifying men with low BMSi. Further research is warranted to derive optimal cut points for BMSi that discriminate fracture risk. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Added Value of Impact Microindentation in the Evaluation of Bone Fragility: A Systematic Review of the Literature

The current gold standard for the diagnosis of osteoporosis and the prediction of fracture risk is the measurement of bone mineral density (BMD) using dual energy x-ray absorptiometry (DXA). A low BMD is clearly associated with increased fracture risk, but BMD is not the only determinant of bone strength, particularly in secondary osteoporosis and metabolic bone disorders in which components other than BMD are affected and DXA often underestimates true fracture risk. Material properties of bone which significantly contribute to bone strength have become evaluable in vivo with the impact microindentation (IMI) technique using the OsteoProbe® device. The question arises whether this new tool is of added value in the evaluation of bone fragility. To this effect, we conducted a systematic review of all clinical studies using IMI in vivo in humans also addressing practical aspects of the technique and differences in study design, which may impact outcome. Search data generated 38 studies showing that IMI can identify patients with primary osteoporosis and fractures, patients with secondary osteoporosis due to various underlying systemic disorders, and scarce longitudinal data also show that this tool can detect changes in bone material strength index (BMSi), following bone-modifying therapy including use of corticosteroids. However, this main outcome parameter was not always concordant between studies. This systematic review also identified a number of factors that impact on BMSi outcome. These include subject- and disease-related factors such as the relationship between BMSi and age, geographical region and the presence of fractures, and technique- and operator-related factors. Taken together, findings from this systematic review confirm the added value of IMI for the evaluation and follow-up of elements of bone fragility, particularly in secondary osteoporosis. Notwithstanding, the high variability of BMSi outcome between studies calls for age-dependent reference values, and for the harmonization of study protocols. Prospective multicenter trials using standard operating procedures are required to establish the value of IMI in the prediction of future fracture risk, before this technique is introduced in routine clinical practice.

Adverse Effects of Proton Pump Inhibitors-Evidence and Plausibility

Proton pump inhibitors (PPIs) have been increasingly used over the last decades and there are concerns about overuse and the numerous reported side-effects. It is uncertain whether associations between PPI use and potential side effects are causal. However, important evidence from experimental and mechanistic studies that could support a causal relationship may have been underestimated by epidemiologists and meta-analysists. In the current manuscript we review the combined epidemiological and mechanistic evidence of the adverse effects of PPI use.

Associations Between Bone Impact Microindentation and Clinical Risk Factors for Fracture

Impact microindentation (IMI) measures bone material strength index (BMSi) in vivo. However, clinical risk factors that affect BMSi are largely unknown. This study investigated associations between BMSi and clinical risk factors for fracture in men. BMSi was measured using the OsteoProbe in 357 men (ages 33 to 96 years) from the Geelong Osteoporosis Study. Risk factors included age, weight, height, body mass index (BMI), femoral neck bone mineral density (BMD), parental hip fracture, prior fracture, type 2 diabetes mellitus (T2DM), secondary osteoporosis, smoking, alcohol consumption, sedentary lifestyle, medications, diseases, and low serum vitamin D levels. BMSi was negatively associated with age (r = -0.131, P = 0.014), weight (r = -0.109, P = 0.040), and BMI (r = -0.083, P = 0.001); no correlations were detected with BMD (r = 0.000, P = 0.998) or height (r = 0.087, P = 0.10). Mean BMSi values for men with and without prior fracture were 80.2 ± 6.9 vs 82.8 ± 6.1 (P = 0.024); parental hip fracture, 80.1 ± 6.1 vs 82.8 ± 6.9 (P = 0.029); and T2DM, 80.3 ± 8.5 vs 82.9 ± 6.6 (P = 0.059). BMSi did not differ in the presence vs absence of other risk factors. In multivariable models, mean (± SD) BMSi remained associated with prior fracture and parental hip fracture after adjusting for age and BMI: prior fracture (80.5 ± 1.1 vs 82.8 ± 0.4, P = 0.044); parental fracture (79.9 ± 1.2 vs 82.9 ± 0.4, P = 0.015). No other confounders were identified. We conclude that in men, BMSi discriminates prior fracture and parental hip fracture, which are both known to increase the risk for incident fracture. These findings suggest that IMI may be useful for identifying men who have an increased risk for fracture.

Deficiency of micronutrients in patients affected by chronic atrophic autoimmune gastritis: A single-institution observational study

BACKGROUND

Chronic atrophic autoimmune gastritis (CAAG) leads to vitamin B12 deficiency, but other micronutrient deficiencies are largely understudied.

AIMS

To investigate the prevalence of micronutrient deficiencies in CAAG patients and their potential relationship with the grading of gastric atrophy or entero-chromaffin-like cells hyperplasia or body mass index (BMI).

METHODS

From 2005 to 2016 a number of CAAG patients underwent regular follow-up with annual blood testing and upper gastrointestinal tract endoscopy every years.

RESULTS

Out of the 122 CAAG patients checked (100 F; median age 65 years), 76 presented nutritional deficiencies, single in 24 and multiple in 52 cases: a deficiency of B12 and iron showed in 42 patients, 25-OH vitamin D lacked in 76 and folic acid in 6 cases. 25-OH vitamin D levels directly correlated with B12 levels and were significantly lower in patients with macronodular than in those with linear or micronodular hyperplasia. No significant correlation was observed between B12, folic acid or ferritin levels and BMI, blood gastrin levels, the grading of gastric atrophy or ECL cells hyperplasia.

CONCLUSIONS

25-OH vitamin D deficiency was the main one in CAAG patients: its correlation with B12 deficiency may indicate underlying shared pathogenic mechanisms, although further studies are needed to confirm this hypothesis.

Atrophic Gastritis as a Risk Factor for Bone Loss in Premenopausal Women in Their 40s: A Retrospective Cohort Study

This study assessed the effects of atrophic gastritis on bone mineral density (BMD) in premenopausal women in their 40s. We performed a retrospective analysis of medical records of premenopausal women in their 40s who underwent a health checkup, esophagogastroduodenoscopy, and bone densitometry at least thrice, 24 months apart, between January 2006 and December 2016. Based on first-visit esophagogastroduodenoscopy results, patients were divided into atrophic and non-atrophic gastritis groups; BMD changes over time were analyzed. Patients were further divided into subgroups depending on atrophic gastritis persistence; differences and absolute changes in BMD were assessed. BMD in both groups exhibited group-by-time interaction (p < 0.001). After adjusting for confounding factors, the mean BMD was significantly different at the 24-month and the 48-month follow-up (p = 0.049, p < 0.001, respectively). Subgroup analysis after adjusting for confounding factors showed a mean BMD of 1.128 and 1.104 at baseline, 1.110 and 1.100 at the 24-month follow-up, and 1.106 and 1.065 at the 48-month follow-up for persistent atrophic and non-atrophic gastritis groups, respectively. The difference between mean BMD was not significant at baseline (p = 0.171), but was significant at the 24-month and 48-month follow-ups (p = 0.044 and p < 0.001, respectively). Absolute changes in BMD over 48 months were - 0.010 and - 0.051 for the two subgroups, which was significantly different (p < 0.001). Atrophic gastritis reduces BMD in premenopausal women in their 40s. Patients with atrophic gastritis exhibited lower BMD than patients without, and patients with persistent atrophic gastritis exhibited a greater decrease in BMD.

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 (rs = 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.

A cumulative effect involving malfunction of the PTH1R and ATP4A genes explains a familial gastric neuroendocrine tumor with hypothyroidism and arthritis

BACKGROUND

Type I gastric neuroendocrine tumors (gNETs) classically arise because of hypergastrinemia and involve destruction of parietal cells, which are responsible for gastric acid secretion through the ATP4A proton pump and for intrinsic factor production.

METHODS

By whole exome sequencing, we studied a family with three members with gNETs plus hypothyroidism and rheumatoid arthritis to uncover their genetic origin.

RESULTS

A heterozygous missense mutation in the ATP4A gene was identified. Carriers of this variant had low ferritin and vitamin B₁₂ levels but did not develop gNETs. A second heterozygous mutation was also uncovered (PTH1R p.E546K). Carriers exhibited hypothyroidism and one of them had rheumatoid arthritis. Gastrin activates parathyroid hormone like hormone/parathyroid hormone 1 receptor (PTH1R) signaling, which is involved in gastric cell homeostasis. Activation of parathyroid hormone/PTH1R, which is upregulated by thyrotropin in the thyroid, is also involved in RANKL expression, which regulates bone homeostasis. Thyrotropin and RANKL expression were deregulated in PTH1R mutation carriers, suggesting a link between the PTH1R gene, hypothyroidism, rheumatoid arthritis, and gastric disease. Only patients with both mutations developed gNETs plus hypothyroidism and rheumatoid arthritis.

CONCLUSION

Both mutations suggest that a collaborative mechanism is operative in this family, in which mutations in these genes affect the function and viability of parietal cells and lead to the achlorhydria that drives hypergastrinemia and the formation of gNETs.

Clinical experience with microindentation in vivo in humans

Densitometry and imaging techniques are currently used in clinical settings to measure bone quantity and spatial structure. Recently, Reference Point Indentation has opened the possibility of directly assessing the mechanical characteristics of cortical bone in living individuals, adding a new dimension to the assessment of bone strength. Impact microindentation was specifically developed for clinical studies and has been tested in several populations where there are discrepancies between bone density and fracture propensity, such as type 2 diabetes, atypical femoral fracture, stress fractures, glucocorticoid treatment, patients with osteopenia and fragility fractures, and individuals infected with HIV, among others. Microindentation will complement, not replace, existing bone analysis methods, particularly where bone mineral density does not fully explain fracture propensity. The available evidence provides solid proof of concept; future studies will fully define the role of microindentation for the assessment of bone health both in clinics and in research.

Micronutrient deficiencies in patients with chronic atrophic autoimmune gastritis: A review

Chronic atrophic autoimmune gastritis (CAAG) is an organ-specific autoimmune disease characterized by an immune response, which is directed towards the parietal cells and intrinsic factor of the gastric body and fundus and leads to hypochlorhydria, hypergastrinemia and inadequate production of the intrinsic factor. As a result, the stomach's secretion of essential substances, such as hydrochloric acid and intrinsic factor, is reduced, leading to digestive impairments. The most common is vitamin B12 deficiency, which results in a megaloblastic anemia and iron malabsorption, leading to iron deficiency anemia. However, in the last years the deficiency of several other vitamins and micronutrients, such as vitamin C, vitamin D, folic acid and calcium, has been increasingly described in patients with CAAG. In addition the occurrence of multiple vitamin deficiencies may lead to severe hematological, neurological and skeletal manifestations in CAAG patients and highlights the importance of an integrated evaluation of these patients. Nevertheless, the nutritional deficiencies in CAAG are largely understudied. We have investigated the frequency and associated features of nutritional deficiencies in CAAG in order to focus on any deficit that may be clinically significant, but relatively easy to correct. This descriptive review updates and summarizes the literature on different nutrient deficiencies in CAAG in order to optimize the treatment and the follow-up of patients affected with CAAG.