Association between Helicobacter pylori infection and nonalcoholic fatty liver disease: a systemic review and meta-analysis

Relationship between Helicobacter pylori infection and risk of metabolic dysfunction-associated steatotic liver disease: An updated meta-analysis

BACKGROUND

Recent observational studies examining the association between Helicobacter pylori infection and the risk of metabolic dysfunction-associated steatotic liver disease (MASLD) have reported conflicting results. We performed a meta-analysis to quantify the magnitude of the association between H. pylori infection and the risk of MASLD.

METHODS

We systematically searched three large electronic databases to identify eligible observational studies (published up to 30 November 2023) in which liver biopsy, imaging methods or blood-based biomarkers/scores were used for diagnosing MASLD. Data from selected studies were extracted, and meta-analysis was performed using common and random-effects modelling. Statistical heterogeneity among published studies, subgroup analyses, meta-regression analyses and publication bias were assessed.

RESULTS

A total of 28 observational studies (24 cross-sectional and 4 longitudinal studies) were identified, including 231 291 middle-aged individuals of predominantly Asian ethnicity (~95%). Meta-analysis of cross-sectional studies showed that H. pylori infection was significantly associated with a small increase in the risk of prevalent MASLD (n = 24 studies; random-effects odds ratio 1.11, 95% CI 1.05-1.18; I2 = 63%). Meta-analysis of data from longitudinal studies showed that H. pylori infection was significantly associated with an increased risk of developing incident MASLD over a mean 5-year follow-up (n = 4 studies; random-effects odds ratio 1.20, 95%CI 1.08-1.33; I2 = 44%). Sensitivity analyses did not modify these results. The funnel plot did not reveal any significant publication bias.

CONCLUSIONS

H. pylori infection is associated with a mildly increased risk of prevalent and incident MASLD. Further well-designed prospective and mechanistic studies are required to better decipher the complex link between H. pylori infection and the risk of MASLD.

An update: is there a relationship between H. pylori infection and nonalcoholic fatty liver disease? why is this subject of interest?

Helicobacter pylori (H. pylori) infection is thought to impact various extragastric diseases, including nonalcoholic fatty liver disease (NAFLD), the most common chronic liver disease. Meanwhile, the pathogenesis of NAFLD needs further research, and effective treatment for this disease remains elusive. In this mini-review, we enumerate and ponder on the evidence demonstrating an association between H. pylori infection and NAFLD. Primarily, we delve into high-quality meta-analyses and clinical randomized controlled trials focusing on the association studies between the two. We also discuss clinical studies that present opposite conclusions. In addition, we propose a mechanism through which H. pylori infection aggravates NAFLD: inflammatory cytokines and adipocytokines, insulin resistance, lipid metabolism, intestinal barrier and microbiota, H. pylori outer membrane vesicles and H. pylori-infected cell-extracellular vesicles. This mini-review aims to further explore NAFLD pathogenesis and extragastric disease mechanisms caused by H. pylori infection.

HELICOBACTER AND HEPATOBILIARY DISEASES: UPDATE 2023

•Clinical studies have shown that hepatobiliary diseases of inflammatory and neoplastic origin are associated with Helicobacter infection. •Translocation and the ascending pathway are putative mechanisms for Helicobacter spp to enter the hepatobiliary system. •H. pylori infection has a systemic effect through the activity of pro-inflammatory cytokines, TNF-α, leukotrienes, interferon-β, interferon-γ, and acute phase proteins. •Histopathological confirmation is needed to present that H. pylori eradication prevents or improves hepatobiliary disease progression. Helicobacter Pylori (H. pylori) is one of the main infectious causes of gastroduodenal diseases, however, its role in developing different extragastric diseases has been proven. The possible involvement of H. pylori in the pathogenesis of cardiovascular, metabolic, neurodegenerative, skin, and hepatobiliary diseases is suggested. The bacterium has been found in tissue samples from the liver, biliary tract, and gallstones of animals and humans. However, the role of H. pylori infection in the pathogenesis of liver and biliary diseases has not been finally established. The histopathological confirmation of the positive effect of H. pylori eradication is needed. In addition, there are discussions on the clinical significance of other Helicobacter species. The review presents the data available for and against the involvement of H. pylori in hepatobi-liary disease development and progression.

Nonalcoholic fatty liver disease and non-liver comorbidities

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by excess fat accumulation in the liver. It is closely associated with metabolic syndrome, and patients with NAFLD often have comorbidities such as obesity, type 2 diabetes mellitus, and dyslipidemia. In addition to liver-related complications, NAFLD has been associated with a range of non-liver comorbidities, including cardiovascular disease, chronic kidney disease, and sleep apnea. Cardiovascular disease is the most common cause of mortality in patients with NAFLD, and patients with NAFLD have a higher risk of developing cardiovascular disease than the general population. Chronic kidney disease is also more common in patients with NAFLD, and the severity of NAFLD is associated with a higher risk of developing chronic kidney disease. Sleep apnea, a disorder characterized by breathing interruptions during sleep, is also more common in patients with NAFLD and is associated with the severity of NAFLD. The presence of non-liver comorbidities in patients with NAFLD has important implications for the management of this disease. Treatment of comorbidities such as obesity, type 2 diabetes mellitus, and dyslipidemia may improve liver-related outcomes in patients with NAFLD. Moreover, treatment of non-liver comorbidities may also improve overall health outcomes in patients with NAFLD. Therefore, clinicians should be aware of the potential for non-liver comorbidities in patients with NAFLD and should consider the management of these comorbidities as part of the overall management of this disease.

Discussion on the common controversies of Helicobacter pylori infection

BACKGROUND

Helicobacter pylori ( H. pylori ) can persistently colonize on the gastric mucosa after infection and cause gastritis, atrophy, metaplasia, and even gastric cancer (GC).

METHODS

Therefore, the detection and eradication of H. pylori are the prerequisite.

RESULTS

Clinically, there are some controversial issues, such as why H. pylori infection is persistent, why it translocases along with the lesser curvature of the stomach, why there is oxyntic antralization, what the immunological characteristic of gastric chronic inflammation caused by H. pylori is, whether H. pylori infection is associated with extra-gastric diseases, whether chronic atrophic gastritis (CAG) is reversible, and what the potential problems are after H. pylori eradication. What are the possible answers?

CONCLUSION

In the review, we will discuss these issues from the attachment to eradication in detail.

Relationship of Helicobacter pylori Infection with Nonalcoholic Fatty Liver Disease: A Meta-Analysis

Background and Aims

Helicobacter pylori (H. pylori) and nonalcoholic fatty liver disease (NAFLD) have become increasingly recognized, both of which affect human health globally. The association of H. pylori infection with NAFLD remains unclear.

Methods

PubMed, EMBASE, and Cochrane Library databases were searched. Only a random-effects model was used. Odds ratios (ORs) and risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for the combined estimates of raw data. Adjusted ORs (aORs) and hazard ratios (aHRs) with 95% CIs were calculated for the combined estimates of data adjusted for confounders.

Results

Thirty-four studies with 218573 participants were included. Based on unadjusted data from 26 cross-sectional studies and 3 case-control studies, H. pylori infection was significantly associated with the presence of NAFLD (OR = 1.26, 95% CI = 1.17-1.36, P < 0.001). Based on adjusted data from 15 cross-sectional studies and 1 case-control study, H. pylori infection was significantly associated with the presence of NAFLD (aOR = 1.25, 95% CI = 1.08-1.44, P < 0.001). Compared with control subjects without NAFLD, patients with moderate (OR = 1.67, 95% CI = 1.17-2.39, P = 0.005) and severe (OR = 1.71, 95% CI = 1.30-2.24, P < 0.001) NAFLD, but not those with mild NAFLD (OR = 1.14, 95% CI = 0.9-1.45, P = 0.286), had significantly higher proportions of H. pylori infection. The association of H. pylori infection with the occurrence of NAFLD was statistically significant based on adjusted data from 3 cohort studies (aHR = 1.18, 95% CI = 1.05-1.34, P = 0.007), but not based on unadjusted data from 3 cohort studies (RR = 1.41, 95% CI = 0.80-2.48, P = 0.237).

Conclusion

H. pylori infection is associated with NAFLD, especially moderate and severe NAFLD. The impact of H. pylori eradication on the prevention of NAFLD should be further explored.

Association between Helicobacter pylori infection and non-alcoholic fatty liver disease for Asian and non-Asian population: A systematic review and meta-analysis

Background

Several studies have revealed a positive correlation between a Helicobacter pylori (HP) infection and the risk of non-alcoholic fatty liver disease (NAFLD). This meta-analysis was conducted to explore further the relationship between HP infection and NAFLD in the Asian and non-Asian populations.

Methods

Relevant studies published from inception to July 22, 2021, in the following databases: PubMed, EMBASE, the Cochrane library, and Web of Science were comprehensively searched. The odds ratio (OR) and hazard ratio (HR) with a 95% confidence interval (95%CI) were pooled by the random-effects model or fixed-effects model. Additionally, subgroup and sensitivity analyses were performed. The funnel plot and the Egger test were used to estimate publication bias.

Results

This meta-analysis included 25 studies involving 107,306 participants. Positive associations between HP infection and NAFLD were found both for the Asian (OR = 1.30, 95% CI: 1.13-1.49, P < 0.01; I 2 = 94.30%, P < 0.01) and non-Asian populations (OR = 1.42, 95% CI: 1.04-1.94, P = 0.03; I 2 = 44.90%, P = 0.09). Moreover, similar results were observed in the Asian female group (OR = 1.31, 95% CI: 1.17-1.46, P < 0.01; I 2 = 46.30%, P = 0.07) but not for the Asian male group. Subgroup analyses for the Asian population showed that there were differences in the association among NAFLD diagnosis methods (P < 0.01) and the study design (P < 0.01). However, subgroup and sensitivity analyses results showed that the association for the non-Asian population was not stable enough.

Conclusions

The data obtained in this systematic review and meta-analysis suggested that an HP infection was associated with an increased risk of NAFLD for Asian and non-Asian populations. However, the association was not found for Asian males. Further studies are required to establish the causal association, especially for the non-Asian population.

Systematic review registration

Identifier: CRD42021266871.

Management of Helicobacter pylori infection: the Maastricht VI/Florence consensus report

Helicobacter pyloriInfection is formally recognised as an infectious disease, an entity that is now included in the International Classification of Diseases 11th Revision. This in principle leads to the recommendation that all infected patients should receive treatment. In the context of the wide clinical spectrum associated with Helicobacter pylori gastritis, specific issues persist and require regular updates for optimised management.The identification of distinct clinical scenarios, proper testing and adoption of effective strategies for prevention of gastric cancer and other complications are addressed. H. pylori treatment is challenged by the continuously rising antibiotic resistance and demands for susceptibility testing with consideration of novel molecular technologies and careful selection of first line and rescue therapies. The role of H. pylori and antibiotic therapies and their impact on the gut microbiota are also considered.Progress made in the management of H. pylori infection is covered in the present sixth edition of the Maastricht/Florence 2021 Consensus Report, key aspects related to the clinical role of H. pylori infection were re-evaluated and updated. Forty-one experts from 29 countries representing a global community, examined the new data related to H. pylori infection in five working groups: (1) indications/associations, (2) diagnosis, (3) treatment, (4) prevention/gastric cancer and (5) H. pylori and the gut microbiota. The results of the individual working groups were presented for a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in various clinical fields.

Is the Occurrence or Reversal of Nonalcoholic Fatty Liver Disease Associated with Long-Term Helicobacter pylori Infection among Chinese Adults? A Cohort Study

Background

Previous studies have suggested a link between Helicobacter pylori (H. pylori) infection and nonalcoholic fatty liver disease (NAFLD), yet long-term follow-up studies to elucidate this association are lacking. We aimed to identify the relationship between NAFLD and H. pylori in these people.

Methods

A total of 2,934 adults between June 2013 and October 2017 were collected; among them, 675 people met the requirements. People were assessed for H. pylori infection diagnosis as detected by the carbon-13 urea breath test; they were also assessed for NAFLD diagnosis by ultrasound.

Results

H. pylori infection was present in 206 patients (30.5%), and 469 (69.5%) participants were classified as controls. Participants with H. pylori infection had a higher rate of incident NAFLD than those who were uninfected (37/206; 18% versus 73/469; 15.6%) (p < 0.001). Compared with the control group, the recovery rate of NAFLD in the H. pylori+ve group was low (6/206, 2.9% versus 33/469, 7.0%) (p < 0.001). Besides, the incidence of uric acid, postprandial blood glucose, TG, LDL-C, HDL-C, and fasting plasma glucose was significantly different between the two groups (p < 0.001), but no difference was found in alanine aminotransferase (ALT), liver-total protein, urea nitrogen, and cholesterol (p > 0.05).

Conclusion

H. pylori infection was a risk factor for NAFLD and affected the occurrence or reversal of NAFLD, indicating that H. pylori infection eradication might play a role in reducing the risk of NAFLD.

A bridge for short-chain fatty acids to affect inflammatory bowel disease, type 1 diabetes, and non-alcoholic fatty liver disease positively: by changing gut barrier

PURPOSE

In previous studies, short-chain fatty acids (SCFAs) have been found to regulate gut microbiota and change gut barrier status, and the potential positive effects of SCFAs on inflammatory bowel disease (IBD), type 1 diabetes mellitus (T1D), and non-alcoholic fatty liver disease (NAFLD) have also been found, but the role of SCFAs in these three diseases is not clear. This review aims to summarize existing evidence on the effects of SCFAs on IBD, T1D, and NHFLD, and correlates them with gut barrier and gut microbiota (gut microbiota barrier).

METHODS

A literature search in PubMed, Web of Science, Springer, and Wiley Online Library up to October 2020 was conducted for all relevant studies published.

RESULTS

This is a retrospective review of 150 applied research articles or reviews. The destruction of gut barrier may promote the development of IBD, T1D, and NAFLD. SCFAs seem to maintain the gut barrier by promoting the growth of intestinal epithelial cells, strengthening the intestinal tight connection, and regulating the activities of gut microbiota and immune cells, which might result possible beneficial effects on the above three diseases at a certain dose.

CONCLUSIONS

Influencing gut barrier health may be a bridge for SCFAs (especially butyrate) to have positive effects on IBD, T1D, and NAFLD. It is expected that this article can provide new ideas for the subsequent research on the treatment of diseases by SCFAs and help SCFAs be better applied to precise and personalized treatment.

Helicobacter pylori and non-alcoholic fatty liver disease

Helicobacter pylori is the most prevalent infection worldwide, while non-alcoholic fatty liver disease emerged as the most frequent liver disease. The common occurrence can be either by chance or due to certain pathogenetic factors. Epidemiologic studies revealed that the risk of non-alcoholic liver disease is increased in patients infected with Helicobacter pylori. DNA fragments of Helicobacter pylori were rarely identified in human samples of liver carcinoma and fatty liver. Helicobacter pylori could influence the development of non-alcoholic fatty liver either by hormonal (ghrelin? gastrin? insulin?), or by effect of pro-inflammatory cytokines (interleukin 1 and 8, tumor necrosis factor ɑ, interferon ɣ) and by changes of gut microbiome as well. Probiotic supplementation could improve some clinical parameters of non-alcoholic fatty liver disease and eradication rates of Helicobacter pylori. Regimens used for eradication can be safely administered, although non-alcoholic fatty liver increases the risk of drug-induced liver damage. Controlled studies of the effect of eradication on the development and progression of non-alcoholic fatty liver are warranted.

Action of hormonal therapy in amyotrophic lateral sclerosis: a systematic review

Amyotrophic Lateral Sclerosis (ALS) is a fatal disease characterized by muscle weakness, atrophy, fasciculations, and decreased reflexes due to upper and lower motor neurons death. It can be present in both sexes (55-65 years), but with predominance in males. However, in female patients, ALS presents its first symptoms when they are already postmenopausal, when then the incidence ratio of the disease is practically equal between the sexes, which leads to a probable involvement of sex hormones in the development and protection against ALS. The aim of this systematic review, which used the PRISMA consensus and NOS (New Castle-Ottawa Scale) score, was to evaluate the evidence of the action of hormone therapy in women with ALS. The Medline and Cochrane databases were accessed from March 2019 to June 2019, and only full-text articles in Spanish, English, and Portuguese were included. Only four articles matched our inclusion criteria. Postmenopausal women who used exogenous estrogen did not have the same protective factor as women still under the action of endogenous estrogen in the same age group. There was also no increase in the survival of these women.

Associations between Helicobacter pylori with nonalcoholic fatty liver disease and other metabolic conditions in Guatemala

BACKGROUND

Previous studies have suggested an association between Helicobacter pylori (H pylori) and nonalcoholic fatty liver disease (NAFLD). The aim of the current study was to examine the association in Guatemala, a region with elevated prevalences of both H pylori and NAFLD. Associations between H pylori and other metabolic conditions were also examined, as were associations between H hepaticus and H bilis and the metabolic conditions.

MATERIALS & METHODS

The analysis included 424 participants from a cross-sectional study in Guatemala. H pylori seropositivity was defined as positivity for ≥ 4 antigens. Seropositivities for H bilis and H hepaticus were defined as positivity for ≥ 2 antigens. NAFLD was estimated using the Fatty Liver Index and the Hepatic Steatosis Index. Other conditions examined were obesity, central obesity, hypercholesterolemia, low HDL, diabetes and metabolic syndrome (MetSyn). Prevalence odds ratios (POR) and 95% confidence intervals (CIs) were estimated.

RESULTS

No overall associations between H pylori,H hepaticus, or H bilis and NAFLD or related metabolic conditions were found. Seropositivity for H pylori antigens CagA and VacA and H hepaticus antigen HH0713 was each significantly associated with NAFLD, however. In addition, associations were observed between the H pylori antigens HyuA, HP1564, and UreA and specified metabolic conditions.

CONCLUSIONS

While no overall associations between H pylori or Helicobacter species with NAFLD or related conditions were observed, some selected Helicobacter spp. antigens were associated with NAFLD. Further research is warranted to examine whether H. species are associated with any metabolic condition.

Review: Extragastric diseases and Helicobacter pylori

The involvement of Helicobacter pylori infection in many extra-gastroduodenal manifestations remains a fascinating field of investigation. However, for several of these supposed associations, the potential pathogenic mechanism remains unclear. The present review highlights the main associations of H pylori with extra-gastroduodenal manifestations reported during the last year. We searched for the most relevant studies on this topic, published between April 2019 and March 2020, identified using the term "Helicobacter" in the MEDLINE/Pubmed database. Consistent data emerged from studies investigating metabolic syndrome and ischaemic cardiovascular diseases. Other reported fields of investigation were hepatology, especially focused on non-alcoholic steatohepatitis, neurology, including Parkinson's disease and Alzheimer's disease, as well as dermatology. Inflammatory bowel disease (IBD), that comprises Crohn's disease and ulcerative colitis, may originate from a dysregulation of the host's immune response to commensal bacteria in individuals with genetic predisposition. The reduction of biodiversity and other specific imbalances in the faecal microbiome composition of IBD patients compared to that of healthy controls support this hypothesis. In this context, an inverse correlation between H pylori infection and IBD prevalence has been confirmed. Similar results were found in patients with kidney diseases and allergic manifestations. There are indications of the possible involvement of H pylori infection in metabolic syndrome and ischaemic cardiovascular diseases. However, due to a series of factors linked to study designs and the multifactorial pathogenesis of some diseases, further studies are needed.

The relationship between Helicobacter pylori and chronic kidney disease: update 2020

A number of studies has confirmed that the epidemiology of Helicobacter pylori is changing worldwide, with a decrease especially in developed countries. Nevertheless, since this gram-negative bacterium infects almost 50% of the world's population, it remains a global problem. Beyond its role in the pathogenesis of the main gastroduodenal diseases, including gastritis, peptic ulcer and gastric cancer, Helicobacter pylori has been suspected to be involved in several extra-gastroduodenal disorders. Patients with chronic kidney disease (CKD) present gastric mucosal injuries and dyspepsia more often than the general population. However, the reported relationship between CKD and Helicobacter pylori infection is conflicting. In fact, in this population these conditions have a multifactorial pathogenesis and Helicobacter pylori infection could play a limited role in their development. Nevertheless, while it seems that the prevalence of the bacterium is lower in patients with CKD than in controls, Helicobacter pylori has been shown to be associated to an increased occurrence of proteinuria in patients with type 2 diabetes mellitus. This narrative review analyzes the results of recent literature in this field with particular focus on data reported by meta-analyses.

Active Helicobacter pylori Infection is Independently Associated with Nonalcoholic Steatohepatitis in Morbidly Obese Patients

Nonalcoholic fatty liver disease (NAFLD) emerges as an important global burden and Helicobacter pylori infection (Hp-I) has been suggested as a risk factor of NAFLD, although controversy exists. This retrospective study aimed to investigate a potential impact of active Hp-I on NAFLD severity in morbidly obese patients, subjected to bariatric surgery and gastric biopsy for documentation of Hp-I. Of 64 eligible participants, 15 (23.4%) were diagnosed with active Hp-I, showing higher rates of nonalcoholic steatohepatitis (NASH) than those without Hp-I (86.7% vs. 26.5%, respectively; p < 0.001). Concerning histological lesions, steatosis grade (p = 0.027), ballooning (p < 0.001), lobular inflammation (p = 0.003), and fibrosis stage (p < 0.001) were also more severe in Hp-I positive patients. Likewise, liver function tests, insulin resistance, dyslipidemia, and arterial hypertension were significantly higher in Hp-I positive patients. Hp-I was independently positively associated with NASH (beta = 3.27; p = 0.002), severe NASH (beta = 2.37; p = 0.018), and the presence of fibrosis (beta = 3.86; p = 0.001) in a binary regression model, after adjustment for potential confounders. In conclusion, active Hp-Ι was independently associated with NASH and fibrosis, findings offering potential clinical implication.

Diet, Gut Microbiota and Non-Alcoholic Fatty Liver Disease: Three Parts of the Same Axis

Non-Alcoholic Fatty Liver Disease (NAFLD) is the most common liver disease in the world. NAFLD is principally characterized by an excessive fat accumulation in the hepatocytes. Diet is considered as one of the main drivers to modulate the composition of gut microbiota, which participate in different processes, affecting human metabolism. A disruption in the homeostasis of gut microbiota may lead to dysbiosis, which is commonly reflected by a reduction of the beneficial species and an increment in pathogenic microbiota. Gut and liver are in close relation due to the anatomical and functional interactions led by the portal vein, thus altered intestinal microbiota might affect liver functions, promoting inflammation, insulin resistance and steatosis, which is translated into NAFLD. This review will highlight the association between diet, gut microbiota and liver, and how this axis may promote the development of NAFLD progression, discussing potential mechanisms and alterations due to the dysbiosis of gut microbiota. Finally, it will revise the variations in gut microbiota composition in NAFLD, and it will focus in specific species, which directly affect NAFLD progression.

Relationship Between Helicobacter pylori Infection and Nonalcoholic Fatty Liver Disease (NAFLD) in a Developing Country: A Cross-Sectional Study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a very common disease that affects 25-30% of the population in western countries. Many studies have observed the importance of H. pylori infection in the development of insulin resistance, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, and liver fibrosis and cirrhosis. However, the evidence from different studies was controversial. The present study aimed to investigate the relationship between H. pylori infection and NAFLD in a developing country.

PATIENTS AND METHODS

This cross-sectional study included all the attending outpatient clinics at four Major University hospitals and two research and clinical institutes in a developing country in the period between June and October 2019. Patients were assessed for the diagnosis of H. pylori infection as detected by H. pylori antigen in stool; they were also assessed for the diagnosis of NAFLD by ultrasound, fibroscan, and CAP.

RESULTS

The study was conducted on 646 patients; H. pylori infection was found to be present in 538 patients (83.3%). NAFLD (diagnosed by both U/S and Fibroscan with CAP), ALT, AST, hepatomegaly, hypertension, fasting blood sugar were significantly higher in H. pylori +ve group than H. pylori -ve group. After performing Linear regression of independent risk factors of NAFLD to prove or to refute the role of Helicobacter; H. pylori positivity, total cholesterol, degree of fatty liver by ultrasound, fasting blood sugar and diastolic blood pressure were independent risk factors for NAFLD.

CONCLUSION

Helicobacter pylori infection was independent risk factors for NAFLD and correlated with increased degree of steatosis.

Review: Helicobacter pylori and extragastric diseases

In the last year, many studies have demonstrated a potential role of Helicobacter pylori in the pathogenic mechanisms of different extragastric diseases. While the role of H pylori in idiopathic thrombocytopenic purpura, idiopathic iron deficiency anemia, and vitamin B12 deficiency has already been demonstrated, there is growing evidence of other related conditions, especially cardiovascular, metabolic, and neurologic disorders, including neurodegenerative diseases. A summary of the results of the most relevant studies published over the last year on this attractive topic is presented in this review.