Serum γ-glutamyltransferase level is associated with periodontal disease independent of drinking habits in Japanese adults

Role of Nonalcoholic Fatty Liver Disease in Periodontitis: A Bidirectional Relationship

Nonalcoholic fatty liver disease (NAFLD) and periodontitis share common risk factors such as obesity, insulin resistance (IR), and dyslipidemia, which contribute to systemic inflammation. It has been suggested that a bidirectional relationship exists between NAFLD and periodontitis, indicating that one condition may exacerbate the other. NAFLD is characterized by excessive fat deposition in the liver and is associated with low-grade chronic inflammation. There are several risk factors for the development of NAFLD, including gender, geriatric community, race, ethnicity, poor sleep quality and sleep deprivation, physical activity, nutritional status, dysbiosis gut microbiota, increased oxidative stress, overweight, obesity, higher body mass index (BMI), IR, type 2 diabetes mellitus (T2DM), metabolic syndrome (MetS), dyslipidemia (hypercholesterolemia), and sarcopenia (decreased skeletal muscle mass). This systemic inflammation can contribute to the progression of periodontitis by impairing immune responses and exacerbating the inflammatory processes in the periodontal tissues. Furthermore, individuals with NAFLD often exhibit altered lipid metabolism, which may affect oral microbiota composition, leading to dysbiosis and increased susceptibility to periodontal disease. Conversely, periodontitis has been linked to the progression of NAFLD through mechanisms involving systemic inflammation and oxidative stress. Chronic periodontal inflammation can release pro-inflammatory cytokines and bacterial toxins into the bloodstream, contributing to liver inflammation and exacerbating hepatic steatosis. Moreover, periodontitis-induced oxidative stress may promote hepatic lipid accumulation and IR, further aggravating NAFLD. The interplay between NAFLD and periodontitis underscores the importance of comprehensive management strategies targeting both conditions. Lifestyle modifications such as regular exercise, a healthy diet, and proper oral hygiene practices are crucial for preventing and managing these interconnected diseases. Additionally, interdisciplinary collaboration between hepatologists and periodontists is essential for optimizing patient care and improving outcomes in individuals with NAFLD and periodontitis.

Non-alcoholic fatty liver disease and periodontal disease: A systematic review and meta-analysis of cross-sectional studies

Non-alcoholic fatty liver disease (NAFLD) is a chronic liver disease, comprising hepatic steatosis, and non-alcoholic steatohepatitis. Periodontal disease (PD) may be a risk factor for the evolution of liver cirrhosis. This study aimed to evaluate the association between NAFLD and PD.We searched in Pubmed, Scopus, Cochrane, and Lilacs databases with descriptors (Non-alcoholic Fatty Liver Disease OR (non-alcoholic AND Fatty Liver AND disease) OR Nonalcoholic Steatohepatitis) AND (Periodontal Disease OR Gingivitis OR Periodontitis) from January 2021 to September 2021. We selected, by the abstract, cross-sectional, cohort (prospective and retrospective), and case-control studies that address periodontal disease in patients with Non-alcoholic Fatty Liver Disease, and aged ≥ 18 years. The search was without the restriction of language and publication time.The search resulted in 954 articles. After applying the selection criteria, five cross-sectional studies remained. A metanalysis combined the study estimates of periodontal disease in NAFLD, by using the random effects. The Odds Ratio (1.91; 95% CI 1.21-3.02; P = 0.006) indicates that the chance of presenting Periodontal disease is 91% higher in individuals with NAFLD when compared with individuals without NAFLD. There are few studies with appropriate methodology to produce sound evidence about the causal relationship between the use of NAFLD and PD, however, studies support the association. So, dental staff must be aware of this association for better management of periodontal disease in patients with NAFLD.

Associations between Periodontal Status and Liver Function in the Japanese Population: A Cross-Sectional Study

A relationship between periodontitis and liver function has been suggested. Indeed, patients with severe periodontal disease have been found to be more prone to liver dysfunction. The periodontal inflammatory surface area (PISA) has been shown to be a useful indicator of periodontal and systemic diseases. However, little information is available regarding whether the PISA is associated with liver function markers, such as gamma-glutamyltransferase (GGT), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). This study aimed to clarify relationship between liver function markers, AST, ALT, and GGT, and PISA level in a cross-sectional study. The subjects were recruited between 2018 and 2021 at the Medical and Dental Collaboration Center of Kanagawa Dental College Hospital. A periodontal clinical examination was performed, and the PISA was calculated. Peripheral blood samples were collected, and serum levels of liver function markers were measured. The levels of liver function markers were examined in different values of PISA. Participants with high PISA scores were more likely to have increased GGT levels while AST and ALT were not changed with PISA. Increased GGT was found in 10.8% and 29.4% (p = 0.0056), increased AST in 48.2% and 52.9% (p = 0.62), and increased ALT in 35.2% and 47.0% (p = 0.20) among <300 mm² and ≧300 mm² PISA groups, respectively. It was found that males with a PISA of 300 mm² or higher had an elevated level of serum GGT. In conclusion, elevated GGT was found in the high PISA group, particularly in males, while AST and ALT did not differ by PISA.

Involvement of Periodontal Disease in the Pathogenesis and Exacerbation of Nonalcoholic Fatty Liver Disease/Nonalcoholic Steatohepatitis: A Review

The increasing incidence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH), along with global lifestyle changes, requires further in-depth research to elucidate the mechanisms and develop new treatment strategies. In addition, the number of patients with periodontal disease has increased recently, suggesting that periodontal disease is sometimes associated with systemic conditions. In this review, we summarize recent studies linking periodontal disease and NAFLD, the concept of the mouth-gut-liver axis, oral and intestinal microbiota, and liver disease. We suggest new research directions toward a detailed mechanistic understanding and novel targets for treatment and prevention. Forty years have passed since the concepts of NAFLD and NASH were first proposed. however, no effective prevention or treatment has been established. We also found that the pathogenesis of NAFLD/NASH is not limited to liver-related diseases but has been reported to be associated with various systemic diseases and an increasing number of causes of death. In addition, changes in the intestinal microbiota have been shown to be a risk factor for periodontal diseases, such as atherosclerosis, diabetes, rheumatoid arthritis, nonalcoholic fatty liver disease, and obesity.

Periodontal and Hepatic Parameters in Obese Patients Undergoing Bariatric Surgery

PURPOSE

Current discoveries imply a connection between periodontitis and metabolic associated fatty liver disease (MAFLD). This study aimed to determine the prevalence of periodontitis and MAFLD in obese patients with BMI >40, employing the most reliable diagnostic methods, namely liver biopsy, and detailed periodontal examination.

MATERIALS AND METHODS

Liver biopsy and periodontal examination were performed in 30 obese patients with BMI BMI >40 undergoing bariatric surgery. Kleiner's classification was used to determine non-alcoholic steatohepatitis (NAS) activity score, non-alcoholic steatohepatitis (NASH) and liver fibrosis. The periodontal condition was classified following the recent AAP/EFP classification. Patients were divided into periodontitis (PG) and non-periodontitis groups (NPG). Data on systemic health parameters were collected from patients' medical records. Descriptive statistics and simple statistical tests were used to determine the differences between the two groups.

RESULTS

The prevalence of NASH in the sample was 43% (13/30), borderline NASH 37% (11/30), while fibrosis stage 1 was most common (72%, [22/30]). Periodontitis prevalence was 67% (20/30), while all non-periodontitis patients (33%; 10/30) exhibited gingivitis. PG and NPG did not differ in NAS or NASH prevalence (p > 0.05). However, the periodontitis group showed higher C-reactive protein levels, while NPG showed higher gamma-glutamyl transpeptidase levels (p < 0.05).

CONCLUSION

The study results suggest the considerable prevalence of MAFLD, periodontitis and gingivitis in obese patients with BMI >40 undergoing bariatric surgery. Patients with periodontitis had higher CRP levels, while those with gingivitis presented higher gamma-glutamyl transpeptidase levels.

The combination of experimental periodontitis and oral microbiota from periodontitis patients aggravates liver fibrosis in mice

AIM

Periodontitis (PD) is the sixth most prevalent disease around the world and is involved in the development and progression of multiple systemic diseases. Previous studies have reported that PD may aggravate liver injuries. The objective of this study was to investigate whether and how PD affects liver fibrosis.

MATERIALS AND METHODS

Ligature-induced PD (LIP) was induced in male C57/B6J mice, and sub-gingival plaques (PL) from patients with PD were applied to mouse teeth. Liver fibrosis was induced by carbon tetrachloride (CCl₄ ) injection. The mice were randomly divided into six groups: Oil, Oil+LIP, Oil+LIP+PL, CCl₄ , CCl₄ +LIP, and CCl₄ +LIP+PL. Alveolar bone resorption was evaluated by methylene blue staining. Hepatic function was analysed by serum alanine aminotransferase and hepatic hydroxyproline. Picrosirius red and α-smooth muscle actin (SMA) staining were used to evaluate the fibrotic area. RNA sequencing and quantitative RT-PCR were used to measure gene expression. Western blotting was used to measure protein levels. Flow cytometry was used to analyse the accumulation of immune cells. Mouse microbiota were analysed using 16S rRNA gene sequencing.

RESULTS

Mice in the CCl₄ +LIP+PL group displayed higher serum alanine aminotransferase and hepatic hydroxyproline as well as more Picrosirius red-positive and α-SMA-positive areas in liver samples than those of the CCl₄ group, suggesting that PD (LIP+PL) aggravated CCl₄ -induced hepatic dysfunction and liver fibrosis. Consistently, the expression of fibro-genic genes and the protein levels of transforming growth factor β were much higher in the CCl₄ +LIP+PL group than in the CCl₄ group. Flow cytometry revealed that PD increased the accumulation of immune cells, including Kupffer cells, B cells, and Th17 cells, in the liver of mice with CCl₄ treatment. PD also increased the expression of inflammatory genes and activated pro-inflammatory nuclear factor-kappa B pathway in the livers of CCl₄ -injected mice. Moreover, PD altered both oral and liver microbiota in CCl₄ -injected mice.

CONCLUSIONS

PD aggravates CCl₄ -induced hepatic dysfunction and fibrosis in mice, likely through the increase of inflammation and alteration of microbiota in the liver.

Increasing risk factors of non-alcoholic fatty liver disease, a look into chronic periodontitis and insulin resistance

Non-alcoholic fatty liver disease (NAFLD) is marked by the excessive intrusion of triglycerides into hepatocytes without any role of alcohol consumption. Various risk factors have been attributed to this disease pathogenesis which involves metabolic disorders, immune response, and even an intricate relationship between the two. The role of insulin resistance (IR) in NAFLD has long been known; however, the molecular basis of disease progression under this metabolic backdrop is still being investigated. Similarly, the periodontitis-mediated immune response is another major factor involved in NAFLD manifestation which has generated huge interest. The prevalence of pathogenic bacteria elicits a strong immune response which according to studies shows a strong correlation with NAFLD state. Such pre-existing conditions have a strong probability of explaining the disease onset. Additionally, increasing reports of inflammatory response and its links to insulin resistance have further increased the scope of understanding NAFLD. Through this review, we aim to elaborate on these factors explaining their role in the disease progression.

Deciphering the toxicological role of Porphyromonas gingivalis derived endotoxins in liver diseases

Periodontitis is a most prevalent and infectious multifactorial inflammatory disease and is characterized by the progressive destruction of the tooth-supporting tissues. Porphyromonas gingivalis, a Gram‑negative oral anaerobe, mainly causes periodontitis and it is one of the most important risk factors responsible for aggravation of existing systemic diseases. Several experimental and clinical studies have shown the positive association between periodontitis and different forms of liver disease. Periodontal diseases increase the prevalence of non-alcoholic fatty liver diseases and cirrhosis. Infected periodontium and pathogens in the periodontal microenvironments release pathogen-associated molecular patterns such as peptidoglycan, lipopolysaccharides, gingipain, fimbria, bacterial DNA, etc, and damage-associated molecular patterns such as interleukins-1α, β, - 8, and galectin-3, etc. These virulence factors and cytokines enter the bloodstream, disseminate into the whole body, and induce a variety of systemic pathological effects, including liver diseases (steatosis and fibrosis). Maintaining oral hygiene by scaling and root planning significantly improves liver damage in patients with periodontitis. Dentists and physicians should have more awareness in understanding the bidirectional nature of the relationship between oral and systemic diseases. Importantly, periodontitis condition aggravates simple fatty liver into fibrotic disease and therefore, the aim of this review is to understand the possible link between periodontitis and liver diseases.

Evaluation of serum alanine aminotransferase and aspartate aminotransferase enzyme levels in women patients with chronic periodontitis

The authors' aim in this study was to investigate the relationship between chronic periodontitis and liver status using alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in women patients. The researchers conducted a case-control study on women patients referred to Dental School. The researchers collected 5 ml of peripheral venous blood from women for the laboratory process after performing periodontal examination. Participants were 124 women aged 25-50 years (62 cases and 62 control). The difference in serum levels of ALT and the difference in serum levels of AST between the two groups were not statistically significant. However, there was a significant correlation between liver enzymes and periodontitis parameters.

Relationship between NAFLD and Periodontal Disease from the View of Clinical and Basic Research, and Immunological Response

Periodontal disease is an inflammatory disease caused by pathogenic oral microorganisms that leads to the destruction of alveolar bone and connective tissues around the teeth. Although many studies have shown that periodontal disease is a risk factor for systemic diseases, such as type 2 diabetes and cardiovascular diseases, the relationship between nonalcoholic fatty liver disease (NAFLD) and periodontal disease has not yet been clarified. Thus, the purpose of this review was to reveal the relationship between NAFLD and periodontal disease based on epidemiological studies, basic research, and immunology. Many cross-sectional and prospective epidemiological studies have indicated that periodontal disease is a risk factor for NAFLD. An in vivo animal model revealed that infection with periodontopathic bacteria accelerates the progression of NAFLD accompanied by enhanced steatosis. Moreover, the detection of periodontopathic bacteria in the liver may demonstrate that the bacteria have a direct impact on NAFLD. Furthermore, Porphyromonas gingivalis lipopolysaccharide induces inflammation and accumulation of intracellular lipids in hepatocytes. Th17 may be a key molecule for explaining the relationship between periodontal disease and NAFLD. In this review, we attempted to establish that oral health is essential for systemic health, especially in patients with NAFLD.

Association between serum IgG antibody titers against Porphyromonas gingivalis and liver enzyme levels: A cross-sectional study in Sado Island

Background

Previous studies have reported associations between nonalcoholic fatty liver disease, periodontitis, and obesity. Serum immunoglobulin G (IgG) antibody titer against Porphyromonas gingivalis, a major pathogen of periodontitis, is an established indicator of periodontal infection. However, the relationship between the antibody titer and liver enzyme levels has not been clarified yet. A study in the elderly was needed to evaluate the effect of long-term persistent bacterial infection on liver function. The objective of this study was to investigate the association between liver function and infection by P. gingivalis, and the effect of obesity on the association.

Methods

A cross-sectional study was conducted in adult outpatients visiting Sado General Hospital, in Niigata Prefecture, Japan, from 2008 to 2010. The final participants included 192 men and 196 women (mean age 68.1 years). Multivariable logistic regression analyses were performed to assess the association between the serum IgG antibody titer and the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamine transferase (GGT) levels.

Results

In women, serum IgG antibody titers against P. gingivalis was associated with elevated ALT, but not with AST or GGT, independent of covariates (p = 0.015). No significant association was found between the antibody titer and the elevated liver enzymes in men. The effect of obesity on the relationship between antibody titer and liver enzyme levels was not statistically significant.

Conclusions

A cross-sectional analysis of adult outpatients suggested an association between P. gingivalis infection and ALT levels in women. The effect of obesity on this association was not statistically significant.

Efficacy and safety of PERIOdontal treatment versus usual care for Nonalcoholic liver disease: protocol of the PERION multicenter, two-arm, open-label, randomized trial

Background

We report the first protocol for a multicenter, randomized comparison study to compare the efficacies of periodontal scaling and root-planing treatment against that of tooth-brushing treatment for nonalcoholic fatty liver disease (NAFLD) (PERION: PERIOdontal treatment for NAFLD). Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD, which can progress to cirrhosis and hepatocellular carcinoma. Increased endotoxemia is associated with the progression of NAFLD. Periodontal bacteria possess endotoxins; Porphyromonas gingivalis is well-known as a major pathogenic bacterium in periodontitis, and serum antibody levels for P. gingivalis are high in patients with periodontitis. Several reports have indicated that P. gingivalis is related to NAFLD. This study aims to investigate the effect of periodontal treatment for liver damage, P. gingivalis infection, and endotoxemia on patients with NAFLD.

Methods

We will include adult patients (20–85 years old) with NAFLD, alanine aminotransferase (ALT) ≥ 40 IU/L, and equivalent steatosis grade ≥ 1 (target sample size, n = 40 patients; planned number of patients with outcome data, n = 32). Participants will be randomly assigned to one of two groups: a scaling and root-planing group or tooth-brushing as the usual group. The primary outcome will be the change in ALT levels from baseline to 12 weeks; the key secondary outcome will be the change in the serum immunoglobulin G (IgG) antibody titer for P. gingivalis at 12 weeks.

Discussion

This study should determine whether periodontal treatment decreases liver damage, P. gingivalis infection, and endotoxemia in patients with NAFLD.

Trial registration

University Hospital Medical Information Network (UMIN) Clinical Trials Registry, ID: UMIN000022079.

Evaluation of Biochemical Parameters Present in the Saliva of Patients with Chronic Periodontitis: Results from a Meta-Analysis

AIMS

Periodontitis results from the presence of periodontopathogenic bacterial activity in the region of the gingival sulcus promoting tissue degradation and alveolar bone resorption. Biochemical analysis of the saliva can be used as a less invasive method for disease prognosis. This study aimed to evaluate the relationship between biochemical protein levels in the saliva sample of patients with chronic periodontitis and healthy patients.

MATERIALS AND METHODS

A literature review was performed using electronic databases (Cochrane Library, Google Scholar, MEDLINE, PubMed, and Web of Science) for studies published before July 2, 2016. The abstracts were evaluated, and the data extraction was performed by two calibrated examiners. The mean difference, and heterogeneity were calculated, and funnel plots were produced.

RESULTS

Twenty case-control studies were selected with 2436 patients with chronic periodontitis and 1787 controls. The meta-analysis showed that increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatine kinase (CK), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and acid phosphatase (ACP) were all associated with periodontitis (p < 0.05), while blood urea nitrogen (BUN) and osteoprotegerin (OPG) levels did not show statistical differences between cases and controls (p > 0.05).

CONCLUSIONS

This meta-analysis evidenced that increased levels of AST, ALT, CK, gama glutamil transferase (GGT), LDH, ALP, and ACP are associated in patients with chronic periodontitis, while BUN and OPG level in saliva did not present differences between groups.

The association between missing teeth and non-alcoholic fatty liver disease in adults

AIMS

Long-term oral chronic inflammatory process is closely related to systemic inflammation, which is a main mechanism involved in non-alcoholic fatty liver disease (NAFLD). Tooth loss could reflect the accumulation of oral local inflammation, implying that number of missing teeth may associate with NAFLD. This study evaluated the association between missing teeth and presence of NAFLD in a general population.

MATERIALS AND METHODS

A cross-sectional study of 24,470 adults was carried out from the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study. The self-reported number of missing teeth (excluding third molars) was recorded and classified into four categories: 0, 1-2, 3-5, and ≥6. The NAFLD was diagnosed by the liver ultrasonography. Associations were analysed by adjusted multivariable logistic regression.

RESULTS

The multivariable-adjusted odds ratios (95% confidence interval) of NAFLD across the categories of missing teeth were as follows: in males, 1.00 (reference), 1.04 (0.93-1.16), 1.06 (0.90-1.24), and 1.40 (1.09-1.81) (p for trend = 0.04); in females, 1.00 (reference), 0.98 (0.83-1.15), 1.11 (0.90-1.37), and 1.07 (0.77-1.48) (p for trend = 0.45).

CONCLUSIONS

The number of missing teeth was associated with a higher presence of NAFLD in males but not females.

Construction of multiple linear regression models using blood biomarkers for selecting against abdominal fat traits in broilers

Plasma very low-density lipoprotein (VLDL) can be used to select for low body fat or abdominal fat (AF) in broilers, but its correlation with AF is limited. We investigated whether any other biochemical indicator can be used in combination with VLDL for a better selective effect. Nineteen plasma biochemical indicators were measured in male chickens from the Northeast Agricultural University broiler lines divergently selected for AF content (NEAUHLF) in the fed state at 46 and 48 d of age. The average concentration of every parameter for the 2 d was used for statistical analysis. Levels of these 19 plasma biochemical parameters were compared between the lean and fat lines. The phenotypic correlations between these plasma biochemical indicators and AF traits were analyzed. Then, multiple linear regression models were constructed to select the best model used for selecting against AF content. and the heritabilities of plasma indicators contained in the best models were estimated. The results showed that 11 plasma biochemical indicators (triglycerides, total bile acid, total protein, globulin, albumin/globulin, aspartate transaminase, alanine transaminase, gamma-glutamyl transpeptidase, uric acid, creatinine, and VLDL) differed significantly between the lean and fat lines (P < 0.01), and correlated significantly with AF traits (P < 0.05). The best multiple linear regression models based on albumin/globulin, VLDL, triglycerides, globulin, total bile acid, and uric acid, had higher R2 (0.73) than the model based only on VLDL (0.21). The plasma parameters included in the best models had moderate heritability estimates (0.21 ≤ h2 ≤ 0.43). These results indicate that these multiple linear regression models can be used to select for lean broiler chickens.

One or two ligatures inducing periodontitis are sufficient to cause fatty liver

BACKGROUND

Periodontitis is a chronic disease that due to an intense inflammatory response triggers systemic changes such as hepatic alterations. This study aimed to compare hepatic damage in rats that received experimental periodontitis at one or two periodontal sites with ligatures.

MATERIAL AND METHODS

Eighteen rats were separated into three groups: control, without ligature; periodontitis 1, with one ligature; and periodontitis 2, with two ligatures. The following parameters were assessed: gingival bleeding index, probing pocket depth, tooth mobility, alveolar bone loss, malondialdehyde (MDA) and myeloperoxidase (MPO) activity in periodontal tissue; histopathological evaluation of hepatic tissue (steatosis score); glutathione levels (GSH), MDA, MPO, cholesterol and triglycerides in the liver; and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST).

RESULTS

Periodontal evaluation data showed that the periodontitis model worked well. The groups with periodontitis did not differ significantly in relation to MPO activity and MDA levels in the gingival samples, but they were significantly different when compared with the control group. Steatosis was observed in the histological analysis of the groups with periodontitis, but between the periodontitis groups, two ligatures did not cause increase in steatosis score. The levels of GSH, MDA, total cholesterol and triglycerides in the hepatic tissue were not altered between groups with periodontitis, but they showed significant differences in comparison with the control group. The activity of MPO in hepatic tissue and serum levels of AST and ALT did not present significant difference among the three groups.

CONCLUSION

In conclusion, our results demonstrated that one or two ligatures inducing periodontitis were both sufficient to cause fatty liver. Steatosis caused by two ligatures did not present larger extension and severity than steatosis caused by one ligature.

Association of liver enzyme levels and alveolar bone loss: A cross-sectional clinical study in Sado Island

BACKGROUND

The interaction of periodontopathic bacteria with host immune system induces the production of inflammatory mediators which leads to alveolar bone loss (ABL), the essential feature of periodontitis. Concurrently, periodontal diseases cause the elevation of blood cytokine levels, the alteration of gut microbiota and the dissemination of enterobacteria to the liver. Owing to these mechanisms, periodontal disease might be a risk for liver dysfunction. Several epidemiological studies have reported associations between periodontal diseases and liver dysfunction, although the association between ABL and liver dysfunction has not been investigated. This cross-sectional study determined if elevated serum liver enzyme levels were associated with ABL in Japanese adults.

MATERIAL AND METHODS

Japanese adults living on Sado Island who visited Sado General Hospital were invited to participate in the study. Participants over 40 years of age who underwent dental panoramic radiography and blood tests were included. Drinking and smoking habits were self-administered. After excluding patients with edentulous jaw, diagnosed liver diseases, and those on dialysis, data from 44 men and 66 women with a mean age of 73 years were analyzed. The average percentage of ABL for each participant was calculated for mesial and distal sites of all remaining teeth. The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) were determined. Univariate analyses were performed to select covariates to be put in multivariate analyses. The association between elevated serum liver enzyme levels and the highest quartile of ABL were assessed by multiple logistic regression analysis.

RESULTS

After adjusting for covariates, no significant association was found between elevated serum AST, ALT, or GGT levels as dependent variables and the highest quartile of ABL as an explanatory variable.

CONCLUSIONS

There was no significant association between the elevation of serum liver enzyme levels and ABL in Japanese adults. Key words:Liver enzymes, dental panoramic radiography, alveolar bone loss, Japanese adults.

Association of periodontal status with liver abnormalities and metabolic syndrome

Although an association between periodontal status and liver abnormalities has been reported, it has not been described in relation to metabolic syndrome (MetS), which often coexists with non-alcoholic fatty liver disease. We examined the association of a combination of liver abnormality and MetS with periodontal condition in Japanese adults, based on the level of alcohol consumption. In 2008, 4,207 males aged 45.4 ± 8.9 years and 1,270 females aged 45.9 ± 9.7 years had annual workplace health check-ups at a company in Japan. Periodontal status was represented as periodontal pocket depth at the mesio-buccal and mid-buccal sites for all teeth. Alanine aminotransferase (ALT), and metabolic components were examined. Multiple linear regression analysis showed a significant association between deep pocket depth and the coexistence of elevated ALT and MetS in males with low alcohol consumption. Females showed no such relationship. In conclusion, the association between periodontal condition and the combination of elevated ALT and MetS was confirmed in males. That is, a clear association between liver abnormalities and periodontal condition was seen in male subjects with no or low alcohol consumption and MetS, providing new insights into the connection between liver function and periodontal health.

Decrease of Pericytes is Associated With Liver Disease Caused by Ligature-Induced Periodontitis in Rats

BACKGROUND

Damage caused by periodontitis not only affects periodontal tissues, but also increases the severity of various illnesses such as rheumatoid arthritis, diabetes, and liver diseases. The aim of this study is to investigate the association between induced periodontitis and damage caused through its systemic effects on the liver.

METHODS

Twenty rats were divided into two groups: control and periodontitis. The following parameters were evaluated: gingival bleeding index (GBI), probing depth (PD), myeloperoxidase (MPO) activity, alveolar bone loss (ABL) for periodontal tissues; histopathologic examination of gingival and liver tissues; immunohistochemistry to cells positive for neural/glial antigen 2 (NG2) expressed in hepatic pericytes, glutathione (GSH), and malondialdehyde (MDA) concentrations in liver; and serum levels of alanine aminotransferase and aspartate aminotransferase.

RESULTS

GBI, PD, MPO, ABL, and histopathologic examinations demonstrated the development of periodontitis. There was a significant increase in microvesicular steatosis accompanied by a marked reduction in NG2+ pericytes in the periodontitis group compared with the control group. The periodontitis group had significantly lower GSH and higher MDA concentration in the liver compared with the control group.

CONCLUSIONS

The present study results link the systemic effects of induced periodontitis with changes in hepatic tissues such as microvesicular steatosis, likely caused by an increase in oxidative stress and lipid peroxidation. The findings from the present study implicate an association between a decrease of pericytes and liver disease caused by ligature-induced periodontitis in rats.

Interaction between periodontitis and liver diseases

Periodontitis is an oral disease that is highly prevalent worldwide, with a prevalence of 30–50% of the population in developed countries, but only ~10% present with severe forms. It is also estimated that periodontitis results in worldwide productivity losses amounting to ~54 billion USD yearly. In addition to the damage it causes to oral health, periodontitis also affects other types of disease. Numerous studies have confirmed the association between periodontitis and systemic diseases, such as diabetes, respiratory disease, osteoporosis and cardiovascular disease. Increasing evidence also indicated that periodontitis may participate in the progression of liver diseases, such as non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma, as well as affecting liver transplantation. However, to the best of our knowledge, there are currently no reviews elaborating upon the possible links between periodontitis and liver diseases. Therefore, the current review summarizes the human trials and animal experiments that have been conducted to investigate the correlation between periodontitis and liver diseases. Furthermore, in the present review, certain mechanisms that have been postulated to be responsible for the role of periodontitis in liver diseases (such as bacteria, pro-inflammatory mediators and oxidative stress) are considered. The aim of the review is to introduce the hypothesis that periodontitis may be important in the progression of liver disease, thus providing dentists and physicians with an improved understanding of this issue.

Interrelationship Between Periapical Lesion and Systemic Metabolic Disorders

BACKGROUND

Periapical periodontitis, also known as periapical lesion, is a common dental disease, along with periodontitis (gum disease). Periapical periodontitis is a chronic inflammatory disease, caused by endodontic infection, and its development is regulated by the host immune/inflammatory response. Metabolic disorders, which are largely dependent on life style such as eating habits, have been interpreted as a "metabolically-triggered" low-grade systemic inflammation and may interact with periapical periodontitis by triggering immune modulation. The host immune system is therefore considered the common fundamental mechanism of both disease conditions.

METHOD

We have reviewed >200 articles to discuss the interrelationship between periapical lesions and metabolic disorders including type 2 diabetes mellitus, hypertension, and non-alcoholic fatty liver diseases (NAFLD), and their common pathological background in immunology/osteoimmunology and cytokine biology.

RESULTS

An elevated inflammatory state caused by metabolic disorders can impact the clinical outcome of periapical lesions and interfere with wound healing after endodontic treatment. Although additional well-designed clinical studies are needed, periapical lesions appear to affect insulin sensitivity and exacerbate non-alcoholic steatohepatitis.

CONCLUSION

Immune regulatory cytokines produced by various cell types, including immune cells and adipose tissue, play an important role in this interrelationship.