Serum markers of periodontal disease status and inflammation in hemodialysis patients

Gingipain and oncostatin M synergistically disrupt kidney tight junctions in periodontitis-associated acute kidney injury

BACKGROUND

Acute kidney injury (AKI) is characterized by rapid renal decline. Periodontitis, a chronic oral inflammatory disease, is increasingly associated with renal dysfunction. Although periodontitis is recognized as a contributor to kidney damage, the mechanisms linking it to AKI remain unclear.

METHODS

This study explored the effects of Porphyromonas gingivalis (P. gingivalis) W83-infected periodontitis on AKI in C57BL/6J mice, using ischemia-reperfusion injury 55 days post-infection. Gingipain inhibitors, KYT-1 and KYT-36, were applied. Detection of P. gingivalis was performed using quantitative real-time polymerase chain reaction (qRT-PCR) and PCR, while transcriptome sequencing, qRT-PCR, immunohistochemistry, and immunofluorescence staining assessed renal damage. In vitro, HK-2 cells were exposed to P. gingivalis at a multiplicity of infection of 10 for 48 h, with inhibition by gingipain or oncostatin M (OSM). Disruption of tight junctions (TJs) was quantified using qRT-PCR, transepithelial electrical resistance, and cell counting kit-8 assays.

RESULTS

Periodontitis worsened AKI, linked to P. gingivalis infection and renal TJ disruption in the kidney. P. gingivalis infection activated OSM expression, which correlated positively with gingipain. Significantly, OSM and gingipain might collaboratively contribute to the damage of renal TJs, with the reduced expression of TJ proteins. Suppressing gingipain activity presented itself as a protective strategy against the destruction of TJs and the attendant worsening of AKI due to periodontitis.

CONCLUSIONS

Our study enhances the understanding of the interplay between periodontitis and AKI, highlighting the harmful impact of P. gingivalis in AKI.

Association between missing teeth number and all-cause and cardiovascular mortality: NHANES 1999-2004 and 2009-2014

BACKGROUND

The association between tooth loss and all-cause and cardiovascular mortality requires further investigation.

METHODS

This study included 17993 participants from the National Health and Nutrition Examination Surveys (NHANES) 1999-2004 and 2009-2014. Weighted multivariable Cox proportional hazard models were used to assess the association between tooth loss and all-cause and cardiovascular mortality. Restricted cubic splines (RCS) were incorporated in the models to explore potential nonlinear relationships.

RESULTS

Over a median follow-up of 116 months, 2152 participants died, including 625 cardiovascular deaths. Compared to participants without missing teeth, participants with 11-19 missing teeth had the highest risk of all-cause mortality (hazard ratio [HR] 1.89, 95% confidence interval [CI] 1.43-2.51), while participants with 6-10 missing teeth had the highest risk of cardiovascular mortality (HR 2.51, 95% CI 1.68-3.76). RCS analyses revealed nonlinear associations between number of missing teeth and all-cause (p < 0.001) and cardiovascular (p = 0.001) mortality. With < 10 missing teeth, each additional missing tooth increased all-cause and cardiovascular mortality by 6% (HR 1.06, 95% CI 1.03-1.09) and 9% (HR 1.09, 95% CI 1.03-1.15), respectively. However, when the number of missing teeth was ≥10, the risk of mortality did not continue to increase with more missing teeth. A significant interaction was found between tooth loss and age (p < 0.001 for both outcomes).

CONCLUSION

We observed an inverted L-shaped association between tooth loss and mortality, wherein risks increased with more missing teeth until 10, but did not continue increasing thereafter. The association was stronger in adults < 65 years old.

Effect of nonsurgical periodontal therapy on C-reactive protein and iron indices in hemodialysis patients

Background and Aim:

The aim of the study was to evaluate the effect of nonsurgical periodontal therapy on clinical, renal, and hematological parameters at baseline and 3 months postoperatively on chronic kidney disease (CKD) patients undergoing hemodialysis. This comparative interventional study was conducted among CKD patients undergoing hemodialysis.

Materials and Methods:

This study included chronic periodontitis (CP) patients divided into three groups Group I: CKD patients undergoing hemodialysis for less than a year; Group II: CKD patients undergoing hemodialysis for more than a year; and Group III: systemically healthy CP patients. Clinical parameters (bleeding on probing [BOP], probing pocket depth (PPD), and clinical attachment level [CAL]) were recorded at baseline (T0), 1 month (T1), and 3 months after scaling and root planing (SRP) (T2). C-reactive protein (CRP) and transferrin saturation (TSAT) were observed at T0 and at T2. Paired t-test and Chi-square test were applied to find the statistical significance (P < 0.05 was considered statistically significant at 95% confidence interval) between the T0 and T2 time within the groups.

Results:

Clinical parameters such as PPD and CAL decreased with statistical significance in Group III alone, whereas BOP decreased with statistical significance in all the three groups. The study showed statistically significant reduction of CRP (in Group I and Group III) and TSAT increased with statistical significance in all the three groups after SRP.

Conclusion:

This suggests that SRP can bring an improvement in the systemic markers in CP patients under hemodialysis. However, we need a longitudinal study with a larger sample size to confirm the results.

Tooth loss and risk of end-stage renal disease: A nationwide cohort study

BACKGROUND

The association between renal disease and oral health has been studied in previous researches. The purpose of this study is to evaluate whether oral health, depicted by number of natural teeth was associated with an increased risk of kidney diseases.

METHODS

The present study analysed data from the Korean National Health Insurance from 2007 to 2008. Database of 4,544,610 individuals who received routine health checkups and dental examinations were included in this study.

RESULTS

There was an increase in end-stage renal disease with lower number of natural teeth and longer follow-up periods. Hazard ratios and their 95% confidence intervals for end-stage renal disease in participants with a number of natural teeth of 28, 24 to 27, 20 to 23, and <20 were one (reference), 1.066(0.997,1.139), 1.285(1.161,1.422), and 1.285(1.155,1.429), respectively. The association was significantly noted with age and body mass index (P < 0.05). In general, the substantial increase in hazard ratios is seen with loss of teeth and smoking. Hazard ratios and their 95% confidence intervals for end-stage renal disease in male smoking participants with a number of natural teeth <28 is 1.631(1.339,1.988). However, this association was not noted in female group.

CONCLUSIONS

The association between number of natural teeth and end-stage renal disease was suggested after adjusting for confounding factors by using multiple logistic regression analyses from the entire South Korean population. Oral health, depicted by the number of tooth loss showed strong and dose-dependent association with end-stage renal disease in a large population-based cohort.

Immune Dysfunction in Dialysis Patients—Prevention and Treatment Strategies

Immune dysfunction, resulting in infection or inflammation, or both, is closely associated with poor clinical outcome in end-stage renal disease patients. So far, no single measure can effectively address this condition, because many factors, such as uremia per se and dialysis treatment are involved in the pathogenesis. Our review focuses on currently available treatments and prevention options, and identifies future research needs.

Periodontal management of severe periodontitis and generalized gingival enlargement in a patient with chronic renal failure

Gingival enlargement is a common periodontal pathology seen in medically compromised patients. Although it is not the disease itself, certain medications used to treat these chronic diseases are known to precipitate the gingival enlargement. Periodontitis (PD) and gingival enlargement have been reported increasingly in patients with chronic renal failure. Severe enlargement is detrimental to esthetics and function while having a negative impact on the overall oral health-related quality of life. Treatment of such cases requires comprehensive periodontal management by a specialist, keeping in mind the medically compromised state of the patient. This report presents a case of severe PD with generalized gingival enlargement in a 45-year-old male who was a known case of Stage 4 chronic kidney disease, obstructive uropathy, and hypertension. Gingival enlargement was managed by gingivectomy and gingivoplasty. Six months' follow-up showed no sign of recurrence.

Effects of non-surgical periodontal therapy on systemic inflammation and metabolic markers in patients undergoing haemodialysis and/or peritoneal dialysis: a systematic review and meta-analysis

BACKGROUND

This systematic review aimed to investigate whether non-surgical periodontal therapy (NSPT) can reduce systemic inflammatory levels and improve metabolism in patients undergoing haemodialysis (HD) and/or peritoneal dialysis (PD).

METHODS

Electronic databases (PubMed, EMBASE, CENTRAL, CNKI, and WFPD) were searched for randomized controlled trials (RCTs) performed through July 2019. The risk of bias within studies was assessed with the Cochrane Collaboration's risk assessment tool. The systemic inflammatory and metabolic outcomes included the highly sensitive C-reactive protein (hs-CRP), interleukin 6 (IL-6), tumour necrosis factor-a (TNF-a), the albumin (Alb), and lipid metabolite levels. Meta-analyses (MAs) were performed to calculate the overall effect size where appropriate.

RESULTS

Five RCTs were included in this study. Compared with untreated periodontitis groups, the dialysis patients after NSPT significantly showed decreased hs-CRP levels at less than or equal to 2 months (standardized mean difference: - 1.53, 95% confidence interval - 2.95 to - 0.11). No significant difference was found in IL-6 and Alb levels following NSPT at either the 3- or 6- month follow-ups. No MAs could be performed on the TNF-a level and the lipid metabolic markers.

CONCLUSIONS

NSPT can moderately reduce serum hs-CRP levels in HD and/or PD patients, but did not significantly change IL-6 or Alb levels. For TNF-a and lipid metabolism markers, no sufficient evidence supports that these levels are changed after NSPT. Additional scientific research is necessary to assess the effects of NSPT on systemic inflammation and metabolic parameters in dialysis patients.

Association between severe periodontitis and chronic kidney disease severity in predialytic patients: A cross-sectional study

OBJECTIVE

The aim of this cross-sectional study was to evaluate the association between periodontitis and different severities of chronic kidney disease (CKD) in predialytic patients.

MATERIALS AND METHODS

Demographic, socioeconomic, and medical data of 139 patients from the nephrology service of one university hospital in Porto Alegre, Brazil, were obtained through interview and clinical records. Full-mouth six-sites per tooth periodontal examinations were performed. Associations between periodontitis, stages of CKD, and estimated glomerular filtration rate (eGFR) were estimated by multivariable models adjusted for sex, smoking, vitamin D supplementation, physical activity, and renal treatment duration. CKD was classified based on eGFR (<60 ml/min/1.73 m² ) estimated by the Chronic Kidney Disease Epidemiology Collaboration equation.

RESULTS

Patients with severe periodontitis, compared to those without severe periodontitis, had 2.8 (95% CI: 1.25-6.62) and 3.4 (95% CI: 1.27-9.09) times higher risk of being in stages 4 and 5 of CKD, respectively. Having ≥ 2 teeth with clinical attachment loss (CAL) ≥6 mm increased 3.9 times the risk of being in stage 5 of CKD. Patients with severe periodontitis and ≥2 teeth with CAL ≥ 6 mm had 4.4 ml/min/1.73² and 5.2 ml/min/1.73² lower eGFR (p-values < .05), respectively.

CONCLUSION

Severe periodontitis was associated with poor renal conditions in predialytic CKD patients, strengthening the importance of periodontal evaluation in such patient population.

Impact of Periodontal Inflammation on Nutrition and Inflammation Markers in Hemodialysis Patients

Background: Malnutrition-inflammation complex syndrome (MICS) is a common and usually concurrent condition occurring in patients undergoing hemodialysis (HD), with a pathogenesis linked to biological and in situ environmental traditional risk factors. Periodontitis, one of the major types of infection-driven inflammation, often co-occurs in the in the hemodialysis population and correlates with markers of malnutrition and inflammation, such as albumin, creatinine, and C-reactive protein. Aim: The present study aimed to determine whether the periodontal inflammatory status parameters correlate with the albumin, creatinine, and C-reactive protein serum concentrations in HD patients, and investigate whether periodontal treatment improves these markers of nutritional and systemic inflammation. Materials and Methods: The serum creatinine, albumin, and C-reactive Protein (CRP) levels were measured at baseline and after non-surgical periodontal treatment, at 3 months and 6 months. Results: At 3 months, a significant correlation between plaque index and C-reactive protein (p = 0.012), bleeding on probing and C-reactive protein (p < 0.0019), and clinical attachment level and C-reactive protein (p = 0.022) was found. No significant correlation was found between clinical periodontal parameters and nutrition markers at each time. Conclusions: Our results confirmed the association between C-reactive protein serum concentration and periodontal inflammatory status, but further research is necessary to identify the contributing role of periodontitis on the onset and progression of MICS.

An update on possible pathogenic mechanisms of periodontal pathogens on renal dysfunction

Periodontitis is a potential source of permanent systemic inflammation that initiates renal dysfunction and contributes to the development of chronic kidney diseases (CKDs). Although numerous studies have confirmed the bidirectional role of periodontal infection and renal inflammation, no literature has yet highlighted the sophisticated pathogenic mechanisms by which periodontal pathogens, particularly Porphynomonas Gingivalis, induce renal dysfunction and contributed in the development of CKDs. The present review aims to critically analyze and highlight the novel pathogenesis of periodontitis induced CKDs.

Periodontal Disease in Patients Receiving Dialysis

Chronic kidney disease (CKD) is characterized by kidney damage with proteinuria, hematuria, and progressive loss of kidney function. The final stage of CKD is known as end-stage renal disease, which usually indicates that approximately 90% of normal renal function is lost, and necessitates renal replacement therapy for survival. The most widespread renal replacement therapy is dialysis, which includes peritoneal dialysis (PD) and hemodialysis (HD). However, despite the development of novel medical instruments and agents, both dialysis procedures have complications and disadvantages, such as cardiovascular disease due to excessive blood fluid and infections caused by impaired immunity. Periodontal disease is chronic inflammation induced by various pathogens and its frequency and severity in patients undergoing dialysis are higher compared to those in healthy individuals. Therefore, several investigators have paid special attention to the impact of periodontal disease on inflammation-, nutrient-, and bone metabolism-related markers; the immune system; and complications in patients undergoing dialysis. Furthermore, the influence of diabetes on the prevalence and severity of manifestations of periodontal disease, and the properties of saliva in HD patients with periodontitis have been reported. Conversely, there are few reviews discussing periodontal disease in patients with dialysis. In this review, we discuss the available studies and review the pathological roles and clinical significance of periodontal disease in patients receiving PD or HD. In addition, this review underlines the importance of oral health and adequate periodontal treatment to maintain quality of life and prolong survival in these patients.

The association between periodontal conditions, inflammation, nutritional status and calcium-phosphate metabolism disorders in hemodialysis patients

OBJECTIVES

To analyze the association between periodontal conditions and inflammation, nutritional status and calcium-phosphate metabolism disorders in hemodialysis (HD) patients.

MATERIAL AND METHODS

We analyzed 128 HD patients divided into two groups: dentate (n = 103) and edentulous (n=25). The following items were assessed: baseline characteristics, age at the start and duration of HD, biochemical data: C-reactive protein (CRP), serum albumin, calcium, phosphorus, alkaline phosphatase, parathormone. A single dentist performed a complete dental/periodontal examination, including parameters of oral hygiene and gingival bleeding.

RESULTS

One person had healthy periodontium, 62.14% of the patients had gingivitis, and 36.9% had moderate or severe periodontitis. The age at HD onset had a positive impact on periodontal status and negatively correlated with the number of teeth. A positive correlation between age and CRP level and negative correlations between age and serum albumin and phosphorus were found. Pocket depth (PD) was negatively correlated with serum albumin. The number of teeth was negatively correlated with serum CRP.

CONCLUSIONS

High prevalence and severity of periodontal disease are observed in hemodialysis patients. There is a high probability that periodontal disease may be present at the early stages of chronic kidney disease (CKD) before the hemodialysis onset.

Oral inflammation and infection, and chronic medical diseases: implications for the elderly

Oral diseases, such as caries and periodontitis, not only have local effects on the dentition and on tooth-supporting tissues but also may impact a number of systemic conditions. Emerging evidence suggests that poor oral health influences the initiation and/or progression of diseases such as atherosclerosis (with sequelae including myocardial infarction and stoke), diabetes mellitus and neurodegenerative diseases (such as Alzheimer's disease, rheumatoid arthritis and others). Aspiration of oropharyngeal (including periodontal) bacteria causes pneumonia, especially in hospitalized patients and the elderly, and may influence the course of chronic obstructive pulmonary disease. This article addresses several pertinent aspects related to the medical implications of periodontal disease in the elderly. There is moderate evidence that improved oral hygiene may help prevent aspiration pneumonia in high-risk patients. For other medical conditions, because of the absence of well-designed randomized clinical trials in elderly patients, no specific guidance can be provided regarding oral hygiene or periodontal interventions that enhance the medical management of older adults.

Oral health and systemic inflammatory, cardiac and nitroxid biomarkers in hemodialysis patients

Background

Periodontal diseases have systemic inflammatory effects and have been adversely associated with cardiovascular diseases, which are also the most frequent cause of death in the end-stage renal disease. The aim of this cross-sectional study was to investigate the oral health and serum biomarkers among the hemodialysis (HD) patients in Slovenia.

Material and Methods

111 HD patients were periodontally examined and their sera were assayed for C reactive protein (CRP), cardiac troponin T (TnT), nitrite/nitrate (NOx) and antibody levels to A. actinomycetemcomitans and P. gingivalis. The association of oral health with systemic response was analyzed with Kruskal-Wallis test, Fisher’s exact test and multivariate linear regression.

Results

Bleeding on probing without periodontal pockets was present in 5.2%, calculus without periodontal pockets in 42.1%, shallow periodontal pockets in 39.5% and deep periodontal pockets in 13.2% of dentate patients. There were 28.8% edentulous participants. 63.1% of the patients had CRP levels higher than 3 mg/L and 34.2% higher than 10 mg/L. TnT was detectable in all participants, with 25.2% exhibiting levels higher than 100 ng/L. The median level of NOx was 43.1 µmol/L. Participants with higher CRP were more likely to be edentulous and have higher TnT levels. A direct association of oral health with TnT or NOx was not detected.

Conclusions

HD patients in Slovenia have compromised oral health and increased serum inflammatory and cardiac biomarkers. Edentulousness was an independent predictor for the increased CRP, indicating a need for improved dental care to retain the teeth as long as possible.

Key words:Periodontal diseases, edentulousness, C reactive protein, cardiac troponin T, nitric oxide.

C-reactive protein variability is associated with vascular access outcome in hemodialysis patients

BACKGROUND

Hemodialysis (HD) vascular access failure is one of the most important causes of morbidity and contributes to the cost of dialysis care. There is paucity of data evaluating long-term monitoring of C-reactive protein (CRP) on outcome of HD vascular access.

METHODS

We conducted a retrospective study to investigate whether variability of serum CRP level was associated with vascular access failure rate over a 7-year period. A total of 318 HD patients were included. Their demographic data, co-morbidities and biochemical data were reviewed and collected. Serum high-sensitivity CRP (hs-CRP) level was measured every 6 months. Patients were divided into three groups according to their serial hs-CRP levels. Patients with their hs-CRP below 2 mg/L were defined as low group (n=65, 20.4%) and those with higher than 4 mg/L were defined as high (n=39, 12.3%). The rest were classified as fluctuated hs-CRP group (n=214, 67.3%). Treatment of vascular access failure includes angioplasty and access re-creation.

RESULTS

Their body mass index, indicators of dialysis adequacy and serum albumin and hs-CRP levels differed significantly among three groups. The annual vascular access failure rate was significantly higher in fluctuated hs-CRP group than in high hs-CRP group (0.41 vs 0.36, P=.037). Serum albumin was a significant associate of vascular access failure. Kaplan-Meier survival analysis indicated patients with high or fluctuated hs-CRP had shorter free interval of vascular access failure than low hs-CRP group.

CONCLUSIONS

HD patients with fluctuated hs-CRP levels were associated with increased vascular access failure.

Medical and Periodontal Clinical Parameters in Patients at Different Levels of Chronic Renal Failure

Aim. To assess the clinical periodontal and medical parameters in patients with chronic renal failure (CRF) at different levels of renal disease. Background. CRF is a progressive and irreversible loss of renal function associated with a decline in the glomerular filtration rate. Periodontal disease is a destructive inflammatory disease affecting periodontal tissues that shows high prevalence in patients with CRF. Materials and Methods. 102 CRF patients were included and divided into an early stage group (EG), predialysis group (PDG), and hemodialysis group (HDG). The medical parameters were taken from the patients' records. Results. Periodontal clinical condition differed among the CRF groups. Clinical attachment loss was greater in the HDG and PDG group compared to the EG (p = 0.0364); the same was observed in the Plaque Index (p = 0.0296); the others periodontal parameters did not show any differences. Ferritin levels were significantly higher in the HDG when compared to the EG and PGD (p < 0.0001), and fibrinogen was higher in PDG compared with the others (p < 0.0001); the triglycerides also showed higher values in the HDG compared with the other groups (p < 0.0001). Conclusion. The patients with renal involvement should have a multidisciplinary approach to an improvement in their oral and systemic health.

Association of serum immunoglobulin-G to Porphyromonas gingivalis with acute cerebral infarction in the Chinese population

Background/Purpose:

There is evidence supporting an association between ischemic stroke and periodontitis in western countries. Differing genetic backgrounds and lifestyles among populations may affect this association. The aim of our study was to determine whether antibody titers to Porphyromonas gingivalis are associated with acute cerebral infarction in the Chinese population.

Materials and Methods:

This case-control study was conducted on 88 acute cerebral infarction patients and 40 healthy control subjects. Serum immunoglobulin-G (IgG) antibody to P. gingivalis was analyzed by enzyme-linked immune sorbent assay. Serum lipids were determined with the automatic biochemical analyzer. Fibrinogen was measured using automated coagulation analyzer. High-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6) were quantified using commercial ELISA kits. The intima-media thickness of the common carotid arteries (IMT-CCA) was measured by ultrasonography.

Results:

The results showed that P. gingivalis IgG antibody levels were significantly higher in acute cerebral infarction cases than in healthy controls (mean ± standard deviation, 11.06 ± 1.49 vs. 9.15 ± 1.70, P < 0.001). There were significant correlations of P. gingivalis IgG titer with total cholesterol (r = 0.34, P = 0.001), low-density lipoprotein (r = 0.39, P < 0.001), apolipoprotein-B (r = 0.30, P = 0.004), hs-CRP (r = 0.35, P = 0.001), IL-6 (r = 0.27, P = 0.011), and IMT-CCA (left: r = 0.306, P = 0.004; right: r = 0.241, P = 0.024).

Conclusion:

Antibody titers to P. gingivalis are associated with acute cerebral infarction in the Chinese population.

Hemodialysis-specific factors associated with salivary flow rates

The saliva is important to maintain the integrity of tissues and teeth, besides having microbial activity. Hemodialysis (HD) patients usually have reduced salivary flow rate (SFR) and are exposed to all its associated complications. The aim of the present study was to identify HD-related factors associated with reduced SFR. A cross-sectional study was performed with maintenance HD patients. Stimulated whole saliva was collected before and after HD. Xerostomia was assessed through the validated xerostomia inventory and thirst through the dialysis thirst inventory. Parameters of dental health status were obtained by the decayed, missed, and filled teeth index and community periodontal index. One hundred twenty-eight patients (66 males) participated in this study. Stimulated SFR before HD was 0.38 ± 0.28 mL/min. In univariate analysis and after adjusting for several factors, serum urea before HD session, serum intact parathormone (iPTH), calcium-phosphorus product (Ca×Pi), serum ferritin, and number of medications were negatively correlated with SFR in univariate analysis. Moreover, patients taking sevelamer had reduced SFR in comparison with those not receiving it (SFR 0.32 ± 0.19 vs. 0.44 ± 0.23 mL/min, P = 0.003). At multivariate analysis, including dialysis and nondialysis-related factors, age, elevated pre-HD serum urea, higher Ca×Pi product, higher iPTH, and sevelamer use remained as factors that were independently associated with a reduced SFR. After dialysis, there was a significant increment in SFR (0.39 ± 0.28 vs. 0.60 ± 0.34 mL/min, P < 0.001). Several HD-related features were associated with reduced SFR, including serum urea, sevelamer use, and bone and mineral disorders markers.

The odontogenic-related microinflammation in patients with chronic kidney disease

OBJECTIVES

This study estimated plasma levels of interleukin IL-1β, IL-6, tumour necrosis factor-α (TNF-α), interferon-γ (INF-γ) in chronic kidney disease (CKD) patients with a single odontogenic pathology.

MATERIAL AND METHODS

Forty-nine selected adult CKD patients with single odontogenic pathology based on clinical and X-ray examination: patients after proper root canal treatment, without periapical lesions (n = 12), with pulp necrosis (n = 7), with asymptomatic periapical lesions (n = 22), with periodontal disease (n = 8), and 14 with healthy teeth were enrolled. Patients with coexisting different dental pathologies and the evidence of other infection were excluded. In all patients plasma concentrations of CRP, IL-1β, IL-6, TNF-α, and INF-γ were measured.

RESULTS

Patients with periodontitis were characterized by increased concentrations of IL-6 and TNF-α. Those with pulp necrosis had significantly more frequently serum CRP level over 2 mg/L and presented significantly elevated IL-6, but decreased TNF-α concentration than in the subjects with healthy teeth. In patients with periapical lesions and patients after root canal therapy, the concentrations of cytokines did not indicate for the systemic inflammation.

CONCLUSIONS

Periodontitis and pulp necrosis are important sources of systemic microinflammation in CKD patients. Plasma concentrations of IL-6 and TNF-α appear to be more sensitive markers of odontogenic inflammation in CKD patients than CRP.

Bidirectional Relationship between Chronic Kidney Disease & Periodontal Disease

Non communicable diseases (NCDs) affect the life of an individual in terms of mortality, morbidity and financial crises. Main NCDs are diabetes mellitus (DM), cardiovascular diseases (CVD), pulmonary diseases, osteoporosis and chronic kidney diseases (CKD). About 40% of the total deaths can be controlled by eliminating the risk factors for NCDs. Periodontitis have recently been labeled as an important potential risk factor for NCDs. CKD affect the oral health status of patients by inducing gingival hyperplasia, xerostomia, calcification of root canals and delayed eruption of teeth. Periodontitis increases systemic inflammatory burden leading to worsening of CKD which in turn has been has been found to negatively affect CKD of patients on hemodialysis therapy by altering their serum albumin and C-reactive protein levels. As hypoalbuminemia leads to increased mortality in CKD patients, it needs to be avoided by reducing systemic inflammatory burden in patients receiving HD therapy. Treating periodontal disease could be one factor that might decrease the systemic inflammatory burden and thereby improve quality of life of these patients.

Sources of Data: Data from descriptive, cross sectional and longitudinal studies published between 2000 and 2012 were included. Data searches based on human studies only.

Data Extraction: The key words, periodontitis, chronic kidney disease and hemodialysis, on MEDLINE, approximately 120 studies were identified. 35 of them were relevant to all three keywords. Most of them were cross sectional studies and total 7 clinical trials were identified regarding checking of serum levels after periodontal therapy with variable results.

Conclusion: Patients with CKD have higher prevalence of periodontal disease while non-surgical periodontal therapy has been indicated to decrease the systemic inflammatory burden in patients with CKD specially those undergoing HD therapy.

Pretransplantation erythropoiesis-stimulating agent hyporesponsiveness is associated with increased kidney allograft failure and mortality

BACKGROUND

Poor response to erythropoiesis-stimulating agents (ESA) is associated with morbidity and mortality among dialysis patients. It is unclear whether the risk associated with poor ESA response during dialysis extends beyond kidney transplantation. We examined pretransplantation ESA response and its effect on allograft failure and mortality.

METHODS

The cohort included all adult Medicare recipients from the U.S. Renal Data System who had received a kidney transplant during years 2000 to 2007 and had at least 6 months of hemodialysis immediately before transplantation. ESA hyporesponsiveness was primarily defined as a monthly ESA dose of 75,000 units or higher and hematocrit 33% or less for at least 3 consecutive months in the pretransplantation period. Crude and adjusted Cox proportional hazards models and Kaplan-Meier methods were used to estimate the effect of ESA hyporesponsiveness on allograft failure and all-cause mortality.

RESULTS

The study group consisted of 36,450 patients; 1004 exhibited hyporesponsiveness. The adjusted hazard ratios (95% confidence interval) for allograft failure and mortality after transplantation were 1.23 (1.10-1.42) and 1.61 (1.43-1.81), respectively, supporting that poor ESA response during hemodialysis is associated with adverse posttransplantation outcomes.

CONCLUSIONS

ESA hyporesponsiveness may be useful in identifying potential allograft recipients who are at high risk for subsequent morbidity and mortality and may benefit from more intensive pretransplantation and posttransplantation monitoring.

Periodontal disease in chronic kidney disease and end-stage renal disease patients: a review

Periodontal disease is a chronic inflammatory disorder and being so it has been associated with accelerated atherosclerosis and malnutrition. Cardiovascular diseases are the leading cause of mortality in chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients [National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases: Annual Data Report, 2010]. A recent scientific statement released by the American Heart Association [Lockhart et al.: Circulation 2012;125:2520-2544] claims that, even though evidence exists to believe that periodontal interventions result in a reduction in systemic inflammation and endothelial dysfunction, there is little evidence that those interventions prevent atherosclerotic vascular disease or modify the outcomes. In this review, we discuss the periodontal findings and their association with an increased prevalence of inflammatory markers and cardiovascular mortality in ESRD patients and CKD.

Periodontal disease: a covert source of inflammation in chronic kidney disease patients

The prevalence of atherosclerotic complications (myocardial infarction, stroke, and sudden death) is increased in end-stage renal disease (ESRD) patients, especially in haemodialysis patients. Increasing evidence suggests that both in general population and in dialysis patients, systemic inflammation plays a dominant role in the pathogenesis of atherosclerotic complications. In general population, also, evidence shows that moderate to severe periodontitis can contribute to inflammatory burden by increasing serum CRP levels and may increase the prevalence of atherosclerotic events. Moreover, the results of some new interventional studies reveal that effective phase I periodontal therapy may decrease serum CRP levels, the most important acute phase protein, monitored as a systemic marker of inflammation and endothelial dysfunction as well, used as an initial predictor of atherosclerotic events. Considering that moderate to severe periodontal diseases have a higher prevalence in CKD and in dialysis population and that periodontal examination is not part of the standard medical assessment, destructive periodontitis might be an ignored source of systemic inflammation in end-stage renal disease patients and may add to the chronic inflammatory status in CKD.

Severe periodontitis associated with chronic kidney disease

The data on Indian population with regard to severity/prevalence of chronic periodontitis in association with chronic kidney disease (CKD) is scarce. We are describing an interesting case of severe periodontitis associated with CKD. The patient had unusual inflammatory gingival overgrowth which persisted even after treatment. By describing this case we want to highlight our current lack of understanding with regard to etiopathogenesis of periodontal disease in CKD patients and need for further research in this area.

A randomized controlled trial of intensive periodontal therapy on metabolic and inflammatory markers in patients With ESRD: results of an exploratory study

BACKGROUND

Periodontitis is a novel risk factor for inflammation and cardiovascular disease in the dialysis population. Limited information exists about the impact of periodontal therapy in patients receiving dialysis.

STUDY DESIGN

Randomized controlled trial to assess feasibility and gather preliminary data.

SETTING & PARTICIPANTS

Dialysis patients with moderate/severe chronic periodontitis.

INTERVENTION

Intensive treatment, consisting of scaling and root planing, extraction of hopeless teeth, and placement of local-delivery antibiotics, was performed at the baseline visit for treatment-group patients and after study completion for control-group patients.

OUTCOMES

Outcomes were feasibility (screening, recruitment, enrollment, adverse events, and study withdrawal/completion), clinical periodontal parameters (probing depth, clinical attachment level, bleeding on probing, gingival index, and plaque index), and serum albumin and interleukin 6 levels at 3 and 6 months postintervention.

RESULTS

342 dialysis patients were approached for participation: 53 were randomly assigned, with 26 participants assigned to immediate treatment and 27 assigned to a control arm for treatment after 6 months. 51 patients completed baseline appointments; 46 were available for 3-month follow-up, 45 were available for 6-month follow-up examinations, and 43 completed all visits. At 3 months, there was a statistically significant improvement for the treatment group compared to the control group for 3 periodontal parameters: mean probing depth (P = 0.008), extent of probing depth ≥4 mm (P = 0.02), and extent of gingival index ≥1 (P = 0.01). However, by 6 months, the difference between groups was no longer present for any variable except probing depth ≥4 mm (P = 0.04). There was no significant difference between groups for serum albumin or high-sensitivity interleukin 6 level at any time when adjusted for body mass index, diabetic status, and plaque index.

LIMITATIONS

Small sample size and relatively healthy population, imbalance in diabetes.

CONCLUSIONS

This small trial demonstrates successful cooperation between dentists and nephrologists and successful recruitment, treatment, and retention of dialysis patients with periodontitis. Larger studies with longer follow-up are needed to determine whether treatment can improve markers of inflammation and morbidity.

Hyperandrogenism exerts an anti-inflammatory effect in obese women with polycystic ovary syndrome

We determined the effect of chronic androgen suppression on inflammation in women with polycystic ovary syndrome (PCOS) compared to weight-matched controls. We performed a pilot project using samples from previous prospective, controlled studies. Nine women with PCOS (5 obese, 4 lean) and 9 ovulatory controls (5 obese, 4 lean) participated in the study. Androgens, C-reactive protein (CRP), interleukin-6 (IL-6), free fatty acids (FFA) and body weight were measured before and after 3 and 6 months of gonadotropin-releasing hormone (GnRH) agonist administration. GnRH agonist treatment decreased estradiol, testosterone and androstenedione to similar levels in all subjects. CRP and IL-6 increased in obese women with PCOS, was unaltered in lean women with PCOS and obese controls, and decreased in lean controls after 6 months of treatment. FFA decreased and body weight increased in obese women with PCOS, but did not change significantly in lean women with PCOS and in either control group after 6 months of treatment. The testosterone reduction was related to increases in weight and IL-6. The fall in FFA was related to the rise in CRP. The increases in weight and IL-6 were related to the rise in CRP. We propose that hyperandrogenism in PCOS may exert an anti-inflammatory effect when obesity is present, but may not promote inflammation in the disorder; and that circulating androgens have a pleiotropic effect on inflammation depending on the combination of PCOS and weight status in a given individual.

Is vitamin C intake too low in dialysis patients?

Vitamin C has several well-established roles in physiology including synthesis of collagen, carnitine and epinephrine, absorption of dietary iron, and mobilization of storage iron for erythropoeisis. Loss of several of these functions explains the pathology of scurvy, where defective collagen synthesis and anemia are major symptoms. Vitamin C deficiency is very common in dialysis patients and may arise from dialytic vitamin C clearance, restricted intake of vitamin C-rich foods, and increased vitamin C catabolism in vivo from inflammation. In the dialysis population, greater vitamin C intake may be needed for optimal health. Relationships between intake, body distribution, inflammation, and dialytic losses are complex and need further study. Concern about vitamin C metabolism leading to accumulation of tissue oxalate has led to the recommendation that vitamin C intake equals, but not exceeds, the intake recommended for the general population. Vitamin C deficiency in dialysis patients may have clinical consequences; a study in Renal Research Institute clinics found an association with periodontal disease. Data also support a role for vitamin C in prevention of dialysis-related anemia. New research questions are proposed in this editorial, with a discussion of strategies to determine the optimal provision of vitamin C for CKD patients.

Inflammation in Polycystic Ovary Syndrome: underpinning of insulin resistance and ovarian dysfunction

Chronic low-grade inflammation has emerged as a key contributor to the pathogenesis of Polycystic Ovary Syndrome (PCOS). A dietary trigger such as glucose is capable of inciting oxidative stress and an inflammatory response from mononuclear cells (MNC) of women with PCOS, and this phenomenon is independent of obesity. This is important because MNC-derived macrophages are the primary source of cytokine production in excess adipose tissue, and also promote adipocyte cytokine production in a paracrine fashion. The proinflammatory cytokine tumor necrosis factor-α (TNFα) is a known mediator of insulin resistance. Glucose-stimulated TNFα release from MNC along with molecular markers of inflammation are associated with insulin resistance in PCOS. Hyperandrogenism is capable of activating MNC in the fasting state, thereby increasing MNC sensitivity to glucose; and this may be a potential mechanism for promoting diet-induced inflammation in PCOS. Increased abdominal adiposity is prevalent across all weight classes in PCOS, and this inflamed adipose tissue contributes to the inflammatory load in the disorder. Nevertheless, glucose ingestion incites oxidative stress in normal weight women with PCOS even in the absence of increased abdominal adiposity. In PCOS, markers of oxidative stress and inflammation are highly correlated with circulating androgens. Chronic suppression of ovarian androgen production does not ameliorate inflammation in normal weight women with the disorder. Furthermore, in vitro studies have demonstrated the ability of pro-inflammatory stimuli to upregulate the ovarian theca cell steroidogenic enzyme responsible for androgen production. These findings support the contention that inflammation directly stimulates the polycystic ovary to produce androgens.

Treatment of periodontal diseases reduces chronic systemic inflammation in maintenance hemodialysis patients

BACKGROUND

Evidences suggest that chronic systemic inflammation is associated with increasing mortality in maintenance hemodialysis patients due to atherosclerosis and malnutrition. Periodontal diseases are treatable sources of systemic inflammation in hemodialysis patients. We therefore evaluated the effect of periodontal treatment in maintenance hemodialysis patients.

METHOD

Periodontal diseases were evaluated in 30 stable maintenance hemodialysis patients by using clinical periodontal status by plaque index (PI) and periodontal disease index (PDI). Hematologic, biochemical, nutritional, and dialysis-related parameters as well as highly sensitive C-reactive protein (hs-CRP), a sensitive systemic inflammatory marker, were analyzed before and after periodontal therapy.

RESULT

Maintenance hemodialysis patients had high prevalence of periodontal disease (63%). At baseline, hs-CRP positively correlated with clinical periodontal status (PI, r = 0.74, p < 0.001; PDI, r = 0.66, p < 0.001), but negatively correlated with hemoglobin (r = -0.51, p < 0.001), serum albumin (r = -0.61, p = 0.002), and normalized protein catabolic rate (r = -0.42, p = 0.043). After completion of periodontal therapy (duration 6 ± 2 weeks), the PI and PDI significantly declined from 2.13 to 1.48 (p = 0.001) and 3.53 to 2.52 (p = 0.001), respectively, while hs-CRP significantly declined from 3.8 to 0.6 mg/L (p < 0.001). Moreover, erythropoietin dosage could be reduced from 8000 to 6000 unit/week (p = 0.03) after treatment. Pre-dialysis blood urea nitrogen increased from 66.18 to 79.54 mg/dL (p = 0.003) and serum albumin level increased from 3.15 to 3.38 mg/dL (p = 0.003), reflecting improved nutritional status of the patients after periodontal treatment.

CONCLUSION

Periodontitis is an important source of chronic inflammation. Treatment of periodontal diseases can improve systemic inflammation, nutritional status, and erythropoietin responsiveness in the hemodialysis population.

Systemic consequences of poor oral health in chronic kidney disease patients

Changes in the oral cavity, such as periodontitis and other manifestations of poor oral health, are common in patients with chronic kidney disease (CKD) and may contribute to increased morbidity and mortality because of systemic consequences such as inflammation, infections, protein-energy wasting, and atherosclerotic complications. Poor oral health in CKD patients may thus represent an important, but often overlooked, problem. Several studies show that uremic patients have higher rates of decayed, missing, and filled teeth, loss of attachment, and periapical and mucosal lesions than the general population. The consequences of poor oral health may be more severe in CKD patients because of advanced age, common comorbidities such as diabetes, concurrent medications, and a state of immune dysfunction that may increase the risk for systemic consequences of periodontitis and other oral and dental pathologic conditions. Poor dentition and other signs of poor oral health should be an alarm clock also at early stages of CKD. However, it remains to be determined whether more successful management of poor oral health and periodontitis will reduce the risk of inflammation, infection, protein-energy wasting, and atherosclerotic complications in CKD patients. This review explores etiological factors and potential systemic consequences of poor oral health in CKD patients as well as possible preventive and therapeutic strategies.

Biochemistry and biomarkers of inflamed patients: why look, what to assess

Specific laboratory tests and physical findings are available to the practicing clinician that should raise the suspicion of inflammation. Inflammation is related to specific clinical outcomes. Once identified, changes in clinical practice may affect the level of inflammation in individual and or groups of dialysis patients with the hope that these changes may in turn affect outcome in a positive manner. Standard clinical tests and observations associated with inflammation are hypoalbuminemia, erythropoietin resistance, decreased iron saturation accompanied by high ferritin, frailty, low serum creatinine, reduced total and LDL-cholesterol, and increased C reactive protein (CRP). Inflammation is strongly associated with loss of physical function, dyslipidemia (low LDL- and HDL-cholesterol, increased triglycerides), and anemia that is unresponsive to erythropoietin. Inflammation is associated with cardiovascular events, increased hospitalization, and death. Correctible causes of inflammation are tunneled dialysis catheters, arteriovenous grafts, catheter infection, periodontal disease, poor water quality, and dialyzer incompatibility. Obesity also is a source of cytokines but may be less amenable to treatment. Inflammation is multifactorial in dialysis patients. Some sources are recognizable and correctable, such as vascular access type, clinical infection, and water quality, and some are not. Inflammation is strongly associated with outcome.

Significance of elevated gingival crevicular fluid tumor necrosis factor-alpha and interleukin-8 levels in chronic hemodialysis patients with periodontal disease

BACKGROUND AND OBJECTIVE

The prevalence of chronic renal disease in industrialized countries is increasing, and chronic renal disease and periodontitis can have significant, reciprocal effects. The aim of this study was to evaluate the associations between specific clinical parameters and the levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) in the gingival crevicular fluid of hemodialysis (HD) patients with periodontal disease.

MATERIAL AND METHODS

Forty-three HD patients and 43 systemically healthy subjects were enrolled in this study. Plaque index (PI), gingival index (GI) and pocket depth were used to determine periodontal status. Venous blood samples were obtained from each patient in the morning before the dialysis session and analyzed to determine the levels of inflammatory, biochemical and hematological parameters. Gingival crevicular fluid was collected from all subjects, and the levels of TNF-alpha and IL-8 were determined in the gingival crevicular fluid samples.

RESULTS

The following results were obtained from HD patients and controls: TNF-alpha (pg/mL), 31.40 +/- 1.46 and 3.06 +/- 0.15 (p < 0.001); IL-8 (pg/mL), 90.98 +/- 94.03 and 35.05 +/- 16.86 (p < 0.001); PI, 1.69 +/- 1.02 and 0.04 +/- 0.02 (p < 0.001); GI, 0.82 +/- 0.06 and 0.04 +/- 0.02 (p < 0.001); and pocket depth, 2.23 +/- 0.63 and 1.51 +/- 0.05 (p < 0.001), respectively. In addition, there were positive correlations between TNF-alpha and PI (r = 0.642, p < 0.001), between TNF-alpha and GI (r = 0.565, p < 0.001), between TNF-alpha and pocket depth (r = 0.522, p < 0.001), between IL-8 and PI (r = 0.402, p = 0.002), between IL-8 and GI (r = 0.396, p = 0.002), and between IL-8 and pocket depth (r = 0.326, p = 0.012). There were negative correlations between albumin and PI (r = -0.491, p < 0.001), albumin and GI (r = -0.406, p < 0.001), albumin and pocket depth (r = -0.464, p < 0.001) and albumin and CRP (r = -0.467, p = 0.002) and between the gingival crevicular fluid levels of TNF-alpha and IL-8, TNF-alpha and hemoglobin (r = -0.745, p < 0.001; r = -0.285, p < 0.05) (respectively).

CONCLUSION

The levels of TNF-alpha and IL-8 in gingival crevicular fluid were significantly higher in HD patients than in controls. There were strong, positive correlations between clinical periodontal parameters and the levels of inflammatory cytokines in gingival crevicular fluid from the HD patients.

Inflammation as a cause of malnutrition, atherosclerotic cardiovascular disease, and poor outcome in hemodialysis patients

Cardiovascular disease (CVD) remains the major cause of morbidity and mortality in end-stage renal disease (ESRD) patients treated by hemodialysis (HD). Although traditional risk factors are common in dialysis patients, they may not alone be sufficient to account for the unacceptable high prevalence of CVD in this patient group. Recent evidence demonstrates that chronic inflammation, a nontraditional risk factor that is commonly observed in HD patients, may cause malnutrition and progressive atherosclerotic CVD by several pathogenetic mechanisms. The cause(s) of inflammation in HD patients is multifactorial and includes both dialysis-related (such as graft and fistula infections, bioincompatibility, impure dialysate, and back-filtration) and dialysis-unrelated factors. Although inflammation may reflect underlying CVD, an acute-phase reaction may also be a direct cause of vascular injury. Available data suggest that proinflammatory cytokines play a central role in the genesis of both malnutrition and CVD in ESRD. Thus, it could be speculated that suppression of the vicious cycle of malnutrition, inflammation, and atherosclerosis (MIA syndrome) would improve survival in dialysis patients. As there is not yet any recognized, or even proposed, targeted treatment for ESRD patients with chronic inflammation; it would be of considerable interest to study the long-term effect of various anti-inflammatory treatment strategies on nutritional and cardiovascular status as well as outcome in these patients.

Oral Health and Inflammation in Patients with End-Stage Renal Failure

Background/Aims

End-stage renal disease (ESRD) patients have an increased risk of atherosclerotic complications. In both hemodialysis (HD) patients and the general population, it has become evident that inflammation plays an important role in the pathogenesis of atherosclerotic complications. Oral and dental problems in ESRD patients could be an important source of inflammation, thus treatment of these problems is important to protect these patients from potential infections. The decayed, missing, and filled teeth (DMFT) index is an indicator of oral and dental health status. Our aim was to analyze and compare salivary flow rate (SFR), salivary pH (SpH), salivary buffering capacity (SBC), and DMFT index and plaque index (PI) values in PD patients to HD patients and healthy controls (C) and establish the relationship between these parameters and C-reactive protein (CRP).

Methods

76 PD patients, 100 HD patients, and 111 Cs were included in the study. SFR (milliliters/minute) was measured in stimulated whole saliva, SpH was measured using the Merck indicator, and SBC was measured according to the method of Ericsson: 1 mL whole saliva was added to 3 mL 0.005 N HCl and a stream of air was passed through this mixture for 20 minutes. Finally, DMFT index and PI values were calculated.

Results

No statistically significant differences were found in age or gender distribution among PD, HD, and C groups. There was also no significant difference in time on dialysis between PD and HD groups. SFR was significantly lower in the PD and HD groups than in the C group (1.30 ± 0.83 and 0.70 ± 0.32 vs 1.64 ± 0.45 mL/min) and lower in the HD than in the PD group ( p < 0.001). SpH (8.35 ± 0.43 and 8.12 ± 0.74 vs 7.16 ± 0.76) and SBC (7.39 ± 0.47 and 6.82 ± 0.70 vs 5.08 ± 0.73) were significantly higher in the PD and HD groups than in the C group and higher in the PD than in the HD group ( p < 0.05 and p < 0.001 respectively). The numbers of filled teeth were significantly higher in the PD than in the HD and C groups ( p < 0.001). DMFT index was significantly higher in the PD than in the HD group ( p < 0.001). Finally, PI values were significantly higher in the PD and HD groups than in the C group ( p < 0.001) and higher in the HD than in the PD group, although this was not statistically significant. In the present study, we also found higher CRP values in HD than in PD patients and a positive correlation between CRP and PI values in PD patients.

Conclusions

PD patients have higher SFR, SpH, and SBC values than HD patients; however, higher DMFT index and higher numbers of filled teeth were observed in PD patients. Compared to healthy controls, patients on dialysis had worse dental and periodontal findings, which might have a role in microinflammation in this group of patients.

Hyporesponsiveness to erythropoietin: causes and management

In patients with chronic kidney disease, erythropoietin resistance is common, costly, and has implications beyond the management of anemia because the presence of erythropoietin resistance portends mortal outcomes. Exploring the provenance of erythropoietin resistance may be facilitated by the consideration of the pathogenetic triad of iron-restricted erythropoiesis, inflammation, and bone marrow suppression. Challenging to diagnose because of difficulty in interpreting tests of iron deficiency, iron-restricted erythropoiesis should be considered in patients who require high doses of erythropoietin, have low transferrin saturation (eg, <20%-25%), and do not have very high ferritin (eg, <1,200 ng/mL); a therapeutic trial of intravenous iron may be worthwhile. Aluminum intoxication is a rare cause of iron-restricted erythropoiesis that may manifest as microcytic hypochromic anemia. A decrease in serum albumin concentration may signal the presence of inflammation, which may be manifest (such as because of a recent illness or infection) or occult; the latter include clotted synthetic angioaccess, failed renal allograft, dialysis catheter, periodontal disease, underlying malignancy, or uremia per se. Marrow hyporesponsiveness may be improved by increasing the delivered dialysis dose, using ultrapure dialysate, maintaining adequate vitamin B12 and folate stores, or by treating hyperparathyroidism. In summary, improving the outcomes of erythropoietin-resistant patients will require complete patient assessment that goes beyond considerations of iron and erythropoietin dose alone. Given that erythropoietin dose is associated with mortality, mitigating erythropoietin resistance has the potential to improve patient outcomes.

Parenteral ascorbic acid in haemodialysis patients

PURPOSE OF REVIEW

Parenteral ascorbic acid has been frequently used to overcome problems of vitamin C deficiency in haemodialysis patients. The benefits of vitamin C supplementation in clinical studies have been controversial and did not consider toxicological aspects. The review summarizes recent findings of the effects of parenteral ascorbic acid and discusses toxicological effects.

RECENT FINDINGS

Vitamin C deficiency in haemodialysis patients, which has been frequently described, cannot be improved with oral supplementation due to limited absorption of high dosages. To avoid consequences of vitamin C deficiency, parenteral vitamin C solutions should be administered because this intervention is the only way to guarantee a sufficient supply to the cells. A beneficial consequence of parenteral vitamin C on the recombinant human erythropoietin resistance is an additional therapeutic effect, which contributes to the prevention of iron deficiency anaemia in haemodialysis patients. Thus, large amount of supplemental vitamin C are required for extended periods of time (up to 500 mg 3 times a week). To avoid hyperoxaluria, plasma oxalate levels should be monitored on a regular basis, for example, once a week.

SUMMARY

Parenteral administration of ascorbic acid may be an approach that can overcome problems of vitamin C deficiency in haemodialysis patients - in particular problems of iron overload, erythropoetin resistance, and chronic inflammation.

Analysis of the association of polymorphism in the osteoprotegerin gene with susceptibility to chronic kidney disease and periodontitis

BACKGROUND AND OBJECTIVE

Chronic kidney disease (CKD) is a complex disorder, which results in several complications involving disturbance of mineral metabolism. Periodontal disease is an infectious disease that appears to be an important cause of systemic inflammation in CKD patients. Periodontal disease is characterized by clinical attachment loss (CAL) caused by alveolar bone resorption around teeth, which may lead to tooth loss. Osteoprotegerin (OPG) is a key regulator of osteoclastogenesis. Polymorphisms are the main source of genetic variation, and single nucleotide polymorphisms (SNPs) have been reported as major modulators of disease susceptibility. The aim of this study was to investigate the association of a polymorphism located at position -223 in the untranslated region of the OPG gene, previously known as -950, with susceptibility to CKD and periodontal disease.

MATERIAL AND METHODS

A sample of 224 subjects without and with CKD (in hemodialysis) was divided into groups with and without periodontal disease. The OPG polymorphism was analyzed by polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

No association was found between the studied OPG polymorphism and susceptibility to CKD or periodontal disease.

CONCLUSION

It was concluded that polymorphism OPG-223 (C/T) was not associated with CKD and periodontal disease in a Brazilian population. Studies on other polymorphisms in this and other genes of the host response could help to clarify the involvement of bone metabolism mediators in the susceptibility to CKD and periodontal disease.

Interactions between chronic renal disease and periodontal disease

The incidence of end-stage renal disease (ESRD) is increasing and patients receiving renal replacement therapy including hemodialysis, peritoneal dialysis or renal transplantation will comprise an enlarging segment of the dental patient population. Renal replacement therapy can affect periodontal tissues including gingival hyperplasia in immune suppressed renal transplantation patients and increased levels of plaque, calculus and gingival inflammation and possible increased prevalence and severity of destructive periodontal diseases in ESRD patients on dialysis maintenance therapy. Also, the presence of undiagnosed periodontitis may have significant effects on the medical management of the ESRD patient. Periodontitis has been found to contribute to systemic inflammatory burden including the elevation of C-reactive protein (CRP) in the general population. Atherosclerotic complications including myocardial infarction and stroke are the primary causes of mortality in the ESRD population and, in contrast to that of the general population, the best predictor of all cause and cardiac death in this population is CRP. Consequently, periodontitis may be a covert but treatable source of systemic inflammation in the ESRD population. The objective of this review was to explore the interaction between chronic renal disease, renal replacement therapy and periodontal diseases based upon the results of studies published within the last decade.

C-reactive protein associated with periodontitis in a Thai population

AIM

C-reactive protein (CRP) has been implicated as a possible mediator of the association between periodontitis and several systemic diseases. Previous studies suggest an association between increased CRP levels and periodontitis predominantly in Caucasians. This study evaluated the associations of chronic periodontitis and Porphyromonas gingivalis with CRP in systemically healthy Thai adults.

MATERIAL AND METHODS

Serum high-sensitivity CRP was measured in 21 generalized periodontitis, 62 localized periodontitis, and 38 periodontally healthy control subjects. P. gingivalis in subgingival plaque samples was analyzed by polymerase chain reaction.

RESULTS

Overall, these subjects had a median CRP level lower than that reported in the western populations. Subjects with generalized periodontitis and localized periodontitis had higher median CRP levels than controls (1.78 and 0.65 mg/l versus 0.25 mg/l, p<0.001). Multivariate linear regression showed that log CRP levels were increased in subjects with generalized periodontitis (p<0.01) and localized periodontitis (p=0.03) compared with the controls, adjusted for age, body mass index and smoking. Presence of P. gingivalis was also independently associated with elevated log CRP levels (p<0.001).

CONCLUSION

Periodontitis and subgingival P. gingivalis are associated with increased CRP levels. These findings suggest that periodontal infection may contribute to systemic inflammatory burden in otherwise healthy individuals.

Newer strategies for anemia prevention in hemodialysis

Anemia prevention for hemodialysis relies primarily on supplemental erythropoietin (EPO) and intravenous iron (IV-iron). The doses of EPO utilized are somewhat higher than normal endogenous rates of EPO production in healthy subjects, and the amount of IV-iron used to boost red blood cell (RBC) production may be greater than the amounts used for erythropoiesis. EPO and IV-iron might be used more efficiently if two fundamental problems were solved in the management of dialysis patients: better vitamin C status, and avoidance of chronic inflammation. The low levels of plasma vitamin C commonly observed in dialysis patients restrict mobilization of stored iron from the reticuloendothelial system (RES), and inflammation has a very similar effect. The impact of low vitamin C levels and concurrent inflammation causes a large amount of iron to be stored, with relatively inefficient utilization for erythropoiesis. Vitamin C intake for dialysis patients is often restricted because of avoidance of vitamin C-rich foods, and because of concerns about oxalosis. Inflammation is a chronic feature of renal disease, which is compounded by infections from use of catheters. Research strategies to improve vitamin C status and to decrease inflammation would lead to better utilization of iron and EPO, and could have parallel benefits for the long-term health of patients on hemodialysis.

Inflammatory syndrome in patients on hemodialysis

Mortality is markedly elevated in hemodialysis (HD) patients. Between 30 and 50% of prevalent patients have elevated serum levels of inflammatory markers such as C-reactive protein and IL-6. The presence of inflammation, chronic or episodic, has been found to be associated with increased mortality risk. The causes of inflammation are multifactorial and include patient-related factors, such as underlying disease, comorbidity, oxidative stress, infections, obesity, and genetic or immunologic factors, or on the other side, HD-related factors, mainly depending on the membrane biocompatibility and dialysate quality. The adequate knowledge of these causes and their prevention or treatment if possible may contribute to improving the inflammatory state of patients who are on HD and possibly their mortality.