Vulnerable populations and the association between periodontal and chronic kidney disease

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.

Periodontitis and chronic kidney disease: a systematic review of the association of diseases and the effect of periodontal treatment on estimated glomerular filtration rate

AIM

The aim of this systematic review (SR) was to evaluate the association between periodontitis and chronic kidney disease (CKD) and the effect of periodontal treatment (PT) on the estimated glomerular filtration rate (eGFR).

METHODS

MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched up to and including September 30, 2012 to observational (S1) and interventional (S2) studies on the association of periodontitis with CKD. Studies were considered eligible for inclusion if they reported the eGFR. Search was conducted by two independent reviewers. The methodological quality of the observational studies was assessed using the Newcastle-Ottawa Scale (NOS) adapted for this review, and the Cochrane's Collaboration risk of bias assessment tool. A random-effects odds-ratio meta-analysis was conducted to estimate the degree of association between periodontitis and CKD.

RESULTS

Search strategy identified 2456 potentially eligible articles, of which four cross-sectional, one retrospective, and three interventional studies were included. Four S1, 80.0% reported some degree of association between periodontitis and CKD. Similarly, such an outcome was supported by pooled estimates (OR: 1.65, 95% Confidence Interval: 1.35, 2.01, p < 0.00001, χ(2)  = 1.70, I(2 ) = 0%). All interventional studies found positive outcomes related to treatment.

CONCLUSION

There is quite consistent evidence to support the positive association between periodontitis and CKD, as well as the positive effect of PT on eGFR.

Racial disparities in access to pediatric kidney transplantation since share 35

Share 35 was enacted in 2005 to shorten transplant wait times and provide high-quality donors to children with ESRD. To investigate the possible effect of this policy on racial disparities in access to pediatric transplantation, we analyzed data from the US Renal Data System before and after Share 35. Among 4766 pediatric patients with incident ESRD, the probability of receiving a deceased-donor kidney transplant increased 46% after Share 35, with Hispanics experiencing the greatest improvements (increases of 81% for Hispanics, 45% for blacks, and 37% for whites). On average, patients received a deceased-donor kidney transplant earlier after Share 35, but this finding varied by race: 63 days earlier for whites, 90 days earlier for blacks, and 201 days earlier for Hispanics. Furthermore, a shift from living- to deceased-donor sources occurred with Share 35 for all races, with a 25% reduction in living donors for whites compared with 48% and 46% reductions for Hispanics and blacks, respectively. In summary, Share 35 seems to have attenuated racial disparities in the time to and probability of children receiving a deceased-donor kidney transplant. These changes coincided with changes in the rates of living-donor sources, which vary by race. Future studies should explore how these changes may impact racial differences in long-term graft outcomes.

Chronic kidney disease and use of dental services in a United States public healthcare system: a retrospective cohort study

Background

As several studies have shown an association between periodontal disease and chronic kidney disease (CKD), regular dental care may be an important strategy for reducing the burden of CKD. Access to dental care may be limited in the US public health system.

Methods

In this retrospective cohort study of 6,498 adult patients with (n = 2,235) and without (n = 4,263) CKD and at least 12 months of follow-up within the San Francisco Department of Public Health Community Health Network clinical databases, we examined the likelihood of having a dental visit within the observation period (2005-2010) using Cox proportional hazards models. To determine whether dental visits reflected a uniform approach to preventive service use in this setting, we similarly examined the likelihood of having an eye visit among those with diabetes, for whom regular retinopathy screening is recommended. We defined CKD status by average estimated glomerular filtration rate based on two or more creatinine measurements ≥ 3 months apart (no CKD, ≥ 60 ml/min/1.73 m²; CKD, < 60 ml/min/1.73 m²).

Results

Only 11.0% and 17.4% of patients with and without CKD, respectively, had at least one dental visit. Those with CKD had a 25% lower likelihood of having a dental visit [HR = 0.75, 95% CI (0.64-0.88)] than those without CKD after adjustment for confounders. Among the subgroup of patients with diabetes, 11.8% vs. 17.2% of those with and without CKD had a dental visit, while 58.8% vs. 57.8% had an eye visit.

Conclusions

Dental visits, but not eye visits, in a US public healthcare setting are extremely low, particularly among patients with CKD. Given the emerging association between oral health and CKD, addressing factors that impede dental access may be important for reducing the disparate burden of CKD in this population.

Radiographic periodontal bone loss in chronic kidney disease

BACKGROUND

We examined the extent and severity of radiographic periodontal bone loss in patients with different stages of chronic kidney disease (CKD) and explored a potential dose-response relationship between bone loss and CKD-related biomarkers.

METHODS

Panoramic radiographs were obtained from 129 CKD patients (78 males and 51 females; mean age: 63.5 years, range: 24 to 91 years), including 63 patients undergoing dialysis for an average of 3.3 years (range: 0.5 to 14 years). Glomerular filtration rate (GFR), dialysis dose, and levels of serum biomarkers were obtained through a hospital database. Interproximal bone loss was assessed as a percentage of root length.

RESULTS

Twenty-nine participants were edentulous (23.8% of those on dialysis versus 21.2% of those with residual kidney function; χ(2) test, P = 0.724). The extent of bone loss was higher among dialysis patients (analysis of variance [ANOVA], P = 0.007), but no clear dose-response association between CKD stage and extent was evident. GFR, dialysis dose, and levels of serum biomarkers did not differ between edentulous and dentate individuals, and only serum albumin was lower in patients with extensive bone loss (ANOVA, P = 0.030). After adjusting for dialysis status, the severity of bone loss was positively associated with glucose levels (multiple regression, P = 0.019) and white blood cell count (P = 0.032), whereas the number of teeth present was positively associated with plasma phosphorus (P = 0.008) and negatively with glucose levels (P = 0.011).

CONCLUSION

Despite a higher extent of bone loss in dialysis patients, the lack of a dose-response association between bone loss and CKD stage or the levels of CKD-related serum biomarkers underscores the complex relationship between the two conditions.