Sodium phosphate does not increase risk for acute kidney injury after routine colonoscopy, compared with polyethylene glycol.

BACKGROUND & AIMS: Oral sodium phosphate (OSP) is a common bowel purgative administered before colonoscopy; the Food and Drug Administration has warned against its use because of concerns about acute kidney injury (AKI) from the absorbed phosphate and dystrophic calcification. However, it is not clear if OSP is associated with AKI in the general population or in high-risk subgroups undergoing colonoscopy. We estimated the risk of AKI among patients undergoing a screening colonoscopy using OSP vs polyethylene glycol (PEG) for bowel cleansing in a large, US-based claims database. METHODS: We used an insurance database to identify a cohort of patients ages 50 to 75 years who underwent screening colonoscopies as outpatients from January 2000 through November 2008 (before the Food and Drug Administration warning), receiving OSP (n = 121,266) or PEG (n = 429,430) within 30 days beforehand, without prior use of either drug. We collected data from patients for 6 months afterward to identify those who developed AKI or renal failure, or received dialysis. Adjusted and propensity score-matched hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. We investigated the effects in subgroups with higher AKI risk (patients with chronic kidney disease, kidney stones, hypertension, or diabetes, or using antihypertensive or nonsteroidal anti-inflammatory drugs). RESULTS: AKI occurred in 0.2% of OSP users and in 0.3% of PEG users (adjusted HR, 0.86; 95% CI, 0.75-0.99). OSP users matched well with PEG users, producing similar estimates (HR, 0.85; 95% CI, 0.72-1.01). We did not observe a consistent increase in the risk of AKI or other outcomes in any subgroups analyzed. CONCLUSIONS: In a large database analysis, we did not associate administration of OSP before colonoscopy with increased risk of postprocedure AKI, even in high-risk clinical subgroups.

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.

Periodontal disease adversely affects the survival of patients with end-stage renal disease.

Periodontal disease is associated with cardiovascular disease and is thought to accelerate systemic atherosclerosis. Here we examined the relationship between periodontitis and cardiovascular disease mortality in outpatients on hemodialysis using a retrospective analysis of 168 adult patients in New York City and North Carolina. During 18 months of follow-up, cardiovascular disease and all-cause mortality were determined from a centralized dialysis registry. One hundred patients had mild or no periodontal disease but the remaining 68 had moderate-to-severe disease defined as 2 or more teeth with at least 6 mm of inter-proximal attachment loss. At baseline, the proportion of males was significantly lower in the moderate-to-severe group. Compared with mild or no periodontal disease, moderate-to-severe disease was significantly associated with death from cardiovascular causes. Adjustment for age, gender, center and dialysis vintage, smoking status, and history of diabetes mellitus or hypertension did not diminish the strength of this association. Our findings suggest a need for larger studies to confirm this connection, along with intervention trials to determine if treating periodontitis reduces cardiovascular disease mortality in dialysis patients.

The effect of cholesterol reduction with cholestyramine on renal function.

BACKGROUND: Epidemiological studies suggest that dyslipidemia is an independent risk factor for the development of renal insufficiency in otherwise healthy individuals. Yet, data on the effect of cholesterol reduction are lacking in this population. We performed a secondary analysis of a large existing cohort to determine whether treatment with cholestyramine improved renal function compared with placebo. METHODS: A total of 3,603 middle-aged men from the Lipid Research Clinics Coronary Primary Prevention Trial comprised the study group: 1,806 men were randomly assigned to treatment with cholestyramine, and 1,797 men, placebo. The primary outcome is difference in glomerular filtration rates between the 2 groups. RESULTS: A total of 1,806 men were randomly assigned to treatment with cholestyramine, and 1,797 men, placebo. For the entire group, the estimated mean difference in glomerular filtration rates between the cholestyramine and placebo groups was 0.39 mL/min/1.73 m2 (0.007 mL/s/1.73 m2; P = 0.28) during a follow-up period of more than 8 years. CONCLUSION: Cholesterol reduction with cholestyramine treatment did not meaningfully affect renal function compared with placebo in the present analysis. Prospective intervention trials are needed to determine whether decreasing serum cholesterol levels benefits kidney function in otherwise healthy individuals.

Periodontal disease is associated with renal insufficiency in the Atherosclerosis Risk In Communities (ARIC) study.

BACKGROUND: Periodontitis, a chronic bacterial infection of the oral cavity, is a novel risk factor for atherosclerotic cardiovascular disease (CVD). Given the numerous shared risk factors for CVD and chronic kidney disease (CKD), we hypothesized that periodontitis also is associated with renal insufficiency in the Dental Atherosclerosis Risk in Communities study. METHODS: We conducted a cross-sectional study of 5,537 middle-aged black and white men and women. Periodontitis was determined by using an independent clinically derived definition and categorized as healthy/gingivitis, initial, and severe. Renal insufficiency is defined as glomerular filtration rate (GFR) less than 60 mL/min/1.73 m2 . Multivariable logistic regression models were used to estimate odds ratios and 95% confidence intervals for renal insufficiency using healthy/gingivitis as the referent group. RESULTS: A total of 2,276 individuals had initial periodontitis, and 947 individuals had severe periodontal disease. One hundred ten individuals (2%) had a GFR less than 60 mL/min/1.73 m2 . Compared with healthy/gingivitis, initial and severe periodontal disease were associated with a GFR less than 60 mL/min/1.73 m2 (odds ratio, 2.00; 95% confidence interval, 1.23 to 3.24) for initial periodontal disease and an odds ratio of 2.14 for severe disease (95% confidence interval, 1.19 to 3.85) after adjustment for important risk factors for CVD and CKD. Sensitivity analysis showed that initial and severe periodontitis were each associated with an elevated serum creatinine level (men, >1.4 mg/dL [>124 micromol/L]; women, >1.2 mg/dL [>106 micromol/L]; odds ratio, 3.21; 95% confidence interval, 1.32 to 7.76 and odds ratio, 5.39; 95% confidence interval, 2.08 to 13.99, respectively). CONCLUSION: This is the first study to show an association of periodontal disease with prevalent renal insufficiency. A prospective study is necessary to determine the exact nature of the observed relationship.

Association Between Periodontal Disease and Kidney Function Decline in African Americans: The Jackson Heart Study.

BACKGROUND: Chronic kidney disease (CKD) remains a prevalent public health problem that disproportionately affects African Americans, despite intense efforts targeting traditional risk factors. Periodontal disease, a chronic bacterial infection of the oral cavity, is both common and modifiable and has been implicated as a novel potential CKD risk factor. The authors seek to examine to what extent periodontal disease is associated with kidney function decline. METHODS: This retrospective cohort study examines 699 African American participants with preserved kidney function (defined by estimated glomerular filtration rate (eGFR) >60 mL/minute/1.73 m(2) at baseline) who underwent complete dental examinations as part of the Dental-Atherosclerosis Risk in Communities study (1996 to 1998) and subsequently enrolled in the Jackson Heart Study (2000 to 2004). Using multivariable Poisson regression, the authors examined the association of periodontal disease (severe versus non-severe) with incident CKD, defined as incident eGFR <60 mL/minute/1.73 m(2) and rapid (5% annualized) eGFR decline at follow-up among those with preserved eGFR at baseline. RESULTS: Mean (± SD) age at baseline was 65.4 (± 5.2) years, and 16.3% (n = 114) had severe periodontal disease. There were 21 cases (3.0%) of incident CKD after a mean follow-up of 4.8 (± 0.6) years. Compared with participants with non-severe periodontal disease, those with severe periodontal disease had a four-fold greater rate of incident CKD (adjusted incidence rate ratio 4.18 [95% confidence interval 1.68 to 10.39], P = 0.002). CONCLUSIONS: Severe periodontal disease is prevalent among a population at high risk for CKD and is associated with clinically significant kidney function decline. Further research is needed to determine if periodontal disease treatment alters the trajectory of renal deterioration.

Antibodies to periodontal organisms are associated with decreased kidney function. The Dental Atherosclerosis Risk In Communities study.

BACKGROUND/AIMS: Increasing evidence suggests that clinical signs of periodontal disease are independently associated with renal impairment. However, no studies have examined the possible linkage of kidney disease with serum antibody to oral pathogens. METHODS: The periodontal disease status was assessed in an older community-dwelling population (Dental Atherosclerosis Risk in Communities) to include: clinical measurements; oral biofilm microbial composition by DNA checkerboard, and serum antibody immunoglobulin-gamma (IgG) titers to specific bacteria by immunocheckerboard. Baseline characteristics were used to compute estimated glomerular filtration rate defining eGFR <60 ml/min/1.73 m(2) as impaired renal function in 103 of 5,032 subjects. Levels of serum IgG to specific oral bacteria were categorized by quartiles (comparing upper vs. lower three) as high titer and GFR <60 as the dependent variable in logistic regression models, adjusting for multiple comparisons (Hotelling T(2)) and traditional risk factors including age, race, smoking, diabetes, hypertension, body mass, waist-to-hip ratio, serum triglycerides, HDL, and LDL cholesterol. RESULTS: High levels of serum IgG to selected periodontal pathogens including Porphyromonas gingivalis, Treponema denticola and Aggregobacter actinomycetemcomitans were associated with an increased odds for GFR <60 ml/min/1.73 m(2), adjusted odds ratio ranging from 1.6 to 1.8 and p < 0.05. CONCLUSIONS: Elevated IgG to periodontal pathogens is significantly associated with impaired kidney function, independent of traditional risk factors. Prospective studies are necessary to confirm these findings.

Severe periodontitis is associated with low serum albumin among patients on maintenance hemodialysis therapy.

The relationship between periodontitis and two measures of systemic inflammation, serum albumin and C-reactive protein (CRP), were examined among patients who were receiving chronic outpatient hemodialysis. Adult patients at two locations, North Carolina and New York City, were evaluated by dentist examiners. Six sites per tooth (up to 32 teeth per patient) were examined. A periodontitis case was defined as > or = 60% of sites with attachment level > or = 4 mm. Multivariable logistic regression was used to determine the association of periodontitis with low serum albumin, defined as < 3.5 mg/dl, and with high CRP, defined as > 3.0 mg/dl. A total of 154 patients completed the study. The mean age was 54.6 yr (SD 13.3), and average duration of dialysis was 4.0 yr (3 mo to 16 yr). Eighty-six (54.6%) were men, and 89 (58.2%) were black. Common causes of end-stage kidney disease were hypertension (12.3%), diabetes (22.1%), glomerulonephritis (7.1%), and other (58.4%). The average number of teeth was 20.3 (SD 8.4). Thirty-five (23%) patients were periodontitis cases. Severe periodontitis was associated with low serum albumin (odds ratio 8.20; 95% confidence interval 1.61 to 41.82; P = 0.01) compared with individuals without severe periodontitis disease after adjustment for age, gender, race, diabetes, hypertension, body mass index, smoking, study site, total cholesterol, serum calcium, serum phosphorus, and normalized protein catabolic rate. There was no observed association of severe periodontitis with CRP. Investigation of the potential contribution of periodontitis to serum albumin and possibly to morbidity and mortality among patients with end-stage kidney disease seems warranted.