UCSF

Rationale & objective

Observational studies have suggested that periodontal disease may be a modifiable risk factor for chronic kidney disease (CKD). The Kidney and Periodontal Disease (KAPD) Study was designed to determine the feasibility of conducting a periodontal disease treatment trial among a high-risk (mostly poor and racial/ethnic minority) population and estimate the magnitude and variability of kidney and inflammatory biomarker levels in response to intensive periodontal treatment.

Study design

Single-center, unmasked, intention-to-treat, randomized, controlled, pilot trial with 2:1 allocation to the treatment and comparison groups.

Setting & participants

English- and Spanish-speaking individuals aged 20 to 75 years receiving primary care within the San Francisco Community Health Network with evidence of both moderate to severe periodontal disease and CKD.

Intervention

Immediate intensive nonsurgical periodontal treatment versus rescue treatment for progressive disease at baseline and 4, 8, and 12 months.

Outcomes

Feasibility and process outcomes. Levels of biomarkers of kidney function, kidney injury, and systemic inflammation obtained at baseline and 4 and 12 months.

Results

KAPD randomly assigned 51 participants to the immediate (34 participants) or rescue (17 participants) groups. 14% dropped out of the study (4 immediate, 3 rescue) and 80% completed all 4 visits of the 12-month protocol (28 immediate, 13 rescue). Fewer than half the teeth recommended for extraction were extracted and 40% of immediate group visits were outside the protocol window. Bleeding on probing and probing depth improved more in the immediate group than in the rescue group; there was no significant separation in periodontal status. Levels of markers of vascular endothelial and systemic injury declined in both groups.

Limitations

No true control group.

Conclusions

This 12-month, pilot, randomized, controlled trial successfully recruited and retained a high-risk population but was less successful observing treatment adherence, treatment effect, and variability of biomarker levels. Although KAPD did not meet all of its goals, important lessons learned can be applied to future studies.

Funding

National Institute of Diabetes and Digestive and Kidney Disease (Bethesda, MD; grant number 1K23DK093710-01A1) and Harold Amos Medical Faculty Development Program of the Robert Wood Johnson Foundation, Princeton, NJ. Funders had no role in study design; collection, analysis, or interpretation of data; writing the report; or the decision to submit the report for publication.

Trial registration

NCT01802216.