Red blood cell folate level is associated with periodontitis in American adults: results from the NHANES 2009-2014

Abstract Background The relationship between folate and periodontal disease has been previously reported. Red blood cell (RBC) folate is an indicator of long-term folate nutrition. The aim of this study was to use the NHANES database to determine whether red blood cell folate is associated with moderate/severe periodontitis. Methods A cross-sectional analysis of 10,168 participants in the NHANES database from 2009–2014 was performed. Multivariate logistic regression was used to determine the OR and 95% CI for periodontitis in each group. Restriction cube spline model was used for analyzing dose-response relationship. Finally, subgroup analysis was performed to test whether the results were robust in different populations. Results After adjusting for confounding factors, there was an inverse correlation between RBC folate concentration and moderate/severe periodontitis. The lowest fraction Q1 (< 360ng/mL) of RBC folate concentration was used as the reference group, multivariable-adjusted ORs and 95% CIs of the second (360-463ng/mL), third (464-569ng/mL), fourth (570–732 ng/mL), and the highest quintile (> 733 ng/mL) categories were 0.87 (0.76–0.99), 0.81(0.70–0.93),0.75(0.65–0.88),0.62(0.53–0.73) respectively (all p < 0.05). Conclusion In representative samples of American adults, high red blood cell folate was at low risk for moderate/severe periodontitis. At the same time, dentists and policymakers should pay attention to the harm caused by high red blood cell folate level.