Interaction between and impact of IL-6 genotype and alpha-tocopherol levels on periodontal condition in aging individuals.

BACKGROUND AND OBJECTIVES: Few studies have assessed the possible interaction between and impact of IL-6 variants and serum α-tocopherol levels on periodontal condition in older individuals. Here, we assessed the relationship between IL-6 variants and serum α-tocopherol levels on periodontal condition by considering effect modification. MATERIAL AND METHODS: Among the study participants, 359 who were 71 years of age underwent a dental examination, biochemical analysis, and interview. After dividing the participants into tertiles based on serum α-tocopherol levels, we conducted Poisson regression analysis to compare the prevalence rate ratio (PRR) for periodontal disease markers with the IL-6 genotype (rs1800796) based on each tertile adjusted by the number of teeth present (offset). RESULTS: The PRRs of the IL-6 genotype for periodontal condition (probing pocket depth [PPD], clinical attachment level [CAL], and bleeding on probing [BOP]) which were adjusted by the number of teeth present (offset) were 1.17 (P < .001), 1.37 (P < .001), and 1.08 (P = .048), respectively. In addition, a significant association was found between the reciprocal number of PRRs of the IL-6 genotype and three serum α-tocopherol levels. The adjusted PRRs (± standard error) of the IL-6 genotypes for PPD were 0.48 (0.12) for the first group (P < .001), 1.54 (0.04) for the second group (P < .001), and 2.11 (0.03) for the third group (P < .001); similar tendencies were seen for CAL and BOP. CONCLUSION: The results of this study suggest a potential association between the IL-6 genotype and periodontal condition in relation to serum antioxidant concentrations.

Diet and root surface caries in a cohort of older Japanese.

OBJECTIVES: Root surface caries experience tends to increase with age. The purpose of this longitudinal study was to evaluate the relationship between aspects of dietary intake, including milk and sucrose in coffee or tea (SCT), and root surface caries in older Japanese individuals. METHODS: 303 community-dwelling older individuals (age 75 years) were enrolled for analysis. All participants underwent a dental examination at baseline and then annually from 2003 to 2008 (ie six times over a 5-year period). A disease event was considered to have occurred when root surface caries was detected on a previously sound or nonexposed root surface. Over the observation period, disease events in each year were counted. Dietary habits during the preceding month were evaluated using a brief self-administered diet history questionnaire (BDHQ) in 2003 and 2008. Poisson regression analysis performed crude and adjusted increment-rate ratios (IRRs) for root surface caries and the intake of milk and SCT. RESULTS: The adjusted increment-rate ratio (IRR) of the increment of root surface caries for participants in the highest SCT tertile was 1.72 (95%CI: 1.40-2.14) compared with the referent group. In addition, for the amount of milk intake, the adjusted IRR in the highest tertile was 0.63 (95% CI: 0.51-0.78) compared with the referent group. CONCLUSIONS: Much SCT and low milk intake were associated with the increment of root surface caries in community-dwelling older people in Japan. These findings suggest that to help prevent root surface caries, community-dwelling older people in Japan should consume adequate amounts of milk daily and limit their intake of SCT.