Subgingival microbiome at different levels of cognition.

Oral health and declining cognition may have a bi-directional association. We characterized the subgingival microbiota composition of subjects from normal cognition to severe cognitive decline in two cohorts. Memory and Periodontitis (MINOPAR) include 202 home-living participants (50-80 years) in Sweden. Finnish Oral Health Studies in Older Adults (FINORAL) include 174 participants (≥65 years) living in long-term care in Finland. We performed oral examination and assessed the cognitive level with Mini Mental State Examination (MMSE). We sequenced the 16S-rRNA gene (V3-V4 regions) to analyse the subgingival bacterial compositions. The microbial diversities only tended to differ between the MMSE categories, and the strongest determinants were increased probing pocket depth (PPD) and presence of caries. However, abundances of 101 taxa were associated with the MMSE score. After adjusting for age, sex, medications, PPD, and caries, only eight taxa retained the significance in the meta-analyses of the two cohorts. Especially Lachnospiraceae [XIV] at the family, genus, and species level increased with decreasing MMSE. Cognitive decline is associated with obvious changes in the composition of the oral microbiota. Impaired cognition is accompanied with poor oral health status and the appearance of major taxa of the gut microbiota in the oral cavity. Good oral health-care practices require special deliberations among older adults.

Calcified carotid artery atheromas in individuals with cognitive dysfunction.

OBJECTIVE: The aim of this case-control study was to investigate whether cognitively impaired individuals have a higher burden of calcified carotid artery atheroma (CCAA) than controls without cognitive impairment. MATERIAL AND METHODS: The study included 154 cases with Alzheimer's disease (n = 52), mild cognitive impairment (n = 51), or subjective cognitive decline (n = 51) diagnosed at a university memory clinic. Seventy-six cognitively healthy controls were sampled through the Swedish population register. All participants underwent clinical oral and panoramic radiographic examinations. Two oral and maxillofacial radiologists performed blinded analyses of the panoramic radiographs for signs of CCAA, which was registered as absent or present and, if present, unilateral or bilateral. Consensus assessment was used for all statistical analyses. RESULTS: CCAA was common (40%) in this middle-aged and older Swedish population. We found no differences in the prevalence of CCAA between cases and controls (40% vs. 42%). CONCLUSION: Cognitively impaired patients do not have a higher burden of CCAA than matched controls without cognitive impairment.

Periodontal conditions and incident dementia: A nationwide Swedish cohort study.

BACKGROUND: Periodontal disease has been proposed as a putative etiological factor for dementia. The aim of this investigation was to compare the incidence of dementia in individuals with or without deep probing pocket depths (DPPD), serving as a proxy for periodontitis. METHODS: In this cohort study, conducted in Sweden, we identified 7992 individuals with DPPD and 29,182 matched individuals without DPPD (non-DPPD), using the Swedish Quality Registry for Caries and Periodontal Diseases (SKaPa). The two groups were followed for incident dementia (mean follow-up time was 7.6 years) based on data from the Swedish Dementia Registry (SveDem). The exposure-outcome relationship was explored by applying the Royston-Parmar (RP) flexible parametric survival model. RESULTS: The incidence of dementia in the two groups was similar. In the DPPD group 137 (1.7%) developed dementia and 470 (1.6%) in the non-DPPD group. The incidence rate of dementia was estimated to be 2.3 per 1000 person-years (95% confidence interval [CI] 1.9 to 2.7) in the DPPD group and 2.1 per 1000 person-years (95% CI 1.9 to 2.3) in the non-DPPD group. The RP model disclosed no association between DPPD and dementia incidence after controlling for potential confounders (the exponentiated coefficient was estimated to 1.13 [95% CI = 0.39 to 3.24]). CONCLUSION: In this sample, no association was revealed between deep probing pocket depths and the incidence of dementia.

Subgingival microbiota in a population with and without cognitive dysfunction.

Aim: The aim of this study was to compare the subgingival microbiota of people with Alzheimer´s disease (AD), mild cognitive impairment (MCI), subjective cognitive decline (SCD) and cognitively healthy individuals. Materials and methods: The study population was recruited from 2013 to 2017 and comprised 132 cases recently diagnosed with AD (n = 46), MCI (n = 40) or SCD (n = 46), and 63 cognitively healthy controls. Subgingival samples were collected, and the microbiotas were characterized by 16S rRNA gene sequencing. Results: The relative abundance of the ten most common genera did not differ between the cases and control groups. However, the microbial richness and evenness were higher in cases than in controls and differed across the four groups. The variables with the greatest influence on the microbial community composition were related to periodontal disease followed by body mass index, study group affiliation and smoking. Ten taxa exhibited significant differences between case participants and controls. Two Operational Taxonomic Units were particularly abundant in AD compared to controls: Slackia exigua, which was also associated with deep periodontal pockets, and a Lachnospiraceae [G-7] bacterium. Conclusion: It is concluded that in individuals with cognitive impairment or AD, the subgingival microbiota exhibits shifts typical of periodontal disease.

Association between periodontitis and risk of Alzheimer's disease, mild cognitive impairment and subjective cognitive decline: A case-control study.

AIMS: To test the hypothesis that periodontal disease contributes to increased risk of mild cognitive impairment (MCI), subjective cognitive decline (SCD) and Alzheimer's disease (AD). MATERIALS AND METHODS: This case-control study was conducted over a 3-year period in the municipality of Huddinge, Sweden. In total, 154 cases were consecutively enrolled from the Karolinska Memory Clinic at the Karolinska University Hospital and allotted to three diagnostic groups: AD, MCI and SCD, collectively referred to as "cases." Seventy-six cognitively healthy age- and gender-matched controls were randomly sampled through the Swedish population register. All cases and controls underwent clinical and radiographic oral examinations. Statistical analysis was based on logistic regression models adjusted for potential confounders. RESULTS: Poor oral health and marginal alveolar bone loss were more prevalent among cases than among controls. The cases group was associated with generalized marginal alveolar bone loss (odds ratio [OR] = 5.81; 95% confidence interval [CI] = 1.14-29.68), increased number of deep periodontal pockets (OR = 8.43; CI 4.00-17.76) and dental caries (OR = 3.36; CI 1.20-9.43). CONCLUSION: The results suggest that marginal periodontitis is associated with early cognitive impairment and AD. However, the study design does not preclude noncausal explanations.

Dental care utilization in patients with different types of dementia: A longitudinal nationwide study of 58,037 individuals.

INTRODUCTION: Dementia may be associated with discontinuation of regular dental checkups, which in turn results in poorer oral health. METHODS: We investigated the trend of change in dental care utilization and the number of teeth before and after being diagnosed with dementia. Longitudinal cognitive- and dental health-related information were merged using data on 58,037 newly diagnosed individuals from the Swedish Dementia Registry and Swedish Dental Health Register during 2007 to 2015. RESULTS: Following dementia diagnosis, rate of dental care visits significantly declined. Individuals with mixed dementia, dementia with parkinsonism, and those with more severe and faster cognitive impairment had significantly higher rate of decline in dental care utilization. Vascular dementia and lower baseline Mini-Mental State Examination score were significant predictors of faster loss of teeth. DISCUSSION: Dental care utilization markedly declines following dementia diagnosis. The reduction is more prominent in those with rapid progressive cognitive impairment and the ones with extra frailty burden.

Periodontitis Increases the Risk of a First Myocardial Infarction: A Report From the PAROKRANK Study.

BACKGROUND: The relationship between periodontitis (PD) and cardiovascular disease is debated. PD is common in patients with cardiovascular disease. It has been postulated that PD could be causally related to the risk for cardiovascular disease, a hypothesis tested in the Periodontitis and Its Relation to Coronary Artery Disease (PAROKRANK) study. METHODS AND RESULTS: Eight hundred five patients (<75 years of age) with a first myocardial infarction (MI) and 805 age- (mean 62±8), sex- (male 81%), and area-matched controls without MI underwent standardized dental examination including panoramic x-ray. The periodontal status was defined as healthy (≥80% remaining bone) or as mild-moderate (from 79% to 66%) or severe PD (<66%). Great efforts were made to collect information on possibly related confounders (≈100 variables). Statistical comparisons included the Student pairwise t test and the McNemar test in 2×2 contingency tables. Contingency tables exceeding 2×2 with ranked alternatives were tested by Wilcoxon signed rank test. Odds ratios (95% confidence intervals) were calculated by conditional logistic regression. PD was more common (43%) in patients than in controls (33%; P<0.001). There was an increased risk for MI among those with PD (odds ratio, 1.49; 95% confidence interval, 1.21-1.83), which remained significant (odds ratio, 1.28; 95% confidence interval, 1.03-1.60) after adjusting for variables that differed between patients and controls (smoking habits, diabetes mellitus, years of education, and marital status). CONCLUSIONS: In this large case-control study of PD, verified by radiographic bone loss and with a careful consideration of potential confounders, the risk of a first MI was significantly increased in patients with PD even after adjustment for confounding factors. These findings strengthen the possibility of an independent relationship between PD and MI.

Association of periodontitis with persistent, pro-atherogenic antibody responses.

AIM: To study antibody responses associated with molecular mimicry in periodontitis. MATERIAL & METHODS: Fifty-four periodontitis cases (mean age 54.0 years) and 44 controls (53.6 years) were examined, after which cases received periodontal treatment. Established immunoassays were used to analyse levels of antibodies against two pathogens, Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg), heat shock proteins (Hsp), Hsp60, Hsp65, and Hsp70, and epitopes of oxidized low-density lipoprotein (oxLDL) (CuOx-LDL and MDA-LDL) in plasma samples that were collected at baseline and after 3 (n = 48) and 6 (n = 30) months. RESULTS: When age, sex, smoking habit, and the number of teeth were considered in multivariate logistic regressions, Aa and Pg IgG, Hsp65-IgA, CuOx-LDL-IgG and -IgM, and MDA-LDL-IgG antibody levels were associated with periodontitis, whereas Hsp60-IgG2 antibody levels were inversely associated. The Aa antibody levels significantly correlated with the levels of IgA antibodies to Hsp65 and Hsp70, and both OxLDL IgA antibody levels. The levels of antibodies to Pg correlated with IgG antibodies to Hsp60, Hsp70, and both oxLDL antibody epitopes. None of the antibody levels changed significantly after treatment. CONCLUSIONS: Periodontitis is associated with persistently high levels of circulating antibodies that are reactive with pathogen- and host-derived antigens.