Periodontitis and cardiometabolic disorders: The role of lipopolysaccharide and endotoxemia.

Lipopolysaccharide is a virulence factor of gram-negative bacteria with a crucial importance to the bacterial surface integrity. From the host's perspective, lipopolysaccharide plays a role in both local and systemic inflammation, activates both innate and adaptive immunity, and can trigger inflammation either directly (as a microbe-associated molecular pattern) or indirectly (by inducing the generation of nonmicrobial, danger-associated molecular patterns). Translocation of lipopolysaccharide into the circulation causes endotoxemia, which is typically measured as the biological activity of lipopolysaccharide to induce coagulation of an aqueous extract of blood cells of the assay. Apparently healthy subjects have a low circulating lipopolysaccharide activity, since it is neutralized and cleared rapidly. However, chronic endotoxemia is involved in the pathogenesis of many inflammation-driven conditions, especially cardiometabolic disorders. These include atherosclerotic cardiovascular diseases, obesity, liver diseases, diabetes, and metabolic syndrome, where endotoxemia has been recognized as a risk factor. The main source of endotoxemia is thought to be the gut microbiota. However, the oral dysbiosis in periodontitis, which is typically enriched with gram-negative bacterial species, may also contribute to endotoxemia. As endotoxemia is associated with an increased risk of cardiometabolic disorders, lipopolysaccharide could be considered as a molecular link between periodontal microbiota and cardiometabolic diseases.

Salivary IgA antibody to malondialdehyde-acetaldehyde associates with mild periodontal pocket depth.

OBJECTIVE: Oxidized epitopes such as malondialdehyde-acetaldehyde (MAA) play a crucial role in the progression of atherosclerosis through activation of the humoral immune response. The exact mechanism of the association between atherosclerosis and periodontal diseases is not fully understood. The aim of the current study is to evaluate the association of oral humoral immune response to oxidized epitopes with parameters of periodontal disease. MATERIALS AND METHODS: The Parogene cohort consist of patients who have undergone coronary angiography due to cardiac symptoms. In this study, 423 patients were randomly selected for an extensive oral examination. Salivary Immunoglobulin A to oxidized epitopes and bacterial antigens was determined by chemiluminescence immunoassay. RESULTS: In a binary logistic regression model adjusted with periodontal disease confounders, periodontal pocket depth (PPD) 4-5 mm associated with salivary IgA antibodies to MAA-LDL (p = 0.034), heat shock protein 60 of Aggregatibacter actinomycetemcomitans (p = 0.045), Porphyromonas gingivalis (p = 0.045), A. actinomycetemcomitans (p = 0.005), P. intermedia (p = 0.020), and total IgA (p = 0.003). CONCLUSIONS: The current study shows the association of salivary IgA to MAA-LDL with PPD 4-5 mm in a cohort of patients with chronic coronary artery disease. Humoral immune cross-reactivation to oxidized epitopes such MAA-LDL could partly explain the link of periodontitis with systemic diseases.

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.

Saliva and serum biomarkers in periodontitis and coronary artery disease.

AIM: Matrix metalloproteinase (MMP)-8, MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and myeloperoxidase (MPO) participate in extracellular matrix breakdown both in periodontium and atherosclerotic plaques. We investigated the diagnostic value of serum and saliva biomarkers in periodontitis and acute coronary syndrome (ACS). MATERIALS AND METHODS: The population was PAROGENE (n = 481), a random cohort of patients with an indication for coronary angiography. All patients underwent a clinical and radiographic oral examination. Groups consisting of periodontitis versus non-periodontitis, and ACS versus non-ACS patients were compared. RESULTS: Saliva MMP-8, MMP-9 and MPO provided significant area-under-curve (AUC) values for periodontitis, 0.69 (<0.001), 0.66 (<0.001) and 0.68 (<0.001), respectively. Serum MMP-8, MMP-9 and MPO levels distinguished ACS from non-ACS patients with AUCs of 0.73 (<0.001), 0.58 (0.03) and 0.68 (<0.001), respectively. Periodontitis confounded the use of serum MMP-9 in diagnostics of ACS. Cardiac status complicated the use of saliva TIMP-1 in periodontal diagnostics. Saliva biomarkers could not be used in ACS diagnosis, and serum biomarkers were not useful in diagnosis of periodontitis. CONCLUSIONS: MMP-8, MMP-9, TIMP-1and MPO are valuable biomarkers for both ACS and periodontitis, but the selection of sample material is crucial; serum is suitable for ACS and saliva for periodontal diagnostic aid.

Aggregatibacter actinomycetemcomitans serotypes associate with periodontal and coronary artery disease status.

AIM: We investigated the association between the Aggregatibacter actinomycetemcomitans serotypes, periodontal status and coronary artery disease (CAD). MATERIALS AND METHODS: The study population included 497 patients who underwent coronary angiography, and clinical oral examination. Quantitative polymerase chain reaction assays were designed to identify the serotypes from saliva samples. RESULTS: Aggregatibacter actinomycetemcomitans serotype frequencies were as follows: serotype "c" 35.7%, "b" 28.6%, "a" 26.2%, "e" 7.1%, "d" 2.4% and "f" 0%. The subjects with a detectable serotype had less teeth and higher bleeding on probing than those with no serotype. Serotypes "b" and "c" associated with periodontal probing depths and periodontal inflammatory burden. The saliva and subgingival bacterium quantities and serum antibody levels against A. actinomycetemcomitans were highest in patients harbouring serotype "c." Serotypes "b" and "c" were most frequent (59.3%) in patients with CAD (p = .040), and they associated with the risk of stable CAD with an odds ratio of 2.67 (95% confidence interval 1.06-7.44). Also, the severity of CAD (p = .018) associated with serotypes "b" and "c." CONCLUSIONS: Aggregatibacter actinomycetemcomitans serotypes "b" and "c" associate with both periodontal and CAD status. Detectable serotypes associate with the quantity and the serology of the bacterium emphasizing both local and systemic effect of the A. actinomycetemcomitans serotypes.

Mediators between oral dysbiosis and cardiovascular diseases.

Clinical periodontitis is associated with an increased risk for cardiovascular diseases (CVDs) through systemic inflammation as the etiopathogenic link. Whether the oral microbiota, especially its quality, quantity, serology, and virulence factors, plays a role in atherogenesis is not clarified. Patients with periodontitis are exposed to bacteria and their products, which have access to the circulation directly through inflamed oral tissues and indirectly (via saliva) through the gastrointestinal tract, resulting in systemic inflammatory and immunologic responses. Periodontitis is associated with persistent endotoxemia, which has been identified as a notable cardiometabolic risk factor. The serology of bacterial biomarkers for oral dysbiosis is associated with an increased risk for subclinical atherosclerosis, prevalent and future coronary artery disease, and incident and recurrent stroke. In addition to species-specific antibodies, the immunologic response includes persistent, cross-reactive, proatherogenic antibodies against host-derived antigens. Periodontitis may affect lipoprotein metabolism at all levels, and all lipoprotein classes are affected. Periodontitis or its bacterial signatures may be involved not only in increased storage of proatherogenic lipids but also in attenuation of the anti-atherogenic processes, thereby putatively increasing the net risk of atherosclerosis. In this review we summarize possible molecular mediators between the dysbiotic oral microbiota and atherosclerotic processes.

Cumulative use of salivary markers with an adaptive design improves detection of periodontal disease over fixed biomarker thresholds.

OBJECTIVE: Aim was to analyze the diagnostic ability of cumulative risk score (CRS), which uses salivary levels of Porphyromonas gingivalis, interleukin (IL)-1ß, and matrix metalloproteinase (MMP)-8 in an adaptive design, compared to previously reported thresholds of each marker alone. MATERIALS AND METHODS: Oral and general health information of 463 participants were included in the analysis. Having the percentage of bleeding on probing (BOP) > 25%, having at least two sites with probing pocket depth (PPD) of 4-5 mm or having at least one tooth with alveolar bone loss (ABL) of at least 1/3 of the root length were accepted as outcome variables. Being above the salivary threshold concentrations of P. gingivalis, IL-1ß, and MMP-8 and CRS values were used as explanatory variables. Receiver operating characteristics (ROC) producing an area under the curve (AUC) and multinomial regression analysis were used in statistical analysis. RESULTS: CRS provided AUCs larger than any other tested biomarker threshold. Sensitivity and specificity of CRS for detecting clinical markers of periodontitis were acceptable, and a strong association was observed between the highest CRS score and having at least two sites with PPD of 4-5 mm. CONCLUSION: CRS brings additional power over fixed thresholds of single biomarkers in detecting periodontitis.

Lipopolysaccharide, a possible molecular mediator between periodontitis and coronary artery disease.

AIM: We aimed to study how lipopolysaccharide (LPS) in saliva and serum associates with each other, periodontal microbial burden, periodontitis and coronary artery disease (CAD). MATERIALS AND METHODS: The used Parogene cohort comprised N = 505 Finnish adults. Coronary diagnosis was acquired by coronary angiography, and the main outcomes were as follows: no significant CAD (n = 123), stable CAD (n = 184) and acute coronary syndrome (n = 169). Periodontitis was defined according to clinical and radiographic examinations. Levels for 75 strains of subgingival bacteria were determined by checkerboard DNA-DNA hybridization. Saliva and serum LPS activity was analysed by Limulus amebocyte lysate assay. RESULTS: The level of 11 bacterial strains, which were mainly oral and respiratory Gram-negative species, associated with salivary LPS levels in an age- and gender-adjusted linear regression. A total of 4.9% of the serum LPS, that is endotoxemia, variation was explainable by saliva LPS among patients with periodontitis (n = 247, R2  = .049, Pearson's r = .222, p < .001). Endotoxemia associated with stable CAD in a confounder adjusted multinomial logistic regression model (OR 1.99, 95% CI 1.04-3.81, p = .039, 3rd tertile). CONCLUSIONS: In particular in periodontitis patients, subgingival microbial burden contributes to endotoxemia. LPS is a possible molecular mediator between periodontitis and CAD.

Cross-reactive saliva IgA antibodies to oxidized LDL and periodontal pathogens in humans.

AIM: Oxidized low-density lipoproteins (oxLDL) are formed as a result of lipid peroxidation and are highly immunogenic and proatherogenic. In this study, saliva antibodies binding to oxLDL, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) were characterized and their cross-reactivity was evaluated. MATERIALS AND METHODS: Resting and stimulated saliva samples were collected from 36 healthy adults (mean age 26 years). Saliva IgA, IgG and IgM autoantibody levels to copper oxidized LDL (CuOx-LDL) and malondialdehyde acetaldehyde-modified LDL (MAA-LDL) were determined with chemiluminescence immunoassay. RESULTS: Saliva IgA and IgG antibodies binding to MAA-LDL and CuOx-LDL were detected in all samples and they were associated with the saliva levels of IgA and IgG to P. gingivalis and A. actinomycetemcomitans. Competitive immunoassay showed that saliva antibodies to MAA-LDL cross-reacted specifically with P. gingivalis. The autoantibody levels to oxLDL in saliva were not associated with the autoantibody levels to oxLDL in plasma or with saliva apolipoprotein B 100 levels. CONCLUSIONS: Saliva contains IgA and IgG binding to oxLDL, which showed cross-reactive properties with the periodontal pathogens Porphyromonas gingivalis (P.g). The data suggest that secretory IgA to P.g may participate in immune reactions involved in LDL oxidation through molecular mimicry.

Matrix metalloproteinase 8 degrades apolipoprotein A-I and reduces its cholesterol efflux capacity.

Various cell types in atherosclerotic lesions express matrix metalloproteinase (MMP)-8. We investigated whether MMP-8 affects the structure and antiatherogenic function of apolipoprotein (apo) A-I, the main protein component of HDL particles. Furthermore, we studied serum lipid profiles and cholesterol efflux capacity in MMP-8-deficient mouse model. Incubation of apoA-I (28 kDa) with activated MMP-8 yielded 22 kDa and 25 kDa apoA-I fragments. Mass spectrometric analyses revealed that apoA-I was cleaved at its carboxyl-terminal part. Treatment of apoA-I and HDL with MMP-8 resulted in significant reduction (up to 84%, P < 0.001) in their ability to facilitate cholesterol efflux from cholesterol-loaded THP-1 macrophages. The cleavage of apoA-I by MMP-8 and the reduction in its cholesterol efflux capacity was inhibited by doxycycline. MMP-8-deficient mice had significantly lower serum triglyceride (TG) levels (P = 0.003) and larger HDL particles compared with wild-type (WT) mice. However, no differences were observed in the apoA-I levels or serum cholesterol efflux capacities between the mouse groups. Proteolytic modification of apoA-I by MMP-8 may impair the first steps of reverse cholesterol transport, leading to increased accumulation of cholesterol in the vessel walls. Eventually, inhibition of MMPs by doxycycline may reduce the risk for atherosclerotic vascular diseases.

Analysis of matrix metalloproteinases, especially MMP-8, in gingival creviclular fluid, mouthrinse and saliva for monitoring periodontal diseases.

Matrix metalloproteinase-8 is a promising candidate biomarker for oral fluid (gingival crevicular fluid, peri-implant sulcular fluid and saliva) and mouthrinse chair-side/point-of-care diagnostics to predict, diagnose and determine the progressive phases of episodic periodontitis and peri-implantitis, as well as to monitor the treatments and medications. Matrix metalloproteinase-8 can be used alone or together with interleukin-1beta and Porphyromonas gingivalis to calculate cumulative risk score at the subject level as a successful diagnostic tool, especially in large-scale public health surveys, in which a thorough periodontal examination is not feasible.

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.

Genetic variation on the BAT1-NFKBIL1-LTA region of major histocompatibility complex class III associates with periodontitis.

Periodontitis is a chronic inflammatory disease with a multifactorial etiology. We investigated whether human major histocompatibility complex (MHC) polymorphisms (6p21.3) are associated with periodontal parameters. Parogene 1 population samples (n = 169) were analyzed with 13,245 single nucleotide polymorphisms (SNPs) of the MHC region. Eighteen selected SNPs (P ≤ 0.001) were replicated in Parogene 2 population samples (n = 339) and the Health 2000 Survey (n = 1,420). All subjects had a detailed clinical and radiographic oral health examination. Serum lymphotoxin-α (LTA) concentrations were measured in the Parogene populations, and the protein was detected in inflamed periodontal tissue. In the Parogene 1 population, 10 SNPs were associated with periodontal parameters. The strongest associations emerged from the parameters bleeding on probing (BOP) and a probing pocket depth (PPD) of ≥6 mm with the genes BAT1, NFKBIL1, and LTA. Six SNPs, rs11796, rs3130059, rs2239527, rs2071591, rs909253, and rs1041981 (r(2), ≥0.92), constituted a risk haplotype. In the Parogene 1 population, the haplotype had the strongest association with the parameter BOP, a PPD of ≥6 mm, and severe periodontitis with odds ratios (95% confidence intervals) of 2.63 (2.21 to 3.20), 2.90 (2.37 to 3.52), and 3.10 (1.63 to 5.98), respectively. These results were replicated in the other two populations. High serum LTA concentrations in the Parogene population were associated with the periodontitis risk alleles of the LTA SNPs (rs909253 and rs1041981) of the haplotype. In addition, the protein was expressed in inflamed gingival connective tissue. We identified a novel BAT1-NFKBIL1-LTA haplotype as a significant contributor to the risk of periodontitis. The genetic polymorphisms in the MHC class III region may be functionally important in periodontitis susceptibility.

The effect of prolonged systemic doxycycline therapy on serum tissue degrading proteinases in coronary bypass patients: a randomized, double-masked, placebo-controlled clinical trial.

OBJECTIVE: Serum matrix metalloproteinases (MMP-8, MMP-7) and their regulators may be associated with the risk of incident cardiovascular disease events. Doxycycline can be used as matrix metalloproteinase (MMP) inhibitor independent of its antimicrobial activity. We aimed to investigate serum inflammatory biomarkers during 4 months of doxycycline therapy in coronary bypass patients. MATERIALS AND METHODS: Thirty-one non-smoking men who had previous coronary bypass surgery were randomly assigned to receive placebo or 100 mg doxycycline daily for 4 months. Serum samples were collected at baseline before the treatment, and at 2, 4, and 10 months. Serum levels of MMP-7, tissue inhibitor of matrix metalloproteinase (TIMP)-1, myeloperoxidase, and neutrophil elastase were analyzed with enzyme-linked immunosorbent assay, MMP-8 by immunofluorometric assay, and C-reactive protein by rate nephelometry. RESULTS: At baseline, no significant differences existed between the two groups. Serum levels of MMP-8, MMP-7, and MMP-8/TIMP-1 were and remained lower (p = 0.034, p = 0.041, and NS) in the doxycycline group relative to the placebo group at 4 months of follow-up. CONCLUSIONS: Doxycycline decreases the systemic inflammatory burden in patients with myocardial infarction and especially down-regulates MMP-7, MMP-8, and MMP-8/TIMP-1. Doxycycline might prevent or reduce the risk of secondary myocardial infarctions by providing a systemic anti-proteolytic and -inflammatory shield.

Salivary biomarkers of bacterial burden, inflammatory response, and tissue destruction in periodontitis.

AIM: Chronic periodontitis has an episodic and multifactorial character, with fluctuations in bacterial burden, inflammatory response, and tissue destruction. We investigated the association of selected salivary biomarkers with periodontal parameters and validated the use of a novel salivary diagnostic approach, the cumulative risk score (CRS), in detection of periodontitis in subjects with angiographically verified coronary artery disease diagnosis. MATERIALS AND METHODS: The concentrations of matrix metalloproteinase (MMP)-8, interleukin (IL)-1ß, and Porphyromonas gingivalis were analysed from saliva of 493 subjects. The subjects participated in a detailed clinical and radiographic oral examination. The CRS index, combining the three salivary biomarkers, was calculated for each subject. RESULTS: High salivary concentrations of MMP-8, IL-1ß, and P. gingivalis were associated with deepened periodontal pockets and alveolar bone loss, and MMP-8 and IL-1ß with bleeding on probing. The CRS index had a stronger association with moderate to severe periodontitis (OR 6.13; 95% CI 3.11-12.09) than any of the markers alone. CONCLUSIONS: Salivary concentrations of MMP-8, IL-1ß, and P. gingivalis are associated with various clinical and radiographic measures of periodontitis. The CRS index, combining the three salivary biomarkers, is associated with periodontitis more strongly than any of the markers alone regardless of the coronary artery disease status of the patients.

Shotgun metagenomic analysis of the oral microbiome in gingivitis: a nested case-control study.

Background: Gingivitis, i.e. inflammation of the gums, is often induced by dentalplaque. However, its exact link to the oral microbiota remains unclear. Methods: In a case-control study involving 120 participants, comprising 60 cases and 60 controls (mean age (SD) 36.6 (7.6) years; 50% males), nested within a prospective multicentre cohort study, we examined theoral microbiome composition of gingivitis patients and their controlsusing shotgun metagenomic sequencing of saliva samples. Participants underwent clinical and radiographic oral health examinations, including bleeding on probing (BOP), at six tooth sites. BOP ≥33%was considered 'generalized gingivitis/initial periodontitis'(GG/IP), and BOP <33% as 'healthy and localized gingivitis'(H/LG). Functional potential was inferred using HUMANn3. Results: GG/IP exhibited an increase in the abundance of Actinomyces, Porphyromonas, Aggregatibacter, Corynebacterium, Olsenella, and Treponema, whereas H/LG exhibited an increased abundance of Candidatus Nanosynbacter. Nineteen bacterial species and fourmicrobial functional profiles, including L-methionine, glycogen, andinosine-5'-phosphate biosynthesis, were associated with GG/IP. Constructing models with multiple markers resulted in a strong predictive value for GG/IP, with an area under the curve (ROC) of 0.907 (95% CI: 0.848-0.966). Conclusion: We observed distinct differences in the oral microbiome between the GG/IP and H/LG groups, indicating similar yet unique microbial profiles and emphasizing their potential role in progression of periodontal diseases.

The effect of proatherogenic pathogens on adipose tissue transcriptome and fatty acid distribution in apolipoprotein E-deficient mice.

BACKGROUND: Chronic infections have been demonstrated to maintain low-grade systemic inflammation and associate with atherosclerosis. We studied the inflammation- and lipid homeostasis-related effects of Aggregatibacter actinomycetemcomitans (Aa) and Chlamydia pneumoniae (Cpn) infections on the epididymal and inguinal adipose tissue (AT) transcriptomes and fatty acid distribution in apolipoprotein (apo) E-deficient mice. Chow-fed apoE-deficient mice were exposed to 1) chronic intranasal infection with C. pneumoniae (Cpn group), 2) recurrent intravenous infection with A. actinomycetemcomitans (Aa group), 3) a combination of both types of infection (Cpn + Aa group), or 4) infection with the vehicle (control group). Epididymal and inguinal AT gene expression was analyzed using an Illumina Mouse WG-6 v2.0 platform and quantitative PCR (QPCR). Microarray data were analyzed using Gene Ontology enrichment analysis. AT fatty acid analysis was performed using gas-liquid chromatography. RESULTS: The transcriptomics data revealed significant enrichment in inflammation-associated biological pathways in both AT depots derived from the Aa and Cpn + Aa treated mice compared with the control group. The proportion of saturated fatty acids was higher in the inguinal AT in Aa (p = 0.027) and Cpn + Aa (p = 0.009) groups and in the epididymal AT in Aa group (p = 0.003). The proportion of polyunsaturated fatty acids was significantly lower among all Aa-infected groups in both depots. Chronic Cpn infection displayed only minor effects on transcriptomics and fatty acids of the AT depots. CONCLUSIONS: Systemic infection with A. actinomycetemcomitans activates inflammation-related biological pathways and modulates cellular lipid homeostasis. The adverse changes in adipose tissues during chronic infection may promote atherosclerosis.

Subantimicrobial-dose doxycycline treatment increases serum cholesterol efflux capacity from macrophages.

OBJECTIVE: Subantimicrobial-dose doxycycline (SDD) treatment has been reported to reduce the severity of chronic inflammation and to increase serum high-density lipoprotein cholesterol. In a double-blind, placebo-controlled clinical trial, we determined whether SDD affects the ability of serum to facilitate cholesterol removal from macrophages. METHODS: Forty-five postmenopausal osteopenic women with periodontitis were randomly assigned to take placebo (n = 26) or doxycycline hyclate (20 mg, n = 19) tablets twice daily for 2 years. Serum samples were collected at baseline, 1-, and 2-year appointments. The cholesterol efflux capacity of serum from cultured human macrophages (THP-1) was measured. RESULTS: SDD subjects demonstrated a significant increase in serum-mediated cholesterol efflux from macrophages at both time points compared to baseline (p < 0.04 for each). Mean cholesterol efflux levels over the first year of follow-up were 3.0 percentage points (unit change) higher among SDD subjects compared to placebo subjects (p = 0.010), while there was no significant difference in 2-year changes. There were no significant differences in the changes of apolipoprotein A-I, apolipoprotein A-II, or serum amyloid A levels between the groups. CONCLUSIONS: Our results suggest that SDD treatment may reduce the risk of cardiovascular disease in this patient group by increasing the cholesterol efflux capacity of serum.

Salivary type I collagen degradation end-products and related matrix metalloproteinases in periodontitis.

AIM: Type I collagen degradation end-products and related matrix metalloproteinases (MMPs) were examined aiming to detect potential markers of periodontitis in saliva, with high sensitivity and specificity. MATERIALS AND METHODS: The salivary concentrations of MMP-8, MMP-9 and MMP-13, tartrate-resistant acid phosphatase serum type 5b, C-terminal cross-linked telopeptide of type I collagen (CTx), N-terminal cross-linked telopeptide of type I collagen (NTx) and cross-linked carboxyterminal telopeptide of type I collagen were analysed in 230 subjects. Oral health examination included panoramic radiography. RESULTS: The concentrations of MMP-8, MMP-9 and MMP-13 in saliva were higher in subjects with generalized periodontitis than in controls. Of the tested salivary markers, MMP-8 was the only marker capable of differentiating subjects with severe alveolar bone loss from those with slight bone loss (p < 0.001). The association between the salivary MMP-8 levels and periodontitis remained significant after the adjustment with age, gender and smoking. In addition, significant correlations were found between the tested markers and periodontal parameters. CONCLUSION: Enzymes and end-products of type I collagen degradation have different associations with each other and with periodontal status that may reflect their roles in the cascade leading to alveolar bone loss. MMP-8 is a strong biomarker candidate for detecting alveolar bone destruction.

Subgingival Aggregatibacter actinomycetemcomitans associates with the risk of coronary artery disease.

AIM: We investigated the association between angiographically verified coronary artery disease (CAD) and subgingival Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola. MATERIALS AND METHODS: The cross-sectional study population (n = 445) comprised 171 (38.4%) patients with Stable CAD, 158 (35.5%) with acute coronary syndrome (ACS) and 116 (26.1%) with no significant CAD (No CAD). All patients participated in clinical and radiological oral health examinations. Pooled subgingival bacterial samples were analysed by checkerboard DNA-DNA hybridization assays. RESULTS: In all study groups, the presence of P. gingivalis, T. forsythia and T. denticola indicated a significant (p ≤ 0.001) linear association with the extent of alveolar bone loss (ABL), but A. actinomycetemcomitans did not (p = 0.074). With a threshold level of bacterial cells 1 × 10(5) A. actinomycetemcomitans was significantly more prevalent in the Stable CAD group (42.1%) compared to the No CAD group (30.2%) (p = 0.040). In a multi-adjusted logistic regression analysis using this threshold, A. actinomycetemcomitans positivity associated with Stable CAD (OR 1.83, 95% CI 1.00-3.35, p = 0.049), but its level or levels of other bacteria did not. CONCLUSIONS: The presence of subgingival A. actinomycetemcomitans associates with an almost twofold risk of Stable CAD independently of alveolar bone loss.