Remote Ischemic Preconditioning Protects Against Endothelial Dysfunction in a Human Model of Systemic Inflammation: A Randomized Clinical Trial.

OBJECTIVE: Inflammation, oxidative stress, and endothelial dysfunction are known to contribute to ischemia-reperfusion injury. Remote ischemic preconditioning (RIPC) protects from endothelial dysfunction and the damage induced by ischemiareperfusion. Using intensive periodontal treatment (IPT), an established human model of acute systemic inflammation, we investigated whether RIPC prevents endothelial dysfunction and modulates systemic levels of inflammation and oxidative stress. APPROACH AND RESULTS: Forty-nine participants with periodontitis were randomly allocated to receive either 3 cycles of ischemia-reperfusion on the upper limb (N=24, RIPC) or a sham procedure (N=25, control) before IPT. Endothelial function assessed by flow-mediated dilatation of the brachial artery, inflammatory cytokines, markers of vascular injury, and oxidative stress were evaluated at baseline, day 1, and day 7 after IPT. Twenty-four hours post-IPT, the RIPC group had lower levels of IL-10 (interleukin-10) and IL-12 (interleukin-12) compared with the control group (P<0.05). RIPC attenuated the IPTinduced increase in IL-1ß (interleukin-1ß), E-selectin, sICAM-3 (soluble intercellular adhesion molecule 3), and sTM (soluble thrombomodulin) levels between the baseline and day 1 (P for interaction <0.1). Conversely, oxidative stress was differentially increased at day1 in the RIPC group compared with the control group (P for interaction <0.1). This was accompanied by a better flow-mediated dilatation (mean difference 1.75% [95% CI, 0.428­3.07], P=0.011). After 7 days from IPT, most of the inflammatory markers, endothelial-dependent and -independent vasodilation, were similar between groups. CONCLUSIONS: RIPC prevented acute endothelial dysfunction by modulation of inflammation and oxidation processes in patients with periodontitis following exposure to an acute inflammatory stimulus. REGISTRATION: URL: https://clinicaltrials.gov/ct2/show/NCT03072342; Unique identifier: NCT03072342.

Periodontitis affects glucoregulatory hormones in severely obese individuals.

OBJECTIVE: To evaluate the effect of periodontitis (PD) on glucoregulatory hormones in obesity, never explored so far, a cross-sectional study was conducted in 110 severely obese, non-diabetic individuals. METHODS: We collected clinical periodontal parameters, including probing pocket depth (PPD), bleeding on probing (BOP), clinical attachment level (CAL). Insulin, glucagon, GLP-1 and GIP were measured after 3 days of standardized diet. RESULTS: Forty-seven subjects had periodontitis (PD+) and 63 did not (PD-). PD+ showed 30.3% of gingival sites with PPD > 4 mm, 55.2% of BOP sites and a mean CAL loss of 4.1 mm. Compared with PD-, PD+ had higher glucagon (26.60 [25.22] vs 3.93 [7.50] ng/l, p < 0.0001) and GIP levels (10.56 [13.30] vs 6.43 [8.43] pmol/l, p < 0.001), while GLP-1 was reduced (11.78 [10.07] vs 23.34 [16.80] pmol/l, p < 0.0001). Insulin did not differ. In PD+, after adjustment for confounders, PPD was positively related to glucagon (ß = 0.424, p = 0.002) and inversely to GLP-1 (ß = -0.159, p = 0.044). CONCLUSIONS: We describe for the first time an impaired incretin axis coupled with a relative hyperglucagonemia in obese non-diabetic individuals with PD, that might contribute to deteriorate their glucose tolerance and partially explain the higher risk of diabetes observed in these patients.

Practical Guidelines for Patients with Hypertension and Periodontitis.

Arterial hypertension (AH) and periodontitis are among the most common non-communicable chronic diseases worldwide. Besides sharing common risk factors, an increasing body of evidence supports an independent association between the two conditions, with low-grade systemic inflammation acting as the plausible biological link with increased cardiovascular risk. In 2021, the Italian Society of Arterial Hypertension (SIIA) and the Italian Society of Periodontology and Implantology (SIdP) have joined forces and published a joint report on the relationships between AH and periodontitis, reviewing the existing scientific evidence and underlining the need to increase awareness of the strong connection between the two conditions and promote treatment strategies for the control of gums inflammation in patients with AH. The current document extends the previous joint report, providing clinical practical guidelines aimed to support clinicians in the management of patients who suffer from or are at risk of being affected by both conditions. These recommendations are based on careful consideration of the available evidence as well as of the current guidelines on the management of periodontitis and AH and are supported by SIIA and SIdP.

Effect of Treatment of Periodontitis on Incretin Axis in Obese and Nonobese Individuals: A Cohort Study.

CONTEXT: Periodontitis confers an increased risk of developing type 2 diabetes and, in patients with obesity, it might interfere with the incretin axis. The effect of periodontal treatment on glucoregulatory hormones remains unknown. OBJECTIVE: To evaluate the effect of periodontal treatment on incretin axis in obese and lean nondiabetic individuals. SETTING: King's College Dental Hospital and Institute, London, UK. PARTICIPANTS AND METHODS: The metabolic profile of obese and normal-body-mass-index individuals affected by periodontitis was studied at baseline, 2, and 6 months after intensive periodontal treatment, by measuring plasma insulin, glucagon, glucagon-like peptide-1(GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) and markers of systemic inflammation and oxidative stress. MAIN OUTCOME MEASURE(S): Circulating levels of incretins and inflammatory markers. RESULTS: At baseline, periodontal parameters were worse for obese than nonobese; this was accompanied by higher levels of circulating high-sensitivity C-reactive protein (hs-CRP), insulin, and GLP-1. The response to periodontal treatment was less favorable in the obese group, without significant variations of hs-CRP or malondialdehyde. Glucoregulatory hormones changed differently after treatment: while insulin and glucagon did not vary at 2 and 6 months, GLP-1 and GIP significantly increased at 6 months in both groups. In particular, GLP-1 increased more rapidly in obese participants, while the increase of GIP followed similar trends across visits in both groups. CONCLUSIONS: Nonsurgical treatment of periodontitis is associated with increased GLP-1 and GIP levels in nonobese and obese patients; changes in GLP-1 were more rapid in obese participants. This might have positive implications for the metabolic risk of these individuals.

Systemic effects of periodontitis treatment in patients with type 2 diabetes: a 12 month, single-centre, investigator-masked, randomised trial.

BACKGROUND: Chronic inflammation is believed to be a major mechanism underlying the pathophysiology of type 2 diabetes. Periodontitis is a cause of systemic inflammation. We aimed to assess the effects of periodontal treatment on glycaemic control in people with type 2 diabetes. METHODS: In this 12 month, single-centre, parallel-group, investigator-masked, randomised trial, we recruited patients with type 2 diabetes, moderate-to-severe periodontitis, and at least 15 teeth from four local hospitals and 15 medical or dental practices in the UK. We randomly assigned patients (1:1) using a computer-generated table to receive intensive periodontal treatment (IPT; whole mouth subgingival scaling, surgical periodontal therapy [if the participants showed good oral hygiene practice; otherwise dental cleaning again], and supportive periodontal therapy every 3 months until completion of the study) or control periodontal treatment (CPT; supra-gingival scaling and polishing at the same timepoints as in the IPT group). Treatment allocation included a process of minimisation in terms of diabetes onset, smoking status, sex, and periodontitis severity. Allocation to treatment was concealed in an opaque envelope and revealed to the clinician on the day of first treatment. With the exception of dental staff who performed the treatment and clinical examinations, all study investigators were masked to group allocation. The primary outcome was between-group difference in HbA1c at 12 months in the intention-to-treat population. This study is registered with the ISRCTN registry, number ISRCTN83229304. FINDINGS: Between Oct 1, 2008, and Oct 31, 2012, we randomly assigned 264 patients to IPT (n=133) or CPT (n=131), all of whom were included in the intention-to-treat population. At baseline, mean HbA1c was 8·1% (SD 1·7) in both groups. After 12 months, unadjusted mean HbA1c was 8·3% (SE 0·2) in the CPT group and 7·8% (0·2) in the IPT group; with adjustment for baseline HbA1c, age, sex, ethnicity, smoking status, duration of diabetes, and BMI, HbA1c was 0·6% (95% CI 0·3-0·9; p<0·0001) lower in the IPT group than in the CPT group. At least one adverse event was reported in 30 (23%) of 133 patients in the IPT group and 23 (18%) of 131 patients in the CPT group. Serious adverse events were reported in 11 (8%) patients in the IPT group, including one (1%) death, and 11 (8%) patients in the CPT group, including three (2%) deaths. INTERPRETATION: Compared with CPT, IPT reduced HbA1c in patients with type 2 diabetes and moderate-to-severe periodontitis after 12 months. These results suggest that routine oral health assessment and treatment of periodontitis could be important for effective management of type 2 diabetes. FUNDING: Diabetes UK and UK National Institute for Health Research.

Mitochondrial oxidative stress, endothelial function and metabolic control in patients with type II diabetes and periodontitis: A randomised controlled clinical trial.

BACKGROUND: Periodontitis (PD) and type 2 diabetes (T2D) are characterized by increased mitochondrial oxidative stress production (mtROS), which has been associated with a greater risk of cardiovascular diseases (CVD). Intensive PD treatment (IPT) can significantly improve endothelial function and metabolic control, although the mechanisms remain unclear. We explored whether, in patients with PD and T2D, changes of mtROS are associated with improvement of endothelial function and metabolic control after IPT. METHODS: 51 patients with T2D and PD were enrolled in a single-blind controlled trial and randomised to either intensive (n = 27) or standard (CPT, n = 24) PD treatment. Levels of mtROS in peripheral blood mononuclear cells (PBMC) were measured using a FACS-based assay at baseline and 24 h, 1 week, 2 and 6 months after PD treatment. Inflammatory cytokines, CVD risk factors, metabolic control and endothelial function were assessed at baseline and 6 months after intervention. RESULTS: After 6 months from PD treatment, the IPT group had lower mtROS (in both the whole PBMC and lymphocytes), circulating levels of HbA1c, glucose, INF-γ, TNF-α (p < 0.05 for all), and improved endothelial function (p < 0.05) compared to the CPT group. There was an association between higher mtROS and lower endothelial function at baseline (r = -0.39; p = 0.01) and, in the IPT group, changes of mtROS were associated with changes of endothelial function (r = 0.41; p < 0.05). CONCLUSIONS: Reduced mtROS is associated with improved endothelial function and accompanied by better metabolic control in patients with T2D and PD. mtROS could represent a novel therapeutic target to prevent CVD in T2D.

Association between periodontal disease and its treatment, flow-mediated dilatation and carotid intima-media thickness: a systematic review and meta-analysis.

OBJECTIVE: This meta-analysis sought to investigate the association between carotid intima-media thickness (c-IMT), flow-mediated dilation (FMD) and periodontitis (PD) and to assess the effect of periodontal treatment on c-IMT and FMD. METHODS: Electronic database searching, hand searching of bibliographic references of included papers, related reviews, and journals in relation to oral, cardiovascular and ultrasound imaging field was carried out. Random effects meta-analyses were performed to investigate the association of co-existence of increased c-IMT, impaired FMD and PD with potential changes in these variables following periodontal intervention. RESULTS: 2009 citations and 101 full text articles were screened, with 35 meeting the review inclusion criteria of which 22 suitable for quantitative analysis. Meta-analysis demonstrated that the diagnosis of PD was associated with a mean increase in c-IMT of 0.08 mm (95% C.I. = 0.07-0.09) and a mean difference in FMD of 5.1% compared to controls (95% C.I. = 2.08-8.11%). A meta-analysis of the effects of periodontal treatment on FMD showed a mean improvement of 6.64% between test and control (95% C.I. = 2.83-10.44%). CONCLUSIONS: This review demonstrated an association between increased c-IMT, impaired FMD and PD. Data from intervention studies suggested a beneficial effect of periodontal treatment on FMD indicating an improvement in endothelial function. The findings support investigation of periodontitis treatment on cardiovascular outcomes.

Association between short leukocyte telomere length, endotoxemia, and severe periodontitis in people with diabetes: a cross-sectional survey.

OBJECTIVE Shortened leukocyte telomere length (LTL) and diagnosis of periodontitis are associated with an increased risk of complications and mortality in diabetes. This study investigated the association between LTL, endotoxemia, and severity of periodontitis in a large cohort of people with diabetes. RESEARCH DESIGN AND METHODS Six hundred thirty individuals (371 with type 2 and 259 with type 1 diabetes) were recruited from the University College Hospital in London, U.K. During a baseline visit, blood was collected for standard biochemical tests and DNA extraction, while a dental examination was performed to determine diagnosis and extent of periodontitis. LTL was measured by real-time PCR, and endotoxemia was assessed by the limulus amoebocyte lysate method. RESULTS Two hundred fifty-five individuals were diagnosed with gingivitis, 327 with periodontitis (114 with moderate and 213 with severe disease), and 48 with edentulous. Diagnosis of periodontitis was associated with shorter LTL (P = 0.04). A negative association between LTL and endotoxemia was found in the severe periodontitis and type 2 diabetes groups (P = 0.01 for both). Shorter LTL was associated with increased extent of periodontitis (P = 0.01) and increased insulin resistance (homeostatic model assessment). Multiple adjustments for biochemical, anthropometric, and medication-use variables did not affect the results. CONCLUSIONS LTL is associated with endotoxemia and diagnosis of periodontitis in people with diabetes. LTL shortening might represent a novel biological pathway accounting for previous epidemiological data that documented higher prevalence of diabetes and its complications in people with periodontitis and vice versa.

Telomere length and its relationship with chronic diseases - new perspectives for periodontal research.

OBJECTIVE: The ageing process is accompanied by a variety of cellular modifications, and telomere shortening is a common finding. Large epidemiological studies have reported an association between shorter telomere length in peripheral leukocytes and several inflammatory diseases of the elderly including diabetes, atherosclerosis and, recently, periodontitis. The primary aim of this study was to critically discuss available evidence regarding the potential mechanisms relating shorter telomeres to periodontitis. DESIGN: A narrative literature review was performed to report evidence relating shorter telomeres to the ageing process and inflammation. Then, we searched MEDLINE (1950 to May 2012) and ISI WEB OF SCIENCE (1950 to May 2012) databases for the combination of the terms 'telomere' and 'periodontitis'. RESULTS: Although these associations suggest a possible role of telomere attrition in the onset or evolution of chronic inflammatory diseases, only two studies addressed the relationship between telomere length and periodontitis. CONCLUSION: We suggest that the chronic inflammatory burden observed in people with chronic periodontitis could represent the driver of telomere shortening. However, further evidence is needed to confirm whether inflammation is the cause or the consequence of the shorter leukocyte telomere length observed in people with periodontitis.

Oxidative stress, chronic inflammation, and telomere length in patients with periodontitis.

The aim of this study was to determine leukocyte telomere length (LTL) in individuals with periodontitis and controls, exploring its relationship with systemic inflammation and oxidative stress. Five hundred sixty-three participants were recruited for this case-control study: 356 subjects with and 207 subjects without periodontitis. LTL was measured by a qPCR technique from leukocytes' DNA. Global measures of oxidative stress (reactive oxygen metabolites) and biological antioxidant potential in plasma were performed together with high-sensitivity assays for C-reactive protein (CRP). Leukocyte counts and lipid profiles were performed using standard biochemistry. Cases had higher levels of CRP (2.1±3.7mg/L vs 1.3±5.4mg/L, P<0.001) and reactive oxygen metabolites (378.1±121.1 U Carr vs 277.4±108.6 U Carr, P<0.001) compared to controls. Overall, cases had shorter LTL with respect to controls (1.23±0.42 vs 1.12±0.31T/S ratio, P=0.006), independent of age, gender, ethnicity, and smoking habit. When divided by subgroup of periodontal diagnosis (chronic, n=285; aggressive, n=71), only chronic cases displayed shorter LTL (P=0.01). LTL was negatively correlated with age (P=0.001; R=-0.2), oxidative stress (P=0.008; R=-0.2), and severity of periodontitis (P=0.003; R=-0.2) in both the whole population and the subgroups (cases and controls). We conclude that shorter telomere lengths are associated with a diagnosis of periodontitis and their measures correlate with the oxidative stress and severity of disease.