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.

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.

Association of the PGC-1α rs8192678 variant with microalbuminuria in subjects with type 2 diabetes mellitus.

PPAR-γ co-activator-1α (PGC-1α) is a tissue-specific transcriptional co-activator involved in the regulation of antioxidant enzymes. The A-allele of the rs8192678 PGC-1 α} (G>A) gene variant has previously been associated with nephropathy in Korean and Indian-Asian type 2 diabetes mellitus (T2DM) samples. Our aim was to examine the association between this variant and urine albumin exccretion in European subjects with T2DM. Genotyping was performed on 583 European subjects with T2DM and examined in relation to urinary albumin, plasma oxidized-LDL and small dense-LDL percentage. We observed a significant association between genotype (GG/GA/AA) and urinary albumin (normoalbuminuria v micro/macroalbuminuria: 48.6/39.7/11.7% v 38.2/51.2/10.5%, p=0.02; for GG v GA/AA, p=0.01). The odds ratio for micro/macroalbuminuria in GA and AA subjects relative to GG were 1.70 [1.15-2.50], p=0.008 and 1.20 [0.66-2.16], p=0.56 respectively (for GA/AA v GG: 1.58 [95% CI: 1.09-2.27], p=0.02). There was a significant association between the A allele and a higher percentage of small dense-LDL particles (GG v GA v AA: 70.8 [58.01-81.06] % v 72.8 [56.18-81.19] % v 78.9 [67.16-85.33] %, p=0.03). In European subjects with T2DM the GA relative to the GG genotype is associated with a 70% increase in the risk of micro/microalbuminuria. Furthermore, homozygosity for the A-allele is also associated with a preponderance of small dense-LDL particles.

Do people with diabetes understand their clinical marker of long-term glycemic control (HbA1c levels) and does this predict diabetes self-care behaviours and HbA1c?

OBJECTIVE: Research demonstrates that patients have a poor understanding of glycosylated haemoglobin A1c (HbA1c) and that this impacts on effective diabetes self-management. This study attempted to replicate these findings in a UK outpatient sample of people with diabetes. METHOD: 83 participants were recruited and asked to fill in a questionnaire assessing their understanding of HbA1c, diabetes self-care behaviours and diabetes-specific self-efficacy in relation to carrying out these self-care behaviours. RESULTS: Only 26.5% of the participants were classified as having a good understanding of HbA1c. Correlational and univariate analyses indicated that this level of understanding was related to demographic variables, HbA1c levels and certain aspects of self-care and self-efficacy. A series of multiple regressions found that understanding was a significant predictor of HbA1c levels. CONCLUSION: The majority of participants seemed to have a poor understanding of HbA1c and this was related to aspects of their diabetes management, self-efficacy and HbA1c levels. PRACTICAL IMPLICATIONS: These findings provide support for the application of programmes and initiatives aimed at improving patients understanding of clinical disease markers.