The Effects of Obesity on 8-Hydroxy-Deoxyguanosine Levels in Patients With and Without Periodontal Disease
Condition: Obesity
MeSH terms: Obesity
Study type: Observational

Summary: 
      Obesity may affect periodontal health by inducing gingival oxidative damage through increased
      production in circulating reactive oxygen species (ROS). Several studies have demonstrated
      that 8-OHdG in bodily fluids can act as a biomarker of oxidative DNA damage in periodontal
      diseases and for evaluating the effect of periodontal treatment. In the present study we
      hypothesized that high ROS levels in circulation may increase oxidative stress levels in the
      gingival crevicular fluid (GCF) and saliva in obese patients with periodontal disease, thus
      periodontal therapy could have positive effects on ROS levels.
    

Detailed description: 
      The purpose of this study was to investigate the effects of obesity on
      8-Hydroxy-deoxyguanosine (8-OHdG) levels in the bodily fluids of patients with and without
      periodontal disease and to evaluate changes after initial periodontal treatment.

      Diagnosed as obese (n=45) and normal-weight (n=45) individuals were categorized; chronic
      periodontitis (CP), gingivitis (G) and periodontally healthy controls (CTRL). Gingival
      crevicular fluid (GCF), plasma, saliva samples and clinical measurements were obtained at
      baseline and a month after initial periodontal treatment.

      Unstimulated salivary samples were collected using standard techniques. About 2 mL whole
      saliva was collected in disposable tubes and centrifuged immediately to remove cell debris
      (10,000 g x 10 minutes). The supernatants (50µL each) were stored at -40C until analyzed. GCF
      samples were collected from a mesio-buccal and disto-palatal site on each tooth (molars,
      premolars, canines/incisors). In the CP group, the samples were obtained from patients at
      areas with ≥5 mm CAL, ≥6 mm PD and ≥30% bone loss. In gingivitis group, GCF samples were
      obtained from teeth with BOP and without CAL. In the healthy group, GCF samples were
      collected from teeth exhibiting PD<3 mm without CAL and BOP. Six GCF samples were collected
      from each patient. The area was isolated with cotton rolls, saliva contamination elimination
      was ensured, and it was slightly air dried. GCF was sampled with paper strips. Paper strips
      were placed into the crevice until mild resistance was felt (intracrevicular method) and left
      in the position for 30 seconds. Strips contaminated with blood or saliva were discarded. Each
      sampled strip was placed into a 400µl eppendorf centrifuge tube and stored at -40C until
      analyzed.

      Five milliliters of venous blood was taken from antecubital vein by using a standard
      venipuncture method. Obtained blood sample was collected in vacutainer tubes and
      anti-coagulated with EDTA. The blood samples were then stored at -40C until required for use
      in ELISAs.

      Power analysis indicated that 12 individuals for each group would be sufficient to achieve
      80% power to detect a difference of 0.05 between the alternative and the null hypotheses.

      The Shapiro Wilk test was used to investigate whether or not the data were normally
      distributed. Continuous variables with unequal variances were compared by means of Welch and
      Tamhane's T2 post-hoc test for BMI, PD, CAL and the levels of 8-OHdG. The comparison of the
      age, GI, PI and BOP was analyzed using the Kruskal-Wallis non-parametric test followed by
      post hoc group comparisons with the Bonferroni-adjusted Mann-Whitney U test. Paired Student's
      t-test or Wilcoxon rank-sum test was used to compare the measurements at two points (baseline
      and after SRP). The Spearman's rank correlation test was also used to detect the relationship
      between biochemical and clinical findings.
    

Intervention name(s): Procedure: Gingival Crevicular Fluid, Saliva and Blood Sampling
Intervention type(s): Other
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        a population who received periodontal treatment at the Periodontology Department