title: Association of Periodontal Diseases with Elevation of Serum C-reactive Protein and Body Mass Index.
abstract: OBJECTIVE
  C-reactive protein (CRP) is a well-known acute-phase reactant produced by the liver in response to inflammation caused by various stimuli. Periodontal disease is a chronic infection of tooth-supporting structures characterized by attachment loss and alveolar bone loss. The aim of this study was to assess the relationship between serum C-reactive protein levels and periodontal diseases.
  
  
  METHODS
  The study was conducted on 166 patients referring to Tabriz Faculty of Dentistry. The age range was between 35 and 59 years. 83 subjects with periodontitis according to NHANES III index as test group and 83 healthy individuals as controls participated in this study. Body mass index (BMI), waist circumference (WC), probing depth, attachment loss and CRP levels were measured in both test and control groups. Data was analyzed with Student's t-test, odds ratio (OR), Chi-square test and Spearman's correlation coefficient, using SPSS 13.0 software.
  
  
  RESULTS
  The results revealed a statistically significant difference between all of the analyzed variables in test and control groups (P < 0.05). Classifying the test subjects into two subgroups (subjects with CRP ≥ 3 mg/l and subjects with CRP < 3 mg/l), the highest OR in females belonged to WC (OR = 6.4; 95% CI: 1.18-35.2, P = 0.02) and in males to obesity (OR = 4.8; 95% CI: 0.65-35.19, P = 0.05). Considering the correlation between obesity, overweight, WC and CRP with probing depth and attachment loss denoted that obesity presented the highest (r = 1, P = 0.00) and overweight the lowest (r = 0.4, P = 0.07) association. In females, CRP was related to the severity of periodontitis and attachment loss (r = 0.662, P = 0.00). Excluding overweight, the association between all the variables was statistically significant (P < 0.05).
  
  
  CONCLUSIONS
  Our findings indicate that periodontal disease is correlated with CRP elevation and dis-eases associated with obesity.
authors.affiliation: Associate Professor, Department of Periodontics, Faculty of Dentistry, Tabriz University of Medical Sciences, Iran.
authors.forename: Mohammad Taghi
authors.initials: MT
authors.lastname: Chitsazi
authors.forename: Reza
authors.initials: R
authors.lastname: Pourabbas
authors.forename: Adileh
authors.initials: A
authors.lastname: Shirmohammadi
authors.forename: Gazaleh
authors.initials: G
authors.lastname: Ahmadi Zenouz
authors.forename: Amir Hossein
authors.initials: AH
authors.lastname: Vatankhah
keywords: BMI; C-reactive protein; obesity; periodontal disease