title: A trend of increase in periodontal interleukin-6 expression across patients with neither diabetes nor periodontal disease, patients with periodontal disease alone, and patients with both diseases.
abstract: OBJECTIVE
  Epidemiological studies have established that patients with diabetes have increased prevalence and severity of periodontal disease. However, the periodontal expression of inflammatory cytokines and matrix metalloproteinases (MMPs) in diabetic patients has not been well characterized. The objective of this study was to determine the difference in the periodontal expression of MMP-1, MMP-8, interleukin-6, tumor necrosis factor-alpha and interleukin-1beta between diabetic and nondiabetic patients.
  
  
  METHODS
  Periodontal tissue specimens were collected from nine nondiabetic patients without periodontal disease (group 1), from 11 nondiabetic patients with periodontal disease (group 2) and from seven diabetic patients with periodontal disease (group 3). The expression of MMP-1, MMP-8, interleukin-6, tumor necrosis factor-alpha and interleukin-1beta was quantified using real-time polymerase chain reaction.
  
  
  RESULTS
  The nonparametric Kruskal-Wallis test showed that the difference in interleukin-6 expression among the groups was statistically significant (p = 0.04). Furthermore, the generalized Kruskal-Wallis nonparametric linear-by-linear association test showed a statistically significant trend of increase in the expression of interleukin-6 from group 1 to group 2 to group 3 (p = 0.02) and a suggestion of such a trend for MMP-1 (p = 0.05). No increase in MMP-8 expression was observed in patients in group 3 compared to patients in groups 1 and 2. Although the average expression levels of MMP-1, interleukin-1beta and tumor necrosis factor-alpha were increased from group 1 to group 3, the differences were not statistically significant.
  
  
  CONCLUSIONS
  A trend of increased interleukin-6 expression in periodontal tissues was observed across patients with neither diabetes nor periodontal disease, patients with periodontal disease alone, and patients with both diseases.
authors.affiliation: Division of Periodontics, Department of Stomatology, College of Dental Medicine, Medical University of South Carolina, Charleston, SC 29403, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Cole
authors.forename: K P
authors.initials: KP
authors.lastname: Sundararaj
authors.forename: R S
authors.initials: RS
authors.lastname: Leite
authors.forename: A
authors.initials: A
authors.lastname: Nareika
authors.forename: E H
authors.initials: EH
authors.lastname: Slate
authors.forename: J J
authors.initials: JJ
authors.lastname: Sanders
authors.forename: M F
authors.initials: MF
authors.lastname: Lopes-Virella
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D048909:Diabetes Complications / Q000276:immunology* / Q000378:metabolism; D005260:Female; D005883:Gingival Crevicular Fluid / Q000737:chemistry; D006801:Humans; D053583:Interleukin-1beta / Q000032:analysis / Q000096:biosynthesis; D015850:Interleukin-6 / Q000032:analysis / Q000096:biosynthesis*; D008297:Male; D020781:Matrix Metalloproteinase 1 / Q000032:analysis / Q000096:biosynthesis; D020784:Matrix Metalloproteinase 8 / Q000032:analysis / Q000096:biosynthesis; D008875:Middle Aged; D010510:Periodontal Diseases / Q000150:complications / Q000276:immunology* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000032:analysis; D018709:Statistics, Nonparametric; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000096:biosynthesis; D055815:Young Adult
chemical_list: D053583:Interleukin-1beta; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D012313:RNA; D020784:Matrix Metalloproteinase 8; D020781:Matrix Metalloproteinase 1