Association between interleukin-6 polymorphisms and periodontitis in Indian non-smokers.
OBJECTIVE
Genetic polymorphisms (SNPs) in the interleukin-6 (IL-6) gene have been associated with the presence of periodontitis. The aim of this study was to investigate the association between five SNPs in the IL-6 promoter region and the periodontal status of a rural Indian population.


METHODS
Two hundred and fifty-one systemically healthy volunteers were clinically assessed by a single calibrated examiner and divided into: healthy individuals and periodontitis patients based on the European Workshop on Periodontitis definitions and on a recently suggested definition, which takes into account age and clinical attachment levels. Their genomic DNA was analysed blindly using real-time polymerase chain reaction to study IL-6 variants. The association between genetic factors and the presence of periodontitis was assessed by logistic regression.


RESULTS
The IL-6-174 GG genotype was associated with periodontitis in non-smokers and older subjects (>45 years old). No statistically significant associations were detected between IL-6 haplotypes and periodontal status, after adjusting for confounders.


CONCLUSIONS
The IL-6-174 polymorphism showed some evidence of an association with the periodontal status in non-smokers and older subjects in this rural Indian population. This association might be mediated by the effect of IL-6 on inflammatory responses.
Franch-Chillida
Fernando
F
Periodontology Unit, Eastman Dental Hospital, University College London (UCL), London, UK.
Nibali
Luigi
L
Madden
Isobel
I
Donos
Nikos
N
Brett
Peter
P
D000328:Adult; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D007194:India; D015850:Interleukin-6 / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D010518:Periodontitis / Q000235:genetics* / Q000276:immunology; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012016:Reference Values; D012907:Smoking / Q000235:genetics
D015850:Interleukin-6