Correlation between SNP genotypes and periodontitis in Japanese type II diabetic patients: a preliminary study

Abstract

The present study aims to investigate the correlation between SNP genotype patterns and periodontitis severity in Japanese type II diabetic patients. A cross-sectional study in 43 Japanese diabetic patients with periodontitis was performed. Blood samples were drawn for single nucleotide polymorphism (SNP) analyses and periodontal index (probing pocket depth and clinical attachment level) was subsequently recorded. Twelve functional genes with SNPs that had been shown to be associated with diabetes and/or inflammation were genotyped using a nuclease-mediated SNP-specific ligation method. Subjects with two or more sites with clinical attachment level ≥6 mm and who additionally had one or more sites with pocket depth ≥5 mm were classified as having severe periodontitis. Proportions of risk genotypes/non-risk genotypes between severe and non-severe periodontitis were subsequently compared. A high frequency (21/43 participants, 49%) of adiponectin gene polymorphism (ADIPOQ 45T > G) homozygous risk genotype (TT genotype) was observed in the participants. The frequency of TGF-β1 SNP (29C > T) risk genotype (TT genotype) in severe periodontitis (34%, n = 11) was significantly higher than in non-severe periodontitis (0%, n = 0) (p = 0.04). Our study suggests that TGF-β1 SNPs (29C > T) may be used as one of the risk indicators for severe periodontitis in Japanese diabetic patients.

Adipokine gene variability and plasma levels in patients with chronic periodontitis -a case-control study

“…Candidate genes that encode adipokines and their specific genetic variants were selected based on previously described associations in other populations, 7,8 their possible functional impacts on the etiopathogenesis of CP, a minor allele frequency (MAF) higher than 0.1 in the European Caucasian population studied and/or a localization that falls within the haplotype structure of the gene.…”

“…Our results are in contrast to both of the previous studies that focused on ADIPOQ and RET N gene variability in patients with CP and T2DM/ obesity. 7,8 These divergent results may be caused by inter-individual variability between populations. For instance, the ADIPOQ +45C/T (rs2241766) minor allele frequency (MAF, G allele) in the Czech population was 8.4%, while the MAF recorded in the study of a Japanese population was 31.4%; 7 both results are in line with frequencies reported for European or East Asian populations in the NCBI SNP database (https://www.ncbi.nlm.nih.gov/projects/SNP/ snp_ref.cgi?rs=2241766).…”

“…However, while the size of our cohort (n = 409) was relatively small, it was still several times larger than the study populations of the two previous studies that investigated individual adipokine gene variability in patients with known periodontal status (43 Japanese patients/90 Indian participants). 7,8 Unfortunately, we could only analyse plasma levels of the three adipokines, and did not measure salivary/GCF adipokine levels in our patients. Importantly, our study is the first to explore this issue in a Caucasian population, and we can claim a high degree of homogeneity in the study population because the participants were collected from a pool of patients of Czech-Caucasian descent from South Moravia.…”

“…6 Two polymorphisms in the ADIPOQ gene have been studied in Japanese T2DM patients with CP. 7 In Indian population, a gene variant in the RETN gene has been associated with periodontal inflammation in both obese and non-obese patients. 8 To date, no study has analysed the variability in adipokine genes in Caucasian subjects with known periodontal statuses.…”