Association of Polymorphism with Periodontitis and Salivary Levels of Hypoxia-Inducible Factor-1α

Abstract

Objective This investigation aims to investigate the association between HIF-1α genetic polymorphism and periodontitis and examine and contrast the levels of HIF-1α present in the saliva of subjects afflicted with periodontitis and in the control group. Additionally, this study aims to establish diagnostic proficiency of this biomarker in distinguishing between periodontal health and disease. Materials and Methods This study entailed the collection of venous blood samples and unstimulated saliva samples from a total of 160 participants, encompassing 80 individuals diagnosed with periodontitis and 80 periodontitis-free individuals. The periodontal parameters were evaluated, involving the measurement of clinical attachment loss, the probing pocket depth, and the bleeding on probing percentage. Subsequently, genetic analysis of HIF-1α using polymerase chain reaction (PCR) technique, DNA sequencing, and enzyme-linked immunosorbent assays was conducted. Results The genetic analysis of 352 bp of the HIF-1α gene revealed the presence of 66 single-nucleotide polymorphisms (SNPs) in control samples, whereas 78 SNPs were found in periodontitis sample. The nucleotide A was replaced with a C nucleotide at position 207 of the amplified PCR fragments. The homozygous AA pattern was predominant in the control group, with significant differences between the two groups. In contrast, the homozygous CC pattern was more dominant in the periodontitis group, with significant differences between the two groups. The analysis of Hardy–Weinberg equilibrium for the comparison between the observed and the expected genotypes showed significant differences between the observed and the expected values in the control and periodontitis groups, as well as the total sample. The highest mean values of the measured periodontal parameters were found in the periodontitis group (clinical attachment loss = 4.759, probing pocket depth = 4.050, and bleeding on probing = 30.950) with statistically significant differences between the groups. The periodontitis group showed significantly higher salivary HIF-1α levels compared to control group (p < 0.001). Besides, HIF-1α is a good biomarker in distinguishing between periodontal health and periodontitis. Conclusion rs1951795 SNP of HIF-1α has no significant impact on the progression of periodontitis and the salivary level HIF-1α. Periodontitis results in a notable elevation in HIF-1α salivary levels, with an outstanding diagnostic ability to distinguish between periodontitis and periodontal health.