Periodontitis Provokes Retinal Neurodegenerative Effects of Metabolic Syndrome: A Cross-Sectional Study

Abstract

Background: This cross-sectional study aims to investigate the retino-choroidal degenerative effects of periodontitis, metabolic syndrome (Mets), and the combination of these diseases using optical coherence tomography (OCT) measurements.

Methods: Ninety-two patients selected according to inclusion criteria were divided into four groups: systemically and periodontally healthy (control), systemically healthy periodontitis (PD), periodontally healthy metabolic syndrome (MetS), and periodontitis and metabolic syndrome combined (PD-MetS). The systemic inflammatory-oxidative effects of periodontitis and MetS were biochemically evaluated using the serum TNF-α level, IL-1β/IL-10 ratio, and oxidative stress index (OSI: TOS/TAS). Retinal (AMT, pRNFLT, and GCL + T) and choroidal (SFCT) morphometric measurements and vascular evaluations (foveal capillary density) were performed via OCT Angio with swept-source technology.

Results: Both periodontitis and Mets cause systemic inflammatory stress characterized by significant increases in the IL-1β/IL-10 ratio and OSI (p < 0.05). Compared to the control group, the AMT was significantly thinner in the MetS group, the pRNFLT was significantly thinner in the PD-MetS group, and the SFCT was significantly thinner in both groups (p < 0.05). The GCL+ was slightly thicker in the Mets groups. (p > 0.05) Foveal capillary density did not differ significantly among the groups. (p > 0.05).

Conclusions: Periodontitis-related inflammatory stress alone causes changes in retinal and subfoveal choroidal thicknesses that are not statistically significant. On the other hand, when combined with Mets, it may significantly provoke the retinal neurodegenerative effects of this disease.

Keywords: metabolic syndrome; neurodegeneration; optic coherence tomography; oxidative stress; periodontitis.

Figure 1

OCT analysis. (A) AMD measurement, (B) pRNFLT, GCL + T, and SFCT measurements.

Figure 2

FCD measurements. (A) Superficial vessels, (B) foveal and parafoveal capillar density values, (C) view of the foveal area in one of the SS-OCT sections.

Figure 3

Intergroup comparisons of clinical periodontal parameters. PD, periodontitis group; MetS, metabolic syndrome group; PD-MetS, periodontitis–metabolic syndrome group. Data are expressed as mean ± SD. (a) Compared to control and MetS groups; statistically significant difference (p < 0.05).

Figure 4

Intergroup comparisons of biochemical parameters. (A) Interleukin 1-beta (IL-1ß). (B) Interleukin 10 (IL-10). (C) IL-1ß/IL-10. (D) Tumor necrosis factor-alpha (TNF-α). (E) Total oxidant status (TOS). (F) Total antioxidant status (TAS). (G) Oxidative stress index (OSI). PD, periodontitis group; MetS, metabolic syndrome group; PD-MetS, periodontitis–metabolic syndrome group. Data are expressed as mean ± SD. (a) Compared to control group; (b) compared to PD group; (c) compared to MetS group; statistically significant difference (p < 0.05).

Figure 5

Intergroup comparisons of OPT and OPT-Angio measurements. (A) Average macular thickness (AMT). (B) Retinal nerve fiber layer thickness (PRFLT). (C) Total thickness of ganglion cell and inner plexiform layers (GCL + T). (D) Subfoveal choroideal thickness (SFCT). (E) Foveal capillary density (FCD). PD, periodontitis group; MetS, metabolic syndrome group; PD-MetS, periodontitis–metabolic syndrome group. Data are expressed as mean ± SD. (a) Compared to control group; (b) compared to PD group; statistically significant difference (p < 0.05).