To explore the correlation between serum lipid level and periodontitis and the influence of basic periodontal therapy on serum lipid.

Patients with chronic periodontitis treated in Department of Stomatology, Shenzhen Longhua District Central Hospital, from March 2018 to March 2019 were selected. Patients were divided into mild group (36 cases) , moderate group (52 cases) and severe group (30 cases) according to the severity of periodontitis. Periodontal healthy examinees (30 cases) without systemic diseases in the same period were selected as the control group. The changes of serum lipids after basic periodontal treatment were observed. t-test was used to compare the serum levels of triglyceride (TG) , total cholesterol (TC) , high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) between periodontitis patients and the control group, before and after basic periodontal treatment, whereas One-Way ANOVA was carried out in the comparison of the level of TG, TC, HDL-C and LDL-C in mild, moderate and severe groups. The correlation between serum lipid and periodontitis was analyzed by Logistic analysis method.

The serum levels of TG, TC, HDL-C and LDL-C in patients with periodontitis before basic periodontal treatment were (2.2 ± 0.8) , (5.3 ± 1.0) , (1.3 ± 0.3) and (2.8 ± 0.6) mmol/L, and those in the control group were (1.5 ± 0.7) , (4.4 ± 0.9) , (1.9 ± 0.3) and (1.8 ± 0.5) mmol/L. The differences were statistically significant (t_TG= 4.306, P_TG= 0.036; t_TC= 6.781, P_TC= 0.028; t_HDL-C= 5.023, P_HDL-C= 0.031; t_LDL-C= 4.974, P_LDL-C= 0.034) . With the aggravation of periodontitis, the level of HDL-C decreased gradually (F = 0.933, P = 0.192) , without statistical significance between groups. The levels of TG, TC, LDL-C and the proportion of hyperlipidemia increased gradually, and a significant difference was found between groups (F_TG = 5.762, P_TG = 0.033; F_TC = 6.237, P_TC = 0.029; F_LDL-C = 6.685, P_LDL-C = 0.024; χ²_{Hyperlipidemia} = 4.513, P_{Hyperlipidemia} = 0.039) . The Logistic regression analysis showed that the periodontitis was an independent risk factor for the elevation of TG, TC and LDL-C (OR_TG = 3.264, 95% CI_TG = 1.733 ~ 5.934; OR_TC = 2.937; 95% CI_TC = 1.342 ~ 4.926; OR_LDL-C = 2.427, 95% CI_LDL-C = 1.256 ~ 3.125) . After basic periodontal treatment, the serum levels of TG, TC and LDL-C were significantly lower than that before treatment, but the level of HDL-C was significantly higher.

Periodontitis is an independent risk factor for the elevation of TG, TC and LDL-C. Basic periodontal therapy can help improve blood lipid levels and reduce the risk of atherosclerosis and cardiovascular disease.