Abstract
Background:
Type 2 diabetes mellitus (DM) and chronic periodontitis (CP) show common pathophysiological features. We investigated the serum levels of IL-23 and IL-35 in people with type 2 DM and CP.
Methods:
In a cross-sectional study, 72 patients were divided into four equal groups: group A, participants without type 2 DM and CP; group B, patients with type 2 DM without CP; group C, patients with CP and without type 2 DM; and group D, patients with type 2 DM and CP. Demographic data were obtained and periodontal conditions including clinical attachment loss, bleeding on probing, plaque index, gingival index, and probing depth was evaluated on all existing teeth. Fasting blood sugar (FBS) levels, hemoglobin (Hb) A1c, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were assessed. In addition, serum levels of IL-23 and 35 were measured using enzyme-linked immunosorbent assay.
Results:
The serum levels of IL-23 and 35 showed no significant differences between all groups (P>0.05). A significant positive correlation between the serum concentration of IL-23 and clinical attachment loss in the control group (r: 0.548, P=0.019) was detected. A significant negative correlation between IL-35 and the plaque index in group B (r: -0.578, P=0.012), plus significant negative correlations between IL-23 with ESR (r: -0.487, P=0.040) and CRP (r: -0.498, P=0.035) in groups C and D were also detected.
Conclusion:
Despite significant associations of serum concentration of IL-23 and 35 with certain periodontal and inflammatory indices, neither type 2 DM nor CP differentially affects serum levels of these two cytokines.
Key Words: Type 2 diabetes mellitus, Chronic periodontitis, Interleukin-23, Interleukin -35
Periodontitis is an inflammatory condition of the teeth-protecting tissues that is induced mostly by gram-negative and anaerobic species microorganisms (1, 2). Periodontitis results in progressive degeneration of periodontal ligaments, alveolar bone, gingiva, and eventual loss of teeth (3). Gingival plaques contain living bacteria and their biofilm bacteria products such as lipopolysaccharides (LPS) that induce inflammation. The inflamed tissues then release inflammatory cytokines into the bloodstream as signaling proteins (4). On the other hand, diabetes mellitus (DM) is known as a significant risk factor for periodontitis (5, 6). Persistent hyperglycemia, which is seen in prediabetes and diabetic patients, induces damages in the periodontal tissues due to the changes in the activity of polymorphonuclear cells and leukocytes plus alteration of glycosaminoglycans and cytokines production (7).
Thus, patients with type 2 DM have a high prevalence of gingivitis, periodontitis, oral candidiasis, and xerostomia (dry mouth). The severity of these diseases depends on the duration of the patient's diabetes (8).
Interleukin (IL)-23, which is a signaling protein in inflammatory conditions of periodontitis, also plays a role in mild degrees of type 2 DM-related inflammation (9). In chronic infections, antigens stimulate dendritic cells, macrophages, and IL-23 production that motivates the production of IL-17. Also, IL-23 increases the production of IL-6, IL-1 and tumor necrosing factor (TNF)-α in the autocrine/paracrine pathway (10). Moreover, IL-35 is an anti-inflammatory cytokine in the IL-12 family that plays a suppressive role in the immune system (11). Since IL-23 is involved in the pathogenesis of type 2 DM and chronic periodontitis (CP), and there are controversies in some studies (12, 13) and lack of any data about the role of IL-35, we aimed to investigate the serum levels of IL-23 and IL-35 in people with type 2 DM and CP and compare them with the control group.
Methods
Patients: The current cross-sectional study was done in 2016 with the coordination of three private and public dental centers of Sari, North of Iran. Based on the prevalence of CP and DM and the following formula, α=0.05 was considered significant, and the beta level was set at β=0.10. Additionally, four study groups and a sample size of 18 patients per group were calculated for this preliminary study. Based on convenience sampling method, referred patients were followed-up to identify those with DM based on the criteria of the American Association of Diabetes (14) and patients with CP based on the existence of inflammation in the periodontium (15).
Briefly, type 2 DM was confirmed if one of the following conditions was reported: (a) fasting blood sugar (FBS) ≥ 126 mg/dL; (b) random blood sugar ≥ 200 mg/dL with signs of hyperglycemia; and (c) HbA1c ≥ 6.5%. Periodontitis was also diagnosed in patients with at least one site with ≥ 3 mm probing depth and ≥ 2 mm loss of clinical attachments. Exclusion criteria were: patients younger than 18 year, progressed renal failure with serum creatinine level > 2 mg/dL, class III and IV heart failure, hepatic failure, use of certain drugs that induce insulin resistance and hyperglycemia such as prednisolone, cyclosporine and etc., consumption of antibiotics during the past three months, being treated for periodontitis, smoking during pregnancy, hemorrhagic diseases, and those who had less than 14 teeth (Fig. 1). Four groups, each with 18 patients were defined as follows:
Figure 1.
Flow chart of patients’ enrollment. DM, diabetes mellitus; CP, chronic periodontitis
Group A: participants with neither type 2 DM nor CP
Group B: patients with type 2 DM based on laboratory test and without CP based on clinical examination
Group C: patients with CP and without type 2 DM
Group D: patients with type 2 DM and CP
The Ethics Committee of Mazandaran University of Medical Sciences approved the protocol of the study (No. 13959); hence, all investigations have been carried out in accordance with the principles of the Declaration of Helsinki as revised in 2008. Moreover, the aims of the study were described completely for all enrolled participants and written consent informs were obtained.
Evaluations: A face-to-face questionnaire about demographic data, familial history of type 2 DM, and education level was filled out. Then, the periodontal examination was performed using a mirror and a periodontal probe (Williams probe, Medisporex, Pakistan). Clinical attachment loss (CAL) (16), bleeding on probing (BOP) (17), plaque (Loe) index (PI) (18), gingival index (GI) (19) and probing depth (PD) (20) for all teeth were recorded by an expert dentist (the first author). Her correlation coefficient of measurements was 0.84 in the previous pilot study using five CP patients and two measurements with a one-week interval.
Serum measurements: About 4 ml of fasting blood samples obtained from the cubital vein into sterile vacutainers without anticoagulant and serum were harvested after centrifugation (3000 RPM, 10 min). Serums were used for measurements of FBS (mg/dL) using an enzymatic colorimetric method (GOD/PAP) by an autoanalyzer prestige 24i (Tokyo Boeki Medical System, Japan), C-reactive protein (CRP, mg/l) by the nephelometric method, IL-23 and IL-35 concentrations (pg/ml) using the sandwich ELISA (Ebioscience, San Diego, CA, USA). Another 2 ml of the previously drawn blood was placed into the EDTA tube used for measuring HbA1c (%) using the Nycocard Reader II and erythrocyte sedimentation rate (ESR) (mm/h) by the manual method (21, 22).
Our analysis variables had a biological nature and a normal distribution in the population. In addition, we checked the data by the Kolmogorov-Simonov test, and find, with the exception of one or two data that was far from average, all other data had a normal distribution. Therefore, we handled and analyzed them using parametric analyses. All statistical analyses were performed using the software SPSS Version 23. Comparison of age, serum, blood biomarkers, and periodontal indices between the four groups was performed using the one-way analysis of variance (ANOVA) and Tukey's Post Hoc test. Associations between jobs, education, systemic diseases, familial history of type 2 DM, gender, severity, and distribution of periodontal diseases with type 2 DM and CP were checked using the chi-square test. Associations between serum concentrations of all quantitative variables were checked using the Pearson’s correlation test. A p<0.05 was considered as the significant difference.
Results
Subjects in the healthy control group had a significantly lower age (P<0.001) and a higher number of teeth (P<0.05) in comparison with the other three groups. Since the enrollment criteria for the study patients did not include their sex, our four groups were not sex-matched (P<0.001); hence, we had a higher frequency of females in the all groups except the CP group. Most of the participants were unemployed or homemakers (44.4%) while the others had a diploma or associate degree (38.9%) and were without systemic diseases (73.6%) or familial history of DM (52.8%).
Generalized moderate periodontitis was the most frequent form of periodontal diseases in both CP and DM+CP groups (66.7% and 44.4%, respectively) followed by severe diffused periodontitis (16.7% and 38.9% respectively, table 1). FBS and HbA1c were significantly higher in the DM and DM+CP groups in comparison with the other two groups, but no significant differences were detected between these two groups with regard to FBS or HbA1c levels.As shown, all periodontal indices in the CP and DM+CP groups were significantly higher than related indices in the control and DM groups (P<0.05). Despite the significantly lower GI index in the DM+CP group compared with the CP group (P=0.03), no significant differences were detected between the control and DM groups, or the CP and DM+CP groups (p>0.05).
Table 1.
Demographic characteristics of patients in four groups
|
Groups
|
|||||
|---|---|---|---|---|---|
| Variables | Health (n=18) | DM (n=18) | CP (n=18) | DM+CP (n=18) | Total |
| Age (years) | 27.44±10.07a | 46.06±10.53b | 44.78±13.18b | 52.72±9.96b | |
| Number of tooth | 29.00±2.59a | 24.50±5.37b | 24.94±4.14b | 24.33±4.70b | |
| Gender | |||||
| Male | 5 (27.8) | 3 (16.7) | 14 (77.8) | 3 (16.7) | 25 (34.7) |
| Female | 13 (72.2) | 15 (83.3) | 4 (22.2) | 15 (83.3) | 47 (65.3) |
| HbA1c | 5.51±0.36a | 8.53±1.00b | 5.79±0.45a | 8.12±1.09b | |
| FBS | 86.56±5.23a | 184.00±68.91b | 89.44±8.91a | 154.39±43.55b | |
| Periodontal indices | |||||
| Upper tooth | |||||
| CAL | 0.72±2.27a | 3.72±6.26a | 47.61±31.35b | 46.83±29.97b | |
| BOP | 8.17±6.53a | 15.17±11.62a | 33.33±17.16b | 31.55±13.98b | |
| PI | 25.06±23.63a | 47.17±22.26a | 81.67±37.11b | 72.94±19.42b | |
| GI | 32.11±26.43a | 43.67±29.10a | 102.44±44.32b | 74.50±27.44b | |
| PD | 89.11±21.71a | 89.94±23.87a | 118.83±33.06b | 111.17±26.59ab | |
| Lower tooth | |||||
| CAL | 3.11±5.78a | 4.39±5.65a | 64.39±35.30b | 92.61±55.30b | |
| BOP | 5.61±4.50a | 12.11±9.85a | 38.89±15.49b | 32.44±15.93b | |
| PI | 28.78±22.67a | 41.72±17.16a | 95.67±33.39b | 88.94±25.46b | |
| GI | 28.44±25.58a | 39.50±26.95a | 110.00±28.20b | 83.78±31.67b | |
| PD | 85.22±13.17a | 77.00±28.53a | 124.50±25.15b | 113.50±33.55b | |
| Jobs | |||||
| UE or housekeeper | 0 (0) | 11 (61.1) | 7 (38.9) | 14 (77.8) | 32 (44.4) |
| Self-employment | 3 (16.7) | 4 (22.2) | 8 (44.4) | 3 (16.7) | 18 (25.0) |
| Employee | 14 (77.8) | 2 (11.1) | 3 (16.7) | 1 (5.6) | 20 (27.8) |
| Retired | 1 (5.6) | 1 (5.6) | 0 (0) | 0 (0) | 2 (2.8) |
| Education | |||||
| Before the diploma | 0 (0) | 8 (44.4) | 8 (44.4) | 10 (55.6) | 26 (36.1) |
| Diploma or AD | 4 (22.2) | 8 (44.4) | 8 (44.4) | 8 (44.4) | 28 (38.9) |
| BSc and higher | 14 (77.8) | 2 (11.1) | 2 (11.1) | 0 (0) | 18 (25.0) |
| Systemic diseases | |||||
| No | 18 (100) | 10 (55.6) | 16 (88.9) | 9 (50.0) | 53 (73.6) |
| Hypertension | 0 (0) | 2 (11.1) | 0 (0) | 6 (33.3) | 8 (11.1) |
| Thyroid disorders | 0 (0) | 3 (16.7) | 0 (0) | 1 (5.6) | 4 (5.6) |
| CVDs | 0 (0) | 0 (0) | 1 (5.6) | 1 (5.6) | 2 (2.8) |
| Others | 0 (0) | 3 (16.7) | 1 (5.6) | 1 (5.6) | 5 (6.9) |
| Familial history of DM | |||||
| Yes | 1 (5.6) | 16 (88.9) | 2 (11.1) | 15 (83.3) | 34 (47.2) |
| No | 17 (94.4) | 2 (11.1) | 16 (88.9) | 3 (16.7) | 38 (52.8) |
| Periodontitis | |||||
| No | 18 (100) | 18 (100) | 0 (0) | 0 (0) | 36 (50.0) |
| Localized mild | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Generalized mild | 0 (0) | 0 (0) | 2 (11.1) | 3 (16.7) | 5 (6.9) |
| Localize moderate | 0 (0) | 0 (0) | 1 (5.6) | 0 (0) | 1 (1.4) |
| Generalized moderate | 0 (0) | 0 (0) | 12 (66.7) | 8 (44.4) | 20 (27.8) |
| Localized severe | 0 (0) | 0 (0) | 0 (0) | 0 (0) | 0 (0) |
| Generalized severe | 0 (0) | 0 (0) | 3 (16.7) | 7 (38.9) | 10 (13.9) |
UE, un-employed; AD, associate degree; CVDs, cardiovascular diseases; CAL, clinical attachment loss; BOP, bleeding on probing; PI, plaque (Loe) index; GI, gingival index; PD, probing depth. Different superscript letters in each row indicate statistical significant difference (P<0.05).
Accordingly, fig. 2 shows that the DM+CP showed higher inflammation in comparison to the control group, which was based only on higher ESR. However, CRP, IL-23, and IL-35 levels showed no significant differences between the four groups. As a secondary finding, comparisons of periodontal indices of the mandible and maxilla were performed separately.
Figure 2.
Comparison of serum biochemical indices of diabetes and inflammation between the four groups. DM, diabetes mellitus; CP, chronic periodontitis. Significant statistical differences between groups were indicated by different superscript letters (P<0.05)
Our findings were similar to the total indices that have been presented above, except for the lack of significant difference in the PD of the maxillary teeth between the DM+CP and the other three groups and in the GI of the mandible and maxilla between the DM+CP and CP group (p<0.05, data not shown).
Significant negative correlations were seen between IL-35 with PI in DM group; IL-23 with HbA1c and ESR in CP group and between IL-23 with CRP in DM+CP group. Moreover, significant positive correlations were detected between IL-23 with age and CAL in the control group and between IL-23 and PI in the CP group.
Discussion
In the preset study, patients with DM+CP showed higher inflammation (ESR index) in comparison to the control group while CRP, IL-23, and IL-35 levels were similar between the four groups.
Periodontal disease is the sixth most common complication of DM (23), and these two diseases have common pathophysiological mechanisms that have been confirmed by animal (24) and human studies (25). Also, patients with uncontrolled DM show a higher prevalence of periodontal diseases (26). It has been reported that DM-induced over-expression of IL-17 as a pro-inflammatory cytokine (27) in addition to its stimulated expression by IL-23 (28). These two cytokines along with other inflammatory molecules and cells play important roles in the common pathological pathway of DM and CP (29). However, we found no significant difference in the serum concentration of IL-23 between our four groups.
Similar to our findings, Vieira Ribeiro et al., by evaluating different cytokines in healthy patients with DM and chronic periodontitis reported that no significant difference in the level of IL-23 among healthy and controlled diabetic patients (13). Furthermore, Duarte et al. reported that CP- not DM- significantly altered the expression of the immune system and inflammatory markers related genes such as IL-23 (30), which is similar to our report about DM but opposite regarding CP. Moreover, santos et al.detected significant differences in the gingival crevicular fluid (GCF) level of IL-4 and IL-17, not IL-23, between well-controlled and poorly controlled DM subjects with CP before and after periodontal therapy (12). Changes in the IL-17 without any changes in the IL-23 may be due to the regulatory roles of other cytokines involved in the stimulation of IL-17which affect the proliferation and differentiation of Th17 as the producers of IL-17. On the other hand, there may be differences in the source of the biomarker used in the different studies, which could potentially cause the controversial findings. For instance, the inflammatory role of IL-23 was reported by assessing this biomarker in the gingival biopsy (31) and GCF (32) of patients with CP. However, when we assessed the serum level of IL-23, we did not confirm such role.
Significant negative correlations between IL-23 with ESR and CRP in the CP and DM+CP groups were seen, respectively, which seems irrational due to the inflammatory nature of all mentioned parameters. Significant positive correlation between the serum concentration of IL-23 and CAL in the control group was also reported previously in gingivitis and periodontitis tissues (33). In addition, novel significant positive correlation between serum IL-23 concentration and GI is rational and could be investigated further in future research. There are no reports about the comparison of serum levels of IL-35 between patients with and without DM and CP. In addition, no studies have evaluated IL-35 and IL-23 concurrently in DM. Only one study evaluated the expression of IL-23 and IL-35 in GCF and serum of CP and compared their levels with healthy volunteers. They found that the GCF and serum levels of both cytokines were elevated in CP patients (34). Moreover, an increase in the serum level of IL-35 in patients with both types of DM (35) and periodontal diseases (36) were reported separately. Due to the immunosuppressive role of IL-35 and its selective activities to proliferate regulatory T cells and suppress Th17 cells (37), the negative associations between IL-23 and IL-35 is conceivable. However, such a relationship was not detected in our study, which may be related to the evaluation of both biomarkers in the serum - not GCF or gingival biopsy. Contrary to those reported by Koseoglu et al. in the GCF of patients with chronic periodontitis (38), the significant negative correlation between IL-35 and PI in DM group was found in this study, which is also rational based on the anti-inflammatory properties of this immunosuppressive cytokine. This result is about similar to the recent finding of Kaustubh et al. about significantly higher GCF IL-35 levels in a healthy population compared with patients with gingivitis (39).
Other non-significant correlations between any periodontal indices and serum concentrations of IL-35 could reinforce this hypothesis that periodontitis and gingivitis induce no changes in the expression of IL-35. However, a recent study by Kaustubh et al. has reported the suppressing role of IL-35 in gingival inflammation and maintaining periodontal health (40). For more validation and confirmation, it is recommended to evaluate the concentration of IL-35 in GCF and saliva in healthy participants and patients with periodontitis and gingivitis.
Despite our findings, the low number of patients in each group was the one important limitation of our study. The limitation was due to our inclusion/exclusion criteria that limited the number of patients with diabetes and periodontitis with a minimum number of 14 teeth.
In conclusion, no significant differences in the serum levels of IL-23 and IL-35 were detected between patients with and without DM and CP in this preliminary case-control study. It seems that the role of these two ILs should be further evaluated and confirmed in future research, especially cohort studies.
Acknowledgments
The authors would like to thank the staff of the Tooba Endocrine Clinic of Sari and all the staff of the Dentistry School of Mazandaran University of Medical Sciences for their kind help in data collection. The data that support the findings of this study are available from the corresponding author upon reasonable request.
Funding:
This study was supported by research grants from the Mazandaran University of Medical Sciences (Grant no: 95-01-15-13959).
Conflict of interests:
The authors declare that none of them have a conflict of interest and there is no duality of interest associated with this manuscript.
References
- 1.Bascones-Martinez A, Matesanz-Perez P, Escribano-Bermejo M, et al. Periodontal disease and diabetes-review of the literature. Med Oral Patol Oral Cir Bucal. 2011;16:e722–9. doi: 10.4317/medoral.17032. [DOI] [PubMed] [Google Scholar]
- 2.Jenabian N, Ghazi Mirsaeed AM, Ehsani H, Kiakojori A. Periodontal status of patient’s underwent hemodialysis therapy. Caspian J Intern Med. 2013;4:658–61. [PMC free article] [PubMed] [Google Scholar]
- 3.Mohamed HG, Idris SB, Ahmed MF, et al. Influence of type 2 diabetes on local production of inflammatory molecules in adults with and without chronic periodontitis: a cross-sectional study. BMC Oral Health. 2015;15:86. doi: 10.1186/s12903-015-0073-z. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Patiño Marín N, Loyola Rodríguez JP, Medina Solis CE, et al. Caries, periodontal disease and tooth loss in patients with diabetes mellitus types 1 and 2. Acta Odontol Latinoam. 2008;21:127–33. [PubMed] [Google Scholar]
- 5.Marigo L, Cerreto R, Giuliani M, et al. Diabetes mellitus: biochemical, histological and microbiological aspects in periodontal disease. Eur Rev Med Pharmacol Sci. 2011;15:751–8. [PubMed] [Google Scholar]
- 6.Mesgarani A, Haghanifar S, Eshkevari N, et al. Frequency of odontogenic periradicular lesions in diabetic patients. Caspian J Intern Med. 2014;5:22–5. [PMC free article] [PubMed] [Google Scholar]
- 7.Marchetti E, Monaco A, Procaccini L, et al. Periodontal disease: the influence of metabolic syndrome. Nutr Metab. 2012;9:88. doi: 10.1186/1743-7075-9-88. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Barnes VM, Kennedy AD, Panagakos F, et al. Global metabolomic analysis of human saliva and plasma from healthy and diabetic subjects, with and without periodontal disease. PloS One. 2014;9:e105181. doi: 10.1371/journal.pone.0105181. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Ribeiro FV, de Mendonça AC, Santos VR, et al. Cytokines and bone-related factors in systemically healthy patients with chronic periodontitis and patients with type 2 diabetes and chronic periodontitis. J Periodontol. 2011;82:1187–96. doi: 10.1902/jop.2011.100643. [DOI] [PubMed] [Google Scholar]
- 10.Iwakura Y, Ishigame H. The IL-23/IL-17 axis in inflammation. J Clin Invest. 2006;116:1218–22. doi: 10.1172/JCI28508. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Li X, Mai J, Virtue A, et al. IL-35 is a novel responsive anti-inflammatory cytokine-a new system of categorizing anti-inflammatory cytokines. PLoS One. 2012;7:e33628. doi: 10.1371/journal.pone.0033628. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 12.Santos VR, Ribeiro FV, Lima JA, et al. Cytokine levels in sites of chronic periodontitis of poorly controlled and well‐controlled type 2 diabetic subjects. J Clin Periodontol. 2010;37:1049–58. doi: 10.1111/j.1600-051X.2010.01624.x. [DOI] [PubMed] [Google Scholar]
- 13.Vieira Ribeiro F, de Mendonça AC, Santos VR, et al. Cytokines and bone-related factors in systemically healthy patients with chronic periodontitis and patients with type 2 diabetes and chronic periodontitis. J Periodontol. 2011;82:1187–96. doi: 10.1902/jop.2011.100643. [DOI] [PubMed] [Google Scholar]
- 14.American Diabetes Association. Diagnosis and classification of diabetes mellitus. Diabetes Care. 2014;37:S81–90. doi: 10.2337/dc14-S081. [DOI] [PubMed] [Google Scholar]
- 15.Savage A, Eaton KA, Moles DR, Needleman I. A systematic review of definitions of periodontitis and methods that have been used to identify this disease. J Clin Periodontol. 2009;36:458–67. doi: 10.1111/j.1600-051X.2009.01408.x. [DOI] [PubMed] [Google Scholar]
- 16.Armitage GC. Periodontal diagnoses and classification of periodontal diseases. Periodontol. 2004;34:9–21. doi: 10.1046/j.0906-6713.2002.003421.x. [DOI] [PubMed] [Google Scholar]
- 17.Page RC, Eke PI. Case definitions for use in population-based surveillance of periodontitis. J Periodontol. 2007;78:1387–99. doi: 10.1902/jop.2007.060264. [DOI] [PubMed] [Google Scholar]
- 18.Löe H, Silness J. Periodontal disease in pregnancy I Prevalence and severity. Acta Odontol Scand. 1963;21:533–51. doi: 10.3109/00016356309011240. [DOI] [PubMed] [Google Scholar]
- 19.Wang Z, Zhou X, Zhang J, et al. Periodontal health, oral health behaviours, and chronic obstructive pulmonary disease. J Clin Periodontol. 2009;36:750–5. doi: 10.1111/j.1600-051X.2009.01448.x. [DOI] [PubMed] [Google Scholar]
- 20.Bhavsar NV, Dave BD, Brahmbhatt NA, Parekh R. Periodontal status and oral health behavior in hospitalized patients with chronic obstructive pulmonary disease. J Nat Sci Biol Med. 2015;6:S93–7. doi: 10.4103/0976-9668.166097. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Koohi-Hosseinabadi O, Moini M, Safarpoor A, Derakhshanfar A, Sepehrimanesh M. Effects of dietary Thymus vulgaris extract alone or with atorvastatin on the liver, kidney, heart, and brain histopathological features in diabetic and hyperlipidemic male rats. Comp Clin Pathol. 2015;24:1311–5. [Google Scholar]
- 22.Karami M, Sepehrimanesh M, Koohi-Hosseinabadi O, et al. Therapeutic effects of hydroalcoholic and aqueous extracts of Berberis vulgaris fruits in streptozotocin induced type 1 diabetes mellitus rats. Romanian J Diabetes Nutr Metab Dis. 2016;23:239–45. [Google Scholar]
- 23.Löe H. Periodontal disease: the sixth complication of diabetes mellitus. Diabetes Care. 1993;16:329–34. [PubMed] [Google Scholar]
- 24.Cintra LT, da Silva Facundo AC, Azuma MM, et al. Pulpal and periodontal diseases increase triglyceride levels in diabetic rats. Clin Oral Investig. 2013;17:1595–9. doi: 10.1007/s00784-012-0853-7. [DOI] [PubMed] [Google Scholar]
- 25.Marotta PS, Fontes TV, Armada L. Type 2 diabetes mellitus and the prevalence of apical periodontitis and endodontic treatment in an adult Brazilian population. J Endod. 2012;38:297–300. doi: 10.1016/j.joen.2011.11.001. [DOI] [PubMed] [Google Scholar]
- 26.Ueta E, Osaki T, Yoneda K, Yamamoto T. Prevalence of diabetes mellitus in odontogenic infections and oral candidiasis: an analysis of neutrophil suppression. J Oral Pathol Med. 1993;22:168–74. doi: 10.1111/j.1600-0714.1993.tb01051.x. [DOI] [PubMed] [Google Scholar]
- 27.Xiao E, Mattos M, Vieira GHA, et al. Diabetes enhances IL-17 expression and alters the oral microbiome to increase its pathogenicity. Cell Host Microbe. 2017;22:120–8. doi: 10.1016/j.chom.2017.06.014. e4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 28.Starnes T, Broxmeyer HE, Robertson MJ, Hromas R. Cutting edge: IL-17D, a novel member of the IL-17 family, stimulates cytokine production and inhibits hemopoiesis. J Immunol. 2002;169:642–6. doi: 10.4049/jimmunol.169.2.642. [DOI] [PubMed] [Google Scholar]
- 29.Javed F, Al-Askar M, Al-Hezaimi K. Cytokine profile in the gingival crevicular fluid of periodontitis patients with and without type 2 diabetes: a literature review. J Periodontol. 2012;83:156–61. doi: 10.1902/jop.2011.110207. [DOI] [PubMed] [Google Scholar]
- 30.Duarte PM, Miranda TS, Lima JA, et al. Expression of immune-inflammatory markers in sites of chronic periodontitis in patients with type 2 diabetes. J Periodontol. 2012;83:426–34. doi: 10.1902/jop.2011.110324. [DOI] [PubMed] [Google Scholar]
- 31.Ohyama H, Kato-Kogoe N, Kuhara A, et al. The involvement of IL-23 and the Th17 pathway in periodontitis. J Dent Res. 2009;88:633–8. doi: 10.1177/0022034509339889. [DOI] [PubMed] [Google Scholar]
- 32.Himani GS, Prabhuji MLV, Karthikeyan BV. Gingival crevicular fluid and interleukin‐23 concentration in systemically healthy subjects: their relationship in periodontal health and disease. J Periodontal Res. 2014;49:237–45. doi: 10.1111/jre.12100. [DOI] [PubMed] [Google Scholar]
- 33.Honda T, Aoki Y, Takahashi N, et al. Elevated expression of IL-17 and IL-12 genes in chronic inflammatory periodontal disease. Clin Chim Acta. 2008;395:137–41. doi: 10.1016/j.cca.2008.06.003. [DOI] [PubMed] [Google Scholar]
- 34.Cai S, Liu X, Li H, et al. Elevated interleukin (IL)-35-related sCD14 but not IL-23 is associated with the severity of chronic periodontitis. Int J Clin Exp Med. 2017;10:4119–28. [Google Scholar]
- 35.Espes D, Singh K, Sandler S, Carlsson PO. Increased interleukin-35 levels in patients with type 1 diabetes with remaining C-peptide. Diabetes Care. 2017;40:1090–5. doi: 10.2337/dc16-2121. [DOI] [PubMed] [Google Scholar]
- 36.Wang Y, Jin Y, Wang YY, Xu DN, Lin XP. The expression and clinical significance of IL-35 in periodontitis and oral lichen planus. Shanghai Kou Qiang Yi Xue. 2016;25:443–7. [PubMed] [Google Scholar]
- 37.Niedbala W, Wei XQ, Cai B, et al. IL-35 is a novel cytokine with therapeutic effects against collagen-induced arthritis through the expansion of regulatory T cells and suppression of Th17 cells. Eur J Immunol. 2007;37:3021–9. doi: 10.1002/eji.200737810. [DOI] [PubMed] [Google Scholar]
- 38.Koseoglu S, Saglam M, Pekbagriyanik T, Savran L, Sutcu R. Level of interleukin-35 in gingival crevicular fluid, saliva, and plasma in periodontal disease and health. J Periodontol. 2015;86:964–71. doi: 10.1902/jop.2015.140666. [DOI] [PubMed] [Google Scholar]
- 39.Kaustubh TS, Manohar LB, Jaiswal P, Charde P. A comparative evaluation of gingival crevicular fluid (GCF) level of interleukin-35 in chronic gingivitis patients and periodontally healthy subjects. Global J Res Anal. 2017;6:647–9. [Google Scholar]
- 40.Kaustubh TS, Manohar BL, Charde P, Jaiswal P. Comparative evaluation of interleukin-35 levels in gingival crevicular fluid in patients with chronic gingivitis and chronic periodontitis. Int J Oral Care Res. 2017;5:83–6. [Google Scholar]