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 Table of Contents  
ORIGINAL ARTICLE
Year : 2019  |  Volume : 16  |  Issue : 2  |  Page : 104-114

Local and systemic level of adipokines as markers of inflammation in periodontitis and type 2 diabetes mellitus after periodontal therapy


1 Department of Oral Medicine and Periodontology, Faculty of Dentistry, The British University in Egypt (BUE), Cairo, Egypt
2 Department of Biochemistry, Faculty of Dentistry, Cairo University, Giza, Egypt
3 Department of Oral Medicine and Periodontology, Faculty of Dentistry, Cairo University, Giza, Egypt

Date of Submission12-May-2018
Date of Acceptance02-Apr-2019
Date of Web Publication23-Sep-2019

Correspondence Address:
Dalia M Ghalwash
566r Eldyar Compound, New Cairo, Cairo 11835
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/tdj.tdj_42_18

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  Abstract 


Objective
Periodontal disease and diabetes mellitus are common disorders connected mainly by inflammation. While exploring and analyzing the several pathways linking diabetes and periodontitis, adipokines were prominent candidates amongst the biochemical parameters that could elucidate this interrelation. Therefore, the present investigation was conducted to evaluate the effect of nonsurgical periodontal treatment on the glycemic control of well-controlled patients with type 2 diabetes mellitus (T2DM) and chronic periodontitis (CP), as well as on the serum and GCF levels of visfatin, chemerin and adiponectin in systemically healthy subjects with CP, controlled T2DM patients with CP.
Patients and methods
Serum and GCF samples were collected at baseline and 3 months after therapy to evaluate levels of visfatin, chemerin and adiponectin using enzyme linked immunosorbent assay in all study groups. Group I: 15 healthy individuals. Group II: 30 CP patients. Group III: 30 periodontitis patients with T2DM.
Results
Significant reduction in serum and GCF levels of both chemerin and visfatin were recorded 3 months after therapy in periodontitis groups. On the contrary, significant elevation of serum and GCF levels of adiponectin were found. There was a direct positive correlation between percent change in serum glycosylated haemoglobin A1c level and serum visfatin and chemerin level and a negative correlation with serum adiponectin level.
Conclusion
This study demonstrates that serum and GCF levels of chemerin, visfatin and adiponectin play a crucial role in the pathogenesis of periodontitis and diabetes and reinforce the positive effect of periodontal therapy on the glycemic control.

Keywords: adiponectin, chemerin, diabetes, periodontitis, visfatin


How to cite this article:
Ghalwash DM, Shaker OG, Mahmoud EA. Local and systemic level of adipokines as markers of inflammation in periodontitis and type 2 diabetes mellitus after periodontal therapy. Tanta Dent J 2019;16:104-14

How to cite this URL:
Ghalwash DM, Shaker OG, Mahmoud EA. Local and systemic level of adipokines as markers of inflammation in periodontitis and type 2 diabetes mellitus after periodontal therapy. Tanta Dent J [serial online] 2019 [cited 2019 Nov 17];16:104-14. Available from: http://www.tmj.eg.net/text.asp?2019/16/2/104/267565




  Introduction Top


Periodontal disease is a multifaceted inflammatory condition where interactions occur between microbes and the host's immune-inflammatory response. Inappropriate inflammatory responses via proinflammatory cytokines produced in response to plaque biofilm bacteria result in periodontal tissue loss and alveolar bone destruction [1],[2].

Diabetes mellitus (DM) is a metabolic disease concomitant with raised blood glucose levels which causes numerous microvascular and macrovascular complications [3]. DM is now viewed as an inflammatory condition with a low-grade systemic inflammation, and elevated levels of various proinflammatory markers [4],[5], so presenting a vital risk factor for periodontal diseases in many epidemiological studies [6],[7].

In the same context, periodontitis can provide risk factor for diabetes, as chronic inflammation in periodontitis causes a systemic response to bacteria causing insulin resistance predisposing to DM or aggravating glycemic control and increasing the hazard of diabetic complications [8].

While exploring and analyzing the several pathways linking diabetes and periodontitis, the adipo (cyto) kine released from the adipose tissues were prominent candidates amongst the biochemical parameters that could elucidate this interrelation, as they have been linked with insulin resistance in diabetes and with pronounced progression of periodontal disease [3].

Adipose tissue secretes proinflammatory and anti-inflammatory adipokines involved in metabolic regulation and different local and systemic inflammatory processes [9]. Many factors can affect the balance of proinflammatory and anti-inflammatory adipocytokines as the presence of general inflammation, the metabolic status of the host, oxidative stress, smoking status, sex and age [10].

Various adipocytokines including visfatin, resistin, leptin, chemerin, adiponectin, has the capability to modulate inflammation and insulin sensitivity in diabetes and many immune and inflammatory conditions including periodontitis [2],[11].

Visfatin (visceral fat adipokine) is a 52-kDa protein produced mainly by white adipose tissue in the viscera and macrophages and was formerly recognized as pre-B-cell colony-enhancing factor [12],[13]. It is also produced by polymorphonuclear leucocytes in response to pathogens, it affects the synthesis of adhesion molecules, and stimulates monocytes to produce various cytokines as TNF-α, IL-1, IL-6, and IL-10 [11],[14]. Visfatin is considered as one of the important inflammatory mediators which has been linked with periodontal disease was also described in association with type 2 diabetes mellitus (T2DM) [15]. Raised plasma levels of visfatin have been recounted by Hammarstedt et al.[16] in a group of T2DM patients taking hypoglycemic agents. Pradeep et al.[15] reported that the individuals with periodontal disease had higher levels of visfatin compared to healthy subjects.

Another recognized adipokine is chemerin which are released from adipose tissue, fibroblasts, endothelium, epithelial cells, and keratinocytes [17],[18]. Chemerin regulates adipogenesis and metabolic homeostasis in adipocytes[19] and it has been linked with insulin resistance [20]. and involved in the control of proinflammatory mediators such as IL-1β and TNF-α [21],[22]. Beside this proinflammatory properties, Luangsay et al.[23] described chemerin as an inflammatory marker in their experimental study on a lung disease model.

Previous researches have related chemerin with some systemic markers of inflammation in DM and obesity. Hence, chemerin is a nominee in associating inflammation to metabolic disorders such as DM [5],[24],[25]. Furthermore, Patnaik et al.[5] proposed chemerin as a potential periodontal disease biomarker.

Adiponectin is an adipocytokine produced only by adipose tissue with many biological activities, like anti-inflammatory, antiatherogenic and insulin resistance-improving properties [26],[27]. Its serum level has shown to be inversely correlated to proinflammatory markers as CRP and TNF-α [28],[29]. Serum adiponectin has been reported to have a vital part in insulin sensitivity [30],[31] improving insulin resistance through suppressing systemic inflammation [32].

Existing knowledge of the major adipokines function does not provide enough information about their role in the interrelation of periodontitis T2DM. This could be due to the limited number of studies conducted. Hence, further studies concerning the effect of periodontal therapy on several adipokines should be implemented [33].

Therefore, the present investigation was conducted to (a) to compare the effect of nonsurgical treatment on clinical parameters in systemically healthy subjects with periodontitis versus controlled T2DM patients with chronic periodontitis (CP), (b) to evaluate the effect of nonsurgical therapy on the glycemic control of well-controlled T2DM patients and CP, (c) to assess the effect of nonsurgical therapy on the GCF and serum visfatin levels, chemerin and adiponectin in systemically healthy subjects with CP, controlled T2DM patients with CP. (d) To recognize the correlation between all the previously mentioned groups if there is any.


  Patients and Methods Top


Study design

Nonrandomized clinical trial.

Sample size calculation

Sample size was calculated based upon the results of Dogan et al.[34] using GCF Chemerin level as the primary outcome. The effect size (f) was large (f = 10), using α level = 0.05 and β level = 0.20 (80% power); the minimum estimated sample size will be five patients per group for a total of 15 patients. To compensate for a drop-out rate and the use of nonparametric tests the sample size was increased to be a minimum of seven patients per group for a total of 21 patients.

Sample size calculation was done using IBM SPSS (IBM Corp., Armonk, New York, USA) Sample Power Release 3.0.1.

Study population

This study included a total of 75 individuals recruited from Periodontology Clinic, Faculty of Dentistry, Cairo University. The faculty research ethics committee has approved the study in line with the Helsinki Declaration of 1975.

The study sample (n = 75) was divided into three groups as follow:

Group I: Healthy control consisted of 15 individuals who were systematically and periodontally healthy. Group II: CP consisted of 30 individuals who were systematically healthy with mild to moderate CP. Group III: consisted of 30 individuals who have T2DM with CP.

Eligibility criteria

Inclusion criteria included

Individuals with more than 30 years of age, having a minimum of 20 natural teeth not including third molars or teeth with extensive decay indicated for extraction. Both sexes were included.

The periodontally healthy groups had no clinical signs of inflammation [plaque index (PI) and gingival index (GI) scores = 0], probing depth (PD) of up to 3 mm with no radiographic evidence of alveolar bone loss.

CP was diagnosed according to the American Academy of Periodontology (1999) with PD less than 6 mm and clinical attachment loss (CAL) up to 5 mm with radiographic evidence of bone loss [35].

The diabetic patients were defined according to the diagnostic criteria of the American Diabetes Association as those with a diagnosis of at least 1 year T2DM with no other systematic diseases and were being treated with stable doses of antidiabetic agents. The glycemic condition of individuals diagnosed with T2DM was confirmed by glycosylated haemoglobin A1c (HbA1c) and considered well controlled as having their HbA1c less than 8% and more than 6.5% [36].

Exclusion criteria included

Aggressive periodontitis, pregnancy and lactation, current or former smokers within last 5 years, nonsurgical periodontal therapy in the previous 6 months or periodontal surgeries in the past 12 months, statins, anti-inflammatory, antimicrobial, immunosuppressive agents during the previous 6 months, any systemic disease that may modify the path of periodontal disease other than controlled T2DM (metabolic disorders, cardiovascular disease, hypertension, immune disorders, malignancies, etc.).

Eligible participants were informed of the aim of the study and benefits of being part of the study and signed a written informed consent.

Outcomes of the study

Primary outcome

CAL.

Secondary outcomes

Probing pocket depth, PI, GI, HbA1c, serum and GCF level of visfatin, serum and GCF chemerin level and serum and GCF level of adiponectin.

Periodontal examination and clinical evaluation

At baseline, all recruited individuals had undergone full periodontal examination and full periodontal charts as well as full mouth periapical radiographs were obtained for the diagnosis of the periodontal condition. The following clinical measurements were recorded at baseline and 3 months after periodontal treatment by calibrated well-trained examiner (E.A.) as follows:

CAL measured using Williams graduated periodontal probe as the distance from the CEJ to the base of the probable sulcus or pocket at six points (mesiobuccal, midbuccal, distobuccal, and mesiolingual, midligual and distolingual).

Probing pocket depth was measured as the distance from the gingival margin to the base of the gingival sulcus or pocket at six points (mesiobuccal, midbuccal, distobuccal, and mesiolingual, midligual and distolingual).

GI was recorded to estimate the degree of gingival inflammation [37]. PI was record to assess the patient's compliance with oral hygiene practices that may affect the clinical outcome measures and clinical response to periodontal therapy [38].

Periodontal therapy

Periodontitis patients had undergone supra as well subgingival scaling and root planing (SRP) using manual scalers and curettes (Hu-Friedy, Chicago, Illinois, USA) as well as ultrasonic scalers (Cavitron Select SPC; Dentsply Professional, York, Pennsylvania, USA), performed under local anesthesia. Treatment was completed over six visits (twice a week) each lasts for average 45 min. Patients were then given oral hygiene instruction including teeth brushing with modified bass technique and the use of interdental cleansing aids (dental floss and interdental brush) to be performed at least two times per day. No local or systemic antibiotics were prescribed for the patients. All procedures of periodontal therapy was done by the same investigator (E.A.)

Serum and GCF sampling

Serum and GCF samples were collected at baseline and 3 months from all groups. The samples were collected on the day after the patients had their periodontal assessment and diagnosis.

For individuals with healthy periodontium, GCF samples were collected from sites which showed no signs of inflammation (PI and GI = 0). For periodontitis patients, GCF samples were collected from the sites with most obvious signs with clinical inflammation and deepest PD with radiographic evidence of bone loss.

GCF samples at the target sites were collected as follows: all the supragingival plaque must be removed gently using sterile cotton roll, the tooth air dried gently and isolated with sterile cotton roll to avoid contamination with saliva. Paper strips are then placed gently into the sulcus or pocket until minimal resistance is felt and last for 30 s [39]. Any strip contaminated with saliva or blood was discarded.

Serum and GCF samples from each subject were then placed into sterile Eppendorf container, and immediately stored at −80°C until biochemical analysis.

Biochemical analysis

200 μl of phosphate buffer saline was added to the paper strip in the Eppendorf then vortex was done followed by centrifugation for 10 min at 3000g. The supernatant was used for estimation of visfatin, chemerin and adiponectin.

The level of visfatin was measured in GCF and serum samples by using enzyme linked immunosorbent assay (ELISA) kit provided by EIAab (China) catalog no.: E0638h. The ELISA technique is based on the competitive binding enzyme immunoassay. The microtiter plate supplied with the kit has been pre-coated with an antibody specific to C4a which competes with a stable quantity of biotin-labeled C4a for spots on a pre-coated monoclonal antibody specific to C4a during the reaction C4a this occurs in the sample and control. Surplus conjugate and any unbound sample or control are washed away from the plate. Next, addition and incubation of avidin conjugated to horseradish peroxidase is done for each microplate well. Followed by addition of TMB substrate solution to each well. The enzyme-substrate reaction is finished by adding a sulphuric acid solution and the color alteration is assessed by spectrophotometrically at a wavelength of 450 ± 2 nm. The C4a concentration in the samples is then identified by comparing the OD of the samples to the standard curve.

Human adiponectin concentration in GCF and serum was assessed utilizing Human adiponectin ELISA Kit provided from Assay Max Human adiponectin ELISA Kit catalog no. EA2500-1 (St Charles, Missouri, USA). A polyclonal antibody precise for adiponectin has been pre-coated with removable strips onto a 96-well microplate. Then adiponectin in controls and samples is sandwiched by biotinylated polyclonal antibody precise for adiponectin and the immobilized antibody, which is identified by a streptavidin-peroxidase conjugate. Then all unbound substance is washed away followed by addition of a peroxidase enzyme substrate. The development of color is seized and the color intensity is assessed.

The chemerin GCF and serum levels were assessed using the RD191136200R human chemerin ELISA. The kit was supplied by BioVendor – Laboratornímedicína (Guang Zhou, China). In the Biovendor Human Chemerin ELISA, standards, study samples and controls are pre-coated with polyclonal anti-human chemerin antibody and incubated in microtitration wells. Incubated 60 min then washed, polyclonal anti-human chemerin antibody was labelled with biotin then added to and incubated together with the captured chemerin for one hour. After additional washing, streptavidin-horseradish peroxidase conjugate is then added. The residual conjugate is permitted to react with the substrate solution (TMB) after 30 min incubation and the final washing step. The reaction is seized by adding acidic solution followed by assessment of absorbance of the resulting yellow product. The absorbance is related to chemerin concentration of. A standard curve is created by plotting absorbance values against chemerin concentrations in controls, and in unknown samples are identified using this standard curve.

Statistical analysis

Numerical data were explored for normality by checking the distribution of data and using tests of normality (Kolmogorov–Smirnov and Shapiro–Wilk tests). Age, PD, CAL and all markers data showed normal (parametric) distribution while PI, GI, changes and % changes in clinical parameters data showed non-normal (nonparametric) distribution. Parametric data were presented as mean and SD values while nonparametric data were presented as median and interquartile range values.

For parametric data; comparison between mean age values in the three groups was done by one-way analysis of variance (ANOVA). Repeated-measures ANOVA test was used to compare between mean PD, CAL and marker levels in the three groups and to study the changes after treatment within each group. Bonferroni's post-hoc test was utilized for pair-wise comparisons when ANOVA test is significant. Student's t-test was used to compare between CP and CP + DM groups. For nonparametric data; Mann–Whitney U-test was used for comparisons between CP and CP + DM groups. Kruskal–Wallis test was used to compare between the three groups. Dunn's test was used for pair-wise comparisons. Wilcoxon signed-rank test was used to study the changes after treatment within each group. Pearson's correlation coefficient was utilized to define significant correlations between markers and different variables.

Qualitative data were presented as frequencies and percentages. χ2-Test was used for the comparisons.

Receiver operating characteristic (ROC) curve was created to identify the cut-off values of all markers for differentiation between the different groups. Areas under the ROC curve were compared using z-statistic. The significance level was set at P value up to 0.05.

Statistical analysis was performed with IBM SPSS (IBM Corp., Armonk, New York, USA) statistics version 30 for Windows. ROC curve analysis was performed with MedCalc version 11.3 for Windows (MedCalc Software bvba).


  Results Top


This study was conducted to assess the serum and GCF level of various adipokines, namely chemerin, visfatin and adiponectin as key regulators of inflammation in systemically healthy subjects with periodontitis compared to T2DM patients with periodontitis and assess the change of these levels after nonsurgical periodontal treatment.

A total of 75 subjects participated in this study divided in the following manner: group I composed of 15 (eight males and seven females) systemically healthy subjects with healthy periodontium with mean age of 39.4, group II composed of 30 (12 male and 18 females) individuals with periodontitis with mean age of 38.1, group III composed of 30 (10 males and 20 females) well controlled T2DM patients with periodontitis with mean age of 46.7.

No statistically significant difference was found between sex distributions in the three groups. As regards age, no statistically significant difference was found between periodontitis and control groups; where both showed statistically significantly lower mean age values than periodontitis with DM group.

The results of the clinical parameters at baseline and at the end of 3 months are shown in [Table 1]. In PI, in both groups II and III, there was a statistically significant decrease in PI scores postoperatively, however group II showed statistically significantly lower % reduction in PI than group III. As regards GI, there was a statistically significant decrease in GI scores postoperatively, in both groups II and III with no statistically significant difference between % reductions in GI in the two groups.
Table 1: Descriptive statistics and results of comparisons in clinical parameters between groups II and III

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Both groups I and II showed there was a statistically significant reduction in PD measurements and gain in CAL postoperatively with no statistically significant difference in % reductions in PD or % gain in CAL between the two groups.

Biochemical results

Glycosylated haemoglobin A1c

A statistically significant reduction was revealed in serum HbA1c in group III from 6.32 ± 0.45 to 4.6 ± 0.43 3 months post-treatment in group III with P value less than 0.0001.

A direct positive correlation was found between percent change in serum HbA1c level and serum visfatin and chemerin level, while there was a negative correlation between percent change in serum HbA1c level and serum adiponectin level.

The mean % changes in different markers is represented by a bar chart in [Figure 1].
Figure 1: Bar chart representing mean % changes in different markers.

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Visfatin

At baseline serum visfatin level showed statistically significant higher mean value in group III 62.4 ± 6 ng/ml followed by groups II 55.8 ± 6.1 ng/ml compared to the control group 7.9 ± 1.8 ng/ml. Meanwhile, at 3 months post-treatment, groups II 34.1 ± 6.7 ng/ml and III 37.5 ± 5 ng/ml showed nonstatistically significant reduction in serum visfatin level with no statistically significant difference in % reduction in visfatin levels between both groups −38.6 ± 12.2 and 39.9 ± 6.2.

In GCF, group III showed the statistically significantly highest mean visfatin level both at baseline 76.6 ± 12.3 ng/ml and post-treatment 41.1 ± 8.4 ng/ml, followed by group II 52.8 ± 10 and 30.4 ± 9 ng/ml with the least mean level of visfatin shown in the control group 11.4 ± 2.7 ng/ml. In both groups II and III, there was a nonstatistically significant reduction in visfatin level at 3 months post-treatment. No statistically significant difference in mean % reduction in visfatin level was observed, however group II showed statistically significantly lower mean reduction (42.7 ± 12.1) in visfatin level than group III (−46.3 ± 5.3).

Chemerin

At baseline, group III showed the statistically significantly highest mean serum chemerin level 44.2 ± 7.2 ng/ml followed by group II 33.8 ± 4.7 ng/ml, while control group showed the statistically significantly lowest mean chemerin level 18.8 ± 1.9 ng/ml. In group II 20 ± 4.9 ng/ml there was a statistically significant reduction in serum chemerin level post-treatment and a nonstatistically significant reduction in serum chemerin level in group III 23 ± 4.2 ng/ml, with no significant difference between them. Group II showed statistically significantly lower % reduction (−41.4 ± 8.3) in chemerin level than group III (−48 ± 3.9).

In GCF, group III showed the statistically significantly highest mean chemerin level both at baseline 190 ± 32 ng/ml and post-treatment (39.9 ± 29 ng/ml, followed by group II 169.4 ± 26.7 and 118.1 ± 21.2 ng/ml with the least mean level of chemerin shown in the control group 31.1 ± 4.3 ng/ml. In both groups II and III, there was a nonstatistically significant reduction in chemerin level at 3 months post-treatment with group II showing statistically significantly higher % reduction in chemerin level (−30.5 ± 3.7) than group III (−26.7 ± 3.9).

Adiponectin

In serum, control group showed the statistically significantly highest mean serum adiponectin level 98.9 ± 9.7 ng/ml followed by group II 69.2 ± 6.3 ng/ml, while group III showed the statistically significantly lowest mean serum adiponectin level 58.8 ± 5.1 ng/ml. In both groups II and III, there was a nonstatistically significant increase in adiponectin level post-treatment with values being 91.3 ± 7.1 and 85.2 ± 6.9 ng/ml, respectively. However, group III (45.5 ± 13.3) showed statistically significantly higher mean % increase in serum adiponectin level than group II (32.3 ± 9).

Regarding GCF adiponectin level, there was no statistically significant difference between group II 4.9 ± 1.3 ng/ml and group III 2.6 ± 0.5 ng/ml; both showed statistically significantly lower mean adiponectin level than control group 16.6 ± 2.4 ng/ml.

Post-treatment, there was a statistically significant increase in adiponectin level in group II 14 ± 2.9 ng/ml compared to the nonstatistically significant increase in adiponectin level in group III 10.5 ± 2.1 ng/ml, with no statistically significant difference between them or between group II and control group 16.6 ± 2.4 ng/ml. However, same as in serum, group III (625.9 ± 91.7) showed statistically significantly higher mean % increase in serum adiponectin level than group II (263.5 ± 38.3).

Differentiation between chronic periodontitis and control groups

ROC curve analysis of different markers for differentiation between CP and control groups is presented in [Figure 2].
Figure 2: Receiver operating characteristic (ROC) curves of the six markers for differentiation between chronic periodontitis and control groups.

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All markers showed 100% diagnostic accuracy except for adiponectin in serum which showed a diagnostic accuracy of 97.8% [Table 2].
Table 2: Cut-off values for different markers and the corresponding sensitivity, specificity, predictive values, diagnostic accuracy, area under the receiver operating characteristic curve and 95% confidence interval of the area under the curve for differentiation between chronic periodontitis and control groups

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Pair-wise comparison between areas under the ROC curve of the six markers showed nonstatistically significant difference.

Differentiation between chronic periodontitis and chronic periodontitis + diabetes mellitus groups

ROC curve analysis of different markers for differentiation between CP and CP + DM groups is presented in [Figure 3].
Figure 3: Receiver operating characteristic (ROC) curves of the six markers for differentiation between chronic periodontitis (CP) and CP + diabetes mellitus (DM) groups.

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Visfatin in GCF showed the highest diagnostic accuracy (93.3%) while chemerin in GCF showed the lowest diagnostic accuracy (70%) [Table 3].
Table 3: Cut-off values for different markers and the corresponding sensitivity, specificity, predictive values, diagnostic accuracy, area under the receiver operating characteristic curve and 95% confidence interval of the area under the curve for differentiation between chronic periodontitis and chronic periodontitis+diabetes mellitus groups

Click here to view


Pair-wise comparison between areas under the ROC curve of the six markers showed a statistically significant difference between (visfatin in GCF and visfatin in serum) (visfatin in GCF and chemerin in GCF), (chemerin in GCF and chemerin in serum) as well as (chemerin in GCF and adiponectin in serum).


  Discussion Top


Periodontal disease and DM are common disorders connected mainly by inflammation. The local production of various proinflammatory mediators occurring in periodontal disease is exaggerated in presence of diabetes, thus accelerating disease progression, increasing insulin requirements and impairing the glycemic control [6].

This study was conducted to assess the effect of nonsurgical periodontal therapy on the level of various adipokines, namely chemerin, visfatin and adiponectin as key regulators of inflammation in serum as well as in GCF. GCF sample is an optimal medium for analyzing the biochemical nature of the host response in periodontal disease since it consists of local periodontal inflammatory exudate [40]. Serum and GCF levels of the three adipokines were measured at baseline and 3 months after nonsurgical periodontal treatment in all study groups.

Results of this study showed that nonsurgical periodontal treatment improved the glycemic control in T2DM with CP patients with statistically significant reduction in serum HbA1c from 6.32 ± 0.45 to 4.6 ± 0.43 3 months post-treatment with P value less than 0.0001. There are conflicting results in the literature on whether or not periodontal therapy impacts glycemic control with T2DM.

Our results was in agreement with those of Sun et al.[41] who noted that HbAlc was significantly decreased in the T2DM with periodontitis group after 3 months after periodontal therapy. These findings confirmed the hypothesis that periodontal therapy reduces clinically evident inflammation in addition to improving the glycemic control, reducing insulin resistance and improving β cell function in T2DM patients.

On the other hand, Jones et al.[42] found periodontal therapy has no statistically significant effect on glycemic control. This might be accredited to considerable dissimilarities in methodology, sample sizes and nature of the studied groups included.

Adipose tissue is now acknowledged as an active endocrine tissue that produces many adipokines responsible for regulating inflammation and lipid metabolism [9]. Chemerin is a novel adipokine that contributes to both immune and metabolic dysfunction.

Recent research indicated that inflammatory cytokines could stimulate chemerin generation from adipocytes such as CRP, IL-1b, TNF α, IL-6) and prostaglandins, which is mirrored by the raised levels of serum chemerin seen in periodontitis and DM sufferers and this abnormal chemerin generation might aggravate the progression of both conditions [6],[43],[44]. This increase in serum chemerin levels was evident in the present study in both periodontitis group and periodontitis with DM group in which the chemerin level increase was more pronounced. On the other hand, these two groups recorded a significant reduction in chemerin level at 3 months post-treatment, but periodontitis group showed statistically significantly lower % reduction in chemerin level than periodontitis with DM group. These results were also in harmony with a study performed by Jose et al.[45] where the serum levels of chemerin were reported to be significantly higher in the periodontitis group compared to healthy controls and they concluded that chemerin levels can be correlated with higher tissue damage and higher levels of serum chemerin can be a potential marker of periodontal tissue destruction.

Furthermore, in this study, periodontitis with DM group showed the statistically significantly highest mean chemerin level in GCF both at baseline and post-treatment, followed by periodontitis group with the least mean level of chemerin shown in the control group. Furthermore, there was a statistically significant reduction in chemerin GCF level at 3 months post-treatment in both periodontitis and periodontitis with DM groups with periodontitis group showing statistically significantly higher % reduction in chemerin level than periodontitis with DM group.

In line with these results a study by Patnaik et al.[5] evaluated chemerin levels in GCF and tear-fluid in periodontitis and T2DM. They revealed an elevated chemerin levels in both fluids from periodontally healthy individuals to periodontitis to T2DM with periodontitis.

Similarly, Doǧan et al.[34] discovered that GCF chemerin levels were higher amongst CP patients than healthy groups and higher amongst the DM-CP group than the periodontitis group. In accordance with our results they also indicated that nonsurgical periodontal treatment was beneficial to the reduction of chemerin levels, therefore could significantly alleviate periodontal inflammation.

Results of this study also discovered that there was a direct positive correlation between percent change in serum HbA1C level and serum chemerin level. In accordance with these results, Doǧan et al.[34] reported a statistically valuable positive correlation of chemerin levels with HbA1c for all the studied groups. Thus, we could propose the presence of a direct relation between serum chemerin level and the glycemic control in diabetic individuals.

The present investigation revealed that both serum and GCF visfatin levels recorded the highest values in periodontitis with DM group followed by periodontitis group while lowest values were encountered in the control group. In a similar outcome other studies evaluated serum and GCF concentrations of visfatin in periodontal diseases and it was eventually concluded that concentrations of visfatin in the serum and GCF progressively increased amongst patients with periodontitis. Also visfatin levels were found to be greater in periodontitis patients and DM compared to subjects with only periodontitis [7],[15].

Fukuhara et al.[13] linked visfatin with T2DM reporting it to function analogous to insulin. They indicated that properties of visfatin and insulin are alike both in-vivo and in-vitro as administration of high doses of visfatin reduced plasma glucose levels in both. Moreover visfatin was found to activate insulin signaling through insulin receptor but in a different way than insulin do. Also, this concurrent studies also revealed the role of visfatin in the inflammatory process [16],[46].

Significant reduction in serum and GCF visfatin levels was evident in this study at 3 months post-treatment in both periodontitis and periodontitis with DM groups. These findings were in harmony with Raghavendra et al.[47] and Türer et al.[2] who stated that visfatin levels significantly amplified with the severity of periodontitis and reinforced that visfatin is a possible periodontal disease biomarker in serum and GCF.

In this investigation, visfatin levels displayed a significant correlation with HbA1c levels. The mean HbA1c levels of the diabetic patients in the present investigation were comparable to the HbA1c levels of diabetics in a study performed by Lopez et al., where it was 6.9 ± 0.12. Furthermore, in line with our results they stated that visfatin levels were highly correlated with the HbA1c levels. Also diabetics are subjected to altered lipid metabolism and subclinical inflammation caused by reduced activity of insulin leading to increase in visfatin levels regardless of their glycemic control [48],[49].

Our results showed that serum adiponectin level was significantly higher in control group than in periodontitis group. This goes in line with the study of Zimmermann et al.[50] where adiponectin serum levels were lower in CP groups, reflecting the influence of periodontal inflammation on this anti-inflammatory marker level.

Saito et al.[51] found the association of periodontitis with a reduced level of adiponectin compared with those with healthy periodontium did not reach statistical significance. Furugen et al.[52] found that serum adiponectin levels was lower in periodontitis group than control group. These results are similar to results of Nagano et al.[53] where total adiponectin levels between periodontitis and control subjects showed no significant difference.

Evidence proposes a trend toward a reduction in both serum levels and function of adiponectin in periodontitis patients [54]. Our findings emphasize the anti-inflammatory biologic functions of adiponectin, which are linked to the stimulation of anti-inflammatory cytokines, suppression of proinflammatory mediators, and control of inflammation [55],[56].

Diabetic patients with periodontitis showed significantly lower serum adiponectin level than do those who are nondiabetic. Similarly, Lahariya et al.[57] found serum levels of adiponectin in the diabetics with periodontitis are slightly lower than in nondiabetics with periodontitis. Their study, same like ours, also has demonstrated significant difference in adiponectin among T2DM and periodontitis group, nondiabetes and periodontitis group, and healthy control group. This finding means that periodontitis could influence the level of adipokines in serum and the effect would be enhanced combining with T2DM.

Nonsurgical periodontal treatment resulted in a significant elevation of serum level of adiponectin in periodontitis patients. Kardesler et al.[58] reported significant enhancements of periodontal status and glycemic control with increased serum adiponectin after periodontal therapy.

Similarly, Sun et al.[41] found that adiponectin increased significantly compared to those without periodontal intervention three months after periodontal intervention and this was correlated with the reduction in HbA1c level. They assumed that periodontal therapy was able through control of the inflammatory process and accompanied by elevation of serum adiponectin to improve glucose control and improve insulin sensitivity.

Gonçalves et al.[59] in their study reported that although SRP have produced clinical enhancements, it did not affect adiponectin levels in CP patients which was not in line with our results. This could be attributed to the inclusion of deep pockets of at least 7 mm the majority of them were left with residual pockets (PD ≥ 5 mm) following nonsurgical periodontal treatment, these residual sites could be sufficient to sustain a systemic load able to maintain the adiponectin level unaffected despite periodontal therapy [59].

There is limited available data in the literature about GCF adiponectin level in periodontitis patients. In this study, CP nondiabetic patients showed higher GCF adiponectin level than diabetic patients with no significant difference between both groups. On the contrary, Natalina et al.[60] found adiponectin GCF levels in T2DM group was higher than in the nondiabetic group although this did not reach statistical significance.

Periodontal therapy resulted in increased GCF adiponectin level in both periodontitis groups with no significant difference between them. Goncalves et al.[59] reported that a significant elevation in the GCF adiponectin level was perceived in CP nonobese patients following SRP. This increase in adiponectin level may propose a more favorable status of the patients' immunological response perhaps due to their overall improved response to SRP at microbiological and clinical levels.


  Conclusion Top


Our study demonstrates that serum and GCF levels of chemerin, visfatin and adiponectin play a crucial role in the pathogenesis of periodontitis and diabetes and changes in their level could be indicative of disease activity.

Acknowledgements

Supported by Cairo and BUE Universities.

D.G. designed the study and wrote the manuscript, E.A. collected the samples, performed the clinical examinations and periodontal treatment and took part in writing the manuscript. O.S. did the biochemical analysis. All authors read and approved the manuscript.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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