Effect of non-surgical periodontal therapy on salivary resistin and chemerin levels in type 2 diabetes mellitus with chronic periodontitis

Introduction

Periodontal Disease (PD) is a chronic inflammatory disease that has been identified as the leading cause of tooth loss. Because of the related systemic inflammatory response, the effect of PD may not be restricted to the mouth cavity, but may have systemic implications.1

Diabetes Mellitus (DM) is demonstrated by unusually high glucose levels in the blood due to impaired secretion or action of insulin or both. Diabetes is a contributing factor in deteriorating of PD. Similarly, periodontitis is seen more in diabetics. PD is considered to be the sixth complication of DM. The failure of the body's immune system to completely destroy the source of inflammation, such as microorganisms, which causes a persistent inflammatory reaction due to systemic overexpression of pro-inflammatory cytokines such interleukins (IL-1, 4, 6, 8, and 10), tumour necrosis factor (TNF-), and prostanoids (PGE2), is attributed to the coexistence of periodontitis in diabetes individuals. This persistent inflammatory response is the main cause of A two-way relationship exists between PD and DM.2

Adipose tissue is a metabolically active and complicated endocrine organ that secretes bioactive chemicals known as adipokines. As with periodontitis and diabetes, the interaction of pro-inflammatory and anti-inflammatory adipokines can result in a low-grade inflammatory disease.3

Resistin is a 12-kDa adipokine with the function of resisting insulin. Resistin expression appears to be higher in diabetes and inflammatory disorders. Resistin, a proinflammatory molecule, increases the production and secretion of pro-inflammatory cytokines (TNF-, IL-6, IL-12) and monocyte chemoattractant protein (MCP-1). Because diabetes and periodontitis are both considered inflammatory disorders, resistin may have a pathogenic function in both diseases.4

Chemerin is a pro-inflammatory adipocytokine generated by adipose tissue, liver, epithelial cells, endothelium, fibroblasts, and keratinocyte. Chemerin's inflammatory effect is mediated through the generation of pro-inflammatory cytokines as well as the promotion of inflammatory cell chemotaxis to the site of inflammation. It also recruits innate immune cells and functions as an antibacterial peptide against infections. Chemerin levels in saliva were found to be greater in periodontitis patients; as a result, chemerin has been recommended as a biomarker for periodontitis.5

Therefore, this study aims to estimate and compare salivary resistin and chemerin level in healthy, chronic periodontitis (CP) and type 2 DM with CP.

Materials and Methods

The ethics committee approved this study, which was conducted at the Department of Periodontology at Seema Dental College and Hospital in Rishikesh, Uttarakhand. With the consent to treatment agreement, the patients were given a full verbal and written summary of the therapy's risk and benefit.

Results

Biochemical variables

Comparison of the baseline biochemical variables between the groups shows that baseline resistin and chemerin is higher in Group C and Group A respectively. Comparison of the 3-month biochemical variables between the groups shows that 3-month resistin and chemerin is higher in Group C and Group A respectively. There was non-significant difference in mean resistin and chemerin score at 3 months between Group A, Group B and Group C. (Table 1) On intragroup comparison, group B and C showed statistically significant reduction for salivary resistin and chemerin (p<0.05) Group A showed statistically significant reduction for salivary resistin (p<0.05) (Table 2, Table 3, Table 4)

Correlation analysis showed correlation between PPD and CAL with resistin for group A. For group B, gingival index and chemerin showed statistically significant correlation. HbA1c with chemerin showed a strong correlation for group C. (Table 5, Table 6, Table 7)

Table 1

Intergroup comparison between clinical variables

Variable	Group	Mean±SD	ANOVA	p value
Plaque Index	Group A	0.34±0.45	20.782	0.000
	Group B	1.13±0.33
	Group C	1.08±0.32
Gingival Index	Group A	0.05±0.12	76.373	0.000
	Group B	1.15±0.41
	Group C	1.12±0.54
Probing Pocket Depth	Group A	0.66±0.31	55.605	0.000
	Group B	2.21±0.57
	Group C	2.20±0.45
Clinical Attachment Level	Group A	0.12±0.13	44.441	0.000
	Group B	2.30±0.79
	Group C	2.29±1.27
HbA1c	Group A	5.16±0.24	86.063	0.000
	Group B	5.22±0.31
	Group C	6.98±0.63
Salivary Resistin	Group A	4742.16±1943.51	0.472	0.627
	Group B	4141.13±1873.45
	Group C	4169.30±1916.93
Salivary Chemerin	Group A	82.10±40.10	2.201	0.123
	Group B	59.83±23.32
	Group C	74.47±21.53

Table 2

Intragroup comparison for group A

Variable	Time interval	Mean±SD	Mean difference	t value	p value
Plaque Index	Baseline	0.46±0.45	0.11±0.25	1.76	0.099
	3 Months	0.34±0.45
Gingival Index	Baseline	0.06±0.11	0.05±0.10	0.21	0.832
	3 Months	0.05±0.12
Probing Pocket Depth	Baseline	0.78±0.36	0.11±0.10	4.23	0.001
	3 Months	0.66±0.31
Clinical Attachment Loss	Baseline	0.19±0.20	0.67±0.84	3.08	0.008
	3 Months	0.12±0.13
HbA1c	Baseline	5.02±0.28	0.14±0.15	3.60	0.001
	3 Months	5.16±0.24
Salivary Resistin (pg/nl)	Baseline	6013.45±1880.38	1271.28±946.35	5.20	<0.001
	3 Months	4742.16±1943.51
Salivary Chemerin (pg/ml)	Baseline	122.92±114.09	40.82±10.50	1.50	0.155
	3 Months	82.10±40.10

Table 3

Intragroup comparison for group B

Variable	Time interval	Mean±SD	Mean difference	t value	p value
Plaque Index	Baseline	1.71±0.30	0.57±0.25	8.83	0.000
	3 Months	1.13±0.33
Gingival Index	Baseline	1.88±0.51	0.72±0.44	6.29	0.000
	3 Months	1.15±0.41
Probing Pocket Depth	Baseline	2.91±0.54	0.69±0.41	6.51	0.000
	3 Months	2.21±0.57
Clinical Attachment Loss	Baseline	3.12±0.91	0.81±0.43	7.22	0.000
	3 Months	2.30±0.79
HbA1c	Baseline	5.27±0.38	0.46±0.22	0.81	0.432
	3 Months	5.22±0.31
Salivary Resistin (pg/nl)	Baseline	6291.36±2569.24	2150.23±1724.07	4.83	0.000
	3 Months	4141.13±1873.57
Salivary Chemerin (pg/ml)	Baseline	109.74±51.61	49.90±56.76	3.40	0.004
	3 Months	59.83±23.32

Table 4

Intragroup comparison for group C

Variable	Time interval	Mean±SD	Mean difference	t value	p value
Plaque Index	Baseline	1.53±0.32	0.45±0.29	5.85	0.000
	3 Months	1.08±0.32
Gingival Index	Baseline	1.61±0.70	0.49±0.34	5.48	0.000
	3 Months	1.12±0.54
Probing Pocket Depth	Baseline	2.83±0.53	0.62±0.44	5.49	0.000
	3 Months	2.20±0.45
Clinical Attachment Loss	Baseline	3.60±1.18	0.67±0.84	7.43	0.000
	3 Months	2.29±1.27
HbA1c	Baseline	7.12± 0.73	1.40±0.34	1.57	0.137
	3 Months	6.98±0.63
Salivary Resistin (pg/nl)	Baseline	6906.94±1473.91	2737.64±1854.64	5.71	0.000
	3 Months	4169.30±1916.93
Salivary Chemerin (pg/ml)	Baseline	274.12±330.25	199.64±324.88	2.38	0.032
	3 Months	74.47±21.53

Table 5

Correlation between clinical variables and salivary resistin and chemerin for group A

	Resistin		Chemerin
Variables	Correlation coefficient	p value	Correlation coefficient	p value
PI	0.353	0.196	-0.386	0.156
GI	0.275	0.321	-0.335	0.223
PPD	0.629	0.012	-0.440	0.101
CAL	0.564	0.029	-0.177	0.529
HbA1c	-0.499	0.058	-0.168	0.550

Table 6

Correlation between clinical variables and salivary resistin and chemerin for group B

	Resistin		Chemerin
Variables	Correlation coefficient	p value	Correlation coefficient	p value
PI	0.046	0.869	0.318	0.248
GI	0.243	0.383	0.632	0.011
PPD	0.257	0.355	0.082	0.771
CAL	0.075	0.791	0.154	0.585
HbA1c	0.167	0.553	-0.319	0.247

Table 7

Correlation between clinical variables and salivary resistin and chemerin for group C

	Resistin		Chemerin
Variables	Correlation coefficient	p value	Correlation coefficient	p value
PI	-0.381	0.162	0.014	0.960
GI	-0.377	0.166	0.011	0.970
PPD	0.093	0.742	0.136	0.630
CAL	-0.209	0.454	0.046	0.869
HbA1c	0.513	0.050	-0.638	0.011

Figure 1

Healthy patients a: Pre-operative (baseline); b: Post-operative (3 months)

Figure 2

CP a: Pre-operative (baseline); b: Post-operative (3 months)

Figure 3

CP + DM a: Pre-operative (baseline); b: Post-operative (3 months)

Discussion

Periodontitis is characterised by gingival bleeding, alveolar bone loss, and attachment loss. Proinflammatory cytokines released locally in response to the bacterial plaque are likely to alter the levels of proinflammatory biomarkers. As a result, periodontitis may have a higher impact on diabetic's systemic inflammatory condition. Diabetes, on the other hand, is a well-known risk factor for PD, which causes greater periodontal tissue degradation.6

Adipose tissue secretes adipokines which are a collection of bioactive peptides or proteins.7 Sgolastra et al. found that adipokines play an important role in pathogenesis of periodontitis in diabetic patients and reinforced that periodontal therapy can improve diabetes control.8

In the present study, mean difference in PI, GI, PPD and CAL on intragroup comparison from baseline to 3 months were highly significant for group C and B with p<0.05. Shehab RSA et al. showed statistical reduction in CAL after NSPT in all three groups.9

On intergroup comparison, mean PI for baseline and 3 months was statistically highly significant among group B and C when compared to group A (p<0.001) but was non-significant when comparing group B and C. On intergroup comparison, mean GI, PPD and CAL for baseline and 3 months was statistically highly significant among group B and C when compared to group A. (p<0.001). When diabetics with periodontitis and non-diabetics with periodontitis were compared to healthy control groups, Lahariya SN et al found a significant difference in PI, GI, PPD, and CAL.10 Similar results were seen by Furugen R et al for PPD and CAL when they compared healthy group with periodontitis and reported a statistically significant result.11

The decrease in PI, GD, PPD, CAL could be due to NSPT which reduces local inflammation.12

In the present study, mean difference in HbA1c on intragroup comparison from baseline to 3 months significantly increased for group A with p<0.05. Mean difference in HbA1c on intragroup comparison from baseline to 3 months was not statistically significant for group B and C. Ghalwash DM found a reduction in HbA1c in diabetic periodontitis group post‑treatment which was statistically significant.13

On intergroup comparison, mean HbA1c for baseline and 3 months was statistically highly significant among group A and group B when compared to group C. (p<0.001). Similar findings were reported by Weigert J et al, they found a statistically significant difference between T2DM and healthy normal weight subjects at baseline.14

In the present study, mean difference in resistin level on intragroup comparison from baseline to 3 months were highly statistically significant for all the groups with p<0.001. Similar results were seen by Furugen R et al., they compared healthy group with periodontitis at baseline and reported a statistically significant result.11

On intergroup comparison, mean resistin level for baseline and 3 months was not statistically significant among group A, B and C. Hiroshima Y et al found elevated levels of GCF resistin in CP and diabetic periodontitis patients as compared to healthy individuals.15 On the contrary, a statistically significant difference in resistin level was seen between healthy and periodontitis group in a study by Saito et al.16 Similar results were seen in a study conducted by Weigert J et al. when comparing T2DM and healthy normal weight.14

In the present study, mean difference in chemerin level on intragroup comparison from baseline to 3 months were highly statistically significant for all the groups with p<0.001. In a study by Ziaei et al, similar reduction in salivary chemerin levels was seen for diabetic periodontitis group.6

On intergroup comparison, mean chemerin level for baseline and 3 months was not statistically significant among group A, B and C. Similar results were published by Godlewska U et al., they compared healthy group with periodontitis and a non-significant result was obtained.17 Contrary to our findings, El-Mesallamy et al found difference between control and type 2 DM at baseline for serum chemerin level to be statistically significant.18

In a study conducted by Akram Z et al., none of the clinical periodontal factors were found to be linked with changes in salivary resistin levels.12 Ghalwash DM et al. discovered a direct link between serum visfatin and chemerin levels and the percent change in serum glycosylated haemoglobin A1c.13 Devanoorkar A et al. discovered a positive link between serum resistin levels and PI, GI, BI, PPD, but a negative correlation with CAL, which contradicted the findings of the current investigation. 19

Changes in periodontal variables did not correspond with changes in salivary resistin levels following NSPT, according to our findings. It's possible that this result is due to the fact that only shallow and moderately deep periodontal pockets were chosen. Salivary resistin levels have been studied in several research, although only in individuals with widespread and progressing illness.12

Because periodontitis is a chronic inflammatory disease that requires therapy to resolve, as well as a systemic inflammatory state caused by hyperglycemia, the levels for resistin and chemerin have decreased following NSPT.9 The fact that resistin is primarily produced by polymorphonuclear leukocytes and macrophages in inflammatory circumstances, including periodontitis, might explain the rise in these adipokines in patients with periodontitis. Human resistin enhances the synthesis and secretion of TNF-α and IL-12, resulting in a positive feedback cycle that induces its own creation. Second, potential pathogens such as Porphyromonas gingivalis produce resistin from neutrophils in response to a lipopolysaccharide stimulation.20 However, because the concentration of this adipokine in saliva is lower than in serum, the alterations are minor.16 The reduction in parameters and salivary adipokine levels implies that periodontal inflammation and insulin resistance may be linked.10

Conclusion

The study results concluded that, salivary resistin and chemerin levels are higher in diabetic periodontitis subjects followed by periodontitis subjects and least in healthy subjects. Non-surgical periodontal therapy reduces all variables, resistin and chemerin levels. Salivary resistin and chemerin levels can be used as probable biomarker to assess the outcome following NSPT.

Source of Funding

None.

Conflict of Interest

The authors declare no conflict of interest.