Introduction

Periodontitis is an inflammatory disease resulting from the infection and interaction of specific subgingival bacterial species with components of the host immune response, influenced by many systemic factors in disease. Systemic factors play a major role in the pathogenesis and progression of periodontal disease. Many systemic factors have been implicated for periodontal disease like diabetes mellitus, obesity and coronary heart diseases (1). Overweight is recently considered as one of the risk factor for periodontal disease. There are many studies showing significant correlation between overweight and prevalence of periodontitis (2-4). Clarke et al. (1995) proposed a model in which they focused on personal risk factors like smoking, alcohol consumption and overweight/ obesity and concluded that obesity can act as risk factor for periodontal disease (5). Robert et al. (2005) also stated that increased BMI is related to severe periodontal attachment loss (6).

It has also been shown that lipid levels are directly associated with extent of periodontal destruction (7). There are many studies showing correlation between hyper-triglyceridemia and periodontal health (8, 9). Kuramitsu et al. (2003) found that Porphyromonas gingivalis (Pg) in presence of lipid induces foaming of macrophages (10). Lipids may interact directly with the macrophage cell membrane interfering with membrane bound receptors and enzyme systems. Hence altering macrophage gene expression for essential polypeptide growth factors and pro-inflammatory cytokines: like Tumour Necrosis Factor-α and Interleukin 1-β (11, 12). These are believed to be associated with periodontal destruction (13, 14). The aim of the present study was to correlate Triglyceride levels and periodontal disease status in normal weight and overweight/ obese individuals.

Materials and Methods

Sixty patients visiting the outpatient section, Department of Periodontics, H.K.E society’s S. Nijalingappa Institute of Dental Sciences and Research, Gulbarga, Karnataka, India were screened and included in the study. Patients of both genders of age 18 years and above, having at least one site with both a probing depth of > 4 mm and a clinical attachment loss of > 3 mm (to diagnose as Periodontitis) were included. Patient with nephrosis, diabetes mellitus, endocrine disturbances, patients who had previously undergone periodontal treatment, pregnant women, smokers, and patient taking any medication for hyperlipidemia were excluded from the study.

Body weight in kilogram and height in meter were recorded and BMI was calculated for each individual using the formula: body weight divided by the square of height (15). Patients were divided into two group, Group – I with thirty patients of normal weight (BMI < 25 for Normal weight) and Group-II with thirty patients of overweight/ obese (BMI > 25 for Overweight/ obese) depending on BMI decided by world health organization criteria (15).

Periodontal status was assessed by using Community Periodontal Index of Treatment Needs (CPITN), using a CPITN probe. All records were taken by single examiner. The highest CPITN score found among all examined sites were concluded as CPITN score for that individual.

Triglyceride levels were assessed using “Wako and the modification by Mc Gowan et al. (1983) (17) et al. method.” In these methods Triglycerides is converted into quinoneimine dye. Quinoneimine dye is formed at a rate proportional to Triglyceride concentration in the serum. Since it is a coloured compound it can be detected and quantified by a colorimeter (16,17). Patients abstained from eating or drinking, except water for 12 hrs and three millilitres of venous blood was collected using a sterile disposable syringe and the blood sample was allowed to clot, serum was extracted and stored at 4°c till it was subjected to above mentioned Triglyceride estimation test.

Statistical analysis

Results

Mean CPITN score in the Group-I was 3.33 with a standard deviation of 0.48 whereas the mean CPITN score in Group-II was 3.66 with a standard deviation of 0.48 as shown in Table (1).

Figure 1

Table (1): Comparison of Group-I and Group-II with respect to CPITN scores by Mann Whitney U test

When mean CPITN score were compared between groups, it showed that mean CPITN score was significantly greater in Group-II than that in Group-I as shown in Figure- 1.

Figure 2

Figure- 1: Comparison of CPITN scores between Group-I and Group-II

Relationship between Triglyceride levels and CPITN scores was calculated using Karl Pearson correlation coefficient as shown in Table (2).

Figure 3

Table (2): Correlation between CPITN and Triglyceride scores (Karl Pearson’s correlation coefficient)

Mean CPITN score was significantly correlated to mean Triglyceride levels. The mean Triglyceride level in Group-I was 109.80 with a standard deviation of 71.93, and in Group- II, the mean Triglyceride level was 150.80 with standard deviation of 72.84 (Table 3).

Figure 4

Table-3: Comparison of Group-I and Group-II BMI with respect to Triglyceride scores by students‘t’-test

Triglycerides levels were compared between Group-I and Group-II and found that Group- II had significantly higher amount of Triglycerides levels than Group- I (Figure-2).

Figure 5

Figure-2: Comparison of Triglyceride levels between Group I and Group II.

Discussion

Obesity is one of the recently observed risk factor for many chronic diseases like diabetes, coronary heart disease, osteoarthritis and hypertension (1). There are many studies showing that increase in the Body Mass is also one of the significant aggravating factors for periodontal disease (2-4,6). The present study also supplements the above finding that overweight individuals have increased periodontal destruction. Similarly, Al-Zahrani et al. (2003) in their study concluded that BMI and periodontitis were significantly correlated (4). There was one more study correlating smoking and obesity with periodontitis, concluding that obesity may act as an independent risk factor for periodontitis (18).

In our study we have taken patients in the age group of 18yrs and above, similar to the study done by Genco et al. (2005) (6) where they correlated obesity, diabetes and periodontal infection. ^{In our study CPITN index was used because of its simplicity, speed and objectivity.}

Lipid levels in blood have been seen as one of the important risk factors for periodontal destruction (2,4,8,9). In the present study there was a correlation between Triglyceride levels and periodontal destruction. As it has been stated earlier hyperlipidemia may trigger foaming of macrophages (10), leading to release of pre-inflammatory cytokines like Tumour Necrosis Factor-α, Interleukin 1β (11,12). These cytokines are significantly related with periodontal destruction (13,14). It has been shown that P. gingivalis in presence of lipid induces foaming of macrophages (10). Hence Triglycerides may have priming effect on inflammatory cells leading to increased periodontal destruction. In our study we have seen a significant correlation between BMI and Triglyceride levels. Hence overweight may act as a risk factor for periodontal destruction through the pathway of increased Triglyceride levels.

Conclusion

To conclude the present study demonstrates a positive correlation between BMI and periodontal destruction as well as a positive correlation between Triglyceride levels in blood and periodontal destruction. A positive correlation between Triglyceride levels and BMI was also shown; hence it may be one of the pathways of periodontal destruction.