Evaluating Gingival Crevicular Blood Glucose in Periodontitis Patients – A Cross-sectional Study

Introduction

The incidence of diabetes mellitus is growing rapidly worldwide and has reached epidemic proportions. The major proportion of this increase occurred in developing countries, where the disorder predominantly affects younger adults in the economically productive age group. There is also a consensus that South Asia will include three of the top ten countries in the world (Bangladesh, India, and Pakistan) in terms of the estimated absolute number of individuals with diabetes. It is undiagnosed in almost half the number as diabetes mellitus is asymptomatic in its early stage and can remain undiagnosed for many years.¹

It represents one of the major chronic health problems faced by society today, whose complications impact the quality of life, longevity, and health care cost. Diabetes mellitus and periodontitis seem to interact in a bidirectional manner.² Increased prevalence rate and severity of the periodontitis seen in individuals with diabetes mellitus, especially those with poor metabolic control, had resulted in designating periodontal disease as the “Sixth complication of Diabetes mellitus”.³

The crude prevalence rate of diabetes in urban India is 9%, the prevalence in rural areas has also increased to 3% of the total population and the ratio of patients with unknown to known diabetes is 1.8:1.5. These values can be primarily attributed to the fact that the condition is usually undetected in its early stages in most individuals, whereas in others, existing symptoms are often overlooked because of ignorance or negligence on the part of the patient.

By 2030, it has been presumed that diabetes mellitus will affect up to 100 million people in India and 552 million globally.⁴ As a large number of patients seek dental treatment each year, dentists are likely to encounter an increased number of undiagnosed diabetic patients. Detecting subclinical forms of diseases using different evaluation procedures is making significant progress in diminishing the advancement of certain chronic diseases such as diabetes. The incorporation of such procedures into routine office examinations provides clinicians with a better overall chance of an early diagnosis of a previously unsuspected disease entity.

Dental visits can be a great opportunity to screen for diabetes. Thus, there is a crucial need to increase opportunities for diabetes screening and early detection.⁵ Hence, the current study was designed to assess a harmless and minimally interfering method for screening diabetes during regular periodontal examinations.

Materials and Methods

Study subjects

The study comprised 150 patients in the age group of 25-70 years. The study was done in the Department of Periodontology of a Dental College and Hospital, Jaipur in collaboration with the Department of Biochemistry of the same college.

Inclusion criteria: Patients between 25-75 years of age, diagnosed with gingivitis (visible gingival inflammation) and with at least two teeth in the anterior region showing of the upper jaw with bleeding on probing were included in the gingivitis group (Group A). Patients aged 25-75 years, diagnosed with periodontitis (visible gingival inflammation, radiographic evidence of bone loss, probing pocket depth of ≥ 5mm, clinical attachment loss of ≥ 3 mm), and subjects with at least two teeth in the anterior region of the upper jaw with bleeding on probing were included in the periodontitis group (Group B).

Exclusion criteria: Individuals undergoing treatment for anemia, gout, dialysis, bleeding disorders, history of any systemic diseases, medication interfering with the coagulation system, supplemental vitamin C, smokers, and patients on antibiotic prophylaxis were excluded.

Study design

A cross-sectional study was conducted in which the design was reviewed and approved by the ethical committee of the Institute. From each subject, written informed consent was taken and after a full mouth oral examination, they were divided into two groups Gingivitis (Group A) and Periodontitis (Group B) of 75 each.

Following periodontal parameters were taken, Plaque Index (PI), Gingival bleeding index (GBI), Probing Pocket depth (PPD), and Clinical attachment level (CAL). William’s periodontal probe was used for periodontal examination and specially designed proforma to collect data.

Blood collection and analysis

The gingiva located in the upper anterior region surrounding the teeth was selected as the origin of the gingival crevicular blood (GCB) samples. To assist in blood collection, both supra and sub-gingival scaling were performed, and cotton rolls and suction tips were used to minimize salivary contamination. Blood was collected by gently probing the gingival sulcus with a force of approximately 0.2 N and then transferred onto the glucometer strip for measurement and recording. Additionally, finger stick blood (CFB) was collected from the index finger using the preloaded glucometer strip during the same visit.

Sites with effusive bleeding were preferred for the sample, whereas sites with suppuration were avoided. Repeated probing was performed to collect a clean sample wherever necessary, until a sufficient quantity of blood (2-3µl) was present to gather a sample, and the biochemical parameters, fasting blood glucose, and postprandial blood glucose levels were measured by enzymatic analysis. Fasting was defined as no caloric intake for at least 8 hours and in 2-hour post load glucose test a glucose load containing the equivalent of 75g of anhydrous glucose dissolved in water was used.

Blood collected from two selected areas was analyzed using the glucose self-monitoring device (Elegance CT-X11 glucometer) according to the manufacturer’s instructions. Then, to perform a postprandial (PP) blood glucose test from gingiva and finger, subjects were told to consume 75g of glucose after two hours.

Statistical analysis

Data entry and analysis were performed using Statistical Package for the Social Sciences (SPSS) version 22 (IBM Corp. Armonk, NY). Standard descriptive statistics were generated. Pearson’s correlation was used to correlate variables, and the significance of the correlation has been obtained using the Student’s t-test (unpaired). P values from all statistical tests are presented but were considered statistically significant at p < 0.05.

Results

The mean age for the study sample was 37.81±6.66. Table 1 shows the gender and age distributions of the subjects. Group A has subjects with chronic generalized gingivitis (31 males and 44 females) and Group B has subjects with chronic generalized periodontitis (40 males and 35 females) 

Table 2 presents the mean and standard deviation values for GCB and CFB in both groups. It has been observed that both groups A and B had slightly lower mean GCB values (98.43 mg/dl ±18.62 and 136.37 mg/dl ±36.95, respectively) compared to their respective mean CFB values (113.48 mg/dl ± 13.90 and 161.62 mg/dl ± 51.84, respectively).

Table 4 displays the calculated average and deviation values of clinical parameters among subjects with periodontitis. The plaque index, probing pocket depth, and clinical attachment level had mean and standard deviation values of 1.94±0.54, 5.69±1.00, and 5.75±0.83, respectively.

The correlation studies between GCB and CFB were analyzed using Pearson's correlation. A positive correlation was observed between GCB and CFB for all clinical parameters. The association between various biochemical parameters in the periodontitis study population was presented in Table 5. A positive association was found between capillary finger-prick blood glucose levels and GCB glucose levels (r=0.887). Fasting and postprandial blood glucose levels were significantly associated with GCB glucose levels at r=0.435 and r=0.476, respectively.  

Table 3 presents the calculated mean and standard deviation of biochemical parameters in individuals with periodontitis. Specifically, the mean and standard deviation of fasting and postprandial blood glucose levels were found to be 159.20 mg/dl ± 36.10 and 155.84 mg/dl ± 32.35, respectively.

Discussion

Hyperglycemia due to defects in insulin secretion, action, or both, characterizes diabetes mellitus, a metabolic disease. Diabetes mellitus is a significant burden on healthcare facilities worldwide, and early detection and treatment can help reduce the associated complications and burden. China, India, along with United States of America (USA) have the highest number of individuals with undiagnosed diabetes.⁶ Diabetes control is complicated by chronic inflammatory periodontal disease.⁷ In periodontitis patients, the prevalence of diabetes mellitus is twice that in periodontally healthy subjects.⁸

Dentists, specifically periodontists are likely to encounter patients with undiagnosed diabetes, therefore during dental visits diabetes screening presents an opportunity to improve public health. Identifying diabetes early on could potentially prevent the long-term complications that are associated with the high morbidity and mortality rates in diabetic patients.⁹ Stein and Nebbia (1969) first performed a chair-side evaluation of diabetes using gingival blood.¹⁰ The concentration of free glucose in gingival crevicular fluid (GCB) can be influenced by local environmental factors, such as microflora and the activation of hydrolyzing enzymes. As a result, measuring capillary blood glucose through GCB after probing may not provide accurate results.¹¹ In order to address this constraint in our study, we collected blood samples from the external area of the gingiva, thereby removing the chance of any contamination from the fluid within the crevice.

In this study, 45 out of 75 subjects with blood glucose levels >140 mg/dl in the periodontitis group, had undiagnosed diabetes, suggesting that the majority of the Indian population was unaware of their systemic condition. Our study provides evidence of a statistically strong correlation between GCB and CFB. The mean GCB level was 136.13 ± 36.95 mg/dl and CFB levels were 161.62 ± 51.84 mg/dl. A significant correlation (r=0.887, p<0.01) was established, similar to the previous studies by Shylaja et al.,⁹ , Parker et al.,¹¹, Beikler et al.,¹², Strauss et al.,¹³, Shetty et al.,¹⁴, Tsutsui et al.,¹⁵, Ardakani et al.,¹⁶, Bhavsar et al.,¹⁷, Gupta et al.,¹⁸, Parihar et al.,¹⁹, Lalge et al.,²⁰, and Juan Wu et al.²¹

The correlation between the two measures can be affected by several factors, such as the location of sample collection, techniques used, equipment utilized, and taking multiple samples. In addition, contrary to our study Muller et al.,²², Kandwal et al.,²³, and Debnath et al.,²⁴, reported that GCB cannot be used to assess blood glucose levels during periodontal examination.

In this research, a CT-X11 glucometer was utilized to detect glucose levels in blood that had leaked from the gingival crevice. The latest glucometers only require a minimal amount of blood (2-3 µl) for testing purposes. With the help of modern glucometers, measuring glucose levels with a self-observation tool is feasible, even if there is very little bleeding from the gingival crevice, as these glucometers are capable of measuring glucose levels in small amounts of blood, as low as 1 µl. During the regular examination of periodontal status, practitioners can measure blood glucose several times using GCB. This will help in screening suspected diabetics in dental clinics, and referral for further investigations can be performed if required.

Our findings suggest that GCB can be used as a potential source of blood for glucose level examinations. This can be particularly useful in dental clinics, where regular periodontal examinations can provide a non-invasive and cost-effective means of screening for diabetes. However, it is important to note the limitations of our study. Nevertheless, dental professionals should be encouraged to incorporate diabetes screening into their clinical practice for patients suspected to have diabetes, given the simplicity and ease of the procedure for measuring glucose through GCB. However, further longitudinal and interventional studies with a large sample size should be conducted to validate GCB glucose as a reliable source to monitor blood glucose levels.

Conclusion

The study results indicate that during the periodontal examination, GCB collected may be an exemplary source of blood for analysis, and the method described is safe and comfortable for patients. It could be used as a reliable, effective, and non-invasive chair-side mode of monitoring or screening for DM in the periodontal population.

Source(s) of Support

Nil

Conflicts of interest

Nil