In-dental office screening for diabetes mellitus using gingival crevicular blood.

AIM: To evaluate whether during routine periodontal examination blood from gingival tissues can be used for determining glucose levels.
MATERIALS AND METHODS: Thirty patients with gingivitis or periodontitis and bleeding on probing (BOP) were chosen. The following clinical periodontal parameters were noted: probing depth, BOP, gingival bleeding index, and periodontal disease index. Blood samples were collected from gingival crevicular blood (GCB) and capillary finger prick blood (CFB). These samples were analyzed using a glucose self-monitoring device.
RESULTS: Descriptive statistical analysis was carried out in the present study. Data were analyzed using a Pearson's correlation coefficient and Student's t-test. An r-value of 0.97 shows very strong correlation between CFB and GCB, which was statistically highly significant (P < 0.0001).
CONCLUSIONS: The authors conclude that GCB may serve as potential source of screening blood glucose during routine periodontal examination in populations with an unknown history of diabetes mellitus.

INTRODUCTION

The increasing prevalence of obesity and physical inactivity due to population growth, aging, and urbanization has prompted the rise in the incidence of diabetes mellitus (DM). The prevalence of DM for all age groups worldwide was estimated to be 2.8% in 2000 and will be 4.4% in 2030.[1] The countries with the largest number of people with DM will be India, China, and the United States by 2030. It is estimated that every fifth person with DM will be an Indian.[2] Because of these sheer numbers, the economic burden due to diabetes in India is among the highest in the world.[2] About half of the diabetic patients are undiagnosed,[3] as DM is asymptomatic in its early stage and can remain undiagnosed for many years. Screening for type 2 DM would alone lead to earlier recognition of cases, with the potential to intervene earlier in the disease course. Early diagnosis may prevent long-term complications.[3]

Diagnosis of type 2 DM is generally based on plasma glucose values, and fasting plasma glucose is a test generally employed for screening of individuals undiagnosed with type 2 DM. A fasting plasma glucose ≥126 mg/dl and a random blood glucose ≥200 mg/dl are considered diagnostic for DM, along with symptoms.[3]

It is important that dentists understand the association between diabetes and periodontal disease. Uncontrolled diabetes increases the risk of both gingivitis and periodontal disease. In patients with advanced stages of diabetes, periodontal abscess and periodontal attachment loss may occur. While each patient may manifest different signs and symptoms, the following are observed in periodontal patients: red and swollen gum tissue, bleeding while brushing and/or flossing, increased tooth mobility, acute oral infections, persistent mouth odor, increased periodontal pockets, and significant bone and tissue loss in advanced cases.

In addition to exacerbation of periodontal disease, other oral manifestations of diabetes that have been reported in literature include the following:

Xerostomia

Burning mouth or tongue syndrome

Enlarged parotid glands

Taste dysfunction.

Community screening is not a cost-effective approach to screen for DM.[456] It may best be performed in primary care as part of a review of a patient's health. Other settings such as dental clinics may be appropriate. There are large numbers of patients who seek dental treatment each year and there is an association between periodontal disease and DM. The two reinforce each other.[789] The dentist may play an important role in the health team by participating in the search for undiagnosed asymptomatic DM. The use of gingival crevicular blood (GCB) for testing glucose levels can be an alternative to capillary finger prick blood (CFB) as the glucose content of gingival fluid and blood is higher in individuals with DM.[910]

In this study, we used a readily available self-monitoring device (SMD) as a simple method for rapid monitoring of the glucose level in the blood. We compared the blood glucose level between GCB and CFB. The purpose of this study was to assess the usefulness of an SMD for the estimation of the GCB glucose level during routine periodontal examinations.

MATERIALS AND METHODS

Selection criteria

The study population was recruited from patients visiting the Department of Periodontology, Drs. Sudha and Nageswara Rao Siddhartha Institute of Dental Sciences, Chinoutpalli. A total of 30 patients (age range, 25–70 years) with gingivitis or periodontitis and at least one site with positive bleeding on probing (BOP) were randomly selected for the study. Exclusion criteria included the following: Having any indication for antibiotic prophylaxis, any bleeding disorder, severe systemic disease such as cardiovascular, renal, hepatic, immunologic, or hematological disorders, and taking any medication interfering with the coagulation system.

Consent forms were duly signed by the participants. The protocol was reviewed and approved by the institutional ethics and research committee.

Clinical examination

The data recorded were: Probing depth, BOP, gingival bleeding index (GBI),[11] and periodontal disease index (PDI),[12] all measured by the same examiner.

All the sites were probed by Williams probe that was inserted into the gingival sulcus, as is commonly done during a periodontal examination. When the probe was removed, the gingival crevice was observed for bleeding.[10] One site with profuse BOP was chosen for testing (GCB). The sites most commonly selected were the interproximal areas of the maxillary premolar and molar regions. These areas were isolated with cotton rolls to prevent salivary contamination and dried with compressed air, and the remaining fluid in the site was wiped out using a piece of gauze.

Collection of GCB and CFB

For the collection of the GCB sample, we selected a readily available SMD (ARKAY GLUCOCARD 01, OneTouch Horizon Blood Glucose Monitoring System; LifeScan, Inc., Milpitas, California) [Figure 1] with a compact design that facilitated intraoral collection requiring only a small quantity of blood for an accurate reading. The SMD was introduced intraorally with the test strip in place and blood was allowed to flow onto its reactive area according to the manufacturer's instructions [Figure 2].

Figure 1

ARKAY GLUCOCARD 01, OneTouch Horizon Blood Glucose Monitoring System, USA

Figure 2

The SMD was introduced intraorally with the test strip in place and blood was allowed to flow onto its reactive area according to the manufacturer's instructions

The test strip was prevented from contacting the tooth, and its entry into the sulcus was also avoided. Immediately after measuring the GCB, the CFB was assessed using the same glucose GLUCOCARD. The pad of the finger was wiped with alcohol, allowed to dry, and then punctured with a sterile lancet. A CFB sample was drawn onto the test strip preloaded in the SMD [Figure 3]. While loading the blood into the blood strip, care was taken not to squeeze the finger to remove the blood and the prick was deep enough for free blood flow.

Figure 3

Fingerstick

The GCB and CFB glucose readings were recorded. These CFB readings were viewed as “casual” readings because they were taken without regard to the time of meals. Study participants with elevated casual readings were referred to primary care providers for a more detailed medical evaluation.[13]

RESULTS

A descriptive statistical analysis has been carried out in the present study. Results of continuous measurements are presented as mean ± standard deviation (SD) (min-max) and results of categorical measurements as number (%). Significance was assessed at a 5% level of significance. The Pearson's correlation was used to find the correlation between the variables, and the significance of correlation was obtained using the Student's t-test.

Among the 30 patients, the blood glucose in GCB could be determined in only 25 patients, of which 88% consisted of periodontitis cases and 12% were gingivitis cases [Table 1, Figure 1]. In the remaining five cases, the volume of blood procured on probing was insufficient for collection. Of the 25 successfully tested patients, 3 revealed elevated blood glucose levels based on the standard values for CFB. According to the epidemiological data on DM in urban India, the ratio of the unknown to known diabetic population is 1.8:1 and the prevalence of undiagnosed DM is estimated to be 7.2%; in the present study, it was 12%.[14] The glucose measurement from the GCB sample ranged from 43 to 243 mg/dl with a mean of 96.48 ± 62.38 mg/dl, and the glucose measurement obtained from the CFB ranged from 70 to 344 mg/dl with a mean of 131.9 ± 61.1 mg/dl [Table 2].

Table 1

Distribution of Periodontal Index

Table 2

CFB and GCB Glucose levels

Pearson's correlation coefficient showed a positive correlation between GCB and CFB [Table 3]. The linear relationship between GCB and CFB is drawn graphically in a scatter plot [Figure 2]. An r-value of 0.97 shows a very strong correlation between CFB and GCB, which was statistically highly significant (P < 0.0001).

Table 3

Pearson's correlation between CFB and GCB glucose levels

DISCUSSION

DM is a complex metabolic disorder. Periodontitis is considered as the sixth complication of DM.[15] Data show that the prevalence of DM is greater among individuals with periodontitis than among healthy individuals. Adequate blood is extravasated from the gingival crevice during routine oral examination in dental clinics. With regard to the significance of early detection of DM and the need for an easy and quick method for screening of DM, we planned to use this extravasated blood from the gingival crevice for estimation of the blood glucose level using SMD.

The results of the present study are in agreement with the study conducted by Shetty et al.[16] Strauss et al.[17] reported that GCB samples are suitable to screen for DM in individuals with sufficient BOP. However, they failed to give results in individuals with little or no BOP. Sarlati et al.[18] reported that GCB is useful for testing blood glucose during routine periodontal examination in subjects with DM and periodontitis, but not in those without DM. The present study reiterates the results by Parker et al.[19] and Beikler et al.[20] A strong correlation was observed between blood glucose measured in GCB and CFB when diabetic and nondiabetic patients with moderate to advanced periodontitis were examined. Khader et al.[21] reported that GCB can be an acceptable source for measuring the blood glucose level. In contrast to the above study, Muller and Behbehani[22] failed to obtain any correlation between GCB and CFB.

The results of the present study revealed a higher correlation between GCB and CFB with a smaller sample size. A large study sample should be able to demonstrate robustness in the correlation between GCB and CFB.

The relationship between diabetes and periodontal disease has been the subject of more than 200 articles published in English during the past 50 years. The risk of developing periodontitis may be greater in patients with diabetes who have poor glycemic control than that in patients with well-controlled diabetes. Poor glycemic control has been associated with an increased risk of progressive loss of periodontal attachment and alveolar bone.

Diabetes is associated with an increased risk of developing inflammatory periodontal disease, and glycemic control is an important determinant in this relationship. Early diagnosis in the dental setup will enhance the effectiveness of management of patients with DM and subsequently improve periodontal status. Chairside tests will go a long way in helping the dentists diagnose and manage those who are at increased risk.

From the above discussion, it can be concluded that GCB may serve as a potential source for screening of blood glucose during routine periodontal examination in populations with an unknown history of DM. This study sheds light on the screening of individuals not suspected of DM, using GCB blood samples. Thus, with minimal cost and time investment for patients and clinicians, dental professionals can play a critical role in supporting their patients’ overall health. The technique is safe, easy to perform, and comfortable for the patient.

GCB can provide an acceptable technique for evaluating the blood glucose level. However, the technique to obtain the blood sample from gingival crevices is technique-sensitive, which would limit its application as a clinical practice. Additional studies that refine this technique and use larger sample size are recommended. Future studies should be planned with a larger sample size, so that the study outcomes can be assessed for positivity and negativity on a larger scale.