The potential use of gingival crevicular blood for measuring glucose to screen for diabetes: an examination based on characteristics of the blood collection site.

Background: This study examined conditions under which gingival crevicular blood (GCB) could be used to obtain a useful glucose reading to screen for undiagnosed diabetes during routine dental visits.

Methods: GCB and capillary finger-stick blood (CFB) glucose readings obtained with a glucometer were compared for 46 patients recruited from an urban university dental clinic. Study participants were divided into two groups based on probing depth or bleeding on probing (BOP) at the site of collection of the GCB sample. Group 1 participants had blood collected from sites with adequate BOP to obtain a sample without touching the tooth or gingival margin, whereas group 2 participants had blood collected from sites with little or no bleeding. For each group, Pearson correlations were calculated for glucose readings obtained using GCB and CFB samples, and the limits of agreement between the two samples were examined.

Results: For group 1 participants, correlations between CFB and GCB glucose readings were high (0.89), and the limits of agreement were acceptable (-27.1 to 29.7). By contrast, for participants in group 2, correlations between the glucose readings were lower (0.78), and limits of agreement were much broader (-25.1 to 80.5).

Conclusion: GCB samples were suitable to screen for diabetes in persons with sufficient BOP to obtain a sample without touching the tooth or gingival margin (i.e., in patients having the basic clinical signs of gingivitis or periodontal disease).