Diagnosing Diabetes at the Dentist Is Feasible

Pam Harrison

March 03, 2015

Screening patients for high glycemic levels using oral blood collected during a routine dental procedure gives as accurate a reading in HbA1c as traditional finger-stick readings and can identify a large number of patients who do not know they have diabetes or who are at risk for it, new research shows.

The study was published online February 25 in the American Journal of Public Health.

"There are over eight million adults in the US who have diabetes that is not yet diagnosed," lead author Shiela Stauss, PhD, from New York University College of Nursing, New York, told Medscape Medical News.

"And while there are other places that offer diabetes screening — some churches, some ophthalmology offices, some health fairs — we thought the dental office offered a particularly good place to do this…because it is possible to collect blood from the gums, and that blood can be used for diabetes screening because it is quite accurate."

Diabetes screening at the dentist could be particularly successful because about 70% of Americans seek some kind of dental care at least once a year, a greater percentage than those who visit their primary-care provider, William Herman, MD, MPH, from the University of Michigan, Ann Arbor, told Medscape Medical News.

"Only one in about 10 people who have prediabetes knows it, and probably about one-quarter to one-third of people with diabetes are undiagnosed," Dr Herman added. "So I think whatever avenues we can use to increase awareness of diabetes and get people diagnosed and into appropriate therapy are important."

HbA1c Readings from Finger-Prick and Oral Blood Virtually Identical

The study recruited New York University College of Dentistry adult patients who volunteered and met the following criteria: they indicated that their gums bled on brushing or flossing and had been told by a healthcare provider that they had diabetes or they were at risk for diabetes according to American Diabetes Association standards.

The 408 individuals who participated all had paired HbA1c values from a finger-stick blood sample as well as a gingival crevicular blood (GCB) specimen taken from the gums while seated in the dental chair. Specimens were sent to the laboratory for HbA1c analysis.

"HbA1c values assessed with finger-stick blood and GCB were nearly identical, with a correlation of 0.991," the investigators report.

Finger-stick blood HbA1c ranged from 4.2% to 10.8%, while GCB HbA1c ranged from 4.1% to 10.9%, they add.

Approximately half of the study sample had HbA1c levels in the prediabetes or diabetes range regardless of the blood source analyzed.

HbA1c Values in the Prediabetes/Diabetes Range in the Dental-Visit Study

Outcome Finger-stick blood (%) GCB (%) Percent agreement
Prediabetes/diabetes (HbA1c ≥5.7%) 53.2 51.5 92.9
Diabetes (HbA1c ≥6.5%) 13 13.7 97.8

"The gold standard until now has been to collect blood from the finger, but by showing that blood collected from the mouth is essentially identical, we can conclude that a dentist could now just collect oral blood for HbA1c, and that would be sufficient," Dr Strauss observed.

Diabetes Screening by Dentists a Great Idea, With Some Caveats

Asked whether dentists might be willing to participate in such a screening effort, coinvestigator Mark Wolff, DDS, PhD, from the New York University College of Dentistry, New York, told Medscape Medical News that dentists are an important part of the healthcare system and as such, he thought diabetes screening by dentists was a great idea.

"A many as a third of our patients haven't seen a physician within a year," Dr Wolff observed. "And there really is no down side to doing this test and getting the blood analyzed."

Dr Wolff cautioned, however, that there is still no "chair-side" test that would allow dentists to get HbA1c results back instantly.

He also warned that dentists are licensed in certain states to look at HbA1c and tell patients what their findings are, but not in others.

Still, "there are a lot of ways this could be structured that could do wonderful things for patients," he added. "And if public health feels that this is an important measure to have us participate in, then there is no reason why this should not happen."

Periodontal Disease a Complication of Diabetes

Asked by Medscape Medical News to comment, Gail D'Eramo Melkus, EdD, from the New York University College of Nursing, noted that dental clinicians and hygienists would first need to be educated about who is at risk for diabetes before a screening program could be effectively offered by dentists.

Nevertheless this is important because "periodontal disease is a complication of diabetes — there are changes in the vasculature in the gum, people can get bony destruction in the teeth from having a high glucose environment in the mouth," she explained.

"So the majority of patients with periodontal disease have impaired glucose tolerance and the utility of the HbA1c test as a diagnostic test that can be used at the dental visit is important to consider," she added.

Dr Herman seconded the wisdom of screening people whose gums bleed easily on dental procedures for signs of poor glycemic control.

"People who have gums that bleed are more likely to have periodontal disease, and those are the very people who are more likely to have undiagnosed prediabetes or diabetes," he told Medscape Medical News.

Dr Herman added that periodontal disease in turn can exacerbate glycemic abnormalities in diabetes — "so it's a good population to target," he added.

He and his colleagues have similarly looked at the role dentists might play in screening for glycemic abnormalities during routine office visits in a recent study (J Public Health Dent . 2015; DOI:10.1111/jphd.12082).

The New York study was funded by the National Institute of Dental and Craniofacial Research. The authors have reported no relevant financial relationships, as has Dr Herman.

Am J Public Health. Published online February 25, 2015. Abstract


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