SINGAPORE - Severe gum disease could be one of the early signs of diabetes and pre-diabetes among dental patients, a local study has found.

Diabetics, especially those who have poor blood sugar control, are two times more at risk of gum disease than non-diabetics.

From July 2016 to April last year, the National Dental Centre Singapore (NDCS) detected undiagnosed pre-diabetes in more than one-third of 500 patients who underwent gum examination at the centre. Another 29 were identified to have undiagnosed diabetes.

Those with pre-diabetes have a higher than normal blood sugar level, but not as high as the level in Type 2 diabetes.

The study also found that patients with severe gum disease were more likely to have undiagnosed diabetes than those with moderate gum disease, said Dr Chee Hoe Kit, a consultant at NDCS' Restorative Dentistry department and the principal investigator of the study.

Higher blood sugar levels in diabetics can lead to reduced blood flow to the gums, making them more susceptible to bacteria. This produces toxins, which cause gum disease.

Gum disease in turn causes increased insulin resistance and worsened blood sugar control.

There are more than 400,000 Singaporeans who have diabetes, and this figure is projected to reach one million by 2050. One in three Singaporeans has a lifetime risk of getting diabetes.

The study looked at patients aged 21 and above, including those who did not have gum disease. They underwent the HbA1c test, which measures a person's average blood sugar levels over the past two to three months.

Dr Chee said that the study suggests that patients with severe gum disease could be referred for diabetes and pre-diabetes screening, as another way to spot the conditions.

"If you're a diabetic patient, I would recommend that you see a dentist at least once a year and ask for a detailed gum examination," he added.

In order to expand the study, researchers recruited 500 more patients last year.

Mr Kumar Ravichandran, 33, who took part in the study, had no clue he was diabetic. A procedure in a dental clinic in May to remove a wisdom tooth led to the discovery of gum disease.

While being treated for it at the centre, he was told to get himself checked for diabetes. This was confirmed at a polyclinic later.

"I had no idea that there was a link between diabetes and gum disease previously," said the media coordinator, who has cut down on unhealthy food and now flosses more regularly.