By Nancy Volkers
InteliHealth News Service

People with type 1 diabetes are more likely to suffer from dry mouth, which can contribute to increased tooth decay and other oral-health problems. Researchers also have found a link between dry mouth and diabetic neuropathy, which causes numbness, pain or both, usually in the arms, legs, feet or hands.

The results come from a study done at the University of Pittsburgh that compared 406 people with type 1 diabetes to 268 people without the disease.

"It's been an impression within the diabetic community that there's an association between their diabetes and their neuropathy and experiencing a dry mouth," said Paul Moore, D.M.D., Ph.D., a professor at the university's School of Dental Medicine and a lead researcher on the study. "I think this study is the first demonstration of that."

The study was published in the September issue of Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontics.

Type 1 diabetes — also known as juvenile diabetes or insulin-dependent diabetes — occurs when the pancreas stops producing insulin, a hormone that helps the body utilize food for energy. About 14 million people in the United States have type 1 diabetes, but more than a third of them have not been diagnosed with the disease. Currently, diabetes is the sixth leading cause of death in this country.

Although both neuropathy and a lower-than-normal production of saliva are relatively common in diabetics, they may be more than just separate effects of one disease. Said Moore: "There is a kind of relationship between the nerves and the release of saliva. If you have an impairment of nerve function, the nerves that maintain saliva stimulation can become less responsive."

The research also found that:

• Diabetics who reported symptoms of dry mouth were more likely to smoke and/or snack frequently.
• Diabetics taking medications that tend to dry the mouth, and diabetics with high levels of fasting blood glucose (indicating that their diabetes was not well controlled), were more likely to have low salivary flow.
• The lowest salivary flow rates in diabetics were associated with increased dental decay.

"It's crucial to have good salivary flows to maintain good oral health," said Moore. "Saliva washes out all of the sugar in our mouth in about 30 minutes after a meal. Decreased salivary flow can be significant when it comes maintaining teeth and preventing soft-tissue infections." Many medications cause dry mouth as a side effect. The study found that people with diabetes were taking significantly more of these medications than people without diabetes. "The combination of diabetes, neuropathy and medications that might be prescribed for the neuropathy can add to the [dry-mouth] problem," said Moore.

Although people with diabetes may be at increased risk for tooth decay and other oral-health problems, many diabetics are not aware of these risks and do not visit the dentist frequently enough, according to other research done last year by Moore and his colleagues using the same group of people.

"I realize that having type 1 diabetes is quite a burden in the sense that you need to monitor your blood sugar and your diet and visit a doctor, an eye doctor, a foot doctor," said Moore. "Sometimes oral health is just one more thing, and sometimes it falls off the plate."

His advice? "Don't forget your mouth."