Diabetes and Periodontal Disease: A 2-Way Link

Diabetes mellitus is a complex syndrome. It is characterized by abnormalities in carbohydrate, lipid, and protein metabolism. Diabetes results either from an absolute deficiency in insulin or from resistance to the metabolic effects of insulin.

In 1999, the National Center for Health Statistics reported that more than 10 million Americans had diabetes.¹ An estimated 221 million people are projected to have the disease by the year 2010.² The economic burden of diabetes on the health care system is immense. This burden is created by the need for chronic care and the treatment of acute complications. Chronic care is aimed at maintaining normalized blood glucose levels and at preventing or minimizing chronic complications. Patients with diabetes have an increased mortality risk and a shorter life expectancy because of diabetic complications.

When most health care professionals think of diabetic complications, they list retinopathy, neuropathy, nephropathy, peripheral vascular disease, coronary heart disease, dyslipidemia, and hypertension. They often overlook oral health problems. Yet, periodontal diseases, including gingivitis and periodontitis, are prevalent among individuals with diabetes. Other oral manifestations of diabetes are listed in Table 1.

Patients with type 1 diabetes are at an increased risk for developing gingivitis. Children with type 1 diabetes are twice as likely to develop gingivitis as those without diabetes.³ The severity of the gingivitis in these children also is significantly increased.⁴ Although periodontitis is uncommon in children without diabetes, the prevalence is 9.8% in those with diabetes.⁴ Diabetic patients between 40 and 50 years old have been shown to have more sites of advanced periodontitis and bone loss than healthy individuals in that age group.⁵

Fewer studies have been conducted on type 2 diabetics. It is known that patients with type 2 diabetes are 3 times more likely to develop periodontal disease than those without diabetes.⁶ The largest studies pertaining to patients with type 2 diabetes involve Pima Indians. Forty percent of Pima Indians have type 2 diabetes, thus providing a substantial population to study. In these studies, diabetic Indians under 40 years of age had greater tooth-attachment loss than those without diabetes.⁷ The destruction of periodontal tissues increased with age and was higher than in Indians without diabetes.⁷ The tooth loss among the Indians with diabetes was 15 times higher than among those without it.⁷

Periodontal Diseases

Periodontal diseases are chronic infections that affect the gums and bone supporting the teeth. If untreated, they can lead to tooth loss. These infections begin when the bacteria in plaque cause inflammation of the gums.

Gingivitis, the milder form of the disease, consists of red and swollen gums. The gums bleed easily, but there is little or no discomfort. If left untreated, gingivitis will progress to periodontitis, as the plaque spreads below the gum line.

Irritating toxins produced by the bacteria stimulate an inflammatory response. This response causes the body to attack itself and to destroy the tissue and bone supporting the teeth. Infected pockets form between the gums and teeth. As the disease progresses, the pockets deepen, destroying more tissue and bone in the process. Eventually, teeth become loose because of a lack of tissue and bone to anchor them.

Periodontal Disease in Patients with Diabetes

Although periodontal disease is primarily associated with dental plaque, and although there are other factors leading to it (Table 2), periodontal disease is affected by pathological events related to diabetes. Several studies have shown that patients with marginally or poorly controlled diabetes are at increased risk of developing periodontal disease. Patients who maintain rigorous control of their diabetes are less likely to develop severe and extensive periodontal disease. Glycosylated hemoglobin levels exceeding 10% appear to predispose patients to gingivitis.⁸ Because periodontal diseases are infections, they also may impair glycemic control.

Studies have shown that the microorganisms in the mouth flora are similar in patients with diabetes and in those without diabetes. Therefore, differences in a patient's response to these organisms must be factors in increasing the risk of periodontal disease. The first factor is microvascular changes. The second factor is an impaired response to infections. Diabetes is shown to impair cell-mediated immunity, including neutrophil chemotaxis and macrophage function.⁹ The third factor is an increased glucose concentration in the saliva. Excess salivary glucose may play a role in increasing plaque formation and providing a food source for the bacteria.

Oral Care for Diabetics

Consistent oral care and routine dental visits are imperative to prevent long-term oral health problems. For all patients, tooth brushing, flossing, mouth rinsing, and tongue brushing are essential components of oral care. Special focus on these areas is necessary for patients with diabetes.

Teeth should be brushed at least twice daily. If possible, they also should be brushed after meals. The ideal brush contains soft bristles. Hard bristles or vigorous brushing may damage gums and cause potential problems. Patients should be encouraged to floss daily. A variety of flossing tools are available. These tools may prove useful for patients with neuropathies who have difficulty handling thin floss.

Mouth rinsing also can play a role in good oral health. Selection of a product should be based on the patient's needs. Fluoride rinses are intended to decrease cavities, but they do not reduce gum disease or bad breath. For patients with diabetes, a rinse that kills bacteria and removes their by-products will work well. Whenever possible, patients should avoid rinses containing alcohol because they tend to dry the oral mucosa.

Although many patients clean their gums, they often overlook cleaning their tongue. The importance of tongue cleaning in maintaining oral health is now widely recognized. This task is accomplished by using a toothbrush, a tongue scraper, a tongue cleaner, or a tongue brush.

Conclusion

Pharmacists have an opportunity to improve the health of diabetic patients by educating them about the importance of good oral health. While educating patients on the hazards of poorly controlled glucose levels, pharmacists should add periodontal diseases to the list of long-term complications. For some patients, tooth loss may prove to be a more tangible and comprehensible outcome than peripheral vascular disease. The promotion of good daily oral care and routine dental appointments also may improve the patient's overall glycemic control.

Dr. Schlesselman is a clinical pharmacist based in Niantic, Conn.

For a list of references, send a stamped, self-addressed envelope to: References Department, Attn. A. Stahl, Pharmacy Times, 241 Forsgate Drive, Jamesburg, NJ 08831; or send an e-mail request to: astahl@mwc.com.