DIABETES AND NEW INSULINS

What is diabetes?

Diabetes is a disease characterized by blood glucose (sugar) levels that are higher than normal. Glucose is produced in the body from the foods that you eat. The pancreas, an organ located in the abdomen just behind the stomach, produces insulin. Insulin is a hormone that takes the glucose from the bloodstream and carries it inside your body's cells where it is used for energy.

Diabetes occurs when the pancreas does not produce enough insulin or when the body becomes resistant to the effects of insulin. Sometimes it is a combination of both problems. In either case, the result is that glucose does not enter the cells and builds up in the blood.

How is diabetes treated?

There are three major types of diabetes:

· Type 1 Diabetes — Usually seen in children and young adults; with this type of diabetes the pancreas does not produce any insulin.

· Type 2 Diabetes — Usually associated with obesity, an inactive lifestyle and aging.

· Gestational Diabetes — High blood sugars that occurs during pregnancy caused, in part, by normal hormones made by the placenta. It is usually reversible once the mother delivers the baby.

Keeping blood sugar levels as close to normal is the key to preventing a number of serious complications including heart disease, stroke, kidney failure, blindness, nerve damage, and foot problems that may require amputation.

The treatment depends on the type of diabetes you have and how well you respond to them. These can include changes in lifestyle (diet and exercise), oral medications and insulin. (These medications lower your blood sugar in different ways.) Persons with type 1 diabetes need insulin. Patients with type 2 diabetes are usually treated with oral medications (pills) for months to several years, but often go on to require insulin to maintain glucose control. (Some people may never need to go on insulin.)

What are the different types of insulin?

There are several types of insulin. They are classified by how fast they work and how long they continue to work in the body. They include:

Mealtime (or "bolus") insulin. Shortacting insulins given before meals to control the rise of blood glucose levels after eating. They are usually given in combination with basal (long-acting) insulin:

· Short-acting: Regular insulin

· Rapid-acting: Lispro, aspart, glulisine

Basal insulin. Controls blood sugar levels between meals and throughout the night. This is usually given once daily and can be used alone or in combination with oral antidiabetic medications or rapid-acting insulins:

· Intermediate acting: NPH

· Long acting: Glargine and detemir

Pre-mixed — Combination of bolus and basal insulins. Controls blood sugar levels after and between meals. These are usually given twice daily before breakfast and dinner. They can be used alone or in combination with oral medications.

The type of insulin your doctor prescribes will depend on the type of diabetes you have, your lifestyle (e.g., foods you eat, how much you exercise), your age, your body's response to insulin, and how often you are able or willing to check your blood sugar and give yourself injections.

What are the "new" insulins?

In recent years, scientists have developed new products called insulin analogues or "designer" insulins. These have been genetically engineered to better match the insulin produced by your body (or pancreas).

Insulin analogs have been shown to make it easier to control blood glucose. By controlling and preventing blood sugar swings, namely hyperglycemia (high blood glucose) and hypoglycemia (low blood glucose), they may reduce the risk of diabetic complications and improve quality of life for people with diabetes.

Same as traditional insulins, the new insulin analogs are taken by injections with a syringe, an insulin pen or an insulin pump. Injectable products include long-acting, basal insulins (e.g., glargine and determir) and rapid acting, bolus insulins (e.g., lispro, aspart, and glulisine). Another new product is inhaled insulin. This is a regular insulin powder that is inhaled through the lungs. It is a shortacting powder insulin given before each meal. It can be used alone or in combination with oral antidiabetic medications and long-acting insulins.

Some of the new insulins have not yet been approved for use during pregnancy. If you have gestational diabetes, talk with your doctor to see what may be the best insulin for you.

What should you do with this information?

If you have diabetes, it is important that you maintain a healthy lifestyle. Follow your doctor's recommendations for treatment and regularly monitor your blood sugar to avoid high or low blood sugar. Your diabetes can be managed with diet and exercise, with oral medications, or with insulin.

At a glance: In 1998, a researcher presented a theory suggesting that vaccines, depending on when they are administered, may increase or decrease the risk that certain people may develop type 1 diabetes, previously called juvenile onset or insulin-dependent diabetes mellitus (IDDM). The cause of type 1 diabetes is not completely understood but it is believed that genetic and environmental factors may be involved. Vaccinations have been studied as a possible environmental risk factor and the scientific studies conducted have found no relationship between immunizations and type 1 diabetes.

What is diabetes?

Most of the food we eat is turned into glucose, or sugar, for our bodies to use for energy. The pancreas, an organ that lies near the stomach, makes a hormone called insulin to help glucose get into the cells of our bodies. If a person has diabetes, his or her body can’t make enough insulin or can’t use its own insulin as well as it should. This causes sugar to build up in the blood. Diabetes is classified into two main types:

· Type 1 — Previously known as insulin-dependent diabetes mellitus (IDDM) or juvenile diabetes. In Type 1 diabetes, which accounts for 5 percent to 10 percent of all diabetes cases, the body does not produce insulin. Risk factors are less well defined for type 1 diabetes than for type 2 diabetes, but genetic, environmental and autoimmune factors are involved in the development of this type of diabetes.

· Type 2 — Previously known as non-insulin dependent diabetes mellitus (NIDDM) or adult-onset diabetes. In Type 2 diabetes, which accounts for 90 percent to 95 percent of all cases of diabetes, either the body does not produce enough insulin or the insulin does not work. Risk factors for type 2 diabetes include older age, obesity, family history, impaired glucose tolerance, physical inactivity and race/ethnicity (African Americans, Hispanic/Latino Americans, Native Americans, and some Asian Americans and Pacific Islanders are at increased risk).

In discussion below, “diabetes” refers to type 1.

Do vaccines cause diabetes?

No. Carefully performed scientific studies show that vaccines do not cause diabetes or increase a person’s risk of developing diabetes (DeStefano 2001, EURODIAB Substudy 2 Study Group 2000, Karvonen 1999, Heijbel 1997, Parent 1997, Dahlquist 1995, Hyoty 1993, Blom 1991). In 2002, the Institute of Medicine reviewed the existing studies and released a report concluding that the scientific evidence favors rejection of the theory that immunizations cause diabetes. Furthermore, DeStefano and colleagues (2001) recently conducted the first study looking at whether the timing of childhood vaccinations, particularly of hepatitis B, is related to the risk of a child getting diabetes. This study, which examined data from 1,020 children in the United States, did not show an association between any of the recommended childhood vaccines and diabetes, regardless of when the vaccines were given.

Other studies also provide evidence that vaccination does not cause diabetes:

· A study that examined all children born in Denmark over a 10-year period (1990 to 2000) found no significant relationship or causal relationship between childhood vaccination and juvenile onset diabetes (type 1 diabetes). This also was true for genetically predisposed children whom researchers defined as children with siblings who had type 1 diabetes.

· A European study that examined 900 diabetic and 2,302 non-diabetic children found a slight relationship between infections during early infancy and risk of developing diabetes. However, the researchers did not find a relationship between any of the common childhood infections or childhood vaccines and diabetes in children. (EURODIAB Substudy 2 Study Group 2000)

· A study conducted in Sweden looked at 1,267 diabetic children in two groups: a group of children who were born during the time that pertussis vaccination was used and a group of children who were born after pertussis vaccine had been removed from the immunization schedule. The researchers found no difference in the incidence rate of diabetes between the children born before and the children born after 1979, when pertussis was excluded from routine immunizations in Sweden. (Heijbel 1997)

· The results from a study that examined 339 diabetic and 528 non-diabetic Swedish children showed that children that received measles vaccine were slightly protected against getting diabetes. The study showed no relationship, positive or negative, between tuberculosis, smallpox, tetanus, whooping cough, rubella and mumps vaccines and diabetes in children. (Blom 1991)

What about evidence that suggests that vaccines cause diabetes?

The only evidence suggesting a relationship between vaccination and diabetes comes from Dr. John B. Classen (Classen 1996; Classen and Classen 1997; Classen and Classen 2002). He has suggested that certain vaccines, if given at birth, may decrease the occurrence of diabetes, whereas if initial vaccination is performed after 2 months of age, the occurrence of diabetes increases. Dr. Classen's studies have a number of limitations and have not been verified by other researchers.

This theory is based on results from experiments in laboratory animals, as well as comparisons of the rates of diabetes between countries with different immunization schedules (Classen, 1996; Classen & Classen 1997). Applying findings from laboratory animals to humans is fraught with uncertainty. Findings that are noted in animals cannot be directly applied to people because of the large biological differences. In addition, many of the animal experiments involved anthrax vaccine, which is not used in infants and children.

Comparison of diabetes rates between countries provides weak evidence because many factors, including vaccination schedules, may differ by country. For instance, comparisons between countries included vaccines that are infrequently used in the United States (BCG) or are no longer used (smallpox). Furthermore, factors such as genetic predisposition and a number of possible environmental exposures unrelated to vaccines, may influence the development of diabetes in different countries.

Dr. Classen also performed an analysis of data from a large study conducted in Finland of Haemophilus influenzae type B (Hib) vaccine. More than 100,000 children were randomly assigned to receive either 4 doses of vaccine starting at 3 months of age or a single dose at 24 months. Over about a 10-year follow up period, 205 children in the multiple-dose group developed diabetes compared with 185 in the single dose group.

These results are inconclusive because the exact number of children in each group is not known and the noted differences may not be statistically significant (that is, they could be due to “chance”).

The results from a similar study using the same data from Finland were not the same as Dr. Classen’s results (Karvonen et al. 1999). This study was similar to Dr. Classen’s study except that it compared children in three (rather than two) different groups: 1) children who were born before Hib vaccination was recommended (and therefore did not receive the shot as part of their routine immunizations), 2) children who began receiving Hib vaccine at 3 months of age, and 3) children who received a single dose of Hib at 24 months. This study did not find a difference in diabetes risk between any of the three groups of children.

Dr. Classen recently performed another analysis using the same data from the group of children in Finland (Classen and Classen 2002). In this study Dr. Classen suggests that by the age of 7 years old, a greater number of diabetes cases occurred in Finnish children who had received the Hib vaccine than in children that had not received the vaccine.

In order for an association between Hib vaccination and diabetes to be confirmed, the results would have to be replicated in several other scientific studies. No other studies, not even one using the exact same data from the children in Finland (Karvonen 1999), have found a relationship between Hib vaccine and an increase in diabetes (DeStefano 2001, EURODIAB Substudy 2 Study Group 2000).

It appears that Dr. Classen may have conducted his statistical analysis after seeing the results and noting that the largest difference was apparent by 7 years. The validity of this type of “post-hoc” statistical testing, however, is highly questionable. When the full 10 years of follow-up was evaluated, the differences were not statistically significant, which also is what was found by Karvonen and colleagues.

What is being done to monitor the safety of vaccines?

To assure the safety of vaccines, the U.S. Centers for Disease Control and Prevention, the Food and Drug Administration, the National Institutes of Health and other federal agencies routinely monitor vaccine safety and conduct research to examine any new evidence that would suggest possible problems with the safety of vaccines. The CDC's Vaccine Safety Datalink (VSD) project links the immunization and medical records on members of seven HMOs, totaling 2.5 percent of the U.S. population for various vaccine safety studies. The VSD project is a powerful and cost-effective tool for the on-going evaluation of vaccine safety. The Vaccine Adverse Event Reporting System, or VAERS, was designed to give health care workers and others a place to report possible problems following vaccination. VAERS helps the FDA and CDC to continuously monitor vaccine safety.