The prevalence of diabetes, especially that of type 2 in children, is increasing at an alarming rate worldwide. Although no data currently exists to determine the extent to which type 2 diabetes has emerged among U.S. children and adolescents, researchers at the Centers for Disease Control and Prevention estimate that among new cases of childhood diabetes, the proportion of those with type 2 diabetes ranges between 8 percent and 43 percent.1 Over the last 20 years, the prevalence of type 2 diabetes has increased sharply. Prior to the 1990s, documented rates of type 2 diabetes ranged between 1 and 4 percent for adolescents. However, many centers have reported increases in the incidence of type 2 diabetes in children each year of the past decade. In some pediatric populations, the rates of type 2 diabetes now exceed those of type 1.2 Type 2 diabetes is usually diagnosed in patients over the age of 40 while type 1 diabetes typically affects juveniles. However, this distinction has started to blur as more and more adolescents have been diagnosed with type 2. Type 2 diabetes begins when the body develops a resistance to insulin and no longer uses the insulin properly. As the need for insulin rises, the pancreas gradually loses its ability to produce sufficient amounts of insulin to regulate blood sugar. Children who develop type 2 diabetes are typically overweight or obese and have a family history of the disease. In addition to obesity, type 2 diabetes is often characterized by the metabolic syndrome of hyperglycemia, dyslipidemia and insulin resistance. This syndrome is similar in both adults and children diagnosed with type 2 diabetes. For such children, the problems go beyond diabetes itself and include its complications.3 The rate of complications, such as heart disease, kidney disease, blindness and stroke, increases with the length of duration of diabetes.1 With an earlier onset of diabetes, more and more patients are suffering greater rates of these complications. One study has addressed the significant overall increase in the percentage of children referred with new-onset diabetes who were considered to have type 2 diabetes in Florida.4 Several additional papers have addressed this epidemic as the prevalence of type 2 diabetes rises among children and adolescents.2,5 Why Are More Children Developing Type 2 Diabetes? The increase in type 2 diabetes mellitus among children appears to occur in populations that have high rates of the disease among adults. This was noted initially among Pima Indians, a group that has the highest rates of type 2 diabetes in the world. Pima Indian children have higher rates of type 2 than the general population and the rates increase with age. Between the late 1980s and the mid-1990s, the rates of diabetes among adolescent Pima Indians increased 54 percent. Although two decades ago, children who had been diagnosed with type 2 diabetes were found almost exclusively in selected population groups such as the Pima Indians, the problem is spreading. In some clinics, as many as 21 percent of diabetic children of Mexican-American ethnicity have type 2 diabetes. Other clinics have reported that 69 percent of pediatric patients who had type 2 were African-American. Today, although most children with type 2 are American Indian, African-American, Asian or Hispanic/Latino, type 2 diabetes has also been diagnosed more and more frequently in children in all races and ethnic groups.1 What is causing the increased prevalence? Trends in the prevalence of obesity and physical inactivity among children may help to explain the increasing rates of type 2. Large population-based surveillance studies demonstrate increases in the rates of overweight and obesity among all age groups since the 1960s. Rates of overweight and obesity among children are epidemic in parts of the United States. Although this observation does not explain the rise in type 2 diabetes completely, the weight trends parallel the trends of type 2 diabetes among children.2 One of the major issues facing healthcare is the logarithmic association between the risk of complications with increasing glycemia, which has been established for adults with type 2 diabetes, and whether this is likely to hold true for children. While this may be a logical assumption, data from the conclusions of trials in adults must be extrapolated with caution for children. Helpful Pearls On Treating Childhood Diabetes Management of diabetes involves daily self-care skills that may include taking oral medications or insulin injections, dietary management, exercise and self-monitoring of blood glucose levels. Adherence to a complicated treatment plan is often difficult for patients and their families. Therefore, it is optimal to have a working relationship between the primary care practitioner and a diabetes care team experienced in the education and treatment of children who have diabetes. Treatment options vary and range from diet and exercise modifications alone to many different types of medications, including oral agents and insulin. Patients who present with type 2 diabetes without acidosis or considerable ketosis may be prescribed diet and exercise therapy, although most require medication at some time. Insulin may be required at diagnosis for patients who present with acidosis, ketosis or significant dehydration. After a period of improved glycemic control, many of these patients may discontinue insulin therapy and initiate or continue oral medications. The treatment course is dynamic and needs to be re-evaluated periodically. Keep in mind that a patient may change back and forth from monotherapy to combination therapy throughout the course of the disease. Lifestyle changes are important components of the patient’s treatment but can be the most difficult to maintain. Be sure to make appropriate referrals to a dietitian who is knowledgeable in the management of children who have diabetes mellitus. He or she should be able to make appropriate dietary recommendations. You should also emphasize healthy levels of physical activity and regular monitoring of the patient’s blood glucose levels. Assessing Treatment Goals The goal of treatment is to achieve near-normal blood glucose and hemoglobin A1C values. The United Kingdom Prospective Diabetes Study conveys that normalization of blood glucose levels in type 2 patients decreases the frequency of microvascular complications. This is particularly important in affected children because microvascular complications are due to long-term hyperglycemia. Target values for hemoglobin A1C, fasting blood glucose and postprandial blood glucose should be individualized. Measures of glycemia should be as close to normal as possible in order to ensure adequate growth and development without causing significant or frequent hypoglycemia. Practitioners differ in their opinions of these values but a target hemoglobin A1C value of less than 8 percent is a reasonable starting point. Key Insights On Metformin And Other Medications Although insulin is the only FDA-approved medication for the treatment of diabetes mellitus in children, most physicians experienced in treating type 2 diabetes in children use oral medications. Several classes of medications are available. If blood glucose and hemoglobin A1C targets are not met by diet and exercise, the American Diabetes Association recommends metformin as a first-line oral medication. Metformin decreases hepatic glucose production and indirectly enhances insulin sensitivity without directly affecting beta-cell function. Therefore, hypoglycemia from metformin monotherapy is uncommon. While it is a rare but severe complication, lactic acidosis does occur infrequently with metformin therapy. You should discontinue using the drug when dehydration might occur, such as during a gastroenteritic illness or diabetic ketoacidosis, or when radiocontrast material is being administered. Do not give it to patients who are known to have hepatic disease. If additional medications are necessary to achieve near-normal glycemic control, careful consideration should be given to adding a sulfonylurea, a glucosidase inhibitor or insulin. The sulfonylureas have been used for decades in the treatment of adults who have type 2. Given that these medications promote insulin secretion from the pancreas, be aware that hypoglycemia can occur so the ability to detect and self-monitor for hypoglycemia is a prerequisite for their use. Sulfonylureas include chlorpropamide, glipizide, glyburide and tolbutamide. (This class of medications can cause weight gain.) The biguanides also have been used for many years in adults. The thiazolidenediones (rosiglitazone and pioglitazone) are the only diabetes medications that directly improve peripheral insulin sensitivity. Since medications in this class are associated with hepatic toxicity, their use in children is not recommended. The glucosidase inhibitors (acarbose and miglitol) might have a minor role in treating children who have type 2 diabetes because they are not absorbed systemically. These drugs slow the hydrolysis of carbohydrates and their absorption from the gastrointestinal tract. This should be particularly helpful in preventing postprandial hyperglycemia. Although they are safe, the flatulence associated with their use may make them undesirable for some patients. Final Words There is currently no definitive cure for diabetes mellitus. However, with effective glycemic control, disease complications can be minimized as shown by the DCCT trial and other research. With the alarming increase in the prevalence of type 2 diabetes in children, health care practitioners need to be aware of the available treatments and common complications that occur in children with diabetes. Dr. Espensen is the Director of the Providence Diabetic Foot Center at the Providence St. Joseph Medical Center in Burbank, Calif. He lectures frequently on the diabetic foot and wound healing technologies. Dr. Mach is the Director of the Diabetes Center at Providence St. Joseph Medical Center in Burbank, Calif. He is a board-certified endocrinologist and gerontologist. Dr. Mach has a private practice in Orange County, Calif..
References 1. http://www.cdc.gov/diabetes/pubs/factsheets/search.htm 2. Nesmith JD. Type 2 diabetes mellitus in children and adolescents. Pediatr Rev 01-May-2001; 22(5): 147-152. 3. http://www.diabetes.org/main/info/complications/default.jsp 4. Macaluso, CJ et al. Type 2 Diabetes Mellitus among Florida Children and Adolescents. 1994 through 1998. Public Health Rep 2002 Jul-Aug; 117 (4):373-9. 5. Matthews DR, Wallace TM. Children with Type 2 diabetes: the risks of complications. Horm Res 2002;57 suppl 1:34-39. 6. Svensson J, et al. Increased risk of Childhood Type 1 Diabetes in Children born after 1985. Diabetes Care. 2002 Dec;25(12):2197-2201. 7. Gale EA. The Rise of Childhood Type 1 Diabetes in the 20th Century. Diabetes 2002 Dec;51(12):3353-61.