Why has there been an escalation in the prevalence of type 2 diabetes in this previously unaffected population? The answer to this question appears to be closely related to features of our modern way of life. Increased body weight is strongly associated with type 2 diabetes in youth, pointing to lifestyle as a causative factor. Childhood obesity has more than tripled since the 1970s [14]. It is anticipated that obesity will affect the health of 91 million children worldwide by 2025 [15].

Prediabetes is an asymptomatic condition and can only be detected by laboratory testing. Prediabetes includes any one of the following findings of increased risk for diabetes [20]:

The presence or absence of endogenous, or internally produced, insulin in the body is the defining factor that differentiates type 1 and type 2 diabetes (Table 1). Type 1 diabetes is an autoimmune disease that leads to the destruction of the insulin-producing beta cells of the pancreas, resulting in a complete absence of endogenous insulin [26]. It has traditionally been associated with onset in people younger than 30 years of age. Until recently, it was the only type considered prevalent in children. In this type of diabetes, insulin therapy is required and is the only appropriate pharmacologic option. Without insulin therapy, the person with type 1 diabetes will develop ketoacidosis, a life-threatening condition characterized by high blood glucose levels and a buildup of acids in the blood that will result in death if not treated.

Because it is a relatively new phenomenon, there is still much to learn about the epidemiology and pathophysiology of type 2 diabetes in children. While it closely resembles that of adults, youth-onset type 2 diabetes displays unique aspects, such as rapidly progressive beta-cell decline and accelerated development of diabetes complications [20,27,28]. According to the CDC, type 2 diabetes in children is usually diagnosed between 10 and 19 years of age. Risk factors include obesity, having a family member with type 2 diabetes, and being born to a mother with gestational diabetes. After 10 years of age, being a member of minority populations, such as Hispanic, African American, Asian/Pacific Islander, and American Indian, greatly increases the risk for development of type 2 diabetes in youth [29]. Whether it occurs in adults or children, most cases of type 2 diabetes begin with insulin resistance. In this condition, the pancreas initially continues to produce insulin, but the tissues are unable to use it. This may be due to a scarcity of receptors on the cells or because the receptors do not function well. Reasons for poorly functioning receptors include adiposity, muscular inactivity, and genetic factors. The beta cells of the pancreas respond to insulin resistance by producing even more insulin in an attempt to compensate. However, much of the insulin remains unused and blood levels of insulin are temporarily high (hyperinsulinemia). After a period of manufacturing large amounts of insulin, the beta cells of the pancreas eventually become exhausted, the amount of endogenous insulin greatly declines, and clinical diabetes ensues. In some cases, type 2 diabetes can be managed with a combination of diet, exercise, and oral medications. Many times, insulin therapy is required to control blood glucose levels and to prevent long-term complications of the disease. Individuals with type 2 diabetes usually produce enough insulin to prevent ketoacidosis. Therefore, they are not truly "insulin dependent," even if they do use insulin therapy to control blood glucose.

Because it is a relatively new phenomenon, there is still much to learn about the epidemiology and pathophysiology of type 2 diabetes in children. While it closely resembles that of adults, youth-onset type 2 diabetes displays unique aspects, such as rapidly progressive beta-cell decline and accelerated development of diabetes complications [20,27,28]. According to the CDC, type 2 diabetes in children is usually diagnosed between 10 and 19 years of age. Risk factors include obesity, having a family member with type 2 diabetes, and being born to a mother with gestational diabetes. After 10 years of age, being a member of minority populations, such as Hispanic, African American, Asian/Pacific Islander, and American Indian, greatly increases the risk for development of type 2 diabetes in youth [29]. Whether it occurs in adults or children, most cases of type 2 diabetes begin with insulin resistance. In this condition, the pancreas initially continues to produce insulin, but the tissues are unable to use it. This may be due to a scarcity of receptors on the cells or because the receptors do not function well. Reasons for poorly functioning receptors include adiposity, muscular inactivity, and genetic factors. The beta cells of the pancreas respond to insulin resistance by producing even more insulin in an attempt to compensate. However, much of the insulin remains unused and blood levels of insulin are temporarily high (hyperinsulinemia). After a period of manufacturing large amounts of insulin, the beta cells of the pancreas eventually become exhausted, the amount of endogenous insulin greatly declines, and clinical diabetes ensues. In some cases, type 2 diabetes can be managed with a combination of diet, exercise, and oral medications. Many times, insulin therapy is required to control blood glucose levels and to prevent long-term complications of the disease. Individuals with type 2 diabetes usually produce enough insulin to prevent ketoacidosis. Therefore, they are not truly "insulin dependent," even if they do use insulin therapy to control blood glucose.

Uncontrolled hyperglycemia over a number of years is known to cause damage to the small vessels that supply the retina of the eye (retinopathy), the nephrons of the kidney, and the motor, sensory, and autonomic nerves. There is evidence that these complications are especially aggressive in young people with type 2 diabetes; they are also highly prevalent [32,33,37]. The United Kingdom Prospective Diabetes Study demonstrated that intensive treatment of type 2 diabetes in adults can significantly lower the risk for developing diabetes-related eye, kidney, and nerve disease. The findings from this study included a 25% reduction of microvascular disease in subjects who maintained long-term glycemic control [38].

A person has metabolic syndrome if he or she has any three of the following risk factors [39,40]:

A person has metabolic syndrome if he or she has any three of the following risk factors [39,40]:

Risk factors for the development of type 2 diabetes in young people have been identified. These include [7,30,41,42]:

Acanthosis nigricans is a skin condition characterized by brownish-black patches, usually found on the back of the neck, in the axillae, and on areas exposed to repeated friction. They are slightly raised lesions that feel velvety to touch. Presence of the condition is considered a marker of hyperinsulinemia, and it develops in some cases of type 2 diabetes in children. This sign is most frequently recognized in obese, dark-skinned individuals and occurs more frequently in Native Americans, African Americans, and Hispanics when compared to White or Asian-origin individuals [43]. Parents of children with this condition often mistake acanthosis nigricans for poor hygiene and attempt to treat it with vigorous scrubbing and topical medications or cleansers. Some schools have initiated screening procedures for acanthosis nigricans, as many obese children who go on to develop type 2 diabetes present with only this sign [31].

PCOS is a disorder of the female reproductive system and is closely associated with insulin resistance. It is characterized by chronic anovulation, resulting in scanty or infrequent menstruation. In patients with PCOS, estrogen levels are usually normal while androgen levels are high. The elevated androgen levels can result in acne and hirsutism [44].

The American Diabetes Association (ADA) recommends the screening of asymptomatic high-risk youth for type 2 diabetes every three years, beginning at 10 years of age or the onset of puberty, whichever occurs first. For the purposes of screening criteria, the ADA considers children at high risk if they are overweight (BMI ≥85th percentile) or obese (BMI ≥95th percentile) and have one or more of the following additional risk factors [20]:

The American Diabetes Association (ADA) recommends the screening of asymptomatic high-risk youth for type 2 diabetes every three years, beginning at 10 years of age or the onset of puberty, whichever occurs first. For the purposes of screening criteria, the ADA considers children at high risk if they are overweight (BMI ≥85th percentile) or obese (BMI ≥95th percentile) and have one or more of the following additional risk factors [20]:

The primary means for treating type 2 diabetes in youth is lifestyle management, which includes youth-oriented, culturally appropriate self-management education and support, and weight loss through a healthy eating plan coupled with increased daily physical activity [20]. Blood glucose monitoring is important in providing feedback to the individual on how these changes affect glycemia. Clinical practice guidelines from the American Academy of Pediatrics (AAP) recommend starting metformin in newly diagnosed patients with an A1c of 6.5% or greater [46]. This recommendation also is supported by the ADA [20].

Achieving and maintaining a reasonable body weight is the major therapeutic goal in the management of type 2 diabetes in youth. Other goals of medical nutrition therapy include normalizing blood glucose (without excessive hypoglycemia) and maintaining healthy lipid and blood pressure values while allowing for normal growth and development [16,20].

Guidelines for facilitating healthy eating-related behaviors in youth include:

Table 6 lists various medications used in the treatment of type 2 diabetes, although many are not labeled for use in children. Metformin and insulin are approved for children with type 2 diabetes[20,31]. In addition, the GLP-1 agonists dulaglutide, extended-release exenatide, and liraglutide are approved for use in children 10 years of age and older if glycemic targets are not met with metformin (with or without insulin) and if the child's medical and family history allow[20,60]. In metabolically stable patients, metformin, if not contraindicated and if tolerated, is the preferred initial pharmacologic agent for the treatment of type 2 diabetes[20].

Metformin acts by decreasing the amount of glucose produced by the liver and improving insulin sensitivity. For adolescents using metformin, it is important to screen for alcohol abuse, including binge drinking, as this medication is contraindicated in those with moderate-to-heavy alcohol use. Besides being effective in lowering blood glucose levels, metformin has other advantages:

The prevention and control of long-term complications in young patients with diabetes is of vital importance due to the increased risks associated with earlier disease onset. The coexistence of obesity, hypertension, and dyslipidemia, which are common in children with type 2 diabetes, greatly increases the risk for cardiovascular disease. Because of the seriousness of these complications, hypertension and dyslipidemia must be aggressively treated and should be considered as important as blood glucose control. These comorbidities are often already present at the time of diagnosis. Therefore, the ADA recommends that blood pressure measurement, fasting lipid profile, microalbuminuria assessment, and dilated eye exam be performed at the time of diagnosis [20]. In addition to cardiovascular risk, hypertension is a risk factor for the development of eye and kidney disease. Routine preventive care can often delay or slow the progression of complications by ensuring early treatment. The routine preventive care schedule recommended for all patients with diabetes consists of [3,7,20]:

Some parents may cope by trying to achieve perfection in meeting therapeutic goals. This is manifested by rigid adherence to diet and unrealistically expecting blood glucose values to be within the target range all of the time. In these cases, parents should be educated that their child's self-esteem may be threatened by the overemphasis on treatment. They can also be educated that it is appropriate to make compromises in the meal plan as long as the overall eating pattern is healthy. For example, cake and ice cream for a birthday may add calories and raise blood sugar, but consumption of these types of food can occasionally be accommodated by working them into the entire day's meal plan and by maintaining or increasing physical activity.