Diabetes in children
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Jaspinder Kaur, MBBS[2]
Synonyms and keywords: Pediatric Diabetes Mellitus (DM)
Overview
Historical Perspective
Classification
- Type 1 Diabetes mellitus
- Type 2 Diabetes mellitus
- Monogenic diabetes: Neonatal diabetes, MODY-maturity onset diabetes of the young, mitochondrial diabetes, and lipoatrophic diabetes
- Diabetes secondary to other pancreatic diseases, endocrinopathies, infections and cytotoxic drugs
- Diabetes related to certain genetic syndromes
Pathophysiology
Type 1 Diabetes Mellitus
- Insufficient endogenous insulin leads to hyperglycemia, hyperglucagonemia, glucosuria, and without treatment, eventually ketosis, acidosis, dehydration, and death. About one-third of patients with newly-diagnosed type 1 diabetes present with diabetic ketoacidosis (DKA) which has a mortality rate of around 0.3-0.5%, despite aggressive treatment.
- The Diabetes Control and Complications Trial was the pivotal study published in 1993 documenting the clear association of chronic hyperglycemia with long-term microvascular complications such retinopathy, neuropathy, and microalbuminuria (as a surrogate for nephropathy). Follow-up studies have documented the association of chronic hyperglycemia with macrovascular complications as well as all-cause mortality. Iatrogenic hypoglycemia, however, was identified as the major limiting factor to intensive glucose control.
- For the last several decades, therapies have focused on normalizing glucose while minimizing the risk of hypoglycemia while at the same time monitoring for chronic complications and acknowledging the important psychosocial factors that affect a growing and developing children with a chronic disease.
Type 2 Diabetes Mellitus
- Obesity leads to peripheral insulin resistance, which in turn leads to hyperglycemia as discussed. Independent of obesity, certain ethnicities have higher risks of insulin resistance and beta cell dysfunction. Hyperglycemia leads to an osmotic diuresis (polyuria), which increases thirst (polydipsia). This diuresis causes moderate to severe dehydration. Prolonged hyperglycemia can produce two distinct emergent states in type 2 diabetes mellitus in children.
- Diabetic ketoacidosis: much more common in children with type 2 diabetes mellitus compared to adults. Lack of insulin inhibits the body's ability to use glucose for energy and reverts to breaking down fat for energy. This leads to ketosis, acidosis, and electrolyte abnormalities and may lead to coma and death.
- Hyperglycemic Hyperosmolar State (HHS): characterized by hypertonicity, extreme hyperglycemia (> 600 mg/dl), and severe dehydration. The profound hyperglycemia results in continued osmotic diuresis and intravascular depletion.
Causes
Differentiating [disease name] from other Diseases
- Salicylate toxicity
- Pheochromocytoma
- Diabetes insipidus
- Hyperthyroidism
Epidemiology and Demographics
Type 1 Diabetes Mellitus
- Type 1 diabetes may be diagnosed at nearly any age, though peaks in presentation occur between ages 5 to 7 and around puberty. There appears to be seasonal variation with more cases diagnosed in fall and winter. Unlike most autoimmune disorders, type 1 diabetes is slightly more common in boys and men. In the past several decades, type 1 diabetes incidence and prevalence has increased in most age, sex, and race/ethnic groups with some of the fastest growth in young children. There is significant variability in incidence based on geography and ethnicity. For example, the incidence in Finland is 60 per 100,000 person-years, while in China it is 0.1 per 100,000. In the United States, there are approximately 20 to 30 new diagnoses per 100,000 person-years. These incidences have increased by 200% to 300% in the past several decades. In the United States, there are now more than 1.25 million people living with type 1 diabetes., and around 500,000 are children. If a child has type 1 diabetes, concordance in another sibling is around 5%. In fraternal twins, it is around 10% to 30%, and with identical twins, it is 40% to 50%. Children of adults with type 1 diabetes are at an approximately 5% to 8% risk. In the United States, the general population risk is approximately 0.3%.
Type 2 Diabetes Mellitus
- Type 1 diabetes remains the most prevalent form of diabetes in children. However, type 2 diabetes mellitus is estimated to occur in one in three (20% to 33%) of new diagnoses of diabetes in children today. The rate of type 2 diabetes mellitus in children continues to rise even as the obesity rates have plateaued in these age groups. Risk factors include high-risk ethnicity (African American, Hispanic, Native Americans, Pacific Islanders, Asian Americans), a positive first-degree relative with the disorder, obesity, low birth weight, mother with gestational diabetes, and female sex. It is more likely to be diagnosed during adolescence when insulin resistance is common due to multiple factors including hormonal changes.