Defining and Identifying Diabetes Mellitus:
Defining Diabetes Mellitus:
Diabetes means siphon (to pass through) in Greek, while mellitus means sweet in Latin. The roots of these words allude to the inappropriately high passage of sugar in the urine of a patient who is frequently urinating (polyuria).
Diabetes mellitus is a metabolic disease involving inappropriately elevated blood glucose levels (hyperglycemia) because of defects in insulin secretion, insulin action, or both. It is a blanket term referring to various causes of hyperglycemia with different pathophysiologic etiologies. We commonly think of Type 1 diabetes and Type 2 diabetes, but Table 1 lists many other forms of diabetes mellitus.
| Type of Diabetes Mellitus | Description of Etiology |
| Type 1 diabetes | β-cell destruction (mostly immune-mediated but may be idiopathic) leading to absolute insulin deficiency. |
| Type 2 diabetes | Various degrees of β-cell dysfunction and insulin resistance |
| Monogenic diabetes (MODY/Neonatal diabetes) | Specific gene mutations leading to defects in β-cell function or defects in insulin action |
| Diseases of the Exocrine Pancreas (Type 3c diabetes) | Various conditions impacting exocrine pancreatic function (cystic fibrosis, trauma, tumor, pancreatitis, hemochromatosis, infection, etc.) |
| Drug- or chemical-induced diabetes | Iatrogenic diabetes due to drugs such as glucocorticoids, thiazide diuretics, some HIV/AIDs treatments, atypical antipsychotics, alpha-interferon, etc. that increase the risk of developing diabetes |
| Gestational diabetes | Diagnosed in the 2nd or 3rd trimester of pregnancy that was not overt diabetes before gestation. |
| Diabetes secondary to endocrinopathies | Endocrine disorders lead to excess hormone production that antagonizes insulin action (e.g., Cushing’s syndrome, GH excess, hyperthyroidism, pheochromocytoma, etc.) |
| Posttransplant diabetes (PTDM and NODAT) | Hyperglycemia in the post-transplant setting beyond which stress- or steroid-induced hyperglycemia |
| Uncommon “immune-mediated” forms of diabetes | “Stiff-man” syndrome, anti-insulin receptor antibodies, likely others |
| Diabetes secondary to infection | Certain viruses have been associated with β-cell dysfunction (e.g., congenital rubella, coxsackievirus B, cytomegalovirus, adenovirus, and mumps) |
| Genetic syndromes associated with diabetes | Many genetic syndromes are accompanied by an increased incidence of diabetes mellitus, including; Down’s syndrome, Klinefelter’s syndrome, Turner’s syndrome, Wolfram syndrome, Prader-Willi syndrome, porphyria, etc. |
Children may present with very subtle, or even downplayed, symptoms. It often takes a high degree of suspicion when these children are seen in outpatient settings. Mild hyperglycemia may go unnoticed altogether.
The three “P’s” – polyuria, polydipsia, and polyphagia are classically taught as the common presenting clinical symptoms. However, these “P’s” often do not occur simultaneously or can go unrecognized by the child or their caregiver as “abnormal.”
Click through the following graphic to learn more about how these symptoms may present.
Other clinical manifestations of persistent hyperglycemia may include:
If these initial symptoms of hyperglycemia are ignored long enough, more severe manifestations due to progressive dehydration and the buildup of serum ketones lead to diabetic ketoacidosis (DKA).
These symptoms often drive patients to seek more urgent evaluation at urgent-care clinics, same-day visits with their primary care physician, or emergency departments.
Symptoms of diabetic ketoacidosis (DKA) include:
History and Physical Exam:
A thorough history and physical exam are important when suspecting new-onset diabetes for multiple reasons:
- Can help determine the etiology and type of diabetes mellitus
- Evaluates for factors that may cause non-diabetic hyperglycemia
- Identifies risk factors for developing diabetes mellitus (such as those in Table 1)
- Guides clinical decision-making regarding the urgency of work-up and the need for more advanced care
The same applies to a patient with known diabetes mellitus.
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