1. Some combination of antibodies against islet cells, insulin, glutamic acid decarboxylase (GAD65), or tyrosine phosphatases IA-2 and IA-2beta


    2. Patients are also prone to autoimmune thyroid disease, Addison disease, vitiligo, celiac disease, autoimmune hepatitis, myasthenia gravis, and pernicious anemia.

  1. Idiopathic

(β-cell destruction, usually leading to absolute insulin deficiency)


Type 1 diabetes is characterized by almost no circulating insulin and the failure of β-cells to respond to insulinogenic stimuli.

Because of the complete lack of insulin production, patients are at high risk for diabetic ketoacidosis (DKA).


Diabetic neuropathy

High blood sugar levels from type 1 and type 2 diabetes can lead to diabetic neuropathy, or nerve damage.

Damage to nerves controlling the digestive tract can lead to constipation, diarrhea, and incontinence.

Poor blood sugar control over a long period of time may increase the likelihood and frequency of constipation.

In addition to lifestyle choices and neuropathy, people with diabetes sometimes take medications that can slow gut mobility and cause constipation. Talk to your doctor about the side effects of any medications you take.



Updated information about the prevalence of diabetes in the United States is available from the Centers for Disease Control and Prevention (http://www.cdc.gov/diabetes/pubs/estimates.htm#prev).



  1. Insulin therapy is always necessary.




●Blood glucose testing –The parents or caregivers are instructed on the frequency and timing of blood glucose testing.(See 'Blood glucose monitoring' below.)

How to maintain a daily schedule and record of blood glucose test results,

xrecognize and treat hypoglycemia, and measure blood or urine ketone concentration, insulin administration, and the timing and carbohydrate content of meals and snacks.

●Insulin administration – Training includes teaching the family about the different types of prescribed insulin, how to measure and inject insulin, and how to rotate injection sites. Family members and caretakers must learn about the duration and action of the various types of insulin prescribed for their child. They must also understand how to adjust the insulin dose based upon blood glucose concentrations and carbohydrate intake. (See 'Insulin' below.)

In our practice, we encourage the parents to administer the first injection. Although this requires additional assistance and fairly directive behavior on the part of the clinician, we find that it facilitates the learning process. Because most parents are frightened about administering an injection to their child, their ability to learn is limited until they have administered the first injection. We also find it useful to have the parents administer a saline injection to themselves so that they realize the discomfort is minimal.

●Hypoglycemia – Families are taught to recognize the signs and symptoms of hypoglycemia. Detection of hypoglycemia is particularly difficult in the nonverbal young child and infant in whom the signs of hypoglycemia are nonspecific. Parents are trained to check a blood glucose level and, if this is too low, to intervene with dietary measures and/or glucagon. (See "Hypoglycemia in children and adolescents with type 1 diabetes mellitus" and 'Age-based care' below.)

●Blood or urine ketones – Families are taught to check urine for ketones or measure blood beta-hydroxybutyrate concentration at times of illness and/or if two consecutive blood glucose readings are greater than 250 mg/dL (13.9 mmol/L) [7]. This is especially important in young children, insulin pump users, or those with a history of diabetic ketoacidosis (DKA). (See 'Blood glucose monitoring' below.)

The initial educational and care phase may occur either in the inpatient or ambulatory setting. Most institutions have moved from prolonged inpatient admissions for newly diagnosed patients to either short hospitalizations or exclusively ambulatory management. Patient outcome is similar with outpatient and inpatient management, regardless of the length of inpatient hospitalization, and health care costs are much less with outpatient treatment [8-11]. Accordingly, we initiate the care of most newly diagnosed children with type 1 diabetes without ketoacidosis in the outpatient setting. A multidisciplinary team provides close follow-up (daily phone contact and ambulatory visits as necessary), comprehensive education, and an individualized management plan for the child and family.

plans should be made to return the child to school or daycare center, as appropriate. If insulin needs to be administered at the child's school or daycare center, a responsible individual must be identified and trained in basic diabetes management skills. In addition, appropriate individuals at the school or daycare center must be provided with information regarding the detection and management of hypoglycemia. (See "Special situations in children and adolescents with type 1 diabetes mellitus", section on 'School and daycare'.)

Patients with diabetes should wear a medical emergency bracelet/necklace to enable suitable intervention by emergency personnel should an emergency situation arise (ie, hypoglycemia or DKA). MedicAlert provides an excellent resource (www.medicalert.org).



Type 1 diabetes is characterized by an absolute insulin deficiency, so insulin is required.

Currently, all insulin sold in the United States is of human type and manufactured using recombinant DNA technology.

Bovine or porcine insulin can still be obtained via special permission from the U.S. Food and Drug Administration.

Modern insulin is highly pure and stable, and vials in use can be kept up to 30 days at room temperature. All types of insulin are standardized to a concentration of 100 units/mL ("U100").

When extremely high doses of insulin are required, a concentration of 500 units/mL ("U500") of regular insulin can be used.


Commonly Used Insulin Preparations, Their Pharmacokinetics and Unique Features*

Category of Insulin or Analogue Name Pharmacokinetics Unique Properties
Onset (hour) Peak (hour) End (hour)
Rapid acting

Insulin lispro (Humalog®)

Insulin aspart (NovoLog®)

Insulin glulisine (Apidra®)










Fixed duration of action, regardless of dose

Useful in patients allergic to insulin and other analogues13,14,15

More stable than other rapid-acting insulins

Antiapoptotic; may counteract β-cell destruction16

Short acting Regular insulin (Humulin R®, Novolin R®) 0.25–1.0 2–4 6–8
Intermediate acting

NPH (Humulin N®, Novolin N®)

Insulin detemir (Levemir®)








Action is relatively constant with gentle peak

Long acting Insulin glargine (Lantus®) 1.5 No peak 24+ Cannot be mixed with other insulins in same syringe

70/30 Humulin®/Novolin® (70% NPH, 30% regular)

50/50 Humulin®/Novolin® (50% NPH, 50% regular)

75/25 Humalog® (75% NPL, 25% lispro)

50/50 Humalog® (50% NPL, 50% lispro)

70/30 NovoLog Neutral® (70% protamine aspart, 30% aspart)
















Abbreviations: NPH = neutral protamine Hagedorn; NPL = neutral protamine lispro.



In addition to insulin, patients with type 1 diabetes may also be treated with prandial injections of pramlintide, a synthetic form of the β-cell–produced hormone amylin, which aids in suppressing glucagon secretion.4 

Patients with type 1 diabetes may also benefit from β-cell transplantation, pancreas transplantation, or combined kidney/pancreas transplantation.


  • Spontaneous ketoacidosis almost always develops in untreated cases, and insulin is required for survival. 1

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