Disease Description (Causes and Symptoms)
- Definition summary: Type 1 diabetes mellitus (insulin-dependent diabetes mellitus) is a disease caused by the destruction of pancreatic beta cells, resulting in little or no insulin secretion. The resulting absolute insulin deficiency causes hyperglycemia and metabolic abnormalities.
- Causes/pathophysiology:
- Genetic predisposition combined with environmental triggers (viral infections, stress, etc.) causes an autoimmune response that destroys beta cells.
- Insulin deficiency → reduced intracellular use of glucose → increased blood glucose (hyperglycemia) → glucose excretion by the kidneys (glycosuria) → dehydration due to osmotic diuresis and increased ketone production (risk of ketoacidosis).
- Main symptoms:
- Polyuria (increased urination), polydipsia (increased thirst), polyphagia (or loss of appetite in children), weight loss, fatigue, vomiting, abdominal pain
- In severe cases, diabetic ketoacidosis (DKA): vomiting, abdominal pain, dehydration, altered consciousness, etc.
- Diagnostic criteria (blood glucose criteria):
- Random blood glucose ≥ 200 mg/dL when accompanied by symptoms
- Fasting blood glucose ≥ 126 mg/dL
- 2-hour oral glucose tolerance test value ≥ 200 mg/dL
Treatment Methods (Standard Treatment, Medication, Lifestyle Management, and Precautions)
- Basic principles:
- Lifelong insulin therapy is required (absolute insulin replacement).
- Establish an integrated treatment plan combining meals, exercise, and insulin together with self-monitoring of blood glucose (SMBG) or continuous glucose monitoring (CGM).
- Medications and devices:
- Types of insulin: ultra-rapid-acting (rapid-acting), rapid-acting, intermediate-acting, basal (long-acting) insulin, and insulin analogues.
- Administration methods: multiple daily injections (MDI, basal-bolus therapy) or continuous subcutaneous insulin infusion (insulin pump, CSII).
- Continuous glucose monitoring (CGM) is recommended, especially for children/adolescents and when there is a risk of recurrent hypoglycemia.
- Treatment of acute complications:
- DKA: immediate hospital treatment (fluid therapy, intravenous insulin, and electrolyte correction—especially potassium monitoring). Intensive care management is required in severe cases.
- Hypoglycemia: in mild cases, administer 15–20 g of rapidly absorbed sugar (glucose tablets, fruit juice, etc.); in cases of loss of consciousness, use glucagon (injection).
- Lifestyle management:
- Dietary therapy: For growing children, maintain nutritional balance according to age and activity level so as not to impair growth. Adjustment of insulin dosage using carbohydrate counting is recommended.
- Exercise: Regular exercise is recommended (check blood glucose before and after exercise and prepare carbohydrates to prevent hypoglycemia). Dosage adjustment is necessary because insulin sensitivity increases during exercise.
- Education: Carbohydrate counting, injection technique/pump management, recognizing and responding to signs of hypoglycemia, hyperglycemia, and DKA, and how to use medications and devices.
- Preventive testing and complication management:
- Regular HbA1c measurement (adjust the frequency according to treatment goals), fundus examinations (retinopathy), urine/serum urine tests (nephropathy), neurological examinations (neuropathy), and blood pressure/lipid testing (cardiovascular risk).
- Vaccinations: Seasonal influenza, pneumococcal vaccines, etc. are recommended.
- Precautions:
- Managing the risk of hypoglycemia (especially nocturnal hypoglycemia): adjust blood glucose targets and medication dosages, and adjust insulin when exercise or meals change.
- During “sick days” involving infection, surgery, fever, etc., do not stop insulin; frequent blood glucose and ketone testing is necessary.
- If planning a pregnancy, blood glucose should be controlled in advance and consultation with a specialist is necessary.
Outpatient Visit Checkpoints (Including Items to Bring, Records, and Example Questions)
- Items/documents to bring:
- A list of all currently used medications (insulin/other medications), including doses and administration times
- Recent blood glucose records (self-monitoring blood glucose meter records or CGM data), and records of hypoglycemia or hyperglycemia episodes
- Recent HbA1c results and other test results (kidney function, urine tests, etc.), preferably as printed copies
- Notes on weight and height (a growth chart for growing children), and meal and exercise patterns
- The device and data download files when using an insulin pump/CGM
- Checks before the visit:
- Blood glucose patterns over the past several days and the circumstances of any hypoglycemic episodes (time, symptoms, and response)
- Whether there have been changes in symptoms (polyuria, polydipsia, weight change, vomiting, abdominal pain, etc.)
- Any recent infections, surgery, travel, or vaccinations
- Examples of items to confirm during the outpatient visit (to be listed by the patient):
- Recent HbA1c and whether it is within the target range
- Type of insulin and administration method (whether dose adjustment is needed)
- Investigation of the causes of hypoglycemia and hyperglycemia and preventive measures
Examples of General Questions to Ask the Doctor
- "What is my current target HbA1c range? What specific adjustments are needed to achieve it?"
- "What side effects or precautions should I be aware of with this insulin (or pump)?"
- "I frequently experience hypoglycemia. How should I prevent and manage it?"
- "How should I adjust my insulin dose during exercise, infection, menstruation (or growth)?"
Examples of Disease-Specific Questions
- "Which insulin therapy—pump or multiple daily injections—is more suitable for my current lifestyle and blood glucose patterns? What are the expected advantages and disadvantages of switching?"
- "When there is a risk of DKA, based on what signs (including blood glucose and ketone level criteria) should I visit the emergency room from home? Please explain in detail how to test ketones and respond at home."