Diabetes

1) Disease Description (Causes and Symptoms)

• Definition/Pathophysiology

  • Diabetes mellitus is a metabolic disease in which blood glucose levels become chronically elevated due to insufficient insulin secretion or reduced insulin action. Persistent hyperglycemia causes small- and large-vessel damage and metabolic abnormalities.
  • Causes: Interaction between genetic predisposition and environmental factors (obesity, sedentary lifestyle, high-calorie diet, stress, advanced age, medications, etc.). A single-gene abnormality is identified in less than 1% of cases. The recent increase in prevalence is mainly related to obesity and changes in lifestyle.

• Main Symptoms

  • The three classic symptoms caused by hyperglycemia—polydipsia (increased thirst), polyuria (frequent urination), and polyphagia (increased appetite)—as well as fatigue, weight loss (especially in type 1 diabetes), visual disturbances (reduced vision), numbness or tingling in the hands and feet (peripheral neuropathy), and itchy skin (especially vaginal itching in women), etc.
  • Mild hyperglycemia is often asymptomatic.

• Diagnostic Criteria (Representative Criteria; Differences Between Cases With and Without Symptoms)

  • Random blood glucose ≥ 200 mg/dL together with symptoms (polydipsia, polyuria, weight loss, etc.) → diabetes mellitus is suspected (repeat testing is recommended before confirmation; a single test may be sufficient for diagnosis if there are significant symptoms or metabolic abnormalities).
  • Fasting blood glucose (8 hours of fasting) ≥ 126 mg/dL.
  • 2-hour blood glucose ≥ 200 mg/dL during an oral glucose tolerance test (75 g).
  • HbA1c ≥ 6.5% is widely used as an additional diagnostic criterion (supplementary assessment may be necessary depending on the testing method and circumstances).
  • If there are no obvious symptoms of hyperglycemia, the diagnosis is confirmed when the criteria are met on repeat testing on another day.

2) Treatment Methods and Precautions

• Main Treatment Principles

  • The goal of treatment is to maintain appropriate blood glucose levels and prevent or delay acute metabolic abnormalities and chronic complications (retinopathy, nephropathy, neuropathy, and cardiovascular and cerebrovascular disease). Treatment goals should be individualized according to the patient's age, complications, and comorbidities.

• Lifestyle Management (Basic for All Patients)

  • Dietary management: calorie control, weight loss (for people who are overweight or obese), and a balanced diet.
  • Exercise: at least 150 minutes of moderate-intensity aerobic exercise per week is recommended (adjusted according to the physician's judgment).
  • Modification of cardiovascular risk factors, including weight management, smoking cessation, and moderation of alcohol consumption.

• Pharmacological Treatment

  • Type 2 diabetes mellitus: The first-line medication is generally metformin (considering underlying diseases and kidney function). Depending on the patient's characteristics, SGLT2 inhibitors, GLP-1 receptor agonists, DPP-4 inhibitors, sulfonylureas, thiazolidinediones, insulin, and other treatments may subsequently be selected.
    • SGLT2 inhibitors: Medications that reduce the risk of heart failure and chronic kidney disease (kidney function criteria should be carefully considered).
    • GLP-1 analogues: Effects include weight loss and some cardiovascular benefits.
  • Type 1 diabetes mellitus: Basically requires insulin treatment (multiple daily insulin injections or an insulin pump).
  • Insulin: Used when hyperglycemia is inadequately controlled or when acute metabolic abnormalities occur.
  • Medication selection should consider kidney function, the presence of cardiovascular disease, body weight, and the risk of hypoglycemia.

• Procedures/Surgery

  • Metabolic and bariatric surgery (obesity surgery) can be effective for improving blood glucose levels in eligible patients with obesity.
  • Pancreas transplantation or simultaneous pancreas-kidney transplantation may be considered under strict indications (selectively, in limited cases).

• Prevention and Management of Complications (Important)

  • Blood pressure and lipid control: In addition to blood glucose, blood pressure (with individualized targets) and LDL control are important for preventing macrovascular complications.
  • Regular complication screening: Fundus examination (retinopathy), urine albumin/kidney function tests (nephropathy), neurological evaluation (neuropathy), and foot examinations.
  • Recommended vaccinations: influenza, pneumococcal, and hepatitis B vaccinations (for people for whom they are recommended).

• Precautions (During Self-Management)

  • When taking medications that carry a risk of hypoglycemia, do not skip meals; consume sugar immediately in the event of hypoglycemia.
  • During acute infection, surgery, vomiting, or diarrhea, manage blood glucose and hydration and consult a healthcare professional.
  • Medication selection and dosage adjustment are necessary in people with reduced kidney function, pregnant people, and older adults.
  • Seek immediate medical evaluation if a foot wound or laceration occurs (to prevent worsening necrosis or infection).

3) Outpatient Visit Checklist (Including Preparation Items and Example Questions)

• Items to Bring (Recommended for Outpatient Visits)

  • A list of currently used medications and supplements (including dosage and timing) or a photo of the medication prescriptions
  • Recent blood glucose records (including self-monitoring blood glucose records and continuous glucose monitor (CGM) printouts)
  • Recent test results (within the past 3–6 months, including HbA1c, fasting blood glucose, blood lipids, kidney function (BUN·Cr), urine albumin, etc.)
  • Records of weight and blood pressure, and notes on changes in symptoms (polyuria, polydipsia, weight changes, numbness or tingling, etc.)
  • Foot condition (whether wounds are present) and whether there have been changes in vision

• Things to Confirm Before the Outpatient Visit

  • Whether a fasting blood glucose test is scheduled (whether fasting is required before the test)
  • Instructions on stopping or continuing currently used medications (whether any specific medication needs to be stopped before the test)

4) Examples of General Questions to Ask the Doctor

• "If I start this medication (or treatment), how much improvement in blood glucose can I expect?"
• "What are the common and serious side effects of this medication? How should I respond if they occur?"
• "How should we set my target HbA1c and daily target blood glucose range?"
• "What else should I do to reduce my risk of cardiovascular or kidney disease?"

5) Examples of Disease-Specific Questions (1–2)

• If planning a pregnancy or currently pregnant:
  • "How should my blood glucose targets and medication use, especially oral medications, be adjusted before and during pregnancy?"
• Regarding hypoglycemia and driving:
  • "I am at high risk of hypoglycemia. What safety precautions and response measures should I follow while driving or operating machinery?"

(Note: Regular testing and lifestyle improvements are key to diabetes management, and treatment varies according to each individual's condition. Please consult your physician regarding a specific diagnosis and treatment plan.)