1. Introduction
- Definition: Type 1 Diabetes Mellitus (T1DM) is an autoimmune condition characterised by the destruction of insulin-producing beta cells in the pancreas, leading to chronic hyperglycaemia.
- Epidemiology: T1DM accounts for approximately 5–10% of all diabetes cases, often diagnosed in childhood or adolescence but can occur at any age.
- Significance: Requires lifelong insulin therapy and diligent management to prevent acute and chronic complications.
2. Causes and Risk Factors
- Causes:
- Autoimmune destruction of pancreatic beta cells.
- Likely triggered by genetic predisposition and environmental factors.
- Risk Factors:
- Genetic predisposition (e.g., HLA-DR3, HLA-DR4 alleles).
- Family history of autoimmune diseases.
- Environmental triggers: Viral infections (e.g., enterovirus), early introduction of cow’s milk, or vitamin D deficiency.
3. Pathophysiology
- T-cell-mediated autoimmune destruction of beta cells leads to absolute insulin deficiency. Without insulin, glucose uptake in peripheral tissues is impaired, causing hyperglycaemia. Increased lipolysis and ketogenesis result in the production of ketones, leading to diabetic ketoacidosis (DKA) in severe cases.
4. Symptoms and Features
- Classic Symptoms:
- Polyuria (excessive urination).
- Polydipsia (excessive thirst).
- Polyphagia (increased hunger).
- Unexplained weight loss.
- Acute Presentations:
- Diabetic ketoacidosis (DKA): Abdominal pain, nausea, vomiting, fruity-smelling breath, rapid breathing, and confusion.
- Long-term Symptoms:
- Fatigue, recurrent infections, or delayed wound healing.
5. Complications
- Acute:
- Diabetic ketoacidosis (DKA): A life-threatening medical emergency.
- Hypoglycaemia due to insulin overdose or missed meals.
- Chronic:
- Microvascular: Retinopathy, nephropathy, and neuropathy.
- Macrovascular: Cardiovascular disease, stroke, and peripheral vascular disease.
6. Diagnosis
- Clinical Features: Symptoms of hyperglycaemia and a history of autoimmune conditions.
- Diagnostic Tests:
- Fasting plasma glucose ≥7.0 mmol/L (126 mg/dL).
- Random plasma glucose ≥11.1 mmol/L (200 mg/dL) with classic symptoms.
- HbA1c ≥6.5%.
- Autoantibodies: Anti-GAD65, anti-IA2, or islet cell antibodies.
- C-peptide levels: Low or undetectable, confirming insulin deficiency.
7. Management Overview
- Goals: Maintain optimal glycaemic control, prevent acute and chronic complications, and improve quality of life.
- Approach: Lifelong insulin therapy, blood glucose monitoring, lifestyle modifications, and patient education.
8. Treatment Options with Cost (USD)
- Insulin Therapy:
- Basal insulin (e.g., glargine): ~$150–$300 per vial.
- Bolus insulin (e.g., lispro): ~$150–$300 per vial.
- Blood Glucose Monitoring:
- Continuous glucose monitoring (CGM): ~$300–$500 for the device, plus ~$50–$100/month for sensors.
- Glucometer: ~$20–$50, with strips costing ~$25–$50 per box.
9. Advanced Treatment Options with Cost (USD)
- Insulin Pumps:
- Device cost: ~$4,000–$7,000, with ~$100–$300/month for supplies.
- Pancreatic or Islet Cell Transplantation:
- Cost: ~$100,000–$300,000, reserved for select cases of refractory diabetes.
10. Pharmacological Treatment
- Insulin Regimens:
- Basal-Bolus Therapy: Long-acting insulin once daily + rapid-acting insulin before meals.
- Insulin Pump Therapy: Delivers a continuous infusion of rapid-acting insulin.
- Adjunctive Treatments:
- SGLT2 inhibitors (off-label in type 1 diabetes) to reduce glucose levels and cardiovascular risks (use cautiously).
11. Medication Tables
Table 1: Doses and Side Effects
Drug | Indication | Dose | Common Side Effects |
---|---|---|---|
Insulin glargine | Basal insulin | 0.2–0.4 units/kg once daily | Hypoglycaemia, weight gain |
Insulin lispro | Bolus insulin | 4–10 units before meals | Hypoglycaemia, injection site reaction |
Glucagon | Severe hypoglycaemia | 1 mg intramuscularly | Nausea, vomiting |
Metformin | Adjunct for insulin sensitivity (off-label) | 500–2,000 mg daily | GI upset, lactic acidosis (rare) |
Table 2: Brand Names and Approximate Costs (USD)
Drug | Brand Names | Approx. Cost |
---|---|---|
Insulin glargine | Lantus, Basaglar | $150–$300 per vial |
Insulin lispro | Humalog | $150–$300 per vial |
Glucagon | Glucagen, Gvoke | $100–$200 per kit |
Metformin | Glucophage | $10–$30 per month |
12. Lifestyle Interventions
- Follow a structured, balanced diet with attention to carbohydrate counting.
- Regular exercise to improve insulin sensitivity and overall health.
- Avoid smoking and alcohol, which can worsen complications.
- Develop strategies for stress management to reduce glycaemic fluctuations.
13. Monitoring Parameters
- Regular self-monitoring of blood glucose (SMBG) or use of CGM.
- Quarterly HbA1c measurements to assess long-term glycaemic control.
- Annual screening for complications: eye exams, urine albumin-to-creatinine ratio, and foot exams.
- Monitor for hypoglycaemia, especially in patients on intensive insulin therapy.
14. Patient Counseling Points
- Educate on the importance of insulin therapy and adherence to prevent complications.
- Teach proper insulin injection techniques and site rotation to avoid lipodystrophy.
- Discuss symptoms of hypoglycaemia (e.g., sweating, shakiness) and how to treat it promptly.
- Emphasise the importance of routine follow-ups for early detection and management of complications.
15. Special Populations
- In Children: Requires weight-based insulin dosing; education tailored for parents and caregivers.
- In Pregnancy: Tight glycaemic control is essential to reduce risks of congenital abnormalities and pregnancy complications.
- In Elderly: Minimise hypoglycaemia risk; individualise glycaemic targets based on comorbidities.
16. Prevention
- While T1DM cannot be prevented, early screening in high-risk individuals may help delay the onset in some cases.
- Ongoing research is exploring immunomodulatory therapies to prevent beta-cell destruction.
17. FAQs
- What is Type 1 Diabetes?
Answer: An autoimmune condition where the immune system destroys insulin-producing cells in the pancreas. - What causes Type 1 Diabetes?
Answer: A combination of genetic predisposition and environmental triggers. - How is Type 1 Diabetes treated?
Answer: With lifelong insulin therapy, blood glucose monitoring, and lifestyle changes. - Can Type 1 Diabetes be cured?
Answer: No, but it can be effectively managed with treatment. - What is diabetic ketoacidosis (DKA)?
Answer: A life-threatening complication caused by severe insulin deficiency, leading to high blood sugar and ketone production. - How often should blood glucose be monitored?
Answer: At least 4–6 times daily or using a continuous glucose monitor (CGM). - What foods should be avoided in T1DM?
Answer: Sugary, high-carb, and processed foods should be limited. - Can exercise help with T1DM?
Answer: Yes, regular exercise improves insulin sensitivity and overall health. - What is an insulin pump?
Answer: A device that delivers continuous insulin infusion, replacing multiple daily injections. - Is T1DM genetic?
Answer: There is a genetic predisposition, but environmental factors also play a role. - How can hypoglycaemia be managed?
Answer: By consuming fast-acting carbohydrates (e.g., glucose tablets, juice). - Can children live a normal life with T1DM?
Answer: Yes, with proper management, they can lead healthy, active lives. - How often should HbA1c be checked?
Answer: Every 3 months to assess long-term blood sugar control. - What is the target HbA1c for T1DM?
Answer: Generally <7%, though individual targets may vary. - Can stress affect blood sugar levels?
Answer: Yes, stress can cause glycaemic fluctuations and should be managed.