Introduction
Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels (hyperglycemia) resulting from defects in insulin secretion, insulin action, or both. It is a major global health concern due to its increasing prevalence and serious long-term complications.
Types of Diabetes Mellitus
- Type 1 Diabetes: An autoimmune condition where the body destroys insulin-producing beta cells in the pancreas. It usually appears in childhood or adolescence.
- Type 2 Diabetes: A condition characterized by insulin resistance and relative insulin deficiency. It typically develops in adults but is increasingly seen in children.
- Gestational Diabetes: Occurs during pregnancy and usually resolves after childbirth, though it increases the risk of developing type 2 diabetes later in life.
Symptoms of Diabetes Mellitus
- Frequent urination (polyuria)
- Excessive thirst (polydipsia)
- Extreme hunger (polyphagia)
- Unexplained weight loss
- Fatigue and weakness
- Blurred vision
- Slow healing of wounds
Laboratory Tests for Diagnosis of Diabetes Mellitus
Several laboratory tests are used to diagnose diabetes mellitus. These tests help assess glucose metabolism and confirm the presence of diabetes or prediabetes.
1. Fasting Blood Glucose (FBG) Test
- Measures blood sugar after at least 8 hours of fasting.
- Normal: Less than 100 mg/dL
- Prediabetes: 100–125 mg/dL
- Diabetes: 126 mg/dL or higher
2. Oral Glucose Tolerance Test (OGTT)
- Patient fasts overnight, then drinks a glucose-rich beverage. Blood glucose is measured before and 2 hours after consumption.
- Normal: Less than 140 mg/dL
- Prediabetes: 140–199 mg/dL
- Diabetes: 200 mg/dL or higher
3. Glycated Hemoglobin (HbA1c) Test
- Measures average blood glucose over the past 2–3 months.
- Normal: Below 5.7%
- Prediabetes: 5.7–6.4%
- Diabetes: 6.5% or higher
4. Random Blood Glucose Test
- Can be taken at any time, regardless of meals.
- A result of 200 mg/dL or higher, with symptoms, indicates diabetes.
5. C-Peptide Test
- Used to evaluate insulin production. Low C-peptide suggests type 1 diabetes, while normal/high may suggest type 2 diabetes.
6. Autoantibody Tests
- Specific to type 1 diabetes. Detect autoantibodies attacking pancreatic beta cells.
- Examples include GAD (glutamic acid decarboxylase) antibodies and insulin autoantibodies (IAA).
Importance of Early Diagnosis
Early detection of diabetes is crucial to prevent complications such as kidney damage, nerve damage, cardiovascular disease, and vision problems. Laboratory tests help in diagnosis, monitoring treatment effectiveness, and adjusting medications.
Conclusion
Diabetes mellitus is a serious metabolic disorder requiring timely diagnosis and effective management. Laboratory tests play a key role in confirming the diagnosis, classifying the type of diabetes, and guiding treatment. Regular monitoring also helps in preventing long-term complications and maintaining good quality of life.