Diabetes Mellitus for PA

Diabetes Mellitus for the Physician Assistant Licensing Exam

Diabetes Mellitus (DM) is a chronic disorder characterized by hyperglycemia due to defects in insulin secretion, insulin action, or both.

Types:
Type 1 Diabetes Mellitus (T1DM): An autoimmune condition leading to destruction of pancreatic beta cells and absolute insulin deficiency. It typically occurs in children and young adults.
Type 2 Diabetes Mellitus (T2DM): Characterized by insulin resistance and relative insulin deficiency. T2DM is more common in adults and is strongly associated with obesity and physical inactivity.
Gestational Diabetes Mellitus (GDM): Diabetes diagnosed during pregnancy, with increased risk of developing T2DM post-partum.

T1DM: Patients present with the classic triad of polyuria, polydipsia, and polyphagia, often accompanied by weight loss. DKA is a common and life-threatening complication.
T2DM: Often asymptomatic initially or may present with fatigue, recurrent infections, blurred vision, and polyuria. Patients are often diagnosed through routine screening.
DKA: Occurs in T1DM and is characterized by hyperglycemia, ketosis, and metabolic acidosis, leading to dehydration and altered mental status.
HHS: A severe complication of T2DM marked by extreme hyperglycemia, dehydration, and altered consciousness, with minimal ketosis.

Fasting plasma glucose (FPG) ≥126 mg/dL.
2-hour plasma glucose ≥200 mg/dL during a 75 g oral glucose tolerance test (OGTT).
Hemoglobin A1c (HbA1c) ≥6.5%.
Random plasma glucose ≥200 mg/dL with classic symptoms of hyperglycemia.

T1DM: Insulin therapy is essential for survival. Patients use basal-bolus insulin regimens or continuous subcutaneous insulin infusion (CSII).
T2DM:
Lifestyle Modifications: Diet, weight loss, and exercise are first-line interventions.
Metformin: First-line pharmacologic treatment. Other options include GLP-1 receptor agonists, SGLT-2 inhibitors, and insulin in advanced disease.
Complication Management: Includes blood pressure control, lipid management, and annual screening for microvascular complications like retinopathy, nephropathy, and neuropathy.

Key Points

Types: T1DM involves autoimmune beta-cell destruction, while T2DM is due to insulin resistance and progressive beta-cell dysfunction. GDM occurs during pregnancy.
Diagnosis: Criteria include FPG ≥126 mg/dL, 2-hour OGTT ≥200 mg/dL, or HbA1c ≥6.5%.
Management: T1DM requires insulin therapy. T2DM is managed with lifestyle changes and medications, including metformin and other agents like GLP-1 agonists or SGLT-2 inhibitors.
Complications: Include microvascular (retinopathy, nephropathy, neuropathy) and macrovascular (cardiovascular disease) issues, along with acute complications like DKA and HHS.