GOR

Diabetes Mellitus

Definition

  • Diabetes mellitus (DM) is a group of metabolic disorders characterized by chronically elevated blood glucose (BG) and abnormalities in carbohydrate, fat, and protein metabolism.

  • Without effective treatment, DM can lead to acute complications such as diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic syndrome (HHS), and chronic complications affecting microvascular and macrovascular health.

Types of Diabetes Mellitus

Type 1 DM

  • Constitutes 5-10% of cases; typically diagnosed in children and adolescents.

  • Caused by autoimmune destruction of pancreatic β-cells leading to insulin deficiency.

  • Often triggered by an unknown environmental factor in genetically susceptible individuals, mediated by macrophages and T lymphocytes that produce autoantibodies against β-cells.

  • Can lead to a deficiency of amylin, which normally suppresses glucagon secretion and slows gastric emptying.

  • Patients may experience a 'honeymoon' phase post-diagnosis when insulin needs decrease temporarily.

Type 2 DM

  • Represents 90-95% of cases; commonly presents with risk factors such as obesity.

  • Characterized by:

    • Impaired insulin secretion with progressive β-cell failure and reduced mass.

    • Insulin resistance contributing to excessive hepatic glucose production and reduced glucose uptake in muscle.

    • Inadequate suppression of glucagon secretion due to GLP-1 resistance and insulin deficiency.

    • Increased glucose reabsorption due to SGLT-2 upregulation in kidneys.

Gestational Diabetes (GDM)

  • Occurs during pregnancy and can increase risks for both mother and child.

Other Specific Types

  • Includes maturity onset diabetes of the young (MODY), genetic syndromes (e.g., Down syndrome), infections, and drug-induced diabetes from glucocorticoids, thiazides, etc.

Complications of Diabetes Mellitus

  • Microvascular Complications: Retinopathy, neuropathy, nephropathy.

  • Macrovascular Complications: Coronary heart disease, stroke, peripheral vascular disease.

Clinical Presentation

  • Type 1 Diabetes Mellitus:

    • Initial symptoms include polyuria, polydipsia, polyphagia, weight loss, fatigue, and lethargy.

    • Patients may present acutely with DKA, often triggered by infection or psychological stress.

  • Type 2 Diabetes Mellitus:

    • Patients may be asymptomatic or present with mild fatigue and are often overweight or obese.

    • Many are diagnosed incidentally through routine testing or when complications arise.

Diagnosis of Diabetes Mellitus

  • Normal fasting plasma glucose (FPG) levels are 70-99 mg/dL.

  • Impaired fasting glucose (IFG) is 100-125 mg/dL.

  • Criteria for diabetes diagnosis include:

    1. A1C ≥6.5% (?? mmol/mol Hb)

    2. FPG ≥126 mg/dL (7.0 mmol/L)

    3. OGTT ≥200 mg/dL (11.1 mmol/L)

    4. Random plasma glucose ≥200 mg/dL along with classic hyperglycemia symptoms.

  • Prediabetes is diagnosed when A1C is 5.7%-6.4%.

Treatment Goals

  • Primary goal: Prevent or delay long-term microvascular/macrovascular complications.

  • Alleviate hyperglycemia symptoms, optimize quality of life, and minimize hypoglycemia risk.

Initial Assessment for Treatment

  • Comprehensive initial evaluation includes history-taking, physical exam, and lab testing (e.g., A1C, lipid profile).

  • Assess psychosocial conditions and self-management education needs.

Nonpharmacologic Therapy

  • Medical Nutrition Therapy (MNT): Tailored diet focusing on calorie/carb moderation, increasing fiber intake, and ensuring proper micronutrients.

  • Physical Activity: At least 150 minutes of moderate aerobic activity per week; strength training recommended at least twice a week.

  • Diabetes Self-Management Education and Support (DSME/S): Essential for empowering patients in effective self-care and decision-making.

Pharmacologic Therapy

  • Insulin Therapy:

    • Types include rapid-acting, short-acting, intermediate-acting, and long-acting insulins.

    • Insulin offers individualized glucose control but carries risks such as hypoglycemia and weight gain.

  • Oral Medications:

    • First-line treatments like Metformin improve insulin sensitivity, reduce hepatic glucose production, and enhance peripheral glucose uptake. Lower risk of hypoglycemia and neutral or weight-loss promoting effects.

    • May cause gastrointestinal side effects.

  • Additional classes include:

    • Sulfonylureas (increase insulin secretion), TZDs (improve insulin sensitivity), DPP-4 inhibitors, SGLT-2 inhibitors, and GLP-1 receptor agonists targeting blood sugar management and CV benefits.

  • Treatment should be individualized based on patient-specific factors including comorbidities and personal preferences.

Monitoring and Evaluation of Treatment Outcomes

  • Regular monitoring of A1C, glucose levels, and assessment of diabetes-related complications is necessary to evaluate treatment efficacy and patient adherence.