Study guide
Type 2 Diabetes Mellitus Management
AANPCB Adult-Gerontology Primary Care Nurse Practitioner A-GNP
Track your progress as you read
Finished sections get a check mark.
1 Exam Structure, APRN Foundations & Geriatric Assessment
A-GNP Exam Logistics, Blueprint & Scoring Structure APRN Scope of Practice, Consensus Model & Interprofessional Collaboration Comprehensive Health History & Subjective Assessment Across Adult Lifespan Comprehensive Physical Examination & Clinical Assessment Skills
2 Health Assessment, Diagnostic Reasoning & Clinical Procedures
Diagnostic Reasoning, Test Interpretation & Clinical Decision-Making Screening Guidelines & Evidence-Based Health Promotion (USPSTF) Comprehensive Geriatric Assessment (CGA), Frailty & Function In-Office Clinical Procedures, ECG Interpretation & Minor Surgical Skills
3 Cardiovascular & Peripheral Vascular Disorders
Essential Hypertension & Hypertensive Urgency/Emergency Management Coronary Artery Disease, Acute Coronary Syndromes & Post-MI Care Heart Failure (HFrEF & HFpEF) Diagnosis, Staging & 4-Pillar GDMT Arrhythmias (Atrial Fibrillation), Valvular Heart Disease & PAD
4 Respiratory, HEENT & Dermatological Disorders
Asthma Management across the Adult Lifespan (GINA Guidelines) Chronic Obstructive Pulmonary Disease (COPD) Staging & Management (GOLD Guidelines) Community-Acquired Pneumonia & Lower Respiratory Tract Infections Common HEENT Disorders: Otitis, Sinusitis, Pharyngitis, Glaucoma & Macular Degeneration
5 Endocrine, Metabolic & Renal/Genitourinary Disorders
Type 2 Diabetes Mellitus Management Thyroid Disorders: Hypothyroidism, Hyperthyroidism & Subclinical Disease Chronic Kidney Disease (CKD) Staging & Diabetic/Hypertensive Nephropathy Genitourinary Disorders: BPH, Urinary Incontinence, UTIs & Prostatitis
6 Gastrointestinal, Hematologic & Immunologic Disorders
Upper Gastrointestinal Disorders: Dyspepsia, GERD, PUD & H. pylori Lower Gastrointestinal Disorders: IBS, IBD, Diverticulitis & Colorectal Screening Liver, Biliary & Pancreatic Disorders: NAFLD/MASLD, Cirrhosis & Cholecystitis Hematologic & Immunologic Disorders: Anemias, Anticoagulation & Immunizations
7 Neurological, Cognitive & Psychiatric Disorders
Cognitive Assessment: Delirium, Dementia & Mild Cognitive Impairment Neurological Disorders: Stroke, TIA, Parkinson's Disease & Headache Syndromes Major Depressive Disorder & Anxiety Disorders in Adults & Older Adults Sleep Disorders, Insomnia & Restless Legs Syndrome
8 Geriatric Syndromes, Polypharmacy & Deprescribing
The Beers Criteria & STOPP/START Criteria for Potentially Inappropriate Medication Use Polypharmacy Management, Pharmacokinetics/Pharmacodynamics in Aging & Deprescribing Protocols Fall Risk Assessment (CDC STEADI), Gait/Balance & Mobility Impairments Pressure Injury Prevention/Staging, Urinary/Fecal Incontinence & Frailty Assessment
9 APRN Professional Practice, Ethics, Quality & Healthcare Policy
Musculoskeletal Disorders: Osteoarthritis, Osteoporosis, Gout & Back Pain Dermatological Disorders: Lesions, Skin Cancers, Infections & Rash Evaluation Palliative Care, Advance Care Planning, Pain Management & End-of-Life APRN Professional Practice, Quality Improvement, Ethics & Healthcare Policy
Type 2 Diabetes Mellitus Management
Key Takeaways Explain This Topic AI
ADA 2026 diagnostic criteria require Fasting Plasma Glucose >= 126 mg/dL, 2-hour OGTT >= 200 mg/dL, HbA1c >= 6.5%, or random glucose >= 200 mg/dL with classic hyperglycemic symptoms.
Glycemic targets must be strictly individualized: HbA1c < 7.0% for most non-pregnant adults, < 7.5% for healthy older adults, and < 8.0-8.5% for complex/frail older adults to prevent hypoglycemia.
SGLT2 inhibitors and GLP-1 receptor agonists provide cardiorenal protection (ASCVD, Heart Failure, CKD progression) independent of baseline HbA1c or glycemic targets.
Metformin is first-line pharmacotherapy; eGFR dosing rules dictate full dose if eGFR >= 45, max 1000 mg/day if eGFR 30-44 (do not initiate), and strict contraindication if eGFR < 30 mL/min/1.73m².
Sulfonylureas (especially Glyburide) carry severe hypoglycemia risk in older adults and are listed on the Beers Criteria as medications to avoid.
Last updated: July 2026
Type 2 Diabetes Mellitus Management
Type 2 Diabetes Mellitus (T2DM) is a chronic metabolic disorder characterized by insulin resistance, progressive beta-cell dysfunction, and excessive hepatic glucose production. Modern primary care management emphasizes an organ-protective strategy to reduce microvascular, cardiovascular, and renal complications.
Pathophysiology & The Ominous Octet
T2DM involves multiple organ defects, known as the Ominous Octet:
Pancreatic beta-cell failure reducing insulin secretion.
Hepatic gluconeogenesis causing fasting hyperglycemia.
Muscle insulin resistance impairing postprandial glucose uptake.
Accelerated adipocyte lipolysis releasing free fatty acids.
Gastrointestinal GLP-1 deficiency blunting the incretin effect.
Pancreatic alpha-cell hyperglucagonemia.
Renal SGLT2 upregulation enhancing glucose reabsorption.
Central nervous system insulin resistance altering satiety.
ADA Diagnostic Criteria & Screening Guidelines
According to 2026 ADA Standards of Care, diagnosing diabetes requires two abnormal test results from the same sample or two separate test samples, unless classic symptoms of hyperglycemia (polyuria, polydipsia, weight loss) are present.
- Diagnostic Parameter Normal Pre-Diabetes Diabetes Mellitus
- Fasting Plasma Glucose (FPG) < 100 mg/dL 100–125 mg/dL >= 126 mg/dL (fasting >= 8 hrs)
- 2-Hour OGTT (75g load) < 140 mg/dL 140–199 mg/dL >= 200 mg/dL
- Hemoglobin A1c (HbA1c) < 5.7% 5.7%–6.4% >= 6.5% (standardized NGSP)
- Random Plasma Glucose N/A N/A >= 200 mg/dL with classic symptoms
Universal screening begins at age 35 for all asymptomatic adults. Screen earlier in adults of any age with BMI >= 25 kg/m² (>= 23 kg/m² in Asian Americans) and risk factors (first-degree relative with diabetes, high-risk ethnicity, history of CVD, hypertension >= 130/80, HDL < 35 mg/dL or triglycerides > 250 mg/dL, PCOS, or physical inactivity). Repeat screening every 3 years if normal; annually if prediabetic.
Individualized Glycemic Targets & Advanced Monitoring
General Non-Pregnant Adult Target: HbA1c < 7.0% (mean glucose ~154 mg/dL), preprandial glucose 80–130 mg/dL , and 1-to-2-hour postprandial glucose < 180 mg/dL . Early control reduces microvascular (retinopathy, nephropathy, neuropathy) and macrovascular risk.
Geriatric Stratification:
Healthy Older Adults (few chronic conditions, intact cognition/function): HbA1c < 7.5% .
Complex Older Adults (multiple chronic illnesses, mild/moderate cognitive impairment, 2+ IADL deficits): HbA1c < 8.0% .
Frail Older Adults (end-stage illness, severe dementia, ADL dependence): HbA1c < 8.5% . Focus shifts to avoiding symptomatic hyperglycemia and hypoglycemia.
Continuous Glucose Monitoring (CGM) Metrics: For patients utilizing CGM, key clinical targets include Time in Range (TIR, 70–180 mg/dL) > 70% , Time Below Range (TBR < 70 mg/dL) < 4%, and Time Below 54 mg/dL < 1%.
Dawn Phenomenon vs. Somogyi Effect: Early morning hyperglycemia requires checking blood glucose at 3:00 AM. Elevated 3 AM glucose indicates the Dawn Phenomenon (nocturnal surge of growth hormone and cortisol), treated by increasing bedtime basal insulin. Low 3 AM glucose indicates the Somogyi Effect (rebound hyperglycemia following nocturnal hypoglycemia), treated by reducing bedtime basal insulin or providing a bedtime snack.
Pharmacological Management & Organ Protection
First-line therapy combines lifestyle modification (nutrition, physical activity, weight loss) with targeted pharmacotherapy.
Metformin: Foundational Backbone
Metformin decreases hepatic gluconeogenesis and improves peripheral insulin sensitivity. It is weight-neutral and carries no inherent hypoglycemia risk.
Initiate at 500 mg daily with meals; titrate to 1000 mg BID.
Renal Dosing: eGFR >= 45 mL/min/1.73m²: Full dose. eGFR 30–44: Max 1000 mg/day (do not initiate; halve dose if continuing). eGFR < 30: Strictly contraindicated due to lactic acidosis risk.
Monitor Vitamin B12 levels periodically due to impaired ileal absorption.
Organ-Protective Pharmacotherapy (Independent of HbA1c)
SGLT2 Inhibitors (Empagliflozin, Dapagliflozin, Canagliflozin):
Indications: Heart Failure (HFrEF/HFpEF), CKD (eGFR 20–60 or UACR > 30 mg/g), or established ASCVD.
Mechanism: Inhibit proximal tubule SGLT2, promoting osmotic glycosuria and natriuresis.
Benefits: Reduces HF hospitalizations, slows CKD progression, and lowers CV mortality.
Adverse Effects: Mycotic genital infections, UTIs, volume depletion. Risk of euglycemic DKA ; withhold 3–4 days before elective surgery.
GLP-1 Receptor Agonists & Dual GIP/GLP-1 Agonists (Semaglutide, Dulaglutide, Tirzepatide):
Indications: Established ASCVD, high ASCVD risk, CKD, or when weight loss is prioritized.
Mechanism: Glucose-dependent insulin release, glucagon suppression, delayed gastric emptying, and increased satiety.
Contraindication: Personal/family history of Medullary Thyroid Carcinoma (MTC) or MEN 2 .
Additional Agent Classes & Safety Precautions
DPP-4 Inhibitors (Sitagliptin, Linagliptin): Weight-neutral, low hypoglycemia risk. Avoid Saxagliptin in HF. Never combine with GLP-1 RAs.
Sulfonylureas (Glipizide, Glimepiride, Glyburide): Insulin secretagogues. High risk of hypoglycemia and weight gain. Glyburide is on the Beers Criteria (avoid in older adults). Glipizide is preferred in elderly/renal impairment.
Thiazolidinediones (Pioglitazone): Contraindicated in NYHA Class III/IV Heart Failure due to fluid retention.
Basal Insulin Initiation: Start long-acting insulin (Glargine, Detemir, Degludec) at 10 units daily or 0.1–0.2 units/kg/day when non-insulin agents fail, or if HbA1c > 10% or blood glucose >= 300 mg/dL with catabolic symptoms. Titrate by 2 units every 3 days to fasting target (80–130 mg/dL).
Hypoglycemia Management & Comprehensive Diabetes Care
Hypoglycemia is blood glucose < 70 mg/dL (Level 1) or < 54 mg/dL (Level 2). Hypoglycemia unawareness is common in older adults due to blunted adrenergic responses.
Rule of 15: Treat conscious patients with 15g fast-acting carbohydrate (4 oz juice, 4 glucose tablets). Recheck blood glucose in 15 minutes; repeat if < 70 mg/dL. Follow with a complex carbohydrate + protein snack.
Unconscious Patient: Intranasal glucagon (3 mg), IM glucagon (1 mg), or IV D50W.
Hyperosmolar Hyperglycemic State (HHS): Characterized by glucose > 600 mg/dL, serum osmolality > 320 mOsm/kg, severe dehydration, and altered mental status without ketoacidosis. Emergency treatment prioritizes aggressive IV fluid resuscitation.
Preventive Preventive Exams: Annual comprehensive foot exam (10g monofilament testing plus 128Hz tuning fork vibration to screen for peripheral neuropathy and arterial disease), annual dilated eye exam by an optometrist/ophthalmologist for retinopathy, and annual spot urine albumin-to-creatinine ratio (UACR).