How should I manage a patient with a fasting blood glucose of 330 mg/dL and a post‑prandial glucose of 420 mg/dL?

Management of Severe Hyperglycemia: FBS 330 mg/dL, PPBS 420 mg/dL

Initiate insulin therapy immediately—this patient has severe hyperglycemia (fasting glucose >300 mg/dL) that requires urgent intervention with basal insulin, and consider starting at a more advanced therapy stage given the severity of hyperglycemia. 1

Immediate Assessment and Diagnosis

• Confirm diabetes diagnosis: A fasting glucose of 330 mg/dL far exceeds the diagnostic threshold of ≥126 mg/dL and establishes the diagnosis of diabetes mellitus 2
• Check for acute metabolic decompensation: Assess for symptoms of weight loss, ketonuria/ketosis, or diabetic ketoacidosis, as these indicate need for immediate hospitalization and more aggressive insulin regimens 1
• Obtain HbA1c: This will likely be ≥10% given these glucose levels, which further supports starting at an advanced therapy stage 1
• Screen for complications: Evaluate for retinopathy, nephropathy, and cardiovascular risk factors at baseline 2

Initial Treatment Strategy

Start basal insulin immediately because:

• Blood glucose levels of 300-350 mg/dL or greater warrant consideration of starting insulin therapy directly, especially if HbA1c is 10-12% 1
• The fasting glucose of 330 mg/dL indicates severe hepatic glucose overproduction that requires direct hepatic insulinization 3
• Insulin should not be delayed in patients not achieving glycemic goals 1

Basal Insulin Initiation

• Starting dose: Initiate at 10 units or 0.1-0.2 units/kg body weight of basal insulin (NPH, glargine, detemir, or degludec) 1
• Preferred formulation: Use basal insulin analogues (glargine, detemir, degludec) rather than NPH due to reduced risk of hypoglycemia, particularly nocturnal hypoglycemia 1
• Timing: Typically administer before bedtime, though newer analogues allow flexibility in timing 1

Concurrent Oral Agent Therapy

• Start metformin simultaneously: Basal insulin should be used with metformin and perhaps one additional non-insulin agent 1
• Continue organ-protective medications: When insulin is initiated, maintain medications with cardiorenal protection benefits 1
• Avoid sulfonylureas: Discontinue agents that cause hypoglycemia (like sulfonylureas) once insulin is started 1

Addressing Postprandial Hyperglycemia

The postprandial glucose of 420 mg/dL indicates severe mealtime glucose excursions that will require additional intervention:

• After basal insulin titration: Once fasting glucose is corrected but HbA1c remains above target, add combination injectable therapy to reduce postprandial excursions 1
• GLP-1 receptor agonist preferred: Consider GLP-1 RA before advancing to mealtime insulin, as it allows lower glycemic targets with lower injection burden and reduced risk of hypoglycemia and weight gain 1
• Mealtime insulin if needed: If GLP-1 RA is contraindicated or insufficient, add 1-3 injections of rapid-acting insulin (lispro, aspart, or glulisine) immediately before meals 1

Titration Strategy

• Titrate basal insulin promptly: Adjust dose in a timely fashion to achieve individualized fasting glycemic target 1
• Target fasting glucose: Aim for 80-130 mg/dL 1, 2
• Target postprandial glucose: Aim for <180 mg/dL 1, 2
• Monitor frequently: Check fasting glucose daily and A1C every 3 months until target <7% is achieved 2
• Avoid therapeutic inertia: Do not delay intensification when targets are not met 1

Monitoring and Support

• Self-monitoring of blood glucose: Implement regular SMBG, particularly fasting and pre-meal testing 1
• Diabetes self-management education: Refer for DSMES when initiating insulin therapy 1
• Consider continuous glucose monitoring: Technologies allowing continuous monitoring have clear advantages in insulin-treated patients 1

Common Pitfalls to Avoid

• Do not start with oral agents alone: At this level of hyperglycemia (>300 mg/dL), oral agents will be insufficient and delay necessary treatment 1
• Do not ignore postprandial hyperglycemia: While fasting glucose is the primary driver at this HbA1c level, the 420 mg/dL postprandial value indicates significant mealtime dysregulation requiring attention 4
• Do not delay insulin intensification: If basal insulin alone (even when titrated to >0.5 U/kg) does not achieve targets, promptly add mealtime coverage 1
• Do not assume normal postprandial response: The postprandial glucose of 420 mg/dL is severely elevated and indicates need for mealtime intervention 1

Cardiovascular Risk Management

• Assess cardiovascular risk factors systematically: Evaluate dyslipidemia, hypertension, smoking history, family history of premature coronary disease 1
• Consider cardioprotective agents: When appropriate, incorporate SGLT2 inhibitors or GLP-1 RA for cardiovascular and renal protection 1