My hemoglobin A1c improved from 7.9% to 7.3% after increasing basal insulin glargine (Lantus) to 24 U nightly and bolus insulin lispro (Humalog) to 5 U with each meal; what should be the next step in management?

Insulin Dose Adjustment for Improved Glycemic Control

Continue your current regimen of Lantus 24 units nightly and Humalog 5 units TID with meals, and reassess in 3 months—your A1c improvement from 7.9% to 7.3% demonstrates excellent progress toward target, and further dose escalation at this time would increase hypoglycemia risk without meaningful additional benefit. 1

Current Status Assessment

Your A1c reduction of 0.6% (from 7.9% to 7.3%) over the recent period represents clinically significant improvement and places you close to the American Diabetes Association's recommended target of <7.0% for most adults with type 2 diabetes. 1 This trajectory suggests your current insulin regimen is working effectively.

Analyzing Your Insulin Doses

• Your current Lantus dose of 24 units nightly represents approximately 0.3-0.4 units/kg/day for most adults, which is well within the safe and effective range for basal insulin therapy. 1
• Your Humalog dose of 5 units TID (15 units total daily prandial insulin) combined with 24 units basal insulin gives you a total daily dose of 39 units, maintaining an appropriate 62% basal to 38% prandial ratio. 1
• This total daily dose remains well below the critical threshold of 0.5 units/kg/day where further basal escalation becomes counterproductive and increases hypoglycemia risk without improving control. 1

Evidence-Based Titration Principles

The American Diabetes Association recommends systematic insulin titration based on glucose patterns, not arbitrary A1c targets alone. 1 The key question is: what are your fasting and postprandial glucose values?

When to Increase Basal Insulin (Lantus)

• Increase Lantus by 2 units every 3 days if your fasting glucose is consistently 140-179 mg/dL. 1
• Increase Lantus by 4 units every 3 days if your fasting glucose is consistently ≥180 mg/dL. 1
• Target fasting glucose range: 80-130 mg/dL. 1

When to Increase Prandial Insulin (Humalog)

• Increase each meal's Humalog dose by 1-2 units every 3 days if your 2-hour postprandial glucose consistently exceeds 180 mg/dL after that specific meal. 1
• Target postprandial glucose: <180 mg/dL. 1

Critical Decision Point: The 0.5 Units/kg/day Threshold

When basal insulin approaches 0.5-1.0 units/kg/day without achieving glycemic targets, adding or intensifying prandial insulin becomes more appropriate than continuing to escalate basal insulin alone. 1 This prevents "overbasalization"—a dangerous pattern where excessive basal insulin masks inadequate mealtime coverage and increases hypoglycemia risk. 1

Clinical signals of overbasalization include:

• Basal insulin dose >0.5 units/kg/day
• Bedtime-to-morning glucose differential ≥50 mg/dL (large overnight glucose drop)
• Episodes of hypoglycemia
• High glucose variability throughout the day 1

Recommended Next Steps

Option 1: Continue Current Regimen (Most Appropriate)

If your fasting glucose is consistently 80-130 mg/dL and your postprandial glucose values are <180 mg/dL, maintain your current doses and reassess A1c in 3 months. 1 An A1c of 7.3% is already near target, and the modest additional benefit of reaching exactly 7.0% does not justify the increased hypoglycemia risk from aggressive dose escalation.

Option 2: Targeted Dose Adjustment Based on Glucose Patterns

• If fasting glucose remains 140-179 mg/dL: Increase Lantus by 2 units to 26 units nightly. 1
• If specific postprandial values exceed 180 mg/dL: Increase Humalog by 1-2 units before that particular meal only. 1
• If both fasting and postprandial values are elevated: Address basal insulin first (fasting glucose), then adjust prandial insulin based on postprandial patterns. 1

Option 3: Consider Alternative Intensification Strategy

If your A1c remains >7.0% after 3-6 months despite optimized basal insulin (fasting glucose 80-130 mg/dL), consider adding a GLP-1 receptor agonist rather than further insulin escalation. 1, 2 GLP-1 receptor agonists provide comparable or superior A1c reduction with lower hypoglycemia risk, weight loss rather than weight gain, and simpler dosing than intensified insulin regimens. 2

Foundation Therapy Verification

• Ensure you are taking metformin at maximum tolerated dose (up to 2,000-2,550 mg daily) unless contraindicated. 1 Metformin should remain the foundation of type 2 diabetes therapy even when using insulin, as it reduces total insulin requirements by 20-30% and provides superior glycemic control. 1

Monitoring Requirements

• Check fasting glucose daily during any titration phase to guide basal insulin adjustments. 1
• Check 2-hour postprandial glucose after meals to assess prandial insulin adequacy. 1
• Reassess A1c every 3 months during active treatment adjustment. 1

Hypoglycemia Prevention

• Treat any glucose <70 mg/dL immediately with 15 grams of fast-acting carbohydrate, recheck in 15 minutes, and repeat if needed. 1
• If hypoglycemia occurs without an obvious cause, reduce the implicated insulin dose by 10-20% immediately. 1

Common Pitfalls to Avoid

• Do not continue escalating insulin doses based solely on A1c without considering actual glucose patterns. An A1c of 7.3% may reflect excellent fasting and postprandial control, making further dose increases unnecessary and potentially harmful. 1
• Do not increase basal insulin beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia with prandial insulin adjustments or alternative therapies. 1 This leads to overbasalization with increased hypoglycemia risk and suboptimal control.
• Do not discontinue metformin when intensifying insulin therapy unless medically contraindicated. 1 The combination provides superior outcomes with lower insulin requirements.