How to titrate basal (basal insulin) bolus (bolus insulin) insulin, specifically glargine (insulin glargine) and aspart (insulin aspart), in hospitalized patients with type 2 diabetes mellitus (T2DM) who are eating orally?

Basal-Bolus Insulin Titration in Hospitalized Patients Eating Orally

Initial Dosing Strategy

For hospitalized patients with type 2 diabetes eating regular meals, start with a total daily dose of 0.5 units/kg/day, divided as 50% basal insulin (glargine once daily) and 50% bolus insulin (aspart divided equally before three meals). 1, 2

• For a 70 kg patient, this translates to approximately 35 units total daily: 17-18 units glargine once daily and 5-6 units aspart before each meal 2
• Reduce the starting dose to 0.3 units/kg/day for patients at high risk of hypoglycemia (elderly >65 years, renal impairment, thin/frail patients) 1, 3
• For patients on high-dose home insulin (≥0.6 units/kg/day), reduce the total daily dose by 20% upon admission 3

Daily Titration Algorithm

Adjusting Basal Insulin (Glargine)

Titrate glargine every 3 days based on fasting glucose patterns:

• If fasting glucose is 140-179 mg/dL: increase by 2 units 1, 3
• If fasting glucose is ≥180 mg/dL: increase by 4 units 1, 3
• If fasting glucose is <80 mg/dL on more than 2 occasions per week: decrease by 2 units 3
• Target fasting glucose: 80-130 mg/dL 1

Adjusting Bolus Insulin (Aspart)

Titrate aspart every 3 days based on 2-hour postprandial glucose readings:

• Increase by 1-2 units (or 10-15%) if postprandial glucose consistently >180 mg/dL 1, 3
• Decrease by 10-20% if hypoglycemia occurs without clear cause 1, 3
• Target postprandial glucose: <180 mg/dL 1

Four-Day Titration Example

Day 1 (Admission)

Patient: 70 kg, eating regular meals, no prior insulin

• Starting doses: Glargine 17 units at bedtime, aspart 6 units before each meal
• Pre-breakfast: 220 mg/dL → Give 6 units aspart
• 2h post-breakfast: 240 mg/dL
• Pre-lunch: 200 mg/dL → Give 6 units aspart
• 2h post-lunch: 230 mg/dL
• Pre-dinner: 190 mg/dL → Give 6 units aspart
• 2h post-dinner: 210 mg/dL
• Bedtime: Give 17 units glargine

Day 2

Analysis: Fasting glucose ≥180 mg/dL, all postprandial values >180 mg/dL

• Adjustments: Increase glargine by 4 units to 21 units; increase each aspart dose by 2 units to 8 units
• Pre-breakfast: 210 mg/dL → Give 8 units aspart
• 2h post-breakfast: 200 mg/dL
• Pre-lunch: 180 mg/dL → Give 8 units aspart
• 2h post-lunch: 190 mg/dL
• Pre-dinner: 170 mg/dL → Give 8 units aspart
• 2h post-dinner: 180 mg/dL
• Bedtime: Give 21 units glargine

Day 3

Analysis: Fasting glucose still ≥180 mg/dL, postprandial values improving but still elevated

• Adjustments: Increase glargine by 4 units to 25 units; increase breakfast and lunch aspart by 1 unit each to 9 units
• Pre-breakfast: 195 mg/dL → Give 9 units aspart
• 2h post-breakfast: 170 mg/dL
• Pre-lunch: 160 mg/dL → Give 9 units aspart
• 2h post-lunch: 165 mg/dL
• Pre-dinner: 155 mg/dL → Give 8 units aspart
• 2h post-dinner: 160 mg/dL
• Bedtime: Give 25 units glargine

Day 4

Analysis: Fasting glucose 180 mg/dL (borderline), postprandial values approaching target

• Adjustments: Increase glargine by 2 units to 27 units (using 2-unit increment since approaching target); maintain aspart doses
• Pre-breakfast: 180 mg/dL → Give 9 units aspart
• 2h post-breakfast: 155 mg/dL
• Pre-lunch: 145 mg/dL → Give 9 units aspart
• 2h post-lunch: 150 mg/dL
• Pre-dinner: 140 mg/dL → Give 8 units aspart
• 2h post-dinner: 155 mg/dL
• Bedtime: Give 27 units glargine

Critical Monitoring Points

Check point-of-care glucose before each meal and at bedtime (4 times daily) for patients eating regular meals. 1

• For patients with poor oral intake, check glucose every 4-6 hours 1
• Target glucose range for non-critically ill hospitalized patients: 140-180 mg/dL 1

Essential Pitfalls to Avoid

Never use sliding scale insulin as monotherapy—it is explicitly condemned by all major guidelines and leads to dangerous glucose fluctuations. 1, 4

• Do not wait for "stable patterns" before adjusting doses—adjust daily based on glucose trends 3
• Avoid giving rapid-acting insulin at bedtime, as this increases nocturnal hypoglycemia risk 1, 3
• Do not continue full home insulin doses in patients with decreased oral intake—reduce by 50% to prevent severe hypoglycemia 1, 5, 6
• Never mix or dilute glargine with other insulins due to its low pH 7, 8

Special Considerations for Poor Oral Intake

If oral intake decreases during hospitalization, immediately reduce total daily insulin to 0.1-0.15 units/kg/day given primarily as basal insulin, with correctional aspart only for glucose >180 mg/dL. 1, 5

• This represents approximately a 50% dose reduction from standard basal-bolus dosing 5
• Continue basal insulin coverage even with minimal intake—do not rely solely on correction doses 1, 5