What initial insulin pump settings (total daily dose, basal rate, bolus calculator ratios) should be used for a 70‑kg adult with type 1 diabetes and normal renal function?

Initial Insulin Pump Settings for a 70-kg Adult with Type 1 Diabetes

For a 70-kg adult with type 1 diabetes and normal renal function, start with a total daily dose (TDD) of 35 units (0.5 units/kg/day), program 40-50% as basal insulin (17.5 units/day distributed across 24 hours), set the insulin-to-carbohydrate ratio at 1:10, and calculate the correction factor as 1500÷35 = 43 mg/dL per unit. 1

Total Daily Dose Calculation

• Begin with 0.5 units/kg/day as the standard starting dose for metabolically stable adults with type 1 diabetes, which equals 35 units/day for a 70-kg patient 1, 2
• The acceptable range is 0.4–1.0 units/kg/day (28–70 units/day), with higher doses required during puberty, pregnancy, or acute illness 1
• Patients in the "honeymoon period" with residual beta-cell function may require lower doses of 0.2–0.6 units/kg/day 1

Basal Rate Programming

• Allocate 40–50% of TDD to basal insulin, which translates to 17.5 units/day (50% of 35 units) for this patient 1, 2
• Distribute this evenly across 24 hours as a starting point: 17.5 units ÷ 24 hours = 0.73 units/hour 1
• The basal rate typically requires adjustment based on overnight and between-meal glucose patterns, with many patients needing higher rates in early morning hours due to dawn phenomenon 1

Insulin-to-Carbohydrate Ratio (ICR)

• Calculate the ICR using the "450 rule" for rapid-acting analogs: 450 ÷ TDD 1
• For this patient: 450 ÷ 35 = 12.9, round to 1:10 or 1:15 as a starting ratio 1
• This means 1 unit of insulin covers 10–15 grams of carbohydrate 1
• A common starting ratio is 1:10, meaning the patient would take 1 unit for every 10 grams of carbohydrate consumed 1

Insulin Sensitivity Factor (Correction Factor)

• Calculate using the "1500 rule": 1500 ÷ TDD 1
• For this patient: 1500 ÷ 35 = 43 mg/dL per unit 1
• This means 1 unit of insulin will lower blood glucose by approximately 43 mg/dL 1
• Use this to calculate correction doses when pre-meal glucose is above target 1

Target Glucose Settings

• Set pre-meal target glucose at 90–150 mg/dL (5.0–8.3 mmol/L) 1
• Set fasting glucose target at 80–130 mg/dL 1
• Aim for postprandial glucose <180 mg/dL 1

Bolus Calculator Setup

• Program the pump's bolus calculator with the ICR (1:10), insulin sensitivity factor (43 mg/dL per unit), and target glucose (120 mg/dL as midpoint) 1
• The calculator will automatically determine bolus doses based on carbohydrate intake and current glucose level 1
• Set insulin action time to 3–5 hours for rapid-acting analogs to prevent insulin stacking 1

Titration Protocol

• Basal rate adjustment: Evaluate fasting and between-meal glucose patterns over 3 days; increase or decrease basal rates by 10–20% in specific time blocks where glucose is consistently out of range 1
• ICR adjustment: If postprandial glucose is consistently elevated or low 2 hours after meals, adjust the ICR by 1–2 grams per unit 1
• Correction factor adjustment: If correction doses consistently fail to bring glucose into target range, recalculate using the updated TDD 1

Critical Safety Considerations

• Continuous glucose monitoring (CGM) is strongly recommended with pump therapy to optimize time in range and reduce hypoglycemia risk 1
• Automated insulin delivery (AID) systems are preferred over standard pump therapy, as they improve time in range and reduce hypoglycemia while decreasing management burden 1
• 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 clear cause, reduce the implicated insulin parameter by 10–20% 1

Common Pitfalls to Avoid

• Do not use the "500 rule" for rapid-acting analogs; the 450 rule is more accurate for lispro, aspart, and glulisine 1
• Do not set a single flat basal rate for 24 hours; most patients require variable rates throughout the day, particularly higher rates during dawn hours 1
• Do not delay adjustments when patterns emerge; waiting too long to titrate settings prolongs exposure to hyperglycemia 1
• Never discontinue basal insulin delivery completely, even during illness or fasting, as this can precipitate diabetic ketoacidosis 1

Special Populations Requiring Dose Modification

• Newly diagnosed patients presenting with ketoacidosis require higher initial doses of 0.6–1.0 units/kg/day before subsequent titration 1
• Patients during puberty may require doses exceeding 1.0 units/kg/day due to increased insulin resistance 1, 2
• Patients with renal impairment (CKD Stage 5) should reduce TDD by 35–40% to prevent hypoglycemia 2