Get Accurate Insulin Doses for Better Glucoses

Too many lows? Too many highs? Readings all over the place? Feel like a tiny boat on rough seas? Don’t know what to do? Whether you’re newly diagnosed, on multiple daily injections (MDI), new to pumping, new to continuous glucose monitoring (CGM), new to Automated Insulin Delivery (AID), or have years of experience on insulin, we all need some help and guidance now and then. You recognize how vital it is to keep your A1c low, your time in range (TIR) high, and your glucose stable. It’s tempting to give up when you feel like you have no control over the often-baffling situations that arise. But there’s hope.

Our insulin dose guide will shed much-needed light on these situations. The guide helps you start simple, interpret glucose graphs, charts, and real-time CGM displays, and turn them into improved actions, settings, and outcomes.* It also teaches you step-by-step how to improve your settings in a pump, give more accurate insulin doses, and arrive at better glucose readings. You learn to navigate to smoother waters with the long-term rewards of good health and longer life, plus short-term benefits of feeling better now, with more energy to work, play, and be the person you want to be.

Comment, questions, and suggestions are welcome at the bottom of each page.

Learn the Lingo – Read this list now and return when you see a term you don’t know.

  • AGP – Ambulatory Glucose Profile
  • AID – Automated Insulin Delivery or hybrid closed loop
  • Basal/LAI –an all-day steady release of insulin from a pump or a long-acting insulin
  • Bolus/SAI – a quick release of insulin from a pump or injection of short-acting insulin – Carb boluses/injections cover carbs and correction boluses lower high readings
  • Bolus Calculator (BC) – calculates bolus recommendations
  • CarbF or Insulin to Carb Ratio (CarbF, ICR) – the number of grams of carbohydrate covered by 1 unit of insulin
  • CGM – continuous glucose monitor
  • Correction Target – the BG a correction bolus aims for
  • Correction Factor or Insulin Sensitivity Factor (CorrF, ISF) – how many mg/dl or mmol one’s glucose is reduced by 1 unit
  • CV – coefficient of variation, aka glucose variability
  • Duration of Insulin Action (DIA) or Active Insulin Time (AIT) – how long a bolus (5-6 hrs for current insulins) lowers the BG – used as a pump set to calculate residual IOB activity
  • Insulin Stacking – occurs when the action of two or more boluses or SAI doses overlap and drop your glucose too low
  • IOB or BOB – active bolus or SAI insulin on board that is still lowering the glucose from recent boluses
  • MDI – multiple daily injections
  • TIR – time in range, the percentage of time your glucose stays between 70 to 180 mg/dL (3.9 to 10 mmol)
  • TDD – total daily dose – an average of all basal and bolus doses of insulin (or long and short-acting doses) taken per day

But there’s hope!

This insulin dose guide provides more confidence in the use of an insulin pump and CGM, an AID, or a bolus calculator (BC), and MDI with the goal is to keep your glucose in a relatively normal range with few lows. Although this guide is often used with a CGM, it can also be used if you do frequent meter testing to monitor glucose levels and use a BC or a helpful record system, like Smart Charts or the Enhanced Analysis Weekly Logbook. See also Record Keeping.

To minimize variables, make dose adjustments when your routine is as regular as possible. Keep to your normal levels of activity and exercise, and eat foods that have a known impact on your glucose, especially ones that don’t spike it.

Detailed information on current hybrid closed loops, and AID systems can be found at our Comparison of AID Systems. AID systems simplify management through a combination of an insulin pump, a CGM, a software control algorithm, and sometimes a dedicated PDA or smartphone app for remote operation. They are also beginning to appear for smart pen users. The algorithm or “brain” of the system oversees insulin doses that attempt to regulate glucose levels amidst the daily impact of meals, exercise, stress, medications, hormone levels, and other factors.

First, Eliminate Unneeded Variables on a Pump (or BC):

Follow the steps below if you consume a relatively healthy diet. For those on a low carb or keto diet, go directly to Step 3 for Pattern Management.

This Guide Includes the Following Sections:

  1. Size up your situation and select your goal. – Review these glucose goals recommended by diabetes organizations, choose your own glucose goals, and learn how to check your glucose variability.
  2. Adjust your Total Daily Dose (TDD) of Insulin – if you have frequent lows or highs.
      1. For frequent lows:
        1. If your glucose goes below 70 mg/dL (3.9 mmol) 4 or more times a week at different times of the day, go to Lower Your TDD or Frequent Lows.
        2. If your lows usually occur at a particular time of day, go to Frequent Lows at a Certain Time of Day.
        3. If lows frequently occur within 5 hours after treating a high glucose reading, go to Lows from Over-Correcting Highs.
      2. If your average glucose is over 165 mg/dL (9.2 mmol) or a recent A1c was above 7.4%, and your diet is reasonable, go to Raise Your TDD to learn how to increase insulin doses and select more appropriate pump settings with the Pump/BC Settings Tool.
  1. Check for these Common Unwanted Glucose Patterns if you do not have frequent lows, highs, or unwanted swings in your readings. These target specific areas for improving your readings.
    1. Finally, check each of these pump settings:
      1. Check your Basal Rates
      2. Check your CarbF or ICR
      3. Check your CorrF or ISF

Check each step above for guidance on how to improve and stabilize your readings.
Congratulations, you’ve finished learning how to adjust your insulin doses on MDI, pump, CGM, BC, or AID! Revisit this exercise any time your glucose readings start to stray. When life changes, so do insulin doses.

* Caution: For safety, talk with your clinician before and while you diagnose problems, and test and adjust pump or BC settings. Health care providers have your best interest in mind, but time is limited at appointments. To quickly get to critical issues at clinic visits, write down your problems and questions ahead of time. Always bring your CGM or meter record with you. After you or your clinician make adjustments, bring your glucose results to your next appointment for further tuning.

6 thoughts on “Get Accurate Insulin Doses for Better Glucoses”

  2. >50 years w T1D & problems are getting worse. Need to do on my own as cannot afford much from my “medical team.”
    Pumped for a decade before quitting.
    Trying Continuous Glucose Monitor now.
    Too many highs, too many lows, no one to ask for basic explanation. Almost everyone expects me to already know everything (due to my age) or be able to find answers on my own. My memory is starting to fail me.

    Appreciated your article in stacking insulin. Hope to determine my Fiasp DIA before its hypoglycemia events wipe me out.

    Reply

  3. Hi Karen,

    Your excess glucose variability just means that your insulin doses are off, as I’m sure you are aware.

    First, redo your TDD. If you are having frequent lows, lower your TDD, while if a recent A1c is over 8% or avg BG is over 170 mg/dl, your TDD likely needs to be raised. A reasonable guide is to divide your weight in lbs by 4 to estimate your TDD.

    Then redistribute this optimized TDD with the pump or bolus advisor settings tool at https://www.diabetesnet.com/diabetes_tools/pumpsettings/

    On injections, try the Medtronic InPen for meal and correction doses. It has 1/2 unit increments and an excellent bolus advisor that tracks residual insulin action.

    For FiAsp, use a DIA of 4 hours. Most bolus advisors have not integrated the faster decay in action for FiAsp but it’s duration of action is close to or identical to Novolog. Any time less than 4 hrs will cause hidden insulin stacking and unexplained hypoglycemia.

    Best regards,
    John

    Reply

    • Can you tell me if the sixth edition is the latest book you have? any plans for a book geared toward low carb and protein?

      Reply

      • The 6th is the latest!
        We are not fans of low-carb diets as large epidemiology studies show mortality is much higher for people on low-carb diets.
        With diabetes, the key is to eat healthy low-GI carbs and match them with insulin! If weight loss is needed, a reduction in total calories is a better way to go, or discussing the addition of a GLP-1 medication, not yet FDA-approved but often used in Type 1 diabetes. Weight loss drugs in development combine GLP-1 with a GIP (glucose-dependant insulinotropic polypeptide) and are far more effective.

        Reply

  4. I am building a predictive model for my daughter based on DexCom readings but I cannot find actual functions for computing amount of Novolog in the system from time of inject, amount of Levemir in the system from time of injection, and functions for typical rates for carbohydrates, fat, and protein (I know that these can interact, but typical rates are better than leaving these features out given that we have them for every meal). Can you point me to some/all of the functions I need? Thanks very much for your help.

    Reply

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