Medtronic 780G Insulin Pump on Bolus Calculator Screen

The Art of Pre-Bolusing: Timing Insulin for Optimal Blood Sugar Control



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“Do you pre-bolus?” my insulin pump trainer inquired. My response was hesitant: “Not typically.” She smiled knowingly and suggested trying to pre-bolus 15-20 minutes before a meal.

I gave it a shot, but my attempt led to a few unexpected blood sugar lows before my meal had a chance to settle.

The fear of hypoglycemia is one of the key reasons I’ve been hesitant about pre-bolusing. Everyone’s body reacts differently to insulin, making it essential to tailor your pre-bolus timing to your specific needs. In my case, a longer pre-bolus period of 20 minutes or more is only necessary when my blood glucose levels are elevated prior to eating. If my levels are within the normal range, I find that a shorter pre-bolus window, say 5-10 minutes, works best. And if my blood sugar is trending downward, I forgo pre-bolusing altogether, opting instead to bolus as I begin eating.

The crux of pre-bolusing lies in pinpointing the ideal timing of insulin administration. This process is highly individualized and requires careful observation of your own unique patterns to determine what works best for you.

One critical factor to consider when pre-bolusing is the type of food you intend to consume. Foods with a higher glycemic index may necessitate a more extended pre-bolus period to avert post-meal blood sugar spikes. Conversely, if you’re opting for a low-carb meal, a shorter pre-bolus time may suffice.

There’s no one-size-fits-all formula for pre-bolusing. Collaborating closely with your healthcare team is vital to identifying the optimal pre-bolus timing tailored to your needs. Your medical professionals can analyze your blood sugar trends, insulin sensitivity, and unique circumstances to devise a personalized plan.

Please don’t be discouraged if it takes a bit of trial and error to figure out when you should pre-bolus. Achieving in range blood sugar levels is an ongoing learning process, and you may be up against some unpredictable challenges — did you know that during the LADA honeymoon period insulin needs can fluctuate a lot? Also, there’s dozens of other factors that can affect insulin sensitivity, including stress levels, exercise, and hormones.

Always seek guidance from your healthcare provider for personalized advice and recommendations. Maintain a record of your experiences and observations to facilitate effective collaboration with your healthcare team for continuous adjustments to your pre-bolus strategy.

Remember, diabetes management is a continuous journey of self-discovery, and finding the right pre-bolus timing is an integral part of that process.

If you pre-bolus, don’t forget to eat!

The other danger with a pre-bolus is just forgetting. I wish my insulin pump had a timer that could remind me to eat after bolussing. As I describe in this blog post, I use a timer on my fitbit watch to remind me.

I’ve totally gone low by doing a bolus and forgetting. 😞

There’s also the case of “when will it be done?” Cooking times are approximate, and sometimes the food takes longer to complete cooking than expected.

There are so many variables! When you’re hungry, you usually want to eat right away. Who wants to wait? Diabetes changes that… Waiting the right amount of time can be a game changer. Starting to eat a meal while blood glucose is already high or increasing is likely to cause higher blood glucose. Waiting to see that downward trend can help prevent a prolonged high. But, wait too long, and you feel like you are on a race to eat your food before crashing! It can be quite the struggle. Perfection is not possible; doing your best is all you can do.

About the Author

Lin May has a decade of experience living with LADA diabetes and is the author of Success with LADA Diabetes: Achieving Optimal Health with Diet, Exercise, and Insulin. She is dedicated to helping others learn about diabetes.

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