Ask John

Ask John

Welcome to our Ask John column. Here, we'll be posting questions from visitors that John has answered. These questions cover a wide range of topics. If you would like to send John a question, visit our contact page to post them. Please note that any advice given should be discussed with your physician before you try them.

From: JR

I opened a new bottle of humalog about four days back. My blood sugar has never been this high. Checked the humulin and there were things sticking to the inside. Then I took a new one out of frigde. My blood sugar was 222. I took 10 units, checked my sugar 20 mins later. It was 320. I checked both new bottles and they have particles sticking to the inside.


Hi JR,

By now, you have very likely determined that your Humalog and NPH insulins are bad. Any time that particles can be seen or discoloration is present in an insulin bottle, throw it out and get a new one. The particles come from coagulated insulin on the side of the bottle (easy to see) or in the fluid (often present earlier and can be very hard to see). With the NPH bottle also bad, there are two possibilities:

  1. Your refrigerator (or your pharmacy's) is too cold -- make sure the inside of your fridge is above 36 degrees F (or ask your pharmacy what temp their fridge is set at) and never let bottles of insulin get cold inside your car in the winter.
  2. The Humalog and NPH are getting contaminated during mixing -- this is less likely to be causing particles to form or unexplained highs, and will more often cause some discoloration in the Humalog bottle rather than have particles form.

This is not a common problem but a very annoying one when it happens. Some years back, I went through 10 bottles of Humalog of which little ever got used and sent one bottle to Lilly for analysis (nothing wrong with it). With the right lighting, I could clearly see particles in these bottles. On the 11th bottle, at the pharmacy counter, I felt the bottle (very cold) and could see particles in the bottle (the pharmacist could not but they are very small in solution and take practice to see in the right lighting). I advised the pharmacist to turn the temp up a bit in their refrigerator. After a few weeks and many unexplained highs, I sent my prescription to another pharmacy with immediate resolution.

Please let us know how you resolved the issue,


From: JP

I was wondering what pumps can be detached during a sporting contest and reattached after the game? Also, for the Insulet omni pod, are there two entry point for the CGM and the pump? Thanks for your time.


J, any of the pumps with an infusion line can be detached for sports, but an Omnipod has to stay on all the time. Our favorite infusion set for sports is any of the 6 mm steel sets. They have a very low profile and when an IV3000 or Tegaderm adhesive is placed over the needle, the set rarely comes off, even during contact sports. On these sets, the line and pump are detached about 4 inches away from the insertion point. The adhesive and set always stay in place during sports, showers, etc.

The Omnipod and all current infusion set pumps require a separate site for the CGM's sensor and transmitter. The transmitter has a taller profile than a steel needle but can be overlaid with a plastic adhesive or some of the waterproof sport tapes to help minimize detachment or the CGM.

An Omnipod has a higher and larger profile. On the arm, it can be wrapped to reduce the likelihood of detachment, but this is harder to do in other areas of the body. Infusion sites require time to recover between uses and this can become an issue if one or two sites are repeatedly used during sports. Repeated use of sites leads to the build-up of lipohypertrophy and scarring that can delay and even reduce insulin delivery. With contact sports especially, a line pump offers more site options and may be preferred. For most other sports, either will work.

Best regards, John

From: BW

Hello. I'm not diabetic yet, but am getting close, and diabetes runs in myfamily. I'm considering continuous glucose monitoring so I can track how my diet and exercise affect my glucose levels throughout the day. This would not be covered by insurance. I'd like to learn more about my options, and would like to hear suggestions to do this at a reasonable cost.


Thanks for your question B,

Most people have insurance coverage for CGMs except those on Medicare and those like yourself whose beta cells produce insulin and their C-peptide level that measures insulin production is too high to qualify. Given that, your desire to see how your glucose is affected by food choices, activity, and multiple other daily interferences is exactly what you want to do. Diabetes is all about glucose control, so what better way to manage it than with immediate feedback?

Many people, including myself, have to cut corners to afford this optimal diabetes therapy. Right now, the Dexcom CGM is the best way to go. It is currently the most accurate and least interfering CGM, with a great color display. Plus the receiver is small, does not look like a medical device, and is lighter and really easy to carry. Approved for 7 day use, the sensor can generally be used for 10 to 14 days once it has been well attached to the skin. At about $90 per sensor, your ongoing out of pocket expense comes out to roughly $7 to $9 a day for the sensors.

Attachment is critical for cost savings. A good method is to place a layer of Skin-Tac (from wipes or a bottle, available at some pharmacies) onto the skin first with a clean area in the middle where you insert the sensor. Let the Skin-Tac dry and then insert the sensor and press down firmly on the white cotton adhesive around the base of the sensor. This will usually hold it firmly in place for 2 weeks. Mastisol adhesive and Detachol remover can also be used to secure the sensor.

The reusable transmitter that signals your readings from the sensor base to the separate receiver does not require any recharging like the Medtronic CGM but does need to be replaced, usually after a year or more. Dexcom has a somewhat lackluster pricing plan where the transmitters costs over $500 if you don't sign on to their automatic sensor reshipping plan, which you may not want to do since you may not need to use a sensor all the time like most of us. However, they charge only $199 if you approve automatic shipping. You may want to explain to them what you are doing and get a pre-purchase agreement to buy the transmitter at their $199 price. Dexcom ought to be open to this as they'd love to have more people with Type 2 and pre-diabetes use their system.

A CGM is like windshield wipers on a muddy windshield -- you won't know what you've been missing until you use it!


From: MM

My granddaughter is 3 years old and uses the pump. Unfortunately the only place she can use right now is her bottom. Is there any cream made that can help soften injection sites? At this point, she has no fat available on tummy or otherwise to use different areas. We would appreciate any help.


Hi MM,

For a young child like your granddaughter, I always recommend one of the short straight-in metal set like the Contact Detach, Sure-T, or Rapid-D. Metal sets are thinner then Teflon and the easiest to insert by hand and less likely to fail than a Teflon set placed with an autoinserter. Plus, more skin areas can be used. If she is not already using one of these, that would be the way to go.

Keeping sets attached is critical. For children, always place an adhesive like IV3000 or Tegaderm over the metal needle area after it has been inserted. Place any excess adhesive over the infusion line to make the set really secure. If more adhesion is needed for water or sweating, cover the skin with Skin-Tac before inserting the needle, and then overlay with an adhesive material. This makes the set close to failure-proof. Another nice thing about metal sets is that if they do fall off or get pulled off, you can re-insert them again after cleaning with alcohol.

Bottoms are usually best for the young. As she grows, her parents will be able to use other areas like the flanks or abdomen. Short metal needle sets are usually the best way to extend useable infusion site areas.

Hope this helps,