Can too much Lantus cause high AM BG's?

[malli52]

I am a type 1A diabetic with normal insulin sensitivity and predictable bg responses to insulin doses. Until now. I went on a reducing diet (high protein, next to 0 carbs, increased exercise) but never decreased my once daily PM dose of Lantus (10 units.) Immediately my AM bg's jumped to over 200 and stayed there. No hypoglycemia during sleep (I never woke up, anyway.)I could bring my daily bg's down with my shortacting insulin.

I increased the PM dose of Lantus by 1 unit and found the next day my am bg was even higher. And still, no hypo's waking me up from sleep.

I suspect that Lantus' action is so flat that it may cause hypoglycemia that the liver responds to but does not cause the usual hypoglycemic symptoms.

I know this pattern is seen when Lantus is used with cat diabetics. My cat was getting bg's from 300-450  for 2 years until I started dropping his dose; he is now stabilized on 1/2 the dose he used to get! He never had any hypos; the only symptom of too much Lantus was superhyperglycemia.

I suspect this happens with humans too, and me in specific, but I've not seen anything mentioned in any literature or posting mentioning this phenomena.

[JDRF Team SGG]

You did not mention how old the bottle of Lantus is that you are using. Lantus comes with instructions saying to not use any "open" bottle longer than one month. My twin and I, both type 1 diabetics and both on Lantus, do notice unpredictable things happening when a bottle is older than one month, or occasionally when a bottle seems to go "bad a little bit before the one month deadline. Lantus works by creating crystals in your tissues when injected that release slowly all throughout the day. I believe that its abilitly to release is impaired when it gets old or goes "bad". I particularly notice that I will have sudden unexpected blood glucose drops At unpredictable times when the Lantus is a problem, while my twin experiences unexplained high glucose levels when the Lantus is old. Just something else to check. You may want to replace your bottle if there is any doubt. I write the date that I start a new bottle on the bottle with a fine tipped laundry marker so I can't forget.

But your thoughts about possible night lows being corrected by liver sugar dumps sounds very likely. The previous posting's suggestion of 3 am blood tests sounds like an easy way to find out if this is happening. Lantus actually has a slight "peak" action at about 4 hours after injection... that is the time that you probably would want to set your alarm and wake up to check to see where your glucose is: sometime between 4-5 hours after you took your shot.

[galzee]

Hi Malli52!  Can I suggest trying a couple of things?  First I'd definitely be doing several days worth of 3am bg checks, just to be on the safe side.  The more bg information you have, the better you'll be at arriving at the correct insulin dosage for you.  Also, I'd discuss with your endo, switching your PM lantus to an AM injection.  Because of it's slow acting capabilities, and I know that it doesn't seem to make sense, but this seems to be the right combination for some people.    Good luck!

[JDRF-Team-CDB]

Dear malli52,
What an interesting question! Have you experimented with decreasing your dose of Lantus? What about trying 9 units?

I'm not a doc, just the mom of a diabetic teenager. She's also on a once-daily PM dose of Lantus and has predictable bg responses to insulin doses, and Lantus has worked really well for her, but she has not changed her diet. When she's in a period of intense exercise (during swim-team season), she reduces both her Lantus and Novolog doses a little, and it works fine.

Let us know if you've tried lowering the dose and what happened. I also was unable to find out anything about this in the literature.