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letrozole, anastrozole and elevated A1c

Has anyonewith prediabetes developed a dramatic elevation of A1c with either of these drugs?

Comments

  • ratherbesailing
    ratherbesailing Member Posts: 117

    I am not pre-diabetic, but my A1c increased 10% in three years on letrozole. A1c does increase with age, and my oncologist swears it isn't the letrozole. But she always denies side effects. This article is interesting...

    https://www.drugs.com/medical-answers/letrozole-af...


  • moderators
    moderators Posts: 7,670

    Hi moonriver28, and welcome to Breastcancer.org!

    We're sorry for the reasons that bring you here, but we're really glad you've found us. You're sure to find our Community an amazing source of advice, information, encouragement, and support -- we're all here for you!

    While you've already received one helpful reply, you may also want to check out this thread on Diabetes and Breast Cancer, where others share their experience with A1c levels.

    We hope this helps and we look forward to seeing you around the boards! Please let us know if there's anything else we can do to assist you.

    --The Mods

  • quietgirl
    quietgirl Member Posts: 165

    moonriver quick question are you concerned it might happen or has it already happened. I ask because there are a number different times during treatment that can effect a1c. Chemo drugs, radiation treatment that results in dehydration can impact, then there is the whole part of being less active during treatment. So on top of that is the idea that estrogen helps to regulate blood sugar https://www.diabetesincontrol.com/estrogen-treatment-helps-to-prevent-type-2-diabetes/

    so any drug that impacts your estrogen has the potential to impact your A1C. Whether it’s enough to move someone from prediabetes to diabetes is going to depend on any number of factors.

    On a person level my A1C hasn’t change but that doesn’t mean it won’t be overtime.

  • Moonriver28
    Moonriver28 Member Posts: 4

    Thanks for the reply, quietgirl. This is my situation - Prediabetic since 2016, managed with lifestyle, no meds. 72 years old. oct 2020 lumpectomy T1b N0. Tumor was 7mm. Five days of partial breast radiation. Began Letrozole March 2021. Paused March 2022 because of mild, mostly cosmetic, symptoms.

    Oncotype score = 2. Was told letrozole not absolutely necessary- my choice - like extra insurance policy.

    Fourteen months (May 2022) after beginning Letrozole - in midst of my pause - A1c was 6.9 - diabetic range first time ever. (six months before was 6.1)

    July 3 began Anastrozole. July 8 - A1c was 7.9. Took Anastrozole for two+ weeks during which time A1c jumped as high as 9.1. Stopped Anastrozole with doctor’s consent. Waiting for initial appt. with endocrinologist - long wait in NYC.

    I’ve asked oncologist and internist whether there might be a connection between abruptly disrupting my endocrine system and the rapid deterioration of my A1c from pre to diabetic range. They say it is highly unlikely. I understand that correlation is not causation or some such, but can’t help thinking that this has something to do with the year plus of hormone therapy and its lingering after effects. I feel completely fine, but frightened.

    Lipid profile is good, BP is in 105-110/68-74 range. No medication for anything. Weight OK - not overweight or obese. Regular daily walker

    Any thoughts, anyone?

  • Moonriver28
    Moonriver28 Member Posts: 4

    Thanks for the reply, quietgirl. This is my situation - Prediabetic since 2016, managed with lifestyle, no meds. 72 years old. oct 2020 lumpectomy T1bN0. Tumor was 7mm. Five days of partial breast radiation. Began Letrozole March 2021. Paused March 2022 because of mild, mostly cosmetic, symptoms.

    Oncotype score = 2. Was told letrozole not absolutely necessary- my choice - like extra insurance policy.

    Fourteen months (May 2022) after beginning Letrozole - in midst of my pause - A1c was 6.9 - diabetic range first time ever. (six months before was 6.1)

    July 3 began Anastrozole. July 8 - A1c was 7.9. Took Anastrozole for two+ weeks during which time A1c jumped as high as 9.1. Stopped Anastrozole with doctor's consent. Waiting for initial appt. with endocrinologist - long wait in NYC.

    I've asked oncologist and internist whether there might be a connection between abruptly disrupting my endocrine system and the rapid deterioration of my A1c from pre to diabetic range. They say it is highly unlikely. I understand that correlation is not causation or some such, but can't help thinking that this has something to do with the year plus of hormone therapy and its lingering after effects. I feel completely fine, but frightened.

    Lipid profile is good, BP is in 105-110/68-74 range. No medication for anything. Weight OK - not overweight or obese. Regular daily walker

    Any thoughts, anyone?

  • jrnj
    jrnj Member Posts: 407

    moonriver28. Yes I think letrozole is affecting my A1c and my cholesterol. I’ve been struggling with side effects from AIs for 2 years. I’ve been on and off statins which combined with letrozole are killing me. Since on letrozole statins not even working anymore and I don’t want to increase dose. a1c went from 5.4 to 5.9. Doesn’t sound like much compared to yours but I’ve never been that high. I’m not overweight but do eat too much sugar. Started new cholesterol med repatha last week. Literature says increases a1c. Can’t wait for next blood test!! And haven’t slept for a week. I can’t handle these meds there killing me.

  • Moonriver28
    Moonriver28 Member Posts: 4

    Thank you for your reply. Reading through the history of treatment you provide it looks like you’ve been through so much. I hope the medication related discomfort resolves and you feel better. I’ll be meeting with an endocrinologist tomorrow ( first appointment) to see what’s going on with me