T1 and Metformin?

[bvnsheee]

Hello all 🙂

I was being investigated back in October for diabetes - due to my age, they thought T1 but because I'd previously had gestational diabetes they had to investigate for T2 also. I was put on Metformin at this point while we waited. At Christmas I was told I was T1 and have gradually upped my insulin as I'm coming out of the honeymoon period. At the minute I'm on 10 units of Levemir in the morning and 1 unit per 20g carbs for my Novorapid (though this will most likely need changing soon).

I've not actually had any appointments, in person or telephone, with my diabetes nurses and I've only spoken once with the consultant when he told me I was T1. All my insulin dose advice has come from my hospital dietitian. Yesterday I rang the hospital as I've been having hypos during my evening meal and I thought maybe I needed to change something. The nurse saw I was on Metformin and told me I shouldn't be and to come off it. I was on 2 500g tablets twice a day.

Since yesterday, my levels have gone from 4-9 to easily 10+ throughout today and last night overnight I went up to around 17-18 which hasn't happened since I started taking insulin. I'm a healthy weight and have no other reason for insulin resistance so I don't want to go back on Metformin if I don't need to be. I'm wondering if I need to adjust my basal or bolus insulin as maybe the Metformin was making me need less? I'm not sure whether I should call the nurses yet though as they often tell me to get a few days worth of data before calling them for an issue and I'm not comfortable with my levels being so high at bedtime.

 

[Bruce Stephens]

I'm wondering if I need to adjust my basal or bolus insulin as maybe the Metformin was making me need less?

That would be my guess. I'd have thought 17-18 was high enough that contacting your DSN would be justified without more days of readings.

 

[bvnsheee]

That would be my guess. I'd have thought 17-18 was high enough that contacting your DSN would be justified without more days of readings.

Thank you, I've just left a voicemail with them asking for a call back. I didn't realise the Metformin would have such an impact and the nurse didn't mention it when she told me to come off it so it's come as a shock! I thought I'd finally got my levels consistent.

 

[DaveB]

Having Metformin with insulin is not a problem and will reduce your BS by perhaps a mmol. My DN wanted to keep me on it for it's other protective properties. Your nurse was panicking a bit without good reason. Two points. Many of us find splitting Levemir into a Day and Night dose is the best way to use it as you can adjust to different amounts day and night. Despite what Novo say, Levemir doesn't last 24 hours; much nearer to 12-15 hours dependent on dose level. Your Bolus needs to be adjusted for the carb content in each meal. Ask the DN to explain carb-counting.

 

[rayray119]

I'm not sure whether I should call the nurses yet though as they often tell me to get a few days worth of data before calling them for an issue and I'm not comfortable with my levels being so high at bedtime.

do you have a correction factor yet?

 

[rebrascora]

Metformin takes time to build up in your system (a couple of weeks usually and similarly takes take to wear off when you stop taking it so my guess would be that it is just coincidence that your levels have increased significantly just as you have stopped taking it. It also has a relatively minimal effect on levels, certainly not several mmols, so my guess would be that something else is at play..... perhaps honeymoon period coming to an end or perhaps you are coming down with an illness but haven't got symptoms yet. You haven't had a Covid jab recently have you as that can cause havoc with BG levels.

Did you double check the unusually high levels you got? Are you using Libre or finger pricks?

 

[Inka]

Thank you, I've just left a voicemail with them asking for a call back. I didn't realise the Metformin would have such an impact and the nurse didn't mention it when she told me to come off it so it's come as a shock! I thought I'd finally got my levels consistent.

I agree with @rebrascora that there might be something else at play. A sleepless night? Stress? Illness? Missed injection? Degraded insulin?

You’re not alone in being thought to have had GD when you actually had Type 1. I know a number of women who has similar. You’re lucky you’ve got the correct diagnosis now.

Control is an ever-moving target. So much can affect our blood sugars. In the honeymoon, things can be quite erratic so take that into account too.