Diabetes mellitus and pernicious anaemia

[henaddict]

Have just been diagnosed with B12 deficiency and would like anyone's experience of working with it and type II diabetes. Am on metformin, sitagliptin and gliclazide.

[fbirder]

Metformin will cause a Vit B12 deficiency in 30% of patients - medscape.com/viewarticle/71...

Some of the symptoms of B12 deficiency are the same as diabetes - fatigue and peripheral neuropathy are two that spring to mind. So it's likely that you will need B12 injections. The linked paper suggests one per year, but I would try to persuade my GP to follow the guidelines in the British National Formulary -

Dose

By intramuscular injection, pernicious anaemia and

other macrocytic anaemias without neurological

involvement, initially 1mg 3 times a week for 2 weeks

then 1mg every 3 months.

Pernicious anaemia and other macrocytic anaemias

with neurological involvement, initially 1mg on

alternate days until no further improvement, then

1mg every 2 months."

You don't have PA (probably) but your problem is malabsorption - just the same as if you did have PA. Note that, if you do have peripheral neuropathy (tingling/numb fingers/toes) then you need to follow the dosage instruction in the second paragraph.

Just an interesting note on the linked paper - this is the first time I've ever seen a medical professional admit, in print, that it was the patient who suggested B12 may be the problem.

[henaddict in reply to fbirder]

Many thanks - I reckon I do have PA because the symptoms are different to those of diabetes and the GP has confirmed it. I'm having 6 x one-a-week injections then one every three months for life. The question is whether I should question the metformin. The alternatives, apart from blocking B12, don't look particularly attractive.

[fbirder in reply to henaddict]

Yes the symptoms if B12 deficiency are different (though similar) to diabetes. But B12 deficiency can be caused by many things, PA is just one of them.

PA means that you're not absorbing B12 because your immune system is killing off the gastric parietal cells that produce Intrinsic Factor (IF), which is essential for proper absorption of B12 in the ileum (part of the small intestine).

You could ask your GP to do a test for anti-IF antibodies. A positive result means it's pretty sure you have PA, but about half of people with the antibodies give a false negative result (it's not a good test, but it's the best there is at the moment).

However, there's a fair chance that your B12 deficiency isn't due to PA but to your metformin hindering the absorption of B12. The treatment for both PA and metformin-induced malabsorption is the same - B12 injections. But there are some important differences.

With PA the gastric cells that the immune system kills off are also responsible for releasing hydrochloric acid when food hits the stomach. Without this happening one can get horrible IBS-like symptoms, plus an increased risk of gastric cancers.

But if it's due to the metformin then you won't have those troubles. Plus, when (if) they invent something better than metformin, you can switch drugs and your B12 deficiency should disappear.

[Gambit62 Administrator]

There are some studies out there that imply that metformin can actually help the body utilise B12 more efficiently, so may not be a disadvantage if you are receiving B12 shots to continue to be on metformin.

How long have you been diabetic? and is there any family history of diabetes?

2% of diabetics are neither type 1 or type 2 but a genetic variant of MODY. MODY variants are closer to type 1 than type 2, with the result that it is sometimes better treated with drugs that stimulate production of insulin by the pancreas - ie can respond to different drug treatments.

However, GPs are generally unaware of MODY ... and there are probably a lot out there who, even if aware, mistakenly think it is more closely related to type 2. MODY is a dominant gene so if you have a family history of diabetes it may be worth looking into it and making sure that close relatives are aware as there is a 50% chance of passing it on ... and if you have the gene you will develop diabetes ... as opposed to type 2 proper which is triggered by a number of environmental factors.

Metformin is actually a very old drug and, unfortunately perhaps, has gained a prevalence in treatment to the detriment of other drugs that might have been effective... but I start to rant.

Note: MODY runs in my family - a variant that was identified formally in the 'noughties'. I was tested and don't have the gene, though my mother and brother do.

[henaddict in reply to Gambit62]

Thank you for the thought and my father and brother both had/have Type II but all of us were diagnosed in our 50's so don't fit the profile of MODY.

[Gambit62 Administrator in reply to henaddict]

The type of MODY that runs in my family generally kicks in as diabetes between 30 and 45 ... to date there are at least 11 different variants ... and I suspect that they are finding more as time goes on.

[Minx1971]

Hi I know I don't know as much as others on here but when I read your post it sprung to mind, while I was pregnant I had gestational diabetes and had metforim, this is the only reason I know what it is. I can't remember if it was on the information inside your meds or if ii was on a sight I was looking for info on. I clearly remember it listing as a contraindication if you have pa to tell your doctor before taking metforin. Me and baby fine so it didn't affect us and the specialt treating me never mentioned a problem with both that's if she remembered to read through my notes.

Always read the info inside new medication as I've noticed a lot of drugs have warnings like that, I never used to bother but after I realised contra indications can even be don't take ibrufen with certain things for example antidepressants.

[henaddict in reply to Minx1971]

Many thanks for your comments.

[clivealive Forum Support]

Hi henaddict,

I'm coming at this from the opposite direction as I've had P.A. for 43 years and was diagnosed with Type 2 Diabetes in May this year and put on Metformin (4 x 500mg daily) reduced to 2 x 500mg after 3 months after an HbA1c showed the diabetes to be "under control" helped by diet and exercise.

You don't say what is causing your B12 deficiency and of course I receive my B12 by monthly injections so when I too read on the Metformin leaflet "Low vitamin B12 levels in the blood" I was concerned but when I queried this with Diabetes UK I got a reply from their Careline which said:-

"B12 absorption in relation to Metformin use is related to parietal cells, achlorhydria, and failure to produce intrinsic factor, resulting in vitamin B12 malabsorption. This is the same mechanism that causes B12 absorption problems in pernicious anaemia and will not effect the use of Cyanocobalamin 1mg B12 injections as this does not require gastric absorption".

My diet was already very good but I'm finding the 20-25 minutes a day on an exercise bike very exhausting, but then I'm 74 years old....

I hope you find some answers here from more learned folk and wish you well for the future.

clivealive

[henaddict in reply to clivealive]

Many thanks, Clivealive!

[Minx1971 in reply to clivealive]

Hi henaddict, would you mind explaining to me why the failure to produce intrinsict factor resulting in b12 malabsorption problems may or can affect different drugs going in to the system.i was diagnosed with pa 20 plus years ago and know very little apart from the kind people here that answer questions for me,when they come to mind.

[henaddict in reply to Minx1971]

I'm afraid I can't - I'm very recently diagnosed and trying to understand what's going on and what my options are. Perhaps someone else can help?

[fbirder]

Having Aloe Vera Gel helps as it helps for Vit B12 deficiency since one of the few plant sources containing same

If it does contain any B12 then it's is such vanishingly small amounts that it would be of no benefit.