How low should a feline glucose curve go?

Re: How low should a feline glucose curve go?

Martin Atkinson — Thu, 17 Jul 2014 09:14:09 GMT

[[quote user="Gareth Dowdeswell"]

The cat ate at the time of the injection, which I think would have caused the slight rise in blood sugar level. Glucose readings were taken every 2 hours, the nadir was halfway between insulin doses, from memory I think the reading 2 hours after the nadir was around 9 and reading 4 hours post nadir was around 11. If it was an overswing wouldn't the nadir be earlier than halfway between doses?

[/quote]You would expect a slight rise after dosing if the cat had eaten and because the delay of onset of action of the insulin is around 2 hrs.

In a classical curve the nadir should occur 4-5 hours post dosing. then slowly rise over the rest of the curve to back where it started 12 hours later, admittedly it is rarely that perfect. True a classical acute overswing should give you a rapid nadir then a sharp rise but other factors come into play. As you're measuring every 2 hours you may have missed an even lower nadir and, as if this is an overswing it is likely to be chronic, you could have the attempt of the cat to compensate for the hypoglycaemia superimposed so this may delay the nadir giving you a false picture. It could be you have a nigh on perfect dose but there is still too much risk of this cat going hypoglycaemic so as said I would reduce the dose of insulin 25% regardless and start again on the basis that it is not going to die very quickly from poorly controlled DM but if it goes hypo when no-one is observing it its demise may be rather faster! A second half of the day curve would also be useful although I know it is difficult unless you have committed owners capable of performing one at home and you may be restricted by cost consideration.

Incidentally, I am never happy with 2 hourly testing during the critical period 2- 6 hours post dosing and would do one hour testing then even if you go to 2 hours in the second half of a 12 hour curve. This is all of course assuming you are using Caninsulin!

Re: How low should a feline glucose curve go?

Gareth Dowdeswell — Wed, 16 Jul 2014 21:54:00 GMT

[quote user="Martin Atkinson"]

[quote user="Gareth Dowdeswell"]

Did a curve on a diabetic cat this week, started with a BG of 11 prior to food and insulin, rose to 15 then dropped to a nadir of 3.1 before climbing up again. Cat has been on treatment for several months with gradual increases in insulin dose.

In a normal outpatient cat I would think this curve is too low and would be reducing the insulin dose, and the references I've looked at support that. This cat is, however, in a charity rehoming centre, and the curve was performed there so I don't think stress will have affected the curve results, as it would for cats who have been bought into the clinic for the day. No signs of hypoglycemia have been noted. Would people decrease the dose or leave it as it is?

[/quote]The nadir is definitely too low for comfort, I would like to see it near the top end of normal or slightly over, reached 4-5 hours post dosing then gradually rising back to the high point just before the next dose. It is not unusual to see a rise immediately post dose and that is not particularly high although the rise is a little to great for me to be happy.

Important information missing here is how quickly the levels rose after the nadir was reached. Also no information on time of feeding or indeed if the cat ate even if food was offered - all this is important. Notwithstanding this, this sounds as though it could be a Somogyi overswing or otherwise as suggested the cat may be going into remission (maybe the same thing in reality). I would decrease the dose by at least 25% and repeat the curve in a few days.

Fructosamine is a rather unreliable indicator as even with low nadirs if more time is spent above normal due to overswinging it may be high and fool you into increasing dose.

If you continue to get large swings then you may consider Lantus Glargine.

[/quote]

Re: How low should a feline glucose curve go?

Martin Atkinson — Mon, 14 Jul 2014 09:28:40 GMT

[quote user="Gareth Dowdeswell"]

Fructosamine is a rather unreliable indicator as even with low nadirs if more time is spent above normal due to overswinging it may be high and fool you into increasing dose.

If you continue to get large swings then you may consider Lantus Glargine.

Re: How low should a feline glucose curve go?

emerald — Sun, 13 Jul 2014 21:20:08 GMT

I would also have decreased the dose. Don't forget could be the start of remission too?

Re: How low should a feline glucose curve go?

Gareth Dowdeswell — Sun, 13 Jul 2014 12:23:15 GMT

No fructosamine yet, last fructosamine done prior to a couple of dose increases was consistent with poor control.

Thanks for the replies, I did choose to decrease the dose after the curve but was interested to see if anyone was feeling braver than me!

Re: How low should a feline glucose curve go?

Yantha Smyth — Sat, 12 Jul 2014 20:42:20 GMT

Me too. I don't like them to go below about 6mM.

Re: How low should a feline glucose curve go?

Stephen Courtney — Sat, 12 Jul 2014 18:50:18 GMT

I would be nervous about the low reading - has a fructosmaine been done? I'd be inclined to drop the insulin dose a little.