AAHA Diabetes Management Guidelines for Dogs and Cats 2018 – is below just cats?

General info

  • Prevalence of diabetes in increasing possibly due to the rise in obesity
  • Prognosis for cats that are well managed is good, median survival times 13-29 months
Epidemiology

  • Most cats with DM have type II DM (insulin resistance)
  • Type I DM is rare in cats
  • Insulin resistance can be caused by obesity, drugs (e.g. corticosteroids, progestagens), pancreatitis and concomitant endocrinopathies (e.g. hyperadrenocorticism or acromegaly
Clinical signs

  • PU/PD/PP, lethargy and weight loss
  • Less common signs include weakness, plantigrade stance.
  • Depression and anorexia may be seen with diabetic ketoacidosis
Risk factors

  • Obesity (obese cats 4 x more likely to get DM than non obese cats)
  • Indoor and inactive cats
  • Cats > 7 years old
  • Male or neutered cats
  • Burmese cats
Diagnosis

  • Compatible clinical signs with persistent hyperglycaemia and glucosuria
  • Must exclude stress hyperglycaemia (rare to be >16 mmol/l (288 mg/dl))
  • If diagnosis is in doubt home measurement of blood and urine may be helpful or serum fructosamine measurement (as it reflects the average BG during the preceding week)
  • Serum fructosamine may not be elevated in mild DM or in cats diagnosed in the very early stages.
  • Diabetic ketoacidosis is diagnosed by high blood or urine ketone concentrations and metabolic acidosis with compatible clinical signs (anorexia, weakness, vomiting, moribund)
Evaluation of the diabetic cat

  • Thorough history and clinical examination
  • Blood tests – Routine biochemistry, CBC, Fructosamine, T4 (in older cats)
  • Urinalysis – Complete urinalysis with culture (especially if active sediment)
  • Investigations into concurrent diseases e.g abdominal ultrasound +/- fPLI
Overall goals in managing diabetic cats

  • Main aims are to reduce or eliminate the clinical signs while avoiding insulin induced hypoglycaemia
  • Euthanasia or cessation of treatment is less likely if the negative impact of DM on the owner is minimised
  • Maintain blood glucose below the renal threshold 14 mmol/l (252 mg/dl)
  • Diabetic remission is more common in cats with better glycaemic control
  • Avoiding hypoglycaemia BG < 3-3.5 mmol/l (54-63 mg/dl) should be a priority as severe hypoglycaemia can be life threatening
Role of Diet

  • Initially feed  ad lib or multiple times a day to stop the DM associated pathological weight loss
  • Weight loss is encouraged with calorie restriction once good glycaemic control has been achieved in overweight cats
  • Wet foods may be preferred (as they have been shown to increase daily water intake and reduce calorie consumption compared to dry foods)
  • Monitor body-weight and body condition every 1-2 weeks
  • Monitor blood glucose and insulin requirements closely during any weight loss period
  • Preferred diet is a restricted carbohydrate diet (carbohydrate content ≤ 12% ME or 3 g/100 kcal) as they have been shown to improve glycaemic control and increase remission rates.
  • If using these low carbohydrate diets, timing and frequency of feeding  is not critical and should match the cats normal routine (assuming a minimum of 2 meals a day)
  • If clinically indicated e.g. concomitant disease, alternative diets may be used
  • If food has to be withheld e.g. for anaesthesia, administer 50% of the normal insulin dose on the morning and monitor BG, supplementing glucose or insulin as indicated
Role of oral hypoglycaemia agents

  • Indicated when owners refuse insulin therapy
  • Use glipizide 2.5 mg PO q12h for the first 2 weeks
  • If no adverse effects but inadequate glycaemic control increase dose to 5 mg PO q12h
  • Clinical response is usually seen after 4-6 weeks
  • Adverse effects include hypoglycaemia, vomiting and cholestasis and there is a concern that glipizide may actually contribute to the progression of pancreatic amyloidosis
Insulin choices

  • Lente  (e.g. Caninsulin/Vetsulin), peak activity 2-8 hrs post injection, duration 8-10 hrs
  • PZI insulin  (e.g Prozinc), peak activity 2-6 hrs post injection, typical duration 13-24 hrs
  • Glargine (e.g. Lantus) and Detemir (e.g. Levemir), peak activity 12-14 hrs duration 12->24 hrs
  • Be aware that insulin preparations can be 100 IU/ml  or 40 IU/ml and appropriate syringes or pens must be used
  • Do NOT dilute insulin preparations to facilitate dosing
Recommendations for insulin preparations and frequency of dosing

  • Recommended to use longer acting insulins e.g.  Glargine, Detemir and PZI as they may provide better control and a more gradual decline in BG following administration
  • Recommended to use these insulins twice daily (q12hrs +/- 2h)
  • Suggested that although manufacturers advise discarding opened vials after 4-6 wks that in practice refrigerated vials have been safely used for up to 6 months. However caution is advised as there is a risk of bacterial contamination and if insulin becomes cloudy or discoloured it should be discarded
Initial management of the diabetic cat

  • Starting dose 0.25-0.5 U/kg q 12 h (In a non ketotic cat using intermediate or longer acting insulin)
  • Round the dose down to the nearest unit
  • If BG >20 mmol/l (360 mg/dl) use 0.5 U/kg
  • Dose obese and underweight cats to their estimated ideal weight
  • Monitor closely for hypoglycaemia, starting 5-7 days after initiating treatment as if treatment is successful, insulin requirement may decrease over time.
  • Do not adjust doses more than every 5-7 days except in the case of hypoglycaemia
  • It is not necessary to hospitalise diabetic cats that are clinically well but it is important to educate the owners before discharge about the correct handling, storage and administration of insulin and about the risks, signs and home treatment
    of hypoglycaemia
Five to ten days post discharge

  • The cat should be rechecked, laboratory parameters re-evaluated as needed and a BG curve (BGC) should be performed (BG measured every 1-2 hrs for lente preparations and every 2-3 hrs for longer acting preparations)
  • In practice curves have questionable accuracy and ideally home BG curves or fructosamine measurement should be used
  • Continuous glucose monitoring (CGM) is an option to reduce sampling stress in hospitalised cats and can also be used in the home
Interpretation of curves in stabilisation period

  • If blood glucose nadir is <4.5 mmol/l (80 mg/dl) reduce the insulin dose by 50% and if the peak BG is >14 mmol/L (252 mg/dl) consider a longer acting insulin
  • If BG remains between 4.5-14 mmol/l (80-252 mg/dl) throughout the day continue the current dose
  • If nadir is >8 mmol/l (144 mg/dl) and peak BG is >14 mmol/l(252 mg/dl) with signs of ongoing hyperglycaemia, increase the dose by 0.5-1 U/cat q12h
  • If nadir is 4.8-8 mmol/l (80-144 mg/dl) but peak BG >14 mmol/l (252 mg/dl) options include Maintaining therapy and rechecking again after 1-2 wks Changing the insulin to a longer acting insulin (if using Lente) Increasing the dose by 0.5 IU/cat
    q12h (depending on nadir and peak BG)

 
Three weeks after discharge

  • Re-examine the patient and re-evaluate laboratory parameters as indicated.
  • Perform a BGC (ideally at home)
  • Perform weekly home BG curves until stable

 
Intensive management of feline DM

  • This involves daily home BG curves and more regular adjustments of insulin dose with the aim of maintaining BG between 2.8-3 mmol/l (50-54 mg/dl) and 5.5-11 mmol/l (99-200 mg/dl)
  • This approach is not recommended as there is no evidence to suggest a clear clinical benefit and  it is hard for owners to achieve this safely.

 
Long term management of the diabetic cat

  • Owners should be advised to keep a daily record of the cats general demeanour, water intake, urine production, food intake, and insulin dose and time.
  • Owners should be advised to keep a weekly record of weight, body condition score and urine glucose
  • Persistent glucosuria may indicate inadequate control and persistent negative glucose result may indicate diabetic remission, insulin overdose or excellent glycaemic control
  • Home blood glucose curves should ideally be performed every 3-4 weeks using spot blood glucose checks if the owner has any concerns about the cat.
  • Advise owners NOT to alter insulin doses without first consulting the vet

 
Monitoring in the clinic

  • Suggestion to recheck at 1, 2-3, 6-8, 10-12 and 14-16 wks after starting treatment then every 1-2 months depending on stability and ability of efficient home monitoring
  • Each recheck may include history, clinical examination, body weight and body condition score, BGC in clinic if owner unable to regularly perform at home and serum fructosamine

 
Adjusting insulin therapy in cats on long term management

  • Aim to maintain BG between a nadir of 4.5-8 mmol/l (80-144 mg/dl) and a peak of 10-14 mmol/l (180-252 mg/dl)
  • If nadir <4.5 mmol/l (80 mg/dl) Reduce insulin by 0-5-1 IU/cat q12h if receiving 0.5-3 IU/cat q12h If on a higher insulin dose, reduce the insulin by 25-50%
  • If nadir is >8 mmol/l (144 mg/dl) Increase insulin by 0.5-1 IU/cat q12h
  • If pre-insulin BG is 8-10 mmol/L (144-180 mg/dl) Consider reducing insulin by 0.5 IU/cat q12h
  • If pre-insulin BG is 4.5-7.9 mmol/l (80-142 mg/dl) Reduce insulin by at least 0.5 IU/cat q12h
  • If pre-insulin BG is <4.5 mmol/l (80 mg/dl) Withhold insulin. if the BG rises a lot later then give 30-50% of previous dose
  • If the nadir is within the recommended range but the insulin consistently lasts only 8-10 hours, switch to a longer acting insulin preparation
  • BGC’s should be done 5-7 days after any change to the insulin dose or sooner if there is a risk of hypoglycaemia (nadir < 4.5 mmol/l (80 mg/dl) or a pre-injection glucose of <8 mmol/l (144 mg/dl)
  • Extreme care should be taken with insulin adjustments  in cats where BGC’s are not possible. Fructosamine should be utilised where possible.
  • Most cats need between 0.5-6 IU/cat q12h for control of their hyperglycaemia. If the dose needed is >1.5 IU/kg q 12h insulin resistance should be considered

 
Use of fructosamine

  • These reflect the average BG over the preceding week
  • Can be affected by serum protein concentrations, hydration status, serum thyroid levels and acid base balance. There can be variations between individuals and gender
  • <350 μmol/l indicates excellent glycaemic control, diabetic remission or insulin overdose
  • 350-450 μmol/l indicates good glycaemic control
  • 450-550 μmol/l indicates moderate glycaemic control
  • >550 μmol/l indicates poor glycaemic control