Home-monitoring of blood glucose in cats with diabetes mellitus: evaluation over a 4-month period

Frequency of diabetic remission, predictors of remission and survival in cats using a low-cost, moderate-intensity, home-monitoring protocol and twice-daily glargine

OBJECTIVES

The aim of the present study was to retrospectively assess remission rates and survival in diabetic cats managed using a moderate-intensity, low-cost protocol of home blood glucose measurements and insulin adjustment by clients of a cat-only practice, and to determine if predictors of remission, relapse or survival could be identified.

METHODS

The records of a cat-only practice were used to identify 174 cats with newly diagnosed diabetes managed using only pre-insulin home blood glucose measurements for insulin dose adjustments based on a protocol provided to clients aimed at maintaining pre-insulin blood glucose in the range of 6.5-11.9 mmol/l (117-214 mg/dl). Cats were excluded for the following reasons: insufficient follow-up in the records; a lack of owner compliance was recorded; they were receiving ongoing corticosteroids for the management of other conditions; they were euthanased at the time of diagnosis; or they were diagnosed with acromegaly or hyperadrenocorticism.

RESULTS

Using only pre-insulin blood glucose measurements at home to adjust the insulin dose to maintain glucose in the range of 6.5-11.9 mmol/l, 47% of cats achieved remission, but 40% of those cats relapsed. A minority (16%) of cats were hospitalised for hypoglycaemia. The survival time was significantly longer in cats in remission and Burmese cats.

CONCLUSIONS AND RELEVANCE

The cost and time burden of treating diabetic cats may cause some clients to choose euthanasia over treatment. While the highest rates of diabetic remission have been reported in studies of newly diagnosed cats treated with intensive long-acting insulin protocols and low carbohydrate diets, these protocols may not be suitable for all clients. Nearly 50% of cats with newly diagnosed diabetes achieved remission with this low-cost, moderate-intensity, insulin dosing protocol. As remission was significantly associated with survival time, discussing factors in treatment to optimise remission is important, but it is also important to offer clients a spectrum of options. No cats that started treatment in this study were euthanased because the owner did not wish to continue the diabetes treatment.

Glucose Counterregulation: Clinical Consequences of Impaired Sympathetic Responses in Diabetic Dogs and Cats

Insulin induced hypoglycemia (IIH) is common in veterinary patients and limits the clinician's ability to obtain adequate glycemic control with insulin therapy. Not all diabetic dogs and cats with IIH exhibit clinical signs and hypoglycemia might be missed by routine blood glucose curve monitoring. In diabetic patients, counterregulatory responses to hypoglycemia are impaired (lack of decrease in insulin levels, lack of increase in glucagon, and attenuation of the parasympathetic and sympathoadrenal autonomic nervous systems) and have been documented in people and in dogs but not yet in cats. Antecedent hypoglycemic episodes increase the patient's risk for future severe hypoglycemia.

Evaluation of the FreeStyle Libre, a flash glucose monitoring system, in client-owned cats with diabetes mellitus

Objectives

Home blood glucose monitoring using a portable blood glucose meter is important in the management of feline diabetes mellitus, but taking blood samples may be stressful for owners and cats. A flash glucose monitoring system measuring interstitial glucose, such as the FreeStyle Libre, overcomes some of these drawbacks. The aim of this study was to evaluate the practical use and analytical and clinical accuracy of the FreeStyle Libre in 41 client-owned diabetic cats.

Methods

In this prospective study, interstitial glucose concentrations were measured with the FreeStyle Libre and compared with blood glucose concentrations measured with a portable blood glucose meter (AlphaTRAK) on days 1, 7 or 8 and 14 after application of the device. Cat behaviour during application, location, skin reaction at the attachment site and owner satisfaction were assessed. Accuracy was determined by fulfilment of ISO 15197:2013 criteria, including Bland–Altman plotting and error grid analysis.

Results

Placing the device was easy, with 70% of cats showing no reaction. Most sensors were placed on the thoracic wall. Skin reactions at the attachment site were not present or mild in almost all cats. Owners were very satisfied with the use of the FreeStyle Libre. Median functional life of the sensor was 10 days (range 1–14). Good correlation was found between interstitial and blood glucose measurements (rho[r] = 0.88, P <0.0001). Fifty-three percent of interstitial glucose concentrations were within a maximum deviation of 15% from blood glucose concentrations and 92.7% were within the safe risk zones 0 and 1 of the surveillance error grid.

Conclusions and relevance

The flash glucose monitoring system was easy to use and owners of diabetic cats were satisfied with its use. Although the device did not completely fulfil ISO requirements, it is sufficiently accurate for glucose monitoring in diabetic cats.

Comparison of a human portable blood glucose meter and automated chemistry analyser for measurement of blood glucose concentrations in healthy dogs

Blood glucose measurement is one of the most commonly performed clinical diagnostic tests used to monitor glycaemia in several animal diseases. Usually, these laboratory analyses are performed on blood venous samples in remote laboratories, and the results are delayed, at best. The use of portable glucometers could evidently solve many constraints but veterinary‐use glucometers are not usually available. The present study aimed to compare blood glucose levels obtained by Bionime glucometer to the reference method using glucose oxidase. Venous blood was collected from a total number of 140 healthy dogs (72 males and 68 females), of different breeds (28 German Shepherd, 27 Pitt bull, 21 Boxer, 24 Rottweiler and 40 cross‐bred dogs) and different ages (range: 3 months–14 years) for glucose measurement using the reference laboratory method. Capillary blood samples were used to conduct a glucose measurement with a human‐use glucometer. Our results revealed that there was no significant difference between the mean capillary blood glucose (CBG) measured with the human‐use glucometer (5.06 ± 0.84 mmol/L) and the mean venous blood glucose (VBG) measured with the laboratory reference method (4.90 ± 0.73 mmol/L) (p = 0.42). Similarly, there was no significant difference of the mean CBG and VBG in male dogs (5.11 ± 0.88 and 4.97 ± 0.75 mmol/L, respectively) and female dogs (5.01 ± 0.81 and 5.07 ± 0.72 mmol/L, respectively) (p = 0.73 and 0.21, respectively), and no correlation to neither age (5.43 ± 0.90 and 5.20 ± 0.70 mmol/L in 3 to 6 month‐old dogs, 5.03 ± 0.82 and 4.94 ± 0.79 mmol/L in 6 months to 1 year‐old, 4.94 ± 0.67 and 5.13 ± 0.66 mmol/L in 1 to 4 year‐old dogs; 4.88 ± 0.94 and 4.80 ± 0.75 mmol/L in dogs older than 4 years, respectively, p < 0.05), nor to breed (4.94 ± 1.01 and 4.99 ± 0.79 mmol/L in German Shepherd, 5.13 ± 0.84 and 4.99 ± 0.79 mmol/L in Pitt Bull, 5.07 ± 0.94 and 5.07 ± 0.77 mmol/L in Boxer, 5.40 ± 0.59 and 5.48 ± 0.55 mmol/L in Rottweiler and 4.89 ± 0.75 and 4.77 ± 0.59 mmol/L in cross‐bred dogs, respectively, p < 0.05). The present study confirms that human glucometer can be used to measure glucose in dogs with a good accuracy.

2021 AAFP Feline Senior Care Guidelines

The '2021 AAFP Feline Senior Care Guidelines' are authored by a Task Force of experts in feline clinical medicine and serve as an update and extension of those published in 2009. They emphasize the individual patient evaluation and the process of aging, with references to other feline practice guidelines for a more complete discussion of specific diseases. Focusing on each cat encourages and empowers the owner to become a part of the cat's care every step of the way. A comprehensive discussion during the physical examination and history taking allows for tailoring the approach to both the cat and the family involved in the care. Videos and analysis of serial historical measurements are brought into the assessment of each patient. These Guidelines introduce the emerging concept of frailty, with a description and methods of its incorporation into the senior cat assessment. Minimum database diagnostics are discussed, along with recommendations for additional investigative considerations. For example, blood pressure assessment is included as a minimum diagnostic procedure in both apparently healthy and ill cats. Cats age at a much faster rate than humans, so practical timelines for testing frequency are included and suggest an increased frequency of diagnostics with advancing age. The importance of nutrition, as well as senior cat nutritional needs and deficiencies, is considered. Pain is highlighted as its own syndrome, with an emphasis on consideration in every senior cat. The Task Force discusses anesthesia, along with strategies to allow aging cats to be safely anesthetized well into their senior years. The medical concept of quality of life is addressed with the latest information available in veterinary medicine. This includes end of life considerations like palliative and hospice care, as well as recommendations on the establishment of 'budgets of care', which greatly influence what can be done for the individual cat. Acknowledgement is given that each cat owner will be different in this regard; and establishing what is reasonable and practical for the individual owner is important. A discussion on euthanasia offers some recommendations to help the owner make a decision that reflects the best interests of the individual cat.

Home monitoring of heart rate and heart rhythm with a smartphone-based ECG in dogs

The feasibility of the home monitoring of heart rate (HR) and rhythm through ECG tracings recorded by owners with a smartphone ECG device was evaluated in dogs. Smartphone ECG tracings were recorded by owners at home using a single-lead ECG device and sent via email for interpretation. A questionnaire was prepared to assess the owner's opinion regarding this home monitoring service. Recordings were evaluated by two operators, and agreement was evaluated for HR and rhythm diagnosis. Thirty-three dogs were included. Thirty-one owners (94 per cent) felt that the recording technique was easy to learn and that the smartphone ECG device was easy to use. A total of 15 owners (45 per cent) required a second person to hold the dog during recording. Of the 150 smartphone ECG tracings that were received, 134 (89 per cent) were interpretable. The median difference between the two operators to assess the mean HR on the smartphone tracings was 10 bpm (-10, +25 bpm). Perfect agreement (κ=1) between operators was observed in the heart rhythm evaluation. Most owners sent adequate ECG tracings for interpretation via email from their smartphone. Home monitoring of HR and heart rhythm may represent an additional tool in the management of dogs with arrhythmias.

Acceptance of home blood glucose monitoring by owners of recently diagnosed diabetic cats and impact on quality of life changes in cat and owner

Objectives This study aimed to evaluate the acceptance of home blood glucose monitoring (HBGM) by owners of recently diagnosed diabetic cats, and the impact of choosing HBGM on the quality of life (QoL) changes of cat and owner, in addition to glycaemic changes during 6 months of follow-up. Methods Owners of cats diagnosed with diabetes mellitus (DM) and treated with insulin for 6-20 weeks were divided into an HBGM group and a non-HBGM group, based on their ability and willingness to perform HBGM after a standardised instruction session. The HBGM acceptance level and reasons for acceptance failure were documented; a questionnaire evaluated owners' experiences. For the following 6 months, changes in QoL, measured using the validated DIAQoL-pet quantification tool, and changes in glycaemic control parameters (clinical signs, serum fructosamine, blood glucose curve average/minimal/maximal/pre-insulin blood glucose) were compared between HBGM and non-HBGM groups at months 1, 3 and 6, as well as within the groups between baseline and months 1, 3 and 6. Results Thirty-eight cats were enrolled; 28 (74%) entered the HBGM group. There was no significant difference between groups in overall DIAQoL-pet score or glycaemic control parameters at any time point apart from the maximal blood glucose at month 6 (lower in the HBGM group). However, the DIAQoL-pet score, including indicators of owner worry about DM, worry about hypoglycaemia and costs, as well as glycaemic parameters, improved at all time points within the HBGM group but not within the non-HBGM group. Remission occurred in 9/28 (32%) HBGM group cats and 1/10 (10%) non-HBGM group cats ( P = 0.236). Conclusions and relevance HBGM was adopted successfully by most diabetic cat owners. Despite the extra task, positive changes in QoL parameters occurred in the HBGM group and not in the non-HBGM group. Although no difference was found in glycaemic control between the HBGM and non-HBGM groups during the 6 months of follow-up, significant glycaemic improvements were documented in the HBGM group.

Cutpoints for screening blood glucose concentrations in healthy senior cats

Objectives The objectives of this study were to determine the reference interval for screening blood glucose in senior cats, to apply this to a population of obese senior cats, to compare screening and fasting blood glucose, to assess whether screening blood glucose is predicted by breed, body weight, body condition score (BCS), behaviour score, fasting blood glucose and/or recent carbohydrate intake and to assess its robustness to changes in methodology. Methods The study included a total of 120 clinically healthy client-owned cats aged 8 years and older of varying breeds and BCSs. Blood glucose was measured at the beginning of the consultation from an ear/paw sample using a portable glucose meter calibrated for cats, and again after physical examination from a jugular sample. Fasting blood glucose was measured after overnight hospitalisation and fasting for 18-24 h. Results The reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Mean screening blood glucose was greater than mean fasting glucose. Breed, body weight, BCS, behaviour score, fasting blood glucose concentration and amount of carbohydrate consumed 2-24 h before sampling collectively explained only a small proportion of the variability in screening blood glucose. Conclusions and relevance Screening blood glucose measurement represents a simple test, and cats with values from 117-189 mg/dl (6.5-10.5 mmol/l) should be retested several hours later. Cats with initial screening blood glucose >189 mg/dl (10.5 mmol/l), or a second screening blood glucose >116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalisation.

Diagnosis of prediabetes in cats: glucose concentration cut points for impaired fasting glucose and impaired glucose tolerance

Diabetes is typically diagnosed in cats once clinical signs are evident. Diagnostic criteria for prediabetes in cats have not been defined. The objective of the study was to establish methodology and cut points for fasting and 2-h blood glucose concentrations in healthy client-owned senior cats (≥8 yr) using ear/paw samples and a portable glucose meter calibrated for feline blood. Of the 78 cats, 27 were ideal (body condition score [BCS] 4 or 5 of 9), 31 overweight (BCS 6 or 7), and 20 obese (BCS 8 or 9); 19 were Burmese and 59 non-Burmese. After an 18-24-h fast and an ear/paw blood glucose measurement using a portable glucose meter, glucose (0.5 g/kg bodyweight) was administered intravenous and blood glucose measured at 2 min and 2 h. Cut points for fasting and 2-h glucose concentrations were defined as the upper limits of 95% reference intervals using cats with BCS 4 or 5. The upper cut point for fasting glucose was 6.5 mmol/L. Of the overweight and obese cats, 1 (BCS 7) was above this cut point indicating evidence of impaired fasting glucose. The cut point for 2-h glucose was 9.8 mmol/L. A total of 7 cats (4 with BCS 8 or 9 including 1 Burmese; 3 with BCS 6 or 7, non-Burmese) were above this cut point and thus had evidence of impaired glucose tolerance. In conclusion, the methodology and cutpoints for diagnosis of prediabetes are defined for use in healthy cats 8 yr and older with a range of BCSs.

ISFM consensus guidelines on the practical management of diabetes mellitus in cats

PRACTICAL RELEVANCE

Diabetes mellitus (DM) is a common endocrinopathy in cats that appears to be increasing in prevalence. The prognosis for affected cats can be good when the disease is well managed, but clinical management presents challenges, both for the veterinary team and for the owner. These ISFM Guidelines have been developed by an independent, international expert panel of clinicians and academics to provide practical advice on the management of routine (uncomplicated) diabetic cats.

CLINICAL CHALLENGES

Although the diagnosis of diabetes is usually straightforward, optimal management can be challenging. Clinical goals should be to limit or eliminate clinical signs of the disease using a treatment regimen suitable for the owner, and to avoid insulin-induced hypoglycaemia or other complications. Optimising bodyweight, feeding an appropriate diet and using a longer acting insulin preparation (eg, protamine zinc insulin, insulin glargine or insulin detemir) are all factors that are likely to result in improved glycaemic control in the majority of cats. There is also some evidence that improved glycaemic control and reversal of glucose toxicity may promote the chances of diabetic remission. Owner considerations and owner involvement are an important aspect of management. Provided adequate support is given, and owners are able to take an active role in monitoring blood glucose concentrations in the home environment, glycaemic control may be improved. Monitoring of other parameters is also vitally important in assessing the response to insulin. Insulin adjustments should always be made cautiously and not too frequently--unless hypoglycaemia is encountered.

EVIDENCE BASE

The Panel has produced these Guidelines after careful review of the existing literature and of the quality of the published studies. They represent a consensus view on practical management of cats with DM based on available clinical data and experience. However, in many areas, substantial data are lacking and there is a need for better studies in the future to help inform and refine recommendations for the clinical management of this common disease.

Owner Experiences in Treating Dogs and Cats Diagnosed With Diabetes Mellitus in the United StatesS

The objective of this study was to report owner experiences and satisfaction in treating a pet with diabetes mellitus using a descriptive report from an Internet-based survey. Descriptive analysis of results was performed, χ2 tests were used to detect differences in responses between dog and cat owners, and correlations were assessed using the nonparametric Spearman rank correlation. A total of 834 owners participated in the survey. More diabetic dogs (97%) than cats (82%) were treated with insulin injections. Insulin was administered twice daily in 87% of dogs and 73% of cats. Porcine lente and neutral protamine Hagedorn were the most commonly administered insulins in dogs. In cats, glargine and protamine zinc insulin were the most commonly used insulins. Most pets were not fed a prescribed diabetes diet. More cat (66%) than dog (50%) owners were satisfied with the diabetic control achieved. Cat owners were more likely to use home blood glucose monitoring. Treatment was considered expensive by the majority of owners. Few published reports follow diabetic pets after diagnosis or report owner satisfaction. The results of this study provide useful information that may help veterinarians better educate owners and set expectations regarding diabetes treatment and quality of life for diabetic pets.

A survey of Southeastern United States veterinarians' preferences for managing cats with diabetes mellitus

This study evaluated primary practitioners' perceptions of managing feline diabetics. Surveys distributed during local continuing education events achieved a response rate of 46% (90/195). A mean of 74% feline diabetics required chronic insulin; 26% were transient diabetics. Choice of insulin was most influenced by duration of action: human recombinant protamine zinc insulin was ranked first (42%) and glargine second (27%). Dietary management was always/usually recommended by 97% respondents, with prescription or proprietary low-carbohydrate, high-protein diets recommended in 93% responses. More recent graduates (P=0.0419), those who worked in larger practices (P=0.0315), and those who saw more transient diabetics (P=0.0288) were more likely to recommend dietary change. In-house blood glucose curves (BGCs) were the most popular method of assessing glycemic control, while at-home BGCs were least popular, although their use correlated positively with annual diabetic caseload (r=0.43, P=0.0239). Owners mishandling insulin was cited as the most common cause of poor glycemic control, while clinical signs of acromegaly were rarely recognized.

Alternative sampling site for blood glucose testing in cats: giving the ears a rest

BACKGROUND AND STUDY RATIONALE: Home monitoring is an important part of the long-term management of diabetic cats. Despite the extensive use of glucometers in this species, up until now only the pinna of the ear has been validated as a testing site. This cross-sectional study investigated the feasibility and validity of sampling from the metacarpal/metatarsal pads in hospitalised cats with various diseases.

INVESTIGATIONS

The large pads were compared with the ear as a sampling site in 75 cats. Lancing the pads was tolerated very well. If the initial drop of blood was too small, an adequate volume of blood was almost always achieved by squeezing the pads. No significant differences were observed in first-attempt success rate or glucose values between the two sites. Due to the inability to obtain an adequate volume of blood or struggling, no measurement was possible in four cats.

PRACTICAL RELEVANCE

While further work is necessary to assess the utility of this technique, especially in the home environment, the results indicate that the metacarpal pads, in particular, may offer a viable alternative testing site for the measurement of blood glucose concentrations, especially if ear sampling fails.

American association of feline practitioners. Senior care guidelines

BACKGROUND

Cats are the most popular pet in the United States and much of Northern Europe. Although 78% of owners consider their cats to be family members, many cats, particularly seniors, do not receive appropriate preventive care. One of the main obstacles to owner compliance is the lack of a clear recommendation by the veterinary team. Guidelines can help veterinarians to minimize this obstacle, strengthen the human-pet-veterinary bond, and improve the quality of life of cats.

GOALS

The goals of this article are to assist veterinarians to: Deliver consistent high-quality care to senior cats. Promote longevity and improve the quality of life of senior cats by: recognizing and controlling health risk factors; facilitating and promoting early detection of disease; improving or maintaining residual organ function; and delaying the progression of common conditions. Define aspects of screening, diagnosis, treatment and anesthesia of senior cats.

Intensive blood glucose control is safe and effective in diabetic cats using home monitoring and treatment with glargine

Human diabetic patients routinely self-adjust their insulin dose using a protocol and home monitoring, and perform equally well or outperform physician directed adjustments. The objective of this study was to report the outcome of home monitoring of diabetic cats by owners using a protocol aimed at achieving euglycaemia, using ultra-low carbohydrate diets (< or =10% metabolisable energy) and the insulin analogue glargine for >10 weeks and/or until remission was achieved. Fifty-five cats diagnosed with diabetes mellitus, whose owners joined the online German Diabetes-Katzen Forum, were included. An overall remission rate of 64% was achieved in the cohort. Significantly higher remission rates were observed if good glycaemic control was achieved soon after diagnosis: 84% for cats started on the protocol within 6 months of diagnosis went into remission, and only 35% for cats that began more than 6 months after diagnosis (P<0.001). Only one mild clinical hypoglycaemic episode occurred observed despite tight blood glucose control. In conclusion, intensive blood glucose control is safe and effective in diabetic cats using home monitoring and treatment with glargine.

Day-to-day variability of blood glucose concentration curves generated at home in cats with diabetes mellitus

OBJECTIVE

To evaluate day-to-day variability in blood glucose curves (BGCs) generated at home and at the clinic for cats with diabetes mellitus.

DESIGN

Prospective study.

ANIMALS

7 cats with diabetes mellitus. Procedures-BGCs generated at home on 2 consecutive days and within 1 week at the clinic were obtained twice. On each occasion, insulin dose, amount of food, and type of food were consistent for all 3 BGCs. Results of curves generated at home were compared with each other and with the corresponding clinic curve.

RESULTS

Differences between blood glucose concentration determined after food was withheld (fasting), nadir concentration, time to nadir concentration, maximum concentration, and mean concentration during 12 hours had high coefficients of variation, as did the difference between fasting blood glucose and nadir concentrations and area under the curve of home curves. Differences between home curve variables were not smaller than those between home and clinic curves, indicating large day-to-day variability in both home and clinic curves. Evaluation of the paired home curves led to the same theoretical recommendation for adjustment of insulin dose on 6 of 14 occasions, and evaluation of home and clinic curves resulted in the same recommendation on 14 of 28 occasions. Four of the 6 paired home curves in cats with good glycemic control and 2 of the 8 paired home curves in cats with poor glycemic control led to the same recommendation.

CONCLUSIONS AND CLINICAL RELEVANCE

Considerable day-to-day variability was detected in BGCs generated at home. Cats with good glycemic control may have more reproducible curves generated during blood collection at home than cats with poorer control.

Update on Drugs Used to Treat Endocrine Diseases in Small Animals

Drug therapy for the endocrine system is implemented to replace a hormone deficiency or to prevent or reduce the formation or effects of excess hormone. Treatment of endocrine disorders covers diseases of the pituitary, adrenal, parathyroid, and thyroid glands as well as the endocrine pancreas. This article focuses on new therapies currently available for specific diseases. Administration of trilostane for treatment of hyperadrenocorticism and use of insulin glargine, protamine zinc insulin (PZI), and porcine Lente insulin for diabetes mellitus are discussed. In addition, transdermal methimazole therapy for treatment of feline hyperthyroidism and administration of progestins for pituitary dwarfism are considered.

Home monitoring of the diabetic cat

Many owners are able and willing to perform home monitoring of blood glucose concentrations in diabetic cats. Once owners are familiar with the technique, they appreciate its advantages and show long-term compliance. The success of home monitoring hinges greatly on careful preparation and instruction of the owner. Owners must have ready access to veterinary support if needed. Initially, most owners call for advice, and several of them need repeated explanation or demonstration of the procedure. The frequency of re-evaluations of the diabetic cats by veterinarians is not affected by home monitoring. One of its major advantages is that it enables frequent generation of blood glucose curves. In complicated cases, more than one curve can, therefore, be performed at home before a treatment decision is made. According to preliminary data cats managed with home monitoring may have better glycaemic control than those managed without. However, those results need to be confirmed in a large group of cats.