Pharmacokinetics and pharmacodynamics of porcine insulin zinc suspension in eight diabetic dogs

Evaluating insulindysregulation in horses: A two-step insulin-tolerance test using porcine zinc insulin

In insulin dysregulation, hyperinsulinemia (HI) can be accompanied by peripheral insulin resistance (IR) in horses, which can be diagnosed with an insulin-tolerance test (ITT). The administration of 0.1 IU/kg body weight of recombinant regular human insulin (RHI) should elicit a 50 % reduction of the initial blood glucose concentration at 30 min after insulin administration in insulin sensitive horses. Compared to RHI, porcine zinc insulin (PZI) is veterinary-approved and therefore easier accessible for many practitioners. The aim of this study was to compare the insulin and glucose dynamics during a standard ITT with RHI to an ITT performed with PZI. Twelve Icelandic horses were subjected to an ITT with RHI (ITT-RHI) and with PZI (ITT-PZI) at same dosages in a randomised crossover design. The insulin and glucose dynamics that resulted from these tests were compared, and the consistency of classification into insulin-sensitive and IR categories was evaluated. No complications were observed with the use of either RHI or PZI in ITT. A good correlation of the test results was observed (r = 0.88; P < 0.001). The blood glucose concentrations and the percentage reduction in glucose concentration did not differ significantly between the two tests (P = 0.053), but four out of twelve horses were classified as IR in the ITT-RHI whereas with the ITT-PZI seven out of twelve horses were classified as IR with the 50 % glucose reduction from baseline. Based on the Youden index, when using the ITT-PZI, an adjusted cut-off value for blood glucose reduction of 40 % at 30 min resulted in better test performance. With consideration for the seemingly weaker effect of PZI and the adjusted cut-off value, PZI can be an appropriate substitute to RHI in an ITT.

Short-term glycemic variability in non-diabetic, non-obese dogs assessed by common glycemic variability indices

Glycemic variability (GV) refers to swings in blood glucose levels and is an emerging measure of glycemic control in clinical practice. It is associated with micro- and macrovascular complications and poor clinical outcomes in diabetic humans. Although an integral part of patient assessment in human patients, it is to a large extent neglected in insulin-treated diabetic dogs. This prospective pilot study was performed to describe canine within-day GV in non-diabetic dogs with the aim to provide a basis for the interpretation of daily glucose profiles, and to promote GV as an accessible tool for future studies in veterinary medicine. Interstitial glucose concentrations of ten non-diabetic, non-obese beagles were continuously measured over a 48-h period using a flash glucose monitoring system. GV was assessed using the common indices MAGE (mean amplitude of glycemic excursion), GVP (Glycemic variability percentage) and CV (coefficient of variation). A total of 2260 sensor measurements were obtained, ranging from 3.7 mmol/L (67 mg/dL) to 8.5 mmol/L (153 mg/dL). Glucose profiles suggested a meal-dependent circadian rhythmicity with small but significant surges during the feeding periods. No differences in GV indices were observed between day and night periods (p > 0.05). The MAGE (mmol/L), GVP (%) and CV (%) were 0.86 (± 0.19), 7.37 (± 1.65), 6.72 (± 0.89) on day one, and 0.83 (± 0.18), 6.95 (± 1.52), 6.72 (± 1.53) on day two, respectively. The results of this study suggest that GV is low in non-diabetic dogs and that glucose concentrations are kept within narrow ranges.

Insulin Therapy in Small Animals, Part 3: Dogs

Insulin therapy should ideally mimic a basal-bolus pattern. Lente, NPH, NPH/regular mixes, PZI, glargine U100, and detemir are intermediate-acting formulations that are administered twice daily in dogs. To minimize hypoglycemia, intermediate-acting insulin protocols are usually geared towards alleviating (but not eliminating) clinical signs. Insulin glargine U300 and insulin degludec meet the criteria for an effective and safe basal insulin in dogs. In most dogs, good control of clinical signs is achieved when using a basal insulin alone. In a small minority, bolus insulin at the time of at least one meal per day may be added to optimize glycemic control.

Long-term field study of lispro and neutral protamine Hagedorn insulins treatment in dogs with diabetes mellitus

BACKGROUND

The long-term clinical and biofhemical effects of basal-bolus insulin treatment with lispro and NPH in dogs with diabetes mellitus are undocumented.

OBJECTIVES

To perform a prospective pilot field study of the long-term effects of lispro and NPH on clinical signs and serum fructosamine concentrations (SFC) in dogs with diabetes mellitus.

METHODS

Twelve dogs received combined lispro and NPH insulins treatment twice a day and were examined every 2 weeks for 2 months (visits 1-4), and every 4 weeks for up to 4 additional months (visits 5-8). Clinical signs and SFC were recorded at each visit. Polyuria and polydipsia (PU/PD) were scored as absent (0) or present (1).

RESULTS

Median (range) PU/PD scores of combined visits 5-8 (0, 0-1) were significantly lower than median scores of combined visits 1-4 (1, 0-1, p = 0.03) and at enrolment (1, 0-1, p = 0.045). Median (range) SFC of combined visits 5-8 (512 mmol/L, 401-974 mmol/L) was significantly lower than SFC of combined visits 1-4 (578 mmol/L, 302-996 mmol/L, p = 0.002) and at enrolment (662 mmol/L, 450-990 mmol/L, p = 0.03). Lispro insulin dose was significantly and negatively, albeit weakly, correlated with SFC concentration during visits 1 through 8 (r = -0.3, p = 0.013). Median duration of follow up was 6 months (range 0.5-6) and most dogs (8, 66.7%) were followed for 6 months. Four dogs withdrew from the study within 0.5-5 months because of documented or suspected hypoglycaemia, short NPH duration or sudden unexplained death. Hypoglycaemia was noted in 6 dogs.

CONCLUSIONS

Long-term lispro and NPH combination therapy may improve clinical and biochemical control of some diabetic dogs with comorbidities. Risk of hypoglycaemia should be addressed with close monitoring.

Etiology and Pathophysiology of Diabetes Mellitus in Dogs

Canine diabetes results from a wide spectrum of clinical pathophysiological processes that cause a similar set of clinical signs. Various causes of insulin deficiency and beta cell loss, insulin resistance, or both characterize the disease, with genetics and environment playing a role. Understanding the genetic and molecular causes of beta cell loss will provide future opportunities for precision medicine, both from a therapeutic and preventative perspective. This review presents current knowledge of the etiology and pathophysiology of canine diabetes, including the importance of disease classification. Examples of potential targets for future precision medicine-based approaches to therapy are discussed.

One hundred years of insulin: Is it time for smart?

Smarter understanding of diabetes pathophysiology and pharmacology of insulin therapy can lead to better clinical outcomes. Rather than looking for an insulin formulation that is considered "best" for a general population, it could be appropriate to seek the "smart" insulin choice, tailored to the specific clinical situation. Different treatment goals should be considered, with pros and cons to each. Ideally, insulin therapy in most diabetic dogs should mimic a "basal-bolus" pattern. The "intermediate"-acting insulin formulations might provide better "bolus" treatment in dogs than the rapid-acting formulations used in people. In patients with some residual beta cell function such as many diabetic cats, administering only a "basal" insulin might lead to complete normalisation of blood glucose concentrations. Insulin suspensions (neutral protamine Hagedorn, neutral protamine Hagedorn/regular mixes, lente and protamine zinc insulin) as well as insulin glargine U100 and detemir are "intermediate"-acting formulations that are administered twice daily. For a formulation to be an effective and safe "basal" insulin, its action should be roughly the same every hour of the day. Currently, only insulin glargine U300 and insulin degludec meet this standard in dogs, whereas in cats, insulin glargine U300 is the closest option.

Day-to-day variability of porcine lente, insulin glargine 300 U/mL and insulin degludec in diabetic dogs

Background

Day‐to‐day variability impacts safety of insulin therapy and the choice of monitoring strategies. Side‐by‐side comparisons of insulin formulations in diabetic dogs are scarce.

Hypothesis/Objectives

Insulin glargine 300 U/mL (IGla300) and insulin degludec (IDeg) are associated with less day‐to‐day glucose variability compared to porcine lente (PL) in diabetic dogs.

Animals

Seven intact male purpose‐bred beagles with toxin‐induced diabetes.

Methods

In this repeated measured study, PL, IGla300 and IDeg were compared in 2 phases: once‐daily (q24h) and twice‐daily (q12h) administration. Interstitial glucose concentrations (IG) were measured continuously throughout the study. For each formulation, maximal q24h dose was determined using the same algorithm (while avoiding hypoglycemia) and then maintained for 72 hours. In phase 2, 70% of the maximal q24h dose was administered q12h and maintained for 5 days regardless of hypoglycemia. Coefficient of variation (CV) and glycemic variability percentage (GVP) were calculated to determine day‐to‐day and intraday variability, respectively.

Results

There was no difference in day‐to‐day variability between PL, IGla300, and IDeg in the q24h phase. In the q12h phase, day‐to‐day variability was higher (P = .01) for PL (CV = 42.6 ± 6.8%) compared to IGla300 and IDeg (CV = 30.1 ± 7.7%, 25.2 ± 7.0%, respectively). The GVP of PL was lower (P = .02) compared to IGla300. There was no difference between PL, IGla300 and IDeg in %time IG < 70 mg/dL.

Conclusions and Clinical Importance

Insulin degludec and IGla300 administered q12h were associated with lower day‐to‐day variability, which might be advantageous in minimizing monitoring requirements without increasing the risk of hypoglycemia.

Flash glucose monitoring in diabetic dogs: a feasible method for evaluating glycemic control

OBJECTIVE

To alleviate clinical signs and avoid life-threatening complications in dogs with diabetes mellitus, individualized treatment plans and frequent reassessments are necessary. Performing blood glucose profiles every 7-14 days following insulin adjustments and monthly thereafter, is recommended. In 2016, a factory calibrated continuous blood glucose monitoring system was presented as a possible alternative to glucometer readings. The objectives of this study were to summarize the experiences with this new technology and to show, that in combination with simple rules, already the first measurement period can improve glycemic control.

MATERIAL AND METHODS

The electronic database of the endocrine unit of the clinic was retrospectively searched for diabetic dogs with flash glucose monitoring. In case of repeated sensor implantations, only the first sensor was considered. The recordings of day A (starting at midnight after sensor placement) were compared to the measurements of day B (day before sensor failure) and all owners were contacted to fill in a standardized questionnaire.

RESULTS

The final study population consisted of 24 dogs weighing 3.4 to 36 kg. Although the clicking noise during sensor placement irritated most dogs, the application was considered easy and painless. Waiting for disinfectant evaporation and fixation of the sensor disc with forceps helped to avoid sensor detachment when removing the application device. Although transient mild to moderate skin irritations were observed in 80 % of the dogs, 95 % of the owners were highly satisfied with this new monitoring technology. Mean and maximum glucose (p = 0.043, p = 0.003) as well as glucose readings ≥ 11.1 mmol/l (p = 0.032) decreased from day A to B, whereas markers of glycemic variability did not change.

CONCLUSION AND CLINICAL RELEVANCE

Flash glucose monitoring is a feasible, safe method with high user satisfaction and offers a possibility to improve glycemic control in diabetic dogs.

Update on insulin treatment for dogs and cats: insulin dosing pens and more

Insulin therapy is still the primary therapy for all diabetic dogs and cats. Several insulin options are available for each species, including veterinary registered products and human insulin preparations. The insulin chosen depends on the individual patient’s requirements. Intermediate-acting insulin is usually the first choice for dogs, and longer-acting insulin is the first choice for cats. Once the insulin type is chosen, the best method of insulin administration should be considered. Traditionally, insulin vials and syringes have been used, but insulin pen devices have recently entered the veterinary market. Pens have different handling requirements when compared with standard insulin vials including: storage out of the refrigerator for some insulin preparations once pen cartridges are in use; priming of the pen to ensure a full dose of insulin is administered; and holding the pen device in place for several seconds during the injection. Many different types of pen devices are available, with features such as half-unit dosing, large dials for visually impaired people, and memory that can display the last time and dose of insulin administered. Insulin pens come in both reusable and disposable options. Pens have several benefits over syringes, including improved dose accuracy, especially for low insulin doses.

A diet lower in digestible carbohydrate results in lower postprandial glucose concentrations compared with a traditional canine diabetes diet and an adult maintenance diet in healthy dogs

The aim of this study was to compare the effects of three diets with varying macronutrient and fibre contents on postprandial plasma glucose, triglyceride, free fatty acid, and insulin concentrations over a 12 h period in 12 healthy neutered lean dogs. Each diet was fed to each dog for 3 weeks in a three-period cross-over study. Plasma analyte concentrations were measured prior to and after a meal at the end of the third week of each period. Postprandial glucose concentrations for the moderate carbohydrate and fibre diet were 0.4-0.7 mmol/L (8-12 mg/dL) lower than for both higher carbohydrate diets (p≤0.02). Postprandial glucose, insulin, and triglyceride concentrations in some dogs did not return to baseline by 12 h after feeding of each of the three diets. These results indicate that the moderate carbohydrate and fibre diet warrants evaluation in diabetic dogs. Variables should be measured over at least 12 h after feeding to fully evaluate postprandial dietary effects on these analytes.