A dose titration protocol for once-daily insulin glargine 300 U/mL for the treatment of diabetes mellitus in dogs

BACKGROUND

In purpose-bred dogs, insulin glargine 300 U/mL (IGla300) has long duration of action, peakless time-action profile, and low potency, making it suitable for use as a basal insulin.

HYPOTHESIS

To evaluate IGla300 in client-owned diabetic dogs monitored using a flash glucose monitoring system (FGMS).

ANIMALS

Ninety-five client-owned diabetic dogs, newly diagnosed or previously treated with other insulin formulations, with or without concurrent diseases.

METHODS

Prospective multi-institutional study. Clinical signs and standardized assessment of FGMS data, using treatment and monitoring guidelines established a priori, guided dose adjustments and categorization into levels of glycemic control.

RESULTS

The initial IGla300 dose was 0.5 U/Kg q24h for newly diagnosed dogs and (median dose [range]) 0.8 U/Kg (0.2-2.5) q24h for all dogs. Glycemic control was classified as good or excellent in 87/95 (92%) dogs. The IGla300 was administered q24h (1.9 U/kg [0.2-5.2]) and q12h (1.9 U/kg/day [0.6-5.0]) in 56/95 (59%) and 39/95 (41%) dogs, respectively. Meal-time bolus injections were added in 5 dogs (0.5 U/kg/injection [0.3-1.0]). Clinical hypoglycemia occurred in 6/95 (6%) dogs. Dogs without concurrent diseases were more likely to receive IGla300 q24h than dogs with concurrent diseases (72% vs 50%, respectively; P = .04).

CONCLUSIONS AND CLINICAL IMPORTANCE

Insulin glargine 300 U/mL can be considered a suitable therapeutic option for once-daily administration in diabetic dogs. Clinicians should be aware of the low potency and wide dose range of IGla300. In some dogs, twice-daily administration with or without meal-time bolus injections may be necessary to achieve glycemic control. Monitoring with FGMS is essential for dose titration of IGla300.

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.

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.

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.

Detemir improves diabetic regulation in poorly controlled diabetic dogs with concurrent diseases

OBJECTIVE

This study evaluated the use of detemir for treating diabetic dogs with comorbidities that were poorly controlled with intermediate-acting insulins.

ANIMALS

7 insulin-treated diabetic dogs.

PROCEDURES

Retrospective pilot study. Dogs were treated with detemir for at least 3 months, and glycemia was assessed by the owners at home initially 2 to 4 times daily for 6 to 8 weeks and twice daily thereafter. Clinical evaluations occurred on days 7 to 14, day 30, and then every 60 to 90 days, and dosage adjustments of detemir occurred as needed to control glycemia.

RESULTS

The mean, peak, nadir, morning, and evening preinsulin daily blood glucose concentrations were significantly lower after dosing with detemir for 1, 3, or 6 months and during the last month of treatment compared to the final month of treatment with intermediate-acting insulin. Intermediate-acting insulins resulted in significantly worse glycemic control than detemir in all 3 categories of control. The odds of a biochemical hypoglycemic measurement with detemir were not significantly different compared to intermediate-acting insulins. Clinical hypoglycemia did not occur following detemir treatment. When insulin was withheld because of low morning preinsulin blood glucose concentration < 6.7 mmol/L (≤ 120 mg/dL) and dogs were fed, mean blood glucose concentration was significantly higher 1 hour later. Glucose concentrations were also significantly higher 12 hours later on days when insulin was withheld in the morning or evening for either 1 or 12 hours.

CLINICAL RELEVANCE

Detemir is useful in diabetic dogs with other comorbidities and can be considered an alternative treatment in poorly controlled diabetic dogs.

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.

Relationship between HbA1c, fructosamine and clinical assessment of glycemic control in dogs

Background

Serum fructosamine is a routine test used for clinical monitoring of diabetes mellitus (DM) but the usefulness of HbA1c for this purpose has not been extensively studied.

Hypothesis

The study aimed to compare the ability of blood HbA1c and serum fructosamine tests to correctly classify DM control determined using a clinically-based assessment.

Animals

28 client-owned dogs with naturally-occurring diabetes mellitus.

Methods

Cross-sectional observational study. Ability of fructosamine and HbA1c tests to classify diabetes control in dogs was determined.

Results

Clinical assessment classified 50% of dogs as having good diabetic control and 82% as having acceptable diabetic control. Analysis using Cohen’s kappa test showed that agreements between fructosamine and HbA1c results and the clinical assessment ranged from poor to fair. Fructosamine and HbA1c results from each dog showed a moderate correlation. Overall, the HbA1c test showed the best agreement with the clinical assessment when diabetes control was considered either acceptable or unacceptable, although the strength of agreement was considered fair (kappa = 0.27).

Conclusions and clinical importance

The HbA1c concentration was found to be more consistent with clinical evaluation of diabetes control than was the serum fructosamine concentration. The HbA1c level is a useful tool for assessment of glycemic status in diabetic dogs but should be used alongside other tests for outpatient monitoring of clinically stable diabetic dogs.

Insulins for the long term management of diabetes mellitus in dogs: a review

The year 2021 marked the centenary of the isolation of a therapeutic form of insulin and its successful use in dogs. This was a landmark moment that subsequently and rapidly led to the commercial manufacture of insulin for use in humans. The impact of insulin was almost miraculous as those destined to die from their diabetes mellitus returned to life. Over the past 100 years, insulin formulations have been modified to attempt to provide a predictable and prolonged duration of action while avoiding the development of hypoglycaemia. This has led to an ever-growing variety of insulin types in human medicine, many of which have subsequently been used in dogs. The purpose of this review article is to provide an overview of available insulin types and their application to the chronic management of canine diabetes mellitus.

Evaluation of fructosamine concentration as an index marker for glycaemic control in diabetic dogs

BACKGROUND

Although fructosamine is a commonly used surrogate marker to assess glycaemic control in diabetic dogs, its diagnostic accuracy has been questioned. The main objective of this study was to evaluate the reliability of fructosamine measurements to diagnose well and poorly controlled diabetes mellitus (DM), using continuous glucose monitoring as a gold standard.

METHODS

Twenty-four dogs with treated DM and continuous glucose monitoring for mean (±SD) 13.1 (±1.7) days were retrospectively analysed. Two assessment strategies were applied to categorize glycaemic control, and fructosamine concentrations were determined shortly after sensor cessation using a colorimetric assay.

RESULTS

Correlations of individual fructosamine concentrations with mean glucose as well as percentage of measurements > 15 mmol/L were not significant (p = 0.372, p = 0.129). Fructosamine did not differ between dogs with and without hypoglycaemic episodes (p = 0.64). Receiver operating characteristic analysis for fructosamine to diagnose either good or poor glycaemic control revealed AUC values of 0.71 (p = 0.025) indicating moderate accuracy, and 0.7 (p = 0.135) indicating AUC is non-discriminatory, respectively. The respective positive likelihood ratios for the optimal cutoffs to identify good (<396 μmol/L) and poor control (>449 μmol/L) were three.

CONCLUSIONS

Fructosamine measurement is an imperfect surrogate marker for classifying glycaemic control in diabetic dogs and can only complement serial glucose measurements.

Field efficacy and safety of protamine zinc recombinant human insulin in 276 dogs with diabetes mellitus

Twice-daily (BID) insulin injections are a major deterrence to owners treating dogs with diabetes mellitus (DM). The hypothesis for this study was that Protamine Zinc Recombinant Human Insulin (PZIR) is safe and efficacious as a once-daily (SID) treatment for canine DM. This was a prospective, baseline-controlled, multi-center study over 182 ± 5 d. Two hundred seventy-six client-owned dogs with naturally occurring DM (naïve or pre-treated with insulin) were enrolled in the study. Enrollment was based upon demonstration of hyperglycemia, glycosuria, and ≥1 diabetic clinical sign (polyuria (PU), polydipsia (PD), or weight loss). Insulin treatment was initiated at 0.5-1.0 IU/kg SID. An improvement in at least one lab parameter related to DM (mean BG, min BG, Fructosamine) and one clinical parameter (PU/PD, body weight) was achieved in 72% of dogs (80% of naive, 62% of pre-treated). Dogs treated SID and BID showed improvement in 71% and 74% of cases, respectively. In naïve dogs, mean and minimum BG and fructosamine were significantly decreased (P < 0.05) by d 7 and 21, respectively, and in pre-treated dogs by d 63. By d 84, PU/PD improved in 90% and 88% of dogs, respectively, and the mean successful insulin dose was 1.4 IU/kg/d. Safety parameters were measured in 276 dogs for up to 182 d; clinical hypoglycemia occurred in 8.9% of dogs. We conclude that PZIR safely and effectively improved glycemic parameters and clinical signs in naïve and pre-treated diabetic dogs. The significant percentage of dogs on SID treatment with improvement in hyperglycemia and clinical signs confirms the prolonged action of PZIR in many dogs.

Comparison of serum fructosamine and glycated hemoglobin values for assessment of glycemic control in dogs with diabetes mellitus

OBJECTIVE

To evaluate the performance of 2 assays for measurement of serum fructosamine (SF) and glycated hemoglobin (HbA1c) values in dogs and to compare the usefulness of the 2 glycated proteins for assessment of glycemic control in dogs with diabetes mellitus (DM).

SAMPLE

Blood samples from 40 healthy dogs, 13 diabetic dogs, and 23 anemic normoglycemic nondiabetic dogs and results of 200 assessments of glycemic control in 46 diabetic dogs.

PROCEDURES

Colorimetric and immunoturbidimetric methods were used for measurement of SF and HbA1c values, respectively. Linearity and precision were determined. The usefulness of SF and HbA1c values for assessment of glycemic control was evaluated with a clinical scoring method used as the reference standard. Cutoff values obtained from receiver operating characteristic curves were used to identify the percentage of dogs correctly categorized by means of SF and HbA1c values.

RESULTS

Mean intra-assay and interassay coefficients of variation were 3.8% and 2.5%, respectively, for the SF assay, and 1.2% and 1.8%, respectively, for the HbA1c assay. Excellent linearity (R² > 0.99) was obtained for both assays. Values for SF and HbA1c were inversely correlated (r = -0.40 and -0.33, respectively) with clinical score and correctly indicated glycemic control in 99 of 200 (50%) and 88 of 200 (44%) assessments, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

The SF and HbA1c assays were precise, had good linearity, and appeared to be suitable for routine use in veterinary medicine. However, they performed poorly for classifying glycemic control in diabetic dogs.

Insulin-Producing Cell Transplantation Platform for Veterinary Practice

Diabetes mellitus (DM) remains a global concern in both human and veterinary medicine. Type I DM requires prolonged and consistent exogenous insulin administration to address hyperglycemia, which can increase the risk of diabetes complications such as retinopathy, nephropathy, neuropathy, and heart disorders. Cell-based therapies have been successful in human medicine using the Edmonton protocol. These therapies help maintain the production of endogenous insulin and stabilize blood glucose levels and may possibly be adapted to veterinary clinical practice. The limited number of cadaveric pancreas donors and the long-term use of immunosuppressive agents are the main obstacles for this protocol. Over the past decade, the development of potential therapies for DM has mainly focused on the generation of effective insulin-producing cells (IPCs) from various sources of stem cells that can be transplanted into the body. Another successful application of stem cells in type I DM therapies is transplanting generated IPCs. Encapsulation can be an alternative strategy to protect IPCs from rejection by the body due to their immunoisolation properties. This review summarizes current concepts of IPCs and encapsulation technology for veterinary clinical application and proposes a potential stem-cell-based platform for veterinary diabetic regenerative therapy.

Pharmacodynamics and pharmacokinetics of insulin detemir and insulin glargine 300 U/mL in healthy dogs

Insulin glargine 300 U/mL and insulin detemir are synthetic long-acting insulin analogs associated with minimal day-to-day variability or episodes of hypoglycemia in people. Here, 8 healthy purpose-bred dogs each received 2.4 nmol/kg subcutaneous injections of insulin detemir (0.1 U/kg) and insulin glargine 300 U/mL (0.4 U/kg) on 2 different days, >1 wk apart, in random order. Blood glucose (BG) was measured every 5 min, and glucose was administered intravenously at a variable rate with the goal of maintaining BG within 10% of baseline BG ("isoglycemic clamp"). Endogenous and exogenous insulin were measured for up to 24 h after insulin injection. The effect of exogenous insulin was defined by glucose infusion rate or a decline in endogenous insulin. Isoglycemic clamps were generated in all 8 dogs after detemir but only in 4 dogs after glargine. Median time to onset of action was delayed with glargine compared to detemir (4.0 h [3.3-5.8 h] vs 0.6 h [0.6-1.2 h], P = 0.002). There was no difference in time to peak (median [range] = 6.3 h [5.0-21.3 h] vs 4.3 h [2.9-7.4 h], P = 0.15) or duration of action (16.3 h [6.1-20.1 h] vs 10.8 h [8.8-14.8 h], P = 0.21) between glargine and detemir, respectively. Glargine demonstrated a peakless time-action profile in 4/8 dogs. The total metabolic effect and peak action of detemir was significantly greater than glargine. Significant concentrations of glargine were detected in all but 1 dog following administration. Glargine might be better suited than detemir as a once-daily insulin formulation in some dogs based on its long duration of action and peakless time-action profile. Day-to-day variability in insulin action should be further assessed for both formulations.

2018 AAHA Diabetes Management Guidelines for Dogs and Cats*

Diabetes mellitus (DM) is a common disease encountered in canine and feline medicine. The 2018 AAHA Diabetes Management Guidelines for Dogs and Cats revise and update earlier guidelines published in 2010. The 2018 guidelines retain much of the information in the earlier guidelines that continues to be applicable in clinical practice, along with new information that represents current expert opinion on controlling DM. An essential aspect of successful DM management is to ensure that the owner of a diabetic dog or cat is capable of administering insulin, recognizing the clinical signs of inadequately managed DM, and monitoring blood glucose levels at home, although this is ideal but not mandatory; all topics that are reviewed in the guidelines. Insulin therapy is the mainstay of treatment for clinical DM. The guidelines provide recommendations for using each insulin formulation currently available for use in dogs and cats, the choice of which is generally based on efficacy and duration of effect in the respective species. Also discussed are non-insulin therapeutic medications and dietary management. These treatment modalities, along with insulin therapy, give the practitioner an assortment of options for decreasing the clinical signs of DM while avoiding hypoglycemia, the two conditions that represent the definition of a controlled diabetic. The guidelines review identifying and monitoring patients at risk for developing DM, which are important for avoiding unnecessary insulin therapy in patients with transient hyperglycemia or mildly elevated blood glucose.

HEMOGLOBINA GLICADA E FRUTOSAMINA EM CÃES COM DIABETES MELLITUS

Resumo O Diabetes mellitus (DM) ocorre com frequência em cães, sendo a glicemia o teste laboratorial de confirmação. O diagnóstico e monitoramento em pessoas são realizados pelas concentrações de hemoglobina glicada e frutosamina. O objetivo deste estudo foi diagnosticar a DM em 19 cães, com avaliação das concentrações da glicose sérica, hemoglobina glicada e frutosamina. Seis cães com DM e em tratamento com insulina foram acompanhados por um período de doze meses, com as mesmas avaliações hematológicas, até o óbito (três cães) ou controle glicêmico (três cães). Observouse aumento dos valores de glicose, hemoglobina glicada e frutosamina em todos os cães com DM, e valores de hemoglobina glicada e glicose superiores nos animais não sobreviventes, na última avaliação realizada. Estes resultados apontam para a importância da avaliação de hemoglobina glicada e frutosamina em cães com diabetes e para diagnóstico e controle da efetividade do tratamento.