Retrospective evaluation of risk factors and outcome predictors in cats with diabetic ketoacidosis (1997-2007): 93 cases

Feline acute patient physiologic and laboratory evaluation scores and other prognostic factors in cats with first-time diabetic ketoacidosis

BACKGROUND

Acute Patient Physiologic and Laboratory Evaluation (APPLE) scores have not been reported in cats with diabetic ketoacidosis (DKA).

HYPOTHESIS

In cats with DKA, APPLE scores will be significantly higher in non-survivors compared with survivors and these scores will predict mortality.

ANIMALS

Sixty-eight cats with DKA.

METHODS

Retrospective study. The APPLE scores, blood glucose concentration (BG), venous pH, and ketone concentrations were compared between survivors and non-survivors. Simple logistic regression was used to determine if these variables predict the binary variable of survival or non-survival, and if they did, an empirical optimal cut point for mortality prediction was calculated.

RESULTS

The APPLEfast and APPLEfull scores were significantly higher in non-survivors (30 cats; 24.6 ± 7.4 and 45.2 ± 7.3 , respectively) compared with survivors (38 cats; 20.9 ± 6.2 and 41.7 ± 6.5 ; P = .01 and P = .02, respectively). The APPLEfast (P = .03) but not the APPLEfull scores (P = .06) predicted mortality. For every 1 unit increase in the APPLEfast score, the odds of death increased by 1.08 (95% confidence interval [CI], 1.006-1.17; P = .03). Median BG was significantly higher in non-survivors (431 mg/dL; range, 260-832 mg/dL) compared with survivors (343 mg/dL; range, 256-738 mg/dL; P = .01) and BG predicted mortality (P = .02). For every 1 mg/dL increase in BG, the odds of death increased by 1.004 (95% CI, 1.0006-1.008). Empirical optimal cut points for APPLEfast and BG mortality prediction were 24.5 and 358 mg/dL, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

The APPLEfast score and BG predict mortality in cats with DKA and can be used to stratify populations by risk of mortality in clinical trials of DKA in cats.

SGLT2 inhibitor use in the management of feline diabetes mellitus

Sodium-glucose cotransporter-2 (SGLT2) inhibitors are routinely used in the management of human type 2 diabetes and have been shown to effectively mitigate hyperglycemia and reduce the risks of cardiovascular and renal compromise. Two SGLT2 inhibitors, namely bexagliflozin and velagliflozin, were recently FDA approved for the treatment of uncomplicated feline diabetes mellitus. These oral hypoglycemic agents are a suitable option for many newly diagnosed cats, with rapid improvements in glycemic control and clinical signs. Suitable candidates must have some residual β-cell function, as some endogenous insulin production is required to prevent ketosis. Appropriate patient selection and monitoring are necessary, and practitioners should be aware of serious complications such as euglycemic diabetic ketoacidosis.

Efficacy and safety of once daily oral administration of sodium-glucose cotransporter-2 inhibitor velagliflozin compared with twice daily insulin injection in diabetic cats

BACKGROUND

Options for treatment of diabetes mellitus in cats are limited to insulin injections and monitoring for hypoglycemia.

HYPOTHESIS

Once daily sodium-glucose cotransporter-2 inhibitor velagliflozin PO is noninferior to insulin injections.

ANIMALS

Client-owned diabetic cats (127 safety; 116 efficacy assessment).

METHODS

Prospective, randomized (1 mg/kg velagliflozin), positive controlled (titrated Caninsulin), open label, noninferiority field trial, comparing number of cats with treatment success in ≥1 clinical variable and ≥1 glycemic variable (margin Δ: 15%) on Day 45; secondary endpoints included glycemic and clinical assessments during 91 days.

RESULTS

On Day 45, 29/54 (54%) velagliflozin-treated cats and 26/62 (42%) Caninsulin-treated cats showed treatment success, demonstrating noninferiority (difference -11.8%; upper 1-sided 97.5% confidence interval, -∞ to 6.3%). By Day 91, quality of life (QoL), polyuria, and polydipsia had improved in 81%, 54% and 61% (velagliflozin); on blood glucose (BG) curves, mean BG was <252 mg/dL in 42/54 (78%; velagliflozin) and 37/62 (60%; Caninsulin); minimum BG was <162 mg/dL in 41/54 (76%; velagliflozin) and 41/62 (66%; Caninsulin); serum fructosamine was <450 μmol/L in 41/54 (76%; velagliflozin) and 38/62 (61%; Caninsulin). Velagliflozin's most frequent adverse events were loose feces/diarrhea (n = 23/61, 38%), positive urine culture (n = 19/61, 31%), and nonclinical hypoglycemia (BG <63 mg/dL; n = 8/61, 13%); Caninsulin's: clinical and nonclinical hypoglycemia (n = 35/66, 53%), positive urine culture (n = 18/66, 27%), and loose feces/diarrhea (n = 10/66, 15%). Diabetic ketoacidosis occurred in 4/61 (7%; velagliflozin) and 0/66 (Caninsulin).

CONCLUSIONS AND CLINICAL IMPORTANCE

Once daily oral administration of velagliflozin was noninferior to insulin injections, showed good QoL and glycemia without clinical hypoglycemia.

Comparison of insulin infusion protocols for management of canine and feline diabetic ketoacidosis

OBJECTIVE

Describe the use of fixed-rate intravenous insulin infusions (FRIs) in cats and dogs with diabetic ketoacidosis (DKA) and determine if this is associated with faster resolution of ketosis compared to variable-rate intravenous insulin infusions (VRIs). Secondary objectives were to evaluate complication rates, length of hospitalization (LOH), and survival to discharge (STD).

DESIGN

Randomized clinical trial (January 2019 to July 2020).

SETTING

University veterinary teaching hospital and private referral hospital.

ANIMALS

Dogs and cats with DKA and venous pH <7.3, blood glucose concentration >11 mmol/L (198 mg/dL), and β-hydroxybutyrate (BHB) concentration >3 mmol/L were eligible for inclusion. Patients were randomly assigned to receive either FRI or VRI.

INTERVENTIONS

Neutral (regular) insulin was administered IV as an FRI or VRI. For FRI, the rate was maintained at 0.01 IU/kg/h. For VRI, the dose was adjusted according to blood glucose concentration.

MEASUREMENTS AND RESULTS

Sixteen cats and 20 dogs were enrolled. Population characteristics, mean insulin infusion rate, time to resolution of ketosis (BHB <0.6 mmol/L), complications, LOH, and STD were evaluated. In cats, overall resolution of ketosis was low (9/16 [56.3%]), limiting comparison of protocols. In dogs, resolution of ketosis was high (19/20 dogs [95.0%]) but the time to resolution in the FRI group was not different than that in the VRI group (P = 0.89), despite a 25% higher average insulin infusion rate in the FRI group (P = 0.04). The incidence of complications was low and did not differ between protocols. In cats, LOH and STD did not differ between protocols. All cats that died (5/16) did so within 78 hours and none had resolution of ketosis. Dogs receiving FRI had a shorter LOH (P = 0.01) but STD did not differ between protocols. Six dogs (30.0%) did not survive to hospital discharge but all had resolution of ketosis.

CONCLUSIONS

FRIs can be used in veterinary species but may not hasten resolution of ketosis.

Diabetes Ketoacidosis and Hyperosmolar Hyperglycemic Syndrome in Companion Animals

Diabetes mellitus is a common endocrinopathy in dogs and cats. Diabetes ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS) are life-threatening complications of diabetes resulting from an imbalance between insulin and the glucose counter-regulatory hormones. The first part of this review focuses on the pathophysiology of DKA and HHS, and rarer complications such as euglycemic DKA and hyperosmolar DKA. The second part of this review focuses on the diagnosis and treatment of these complications.

Insulin expression in β cells is reduced within islets before islet loss in diabetic cats

OBJECTIVES

Diabetes mellitus is a common condition that requires intensive treatment and markedly impacts the welfare of affected cats. The aim of this study was to identify diabetes mellitus-associated perturbations in the feline pancreatic islet microenvironment. The utility of "clear, unobstructed brain/body imaging cocktails and computational analysis" (CUBIC) for three-dimensional pancreatic analysis was investigated.

METHODS

Formalin-fixed paraffin-embedded tissues from cats with diabetes mellitus, or control cats without pancreatic pathology, were retrospectively identified. Immunohistochemistry for synaptophysin and ionised calcium binding adaptor molecule 1, and immunofluorescence for insulin and synaptophysin, were used to assess changes in islets. An image analysis pipeline was developed to analyse images acquired from two-dimensional immunofluorescence. CUBIC was used to optically clear selected pancreas samples before immunofluorescence and deep three-dimensional confocal microscopy.

RESULTS

Diabetic cats have a significant reduction in synaptophysin-positive islet area. Whilst islets from diabetic patients have similar numbers of β cells to islets from control cats, significantly lower intensity of insulin expression can be observed in the former. CUBIC facilitates clear visualisation of pancreatic islets in three dimensions.

CLINICAL SIGNIFICANCE

The data presented support the theory that there is a decrease in function of β cells before their destruction, suggesting a potentially significant step in the pathogenesis of feline diabetes mellitus. In parallel, we demonstrate CUBIC as a valuable new tool to visualise the shape of feline pancreatic islets and to interrogate pathology occurring in the islets of diabetic pets.

Therapy for feline secondary hypertriglyceridemia with fenofibrate

OBJECTIVES

The aim of this study was to assess the short-term safety and efficacy of fenofibrate in controlling secondary hypertriglyceridemia in cats.

METHODS

This was a prospective cohort study. Seventeen adult cats with hypertriglyceridemia (serum triglycerides [TG] >160 mg/dl) were enrolled. Cats received a median dose of 5 mg/kg (range 3.2-6) fenofibrate (q24h PO) for 1 month. Serum TG, total cholesterol (TC), creatine kinase and liver enzymes (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase) were evaluated before (t0) and after 1 month (t1) of fenofibrate treatment.

RESULTS

The causes of secondary hypertriglyceridemia were diabetes mellitus (DM; 29.4%), obesity (29.4%), hyperadrenocorticism (HAC) and DM (11.7%), HAC without DM (5.9%), hypersomatotropism (HST) and DM (5.9%), hypothyroidism (5.9%), long-term treatment with glucocorticoids (5.9%) and chylothorax (5.9%). Serum TG (t0 median 920 mg/dl [range 237-1780]; t1 median 51 mg/dl [range 21-1001]; P = 0.0002) and TC (t0 median 278 mg/dl [range 103-502]; t1 median 156 mg/dl [range 66-244]; P = 0.0001) concentrations showed a significant decrease after 1 month of fenofibrate treatment. Fifteen cats normalized their TG concentration at t1 (88.2%). Of the eight cats that were hypercholesterolemic at t0, six (75%) normalized their TC concentrations at t1. One of 17 cats (5.9 %) presented with diarrhea; the remaining 16 did not show any adverse effects.

CONCLUSIONS AND RELEVANCE

DM and obesity are the most common endocrine causes of secondary hyperlipidemia, although it can also be found in cats with HAC, HST or hypothyroidism. This study suggests that fenofibrate treatment was associated with reduction and normalization of TG and TC concentrations in cats with moderate and severe hypertriglyceridemia, regardless of the cause of secondary hypertriglyceridemia. Further work should focus on controlled studies with a greater number of cases.

Glargine versus regular insulin protocol in feline diabetic ketoacidosis

Objectives

To determine whether basal‐bolus administration of glargine insulin is a safe and effective alternative treatment compared to the standard continuous rate infusion (CRI) protocol.

Design

Prospective randomized clinical trial.

Setting

University teaching hospital.

Animals

Twenty cats diagnosed with diabetic ketoacidosis (DKA).

Interventions

The cats were block‐randomized to either a CRI protocol using regular insulin (CRI‐group; n = 10) or a basal‐bolus SC and IM glargine protocol (glargine‐group, n = 10). Baseline blood gases, electrolytes, glucose, and β‐hydroxybutyrate (β‐OHB) concentrations were measured at the time of admission and later at predefined intervals until reaching the primary endpoint of the study, defined as a β‐hydroxybutyrate concentration < 2.55 mmol/L.

Measurements and main results

The main outcome measure was time (h) to resolution of ketonemia. Secondary outcome measures were time until first improvement of hyperglycemia and ketonemia, decrease of glucose to ≤13.9 mmol/L (250 mg/dL), resolution of acidosis, consumption of first meal, and discharge from hospital. Additionally, occurrence of treatment‐associated adverse events and death were compared. Seventeen cats (85%) survived to discharge, with no difference in survival between groups (P = 1.0). Median times to β‐OHB < 2.55 mmol/L were 42 (CRI‐group) and 30 (glargine‐group) hours, respectively (P = 0.114). Median times to first improvement of hyperglycemia (glargine‐group: 2 h; CRI‐group: 6 h; P = 0.018) and until discharge from hospital (glargine‐group: 140 h; CRI‐group: 174 h; P = 0.033) were significantly shorter in the glargine‐group. No significant differences were observed in any other parameter under investigation (P > 0.05).

Conclusions

Basal‐bolus administration of glargine insulin appears to be an effective and safe alternative to the current standard CRI‐protocol for the management of DKA in cats. The positive outcomes and simplicity make it a viable option for the treatment of feline DKA.

Lispro insulin and electrolyte supplementation for treatment of diabetic ketoacidosis in cats

Background

Intravenous continuous rate infusion (IVCRI) of lispro at a starting dose of 0.09 U/kg/h and the use of 0.9% sodium chloride (NaCl) for fluid resuscitation in cats with diabetic ketoacidosis (DKA) have not been reported. Protocols for correction of electrolyte deficiencies in cats with DKA are lacking.

Objectives

To characterize the use of IVCRI lispro at an initial dose of 0.09 U/kg/h and the use of NaCl for resuscitation. Explore protocols for electrolyte supplementation in cats with DKA.

Animals

Twelve cats with DKA enrolled from the cat population of a university hospital.

Methods

Randomized, controlled, blinded study. Six cats were randomized into each group, the lispro insulin treatment group (LITG) and regular insulin treatment group (RITG). All cats received IVCRI fluid resuscitation with NaCl. Solutions with higher than previously published electrolyte concentrations were used to treat electrolyte deficiencies.

Results

The median time to blood glucose (BG) concentration <250 mg/dL was significantly shorter in the LITG (median 7 hours, 2‐10 hours) than the RITG (median 12.5 hours, 8‐20 hours; P = .02). Two cats had nonclinical hypoglycemia (BG = 40 mg/dL). The most rapid change in 157 measurements of corrected sodium concentrations was 0.7 mmol/L/h. Low concentrations of serum sodium, potassium, phosphate, and magnesium were over 3 times more common than above normal electrolyte concentrations, despite supplementation with fluids of high electrolyte concentrations.

Conclusions and Clinical Importance

Lispro at a starting dose of 0.09 U/kg/h and NaCl administered for fluid resuscitation are safe and effective for treatment of DKA in cats.

Diabetic ketoacidosis in the cat: Recognition and essential treatment

Practical relevance: Diabetic ketoacidosis (DKA) is a not uncommon emergency in both newly diagnosed and poorly regulated diabetic cats. When there is a heightened metabolic rate and energy requirement due to concurrent illness, an increase in the release of glucose counter-regulatory hormones causes insulin receptor resistance, lipolysis, free fatty acid release and ketogenesis. This necessitates not only treatment to eliminate the ketosis and control blood glucose, but also investigation of concurrent illnesses. Clinical challenges: A number of metabolic derangements can occur with DKA, requiring a comprehensive diagnostic evaluation, elimination of ketones, careful correction of glucose, electrolyte and acid base abnormalities, and close monitoring.

AUDIENCE

Any veterinarian that cares for cats in urgent and emergency situations should understand the pathophysiology of DKA in order to address an individual's clinical signs and metabolic derangements. Evidence base: This review draws evidence from the peer-reviewed literature as well as the author's personal clinical experience.