Evaluation of serum fructosamine concentration as an index of blood glucose control in cats with diabetes mellitus.

Fructosamine, a glycated serum protein, was evaluated as an index of glycemic control in normal and diabetic cats. Fructosamine was determined manually by use of a modification of an automated method. The within-run precision was 2.4 to 3.2%, and the day-to-day precision was 2.7 to 3.1%. Fructosamine was found to be stable in serum samples stored for 1 week at 4 C and for 2 weeks at -20 C. The reference range for serum fructosamine concentration in 31 clinically normal colony cats was 2.19 to 3.47 mmol/L (mean, 2.83 +/- 0.32 mmol/L). In 27 samples from 16 cats with poorly controlled diabetes mellitus, the range for fructosamine concentration was 3.04 to 8.83 mmol/L (mean, 5.93 +/- 1.35 mmol/L). Fructosamine concentration was directly and highly correlated to blood glucose concentration. Fructosamine concentration also remained high in consort with increased blood glucose concentration in cats with poorly controlled diabetes mellitus over extended periods. It is concluded that measurement of serum fructosamine concentration can be a valuable adjunct to blood glucose monitoring to evaluate glycemic control in diabetic cats. The question of whether fructosamine can replace glucose for monitoring control of diabetes mellitus requires further study.     

Evaluation of day-to-day variability of serial blood glucose concentration curves in diabetic dogs

OBJECTIVE: To evaluate day-to-day variability of serial blood glucose concentration curves in dogs with diabetes mellitus. DESIGN: Prospective clinical study. ANIMALS: 10 dogs with diabetes mellitus. PROCEDURE: Paired 12-hour serial blood glucose concentration curves performed during 2 consecutive days were obtained on 3 occasions from each dog. Dogs received the same dose of insulin and meal every 12 hours on both days. For each pair of curves, comparison was made between the results of days 1 and 2. RESULTS: Mean absolute difference (without regard to sign) between days 1 and 2 for each parameter was significantly > 0, disproving the hypothesis that there is minimal day-to-day variability of serial blood glucose concentration curves when insulin dose and meals are kept constant. Coefficient of variation of the absolute difference between days 1 and 2 for each parameter ranged from 68 to 103%. Evaluation of the paired curves led to an opposite recommendation for adjustment of the insulin dose on day 2, compared with day 1, on 27% of occasions. Disparity between dosage recommendations was more pronounced when glucose concentration nadir was < 180 mg/dL (10 mmol/L) on 1 or both days. In this subset of 20 paired curves, an opposite recommendation for dosage adjustment was made on 40% of occasions. CONCLUSIONS AND CLINICAL RELEVANCE: There is large day-to-day variation in parameters of serial blood glucose concentration curves in diabetic dogs. Day-to-day variability of serial blood glucose concentration curves has important clinical implications, particularly in dogs with good glycemic control.     

Systolic blood pressure in cats with diabetes mellitus

OBJECTIVE: To determine the prevalence of systemic hypertension in cats with diabetes mellitus and establish ranges for echocardiographic variables in diabetic cats. DESIGN: Prospective study. ANIMALS: 14 cats with diabetes mellitus and 19 healthy control cats. PROCEDURE: Systolic blood pressure was measured indirectly with a noninvasive Doppler technique. Ophthalmic and echocardiographic examinations were performed, and urine protein concentration was measured. Cats were considered to have hypertension if they had systolic blood pressure > 180 mm Hg and at least 1 other clinical abnormality typically associated with hypertension (eg, hypertensive retinopathy, left ventricular hypertrophy, or proteinuria). RESULTS: None of the diabetic or control cats had systolic blood pressure > 180 mm Hg. One diabetic cat had left ventricular hypertrophy, but systolic blood pressure was 174 mm Hg. None of the cats had evidence of hypertensive retinopathy or proteinuria. Mean values for echocardiographic variables for the diabetic cats were not significantly different from published values for healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that hypertension does not occur or occurs in only a small percentage of cats with diabetes mellitus.     

Portable blood glucose meters as a means of monitoring blood glucose concentrations in dogs and cats with diabetes mellitus

The use of portable blood glucose meters (PBGM) has become common in veterinary medicine as a rapid means of monitoring animals' blood glucose in a variety of medical conditions. These hand-held monitors allow for diagnostic and therapeutic decisions to be made quickly and relatively inexpensively using only a small amount of blood. Both in conditions resulting in hyperglycemia, such as diabetes mellitus, and in those resulting in hypoglycemia, such as sepsis or the presence of an insulinoma, veterinarians have come to rely on PBGM to provide critical information on the status of their animal patients. In particular, PBGM are frequently used to measure individual blood glucose values in an animal over a period to create a blood glucose curve when evaluating the effectiveness of insulin therapy in diabetic dogs and cats.     

Evaluation of long-term home monitoring of blood glucose concentrations in cats with diabetes mellitus: 26 cases (1999-2002)

OBJECTIVE: To evaluate owner compliance with longterm home monitoring of blood glucose concentrations in diabetic cats and assess the influence of home monitoring on the frequency of reevaluation of those cats at a veterinary hospital. DESIGN: Retrospective study. ANIMALS: 26 cats with diabetes mellitus. PROCEDURE: Medical records of diabetic cats for which home monitoring was undertaken were reviewed, and owners were contacted by telephone. Signalment, laboratory test results, insulin treatment regimen, details of home monitoring, clinical signs during treatment, frequency of follow-up examinations, and survival times were evaluated. RESULTS: Monitoring of cats commenced within 12 weeks (median, 3 weeks) after initial evaluation; 8 owners were unable to perform home monitoring, and 1 cat was euthanatized after 1 week. In 17 cats, duration of home monitoring was 4.8 to 46.0 months (median, 22.0 months); 6 cats died after 7.0 to 18.0 months (median, 13.0 months). In 11 cats, home monitoring was ongoing at completion of the study (12.0 to 46.0 months' duration). Fourteen owners completed blood glucose curves every 2 to 4 weeks. Cats managed with home monitoring received higher dosages of insulin, compared with cats that were not monitored. Four of 17 cats managed by home monitoring had transient resolution of diabetes mellitus for as long as 1 year. Home monitoring did not affect the frequency of reevaluation at the veterinary hospital. CONCLUSIONS AND CLINICAL RELEVANCE: Owner compliance with long-term home monitoring appeared to be satisfactory, and home monitoring did not affect the frequency of reevaluation of patients by veterinarians.     

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

Home-monitoring of blood glucose concentrations has recently been introduced to owners. The objectives of this study were to investigate the feasibility of home-monitoring of blood glucose in diabetic cats by owners, the problems encountered and to compare glucose concentrations at home with those measured in the hospital. Twelve of 15 cat owners were able to generate glucose curves over the study period of 4 months. Most problems were related to restraining the cat, generating negative pressure with the lancing device and producing a blood drop. In the majority of cases, these problems could be resolved during the study. Blood glucose concentrations in the clinic tended to be lower than at home; some of the differences were significant. No association between tolerance of the procedure and blood glucose concentrations measured at home was found. We, therefore, assume that the lower glucose levels in the hospital were caused by lack of food intake. In 38% of cases, treatment based on hospital curves would have been different from that based on home curves. Home-monitoring appears to be a valuable tool in the management of cats with diabetes mellitus. One of its major advantages is that it enables frequent generation of blood glucose curves, which is of particular importance in cats that are difficult to regulate.     

Evaluation of a continuous glucose monitoring system in cats with diabetes mellitus

A continuous glucose monitoring system (CGMS) was evaluated in 14 cats with naturally occurring diabetes mellitus. The device measures interstitial fluid glucose continuously, by means of a sensor placed in the subcutaneous tissue. All cats tolerated the device well and a trace was obtained on 15/16 occasions. There was good correlation between the CGMS values and blood glucose concentration measured using a glucometer (r=0.932, P<0.01). Limitations to the use of the CGMS are its working glucose range of 2.2-22.2 mmol/l (40-400 mg/dl) and the need for calibration with a blood glucose measurement at least every 12 h. When compared to a traditional blood glucose curve, the CGMS is minimally invasive, reduces the number of venepunctures necessary to assess the kinetics of insulin therapy in a patient and provides a truly continuous glucose curve.     

Serum insulin-like growth factor-I concentration in cats with diabetes mellitus and acromegaly

BACKGROUND: Serum insulin-like growth factor-I (IGF-I) has been used in place of serum growth hormone quantification for identifying acromegaly in diabetic cats. The utility of IGF-I as a screening test for acromegaly has not been critically evaluated. This retrospective study was performed to evaluate the usefulness of serum IGF-I concentration for identifying acromegaly. HYPOTHESIS: Serum IGF-I is a useful screening test for acromegaly in diabetic cats. ANIMALS: A review was made of the medical records of 74 diabetic cats that had serum IGF-I quantified. The diabetes was classified as well controlled (15 cats), poorly controlled because of problems with the insulin treatment regimen, concurrent disease, or both (40), or poorly controlled with clinical findings consistent with acromegaly (19). METHODS: A review of medical records was made. RESULTS: Serum IGF-I concentration was significantly (P < .0001) increased in acromegalic diabetic cats, compared with well-controlled and poorly controlled diabetic cats. Sensitivity and specificity for serum IGF-I concentration were 84% (95%/ confidence interval [CI] = 60.4-96.6%) and 92% (95% CI = 81.3-97.2%), respectively. There was no significant correlation between serum IGF-I concentration and duration of insulin treatment (r = 0.23, P = .089), insulin dosage (r = 0.14, P = .30), age (r = 0.16, P = .12), and pituitary volume (r = 0.40, P = .11), but a modest correlation was found between serum IGF-I concentration and body weight (r = 0.48, P < .0001). CONCLUSIONS AND CLINICAL IMPORTANCE: Results support the use of serum IGF-I concentration as a screening test for acromegaly in diabetic cats that have clinical findings supportive of the disease.     

Pulmonary lesions in cats with diabetes mellitus

Diabetes mellitus (DM) is a common endocrinopathy of cats and humans. Although few studies have examined the effects of DM on the pulmonary system, changes in pulmonary function and immunology in humans with type I and II diabetes, and pulmonary lesions in a murine diabetic model have been documented. Our objective was to determine whether pulmonary lesions occurred in cats with DM. Medical records and necropsy evaluations of 42 cats with DM were compared with those of 45 age-matched, nondiabetic cats for the presence of clinical evidence of respiratory disease and pulmonary histopathological findings at the time of necropsy. No statistical difference was noted in the presence of clinical evidence of respiratory disease between cats with diabetes and control cats. Nevertheless, there was a significant association between the presence of abnormal pulmonary histopathology and DM (P = .018, odds ratio = 3 inclusive of all cats; P = .005, odds ratio = 5 when non-DM cats with overt clinical evidence of respiratory disease were excluded). Pulmonary abnormalities detected by histopathological examination in cats with diabetes included congestion and edema, histiocytosis, pneumonia, smooth muscle hypertrophy, fibrosis, mineralization, neoplasia, and type II pneumocyte hyperplasia. The observed association between DM and pulmonary lesions in cats, independent of clinical evidence of respiratory disease, emphasizes the need for careful assessment of the respiratory tract in sick cats with diabetes.     

Insulin therapy in cats with diabetes mellitus

Thirteen cats with diabetes mellitus were evaluated. Clinical signs included polydipsia, polyuria, polyphagia, lethargy, and weight loss. Results of physical examination included obesity, hepatomegaly, mild seborrhea sicca, muscle wasting, and dehydration. One cat walked plantigrade and was suspected of having a diabetic neuropathy. Persistent hyperglycemia, glucosuria, high liver enzyme activities, hypercholesterolemia, hyperproteinemia, and low electrolyte concentrations were the common laboratory findings. In 3 cats diabetes mellitus developed after megestrol acetate therapy; 2 of these cats required only temporary insulin treatment. In a 3rd cat, which had no history of receiving diabetogenic drug therapy, remission of diabetes mellitus also was observed. Serum insulin and plasma glucose concentrations were determined in 6 cats after administration of an intermediate-acting insulin (isophane insulin) and in 3 cats after administration of a long-acting insulin (protamine zinc insulin). The insulin concentration peaked 2 to 6 hours after the injection of intermediate-acting insulin and 6 to 12 hours after the injection of long-acting insulin. The lowest glucose concentration was recorded 4 to 8 hours after injection of intermediate-acting insulin, and 6 to 12 hours after injection of long-acting insulin. It was concluded that, although insulin therapy must be adjusted to the individual, the diabetic cat usually requires twice-daily administration of isophane insulin; however, the protamine zinc insulin can be given once daily for satisfactory control.     

Comparison of glucose concentrations in blood samples obtained with a marginal ear vein nick technique versus from a peripheral vein in healthy cats and cats with diabetes mellitus

OBJECTIVE: To compare blood glucose (BG) concentrations measured with a portable blood glucose meter in blood samples obtained with a marginal ear vein (MEV) nick technique, from a peripheral venous catheter, and by direct venipuncture in healthy cats and cats with diabetes mellitus. DESIGN: Prospective study. ANIMALS: 1 0 healthy cats and 11 cats with diabetes mellitus. Procedure-On day 1, blood samples were collected every hour for 10 hours by the MEV nick technique and from a peripheral venous catheter. On day 2, blood samples were collected every hour for 10 hours by the MEV nick technique and by direct venipuncture of the medial saphenous vein. RESULTS: For all cats, mean BG concentration for samples collected by the MEV nick technique was not significantly different from mean concentration for samples obtained from the peripheral venous catheter. For healthy cats, mean BG concentration for samples collected by the MEV nick technique was not significantly different from mean concentration for samples obtained by direct venipuncture. For cats with diabetes mellitus, mean BG concentration for samples collected by the MEV nick technique was significantly different from mean concentration for samples obtained by direct venipuncture; however, for the range of concentrations examined, this difference was not clinically important. Conclusions and Clinical Relevance: Results suggest that for the range of concentrations examined, the MEV nick technique is a reasonable alternative to venous blood collection for serial measurement of BG concentrations in cats.     

Effects of diet on glucose control in cats with diabetes mellitus treated with twice daily insulin glargine

The purpose of this study was to evaluate the effects of dietary modification in addition to twice daily insulin glargine. Cats were treated with insulin glargine twice daily and randomized to receive either a low carbohydrate, high protein (LCHP) diet (n=6) or a control diet (n=6) for 10 weeks. Re-evaluations of clinical signs, blood glucose curves, and serum fructosamine concentrations were performed at weeks 1, 2, 4, 6, and 10. Two of 12 cats achieved complete remission by the end of the study but remission rate was not different between diet groups. Using twice daily insulin glargine and frequent monitoring, all cats in both diet groups achieved successful glycemic control. Frequent monitoring is key to achieving glycemic control in diabetic cats; potential benefits of dietary modification require further evaluation.     

Over representation of Burmese cats with diabetes mellitus

Objective To determine if Burmese cats in Queensland have an increased risk of diabetes mellitus.
Design A retrospective study of diabetic and nondiabetic cats that had blood submitted to a veterinary clinical laboratory over a 22 month study period.
Sample population 4402 cats
Procedure Cats were considered diabetic if blood glucose concentration was > 11 mmol/L and fructosamine was > 406 μmol/L or hydroxybutyrate was >1 mmol/L. Cats were grouped into Burmese and non-Burmese. Adjusted odds ratios of diabetes were calculated for breed, gender and age group amongst cats with blood glucose > 11 mmol/L.
Results Burmese cats comprised 20% of 45 diabetic cats of known breed, which was higher (P < 0.001) than among the normoglycemic reference population of 2203 cats (7% Burmese). There were more females among the diabetic Burmese (62%), but this did not differ (P > 0.05) from the Burmese reference population (45% females). In contrast, males seemed to predominate among diabetic non-Burmese (63%), although this also did not differ (P > 0.05) from the reference population (55%) or from diabetic Burmese (38% males). The majority (90%) of diabetic cats were older than 6 years, irrespective of breed (median age 12 years, interquartile range 10 to 13 years). This was higher (χ²= 8.13, P < 0.005) than among the normoglycaemic reference population, where 69% were older than 6 years.
Conclusions Burmese cats were significantly over represented among cats with diabetes mellitus. Irrespective of breed, the risk of diabetes in the study population increased with age.     

Generalized demodicosis associated with diabetes mellitus in two cats

Generalized demodicosis with concurrent diabetes mellitus was diagnosed in 2 cats. Both cats had generalized alopecia and a bilateral brown aural exudate. Mites were seen microscopically in skin scrapings and ear swab specimens. Histologic examination of the skin showed the follicular orientation of the mites. Abnormal results on oral dexamethasone suppression tests, clinical findings, and bilateral adrenal hyperplasia found on necropsy of one of the cats suggested concurrent hyperadrenocorticism.     

Evaluation of bexagliflozin in cats with poorly regulated diabetes mellitus

The aim of this study was to investigate the effect of bexagliflozin on glycemic control in poorly regulated diabetic cats and to evaluate for adverse events associated with this medication.Sodium-glucose cotransporter 2 inhibitors are a newer class of drugs used in the management of humans with type 2 diabetes mellitus. The objective of this study was to evaluate the effect of the orally administered drug, bexagliflozin in a group of poorly regulated diabetic cats over a 4-week study period. Five client-owned cats with poorly controlled diabetes mellitus receiving insulin therapy were enrolled. Bexagliflozin was administered once daily. Serum fructosamine, serum biochemistry profile, and 10-hour blood glucose curves were assessed at baseline (Day 0), Day 14, and Day 28. All cats had a significant reduction in insulin dose requirement (P = 0.015) and insulin was discontinued in 2 cats. There was a significant decrease in blood glucose concentration obtained from blood glucose concentration curves during the study period (P = 0.022). Serum fructosamine decreased in 4 of the 5 cats with a median decrease of 152 μmol/L (range: 103 to 241 μmol/L), which was not statistically significant (P = 0.117). No cats had any documented episodes of hypoglycemia. Adverse effects were mild. The addition of bexagliflozin significantly improved diabetic management in this group of cats.     

Determination of serum fPLI concentrations in cats with diabetes mellitus

Diabetes mellitus (DM) is one of the most common feline endocrinopathies. Pancreatitis is a reported cause for poor control of DM in cats; however, its prevalence in diabetic cats is unknown. Measurement of serum feline pancreatic lipase immunoreactivity (fPLI) has been proposed as a sensitive and specific test for the detection of pancreatitis in cats. The aim of this study was to assess fPLI concentrations in diabetic cats and compare these with non-diabetic cats of similar age. Samples from 29 cats with DM and 23 non-diabetic cats were analysed. Serum fPLI concentrations were significantly higher in samples from diabetic cats (P<0.01). A weak association was found between serum fructosamine and fPLI concentrations (R(2)=0.355, P=0.015), but there was no association between fPLI concentrations and the degree of diabetic control. There were no significant differences in reported clinical signs between cats with or without DM regardless of serum fPLI concentration. This is the first study to demonstrate elevated serum fPLI concentrations in cats with DM, suggesting that pancreatitis could be a significant comorbidity in these cats.