Changes in amylin and amylin-like peptide concentrations and beta-cell function in response to sulfonylurea or insulin therapy in NIDDM

Amylin and its analogs: a friend or foe for the treatment of Alzheimer's disease?

Amylin, a gut-brain axis hormone, and amyloid-beta peptides (Aβ), a major component of the Alzheimer's disease (AD) brain, share several features, including similar β-sheet secondary structures, binding to the same receptor and being degraded by the same protease, insulin degrading enzyme (IDE). However, while amylin readily crosses the blood brain barrier (BBB) and mediates several activities including improving glucose metabolism, relaxing cerebrovascular structure, modulating inflammatory reaction and perhaps enhancing neural regeneration, Aβ has no known physiological functions. Thus, abundant Aβ in the AD brain could block or interfere with the binding of amylin to its receptor and hinder its functions. Recent studies using animal models for AD demonstrate that amylin and its analog reduce the AD pathology in the brain and improve cognitive impairment in AD. Given that, in addition to amyloid plaques and neurofibrillary tangles, perturbed cerebral glucose metabolism and cerebrovascular damage are the hallmarks of the AD brain, we propose that giving exogenous amylin type peptides have the potential to become a new avenue for the diagnosis and therapeutic of AD. Although amylin's property of self-aggregation may be a limitation to developing it as a therapeutic for AD, its clinical analog, pramlintide containing 3 amino acid differences from amylin, does not aggregate like human amylin, but more potently mediates amylin's activities in the brain. Pramlintide is an effective drug for diabetes with a favorable profile of safety. Thus a randomized, double-blind, placebo-controlled clinical trial should be conducted to examine the efficacy of pramlintide for AD. This review summarizes the knowledge and findings on amylin type peptides and discuss pros and cons for their potential for AD.

Integrating human omics data to prioritize candidate genes

Background

The identification of genes involved in human complex diseases remains a great challenge in computational systems biology. Although methods have been developed to use disease phenotypic similarities with a protein-protein interaction network for the prioritization of candidate genes, other valuable omics data sources have been largely overlooked in these methods.

Methods

With this understanding, we proposed a method called BRIDGE to prioritize candidate genes by integrating disease phenotypic similarities with such omics data as protein-protein interactions, gene sequence similarities, gene expression patterns, gene ontology annotations, and gene pathway memberships. BRIDGE utilizes a multiple regression model with lasso penalty to automatically weight different data sources and is capable of discovering genes associated with diseases whose genetic bases are completely unknown.

Results

We conducted large-scale cross-validation experiments and demonstrated that more than 60% known disease genes can be ranked top one by BRIDGE in simulated linkage intervals, suggesting the superior performance of this method. We further performed two comprehensive case studies by applying BRIDGE to predict novel genes and transcriptional networks involved in obesity and type II diabetes.

Conclusion

The proposed method provides an effective and scalable way for integrating multi omics data to infer disease genes. Further applications of BRIDGE will be benefit to providing novel disease genes and underlying mechanisms of human diseases.

Effects of insulin versus sulphonylurea on beta-cell secretion in recently diagnosed type 2 diabetes patients: a 6-year follow-up study

BACKGROUND

Early insulin treatment is considered more beneficial than anti-diabetic medication with sulphonylureas, because the latter may exert negative effects on beta-cell function, while the former may help preserve it. In a previous study, we found that C-peptide response was increased in the insulin-treated group, whereas it was decreased in the glibenclamide group. However, it was not certain whether the advantage remained in the longer term.

AIM

In this study, we tested whether early insulin treatment is more beneficial than glibenclamide against a 6-year follow-up perspective.

METHODS

We designed a randomized clinical trial in subjects with newly diagnosed type 2 diabetes. Glucagon stimulatory tests, measuring C-peptide and islet amyloid polypeptide (IAPP), were performed after 2, and 3, days of temporary insulin and glibenclamide withdrawal.

RESULTS

18 subjects initially randomized to glibenclamide, and 16 randomized to two daily injections of insulin, participated in end-of-study investigations. C-peptide response to glucagon deteriorated (p < 0.01 vs. baseline) in initially glibenclamide-treated patients (n = 18), but not in insulin-treated patients (p < 0.05 for difference between groups, after 2 days of treatment withdrawal). The IAPP response to glucagon declined in the glibenclamide group (p < 0.001), but not in insulin-treated subjects (p = 0.05 for difference between groups).

CONCLUSIONS

Early insulin treatment preserves beta-cell secretory function better than glibenclamide even in a 6-year perspective.

Efficacy and safety of sitagliptin when added to insulin therapy in patients with type 2 diabetes

OBJECTIVE

To evaluate the efficacy and tolerability of sitagliptin when added to insulin therapy alone or in combination with metformin in patients with type 2 diabetes.

METHODS

After a 2 week placebo run-in period, eligible patients inadequately controlled on long-acting, intermediate-acting or premixed insulin (HbA1c > or = 7.5% and < or = 11%), were randomised 1:1 to the addition of once-daily sitagliptin 100 mg or matching placebo over a 24-week study period. The study capped the proportion of randomised patients on insulin plus metformin at 75%. Further, the study capped the proportion of randomised patients on premixed insulin at 25%. The metformin dose and the insulin dose were to remain stable throughout the study. The primary endpoint was HbA1c change from baseline at week 24.

RESULTS

Mean baseline characteristics were similar between the sitagliptin (n = 322) and placebo (n = 319) groups, including HbA1c (8.7 vs. 8.6%), diabetes duration (13 vs. 12 years), body mass index (31.4 vs. 31.4 kg/m(2)), and total daily insulin dose (51 vs. 52 IU), respectively. At 24 weeks, the addition of sitagliptin significantly (p < 0.001) reduced HbA1c by 0.6% compared with placebo (0.0%). A greater proportion of patients achieved an HbA1c level < 7% while randomised to sitagliptin as compared with placebo (13 vs. 5% respectively; p < 0.001). Similar HbA1c reductions were observed in the patient strata defined by insulin type (long-acting and intermediate-acting insulins or premixed insulins) and by baseline metformin treatment. The addition of sitagliptin significantly (p < 0.001) reduced fasting plasma glucose by 15.0 mg/dl (0.8 mmol/l) and 2-h postmeal glucose by 36.1 mg/dl (2.0 mmol/l) relative to placebo. A higher incidence of adverse experiences was reported with sitagliptin (52%) compared with placebo (43%), due mainly to the increased incidence of hypoglycaemia (sitagliptin, 16% vs. placebo, 8%). The number of hypoglycaemic events meeting the protocol-specified criteria for severity was low with sitagliptin (n = 2) and placebo (n = 1). No significant change from baseline in body weight was observed in either group.

CONCLUSION

In this 24-week study, the addition of sitagliptin to ongoing, stable-dose insulin therapy with or without concomitant metformin improved glycaemic control and was generally well tolerated in patients with type 2 diabetes.

Differential lipid profile and hormonal response in type 2 diabetes by exogenous insulin aspart versus the insulin secretagogue repaglinide, at the same glycemic control

Our aim was to study, at the same glycemic control, how treatment with either the insulin secretagogue repaglinide or exogenous insulin aspart affects endogenous insulin secretion, plasma insulin and IAPP (islet amyloid polypeptide) levels, GH-IGF (growth hormone-insulin-like growth factor) axis and plasma lipoprotein concentrations in patients with type 2 diabetes. Five patients, age 65.0+/-4.1 years (mean+/-SE), body weight 82.5+/-5.0 kg, BMI (body mass index) 27.7+/-1.5 kg/m(2) were treated for 10 weeks with repaglinide or insulin aspart in a randomized, cross-over study. At the end of each treatment a 24-h metabolic profile was performed. Blood glucose, C-peptide, free human insulin, free total (human and analogue) insulin, proinsulin, IAPP, IGF-I, IGFBP-1 (IGF binding protein-1), GHBP (growth hormone binding protein) and plasma lipoprotein concentrations were measured. Similar 24-h blood glucose profiles were obtained with repaglinide and insulin aspart treatment. During the repaglinide treatment, the meal related peaks of C-peptide and free human insulin were about twofold higher than during treatment with insulin aspart. Proinsulin, GHBP were higher and IAPP levels tended to be higher during repaglinide compared to insulin aspart. Postprandial plasma total cholesterol, triglycerides and apolipoprotein B concentrations were higher on repaglinide than on insulin aspart treatment. Our results show that, at the same glycemic control, treatment with exogenous insulin aspart in comparison with the insulin secretagogue repaglinide result in a lower endogenous insulin secretion, and a tendency towards a less atherogenic postprandial lipid profile.

Comparison of gliclazide with insulin as initial treatment modality in newly diagnosed type 2 diabetes

AIM

This study was designed to compare effectiveness and remission rate between gliclazide and insulin as initial treatment in newly diagnosed, drug-naive patients with type 2 diabetes.

METHODS

Newly diagnosed, drug-naive subjects with type 2 diabetes having mean fasting blood glucose >200 mg/dL were enrolled into either of two groups (gliclazide or insulin). The former received gliclazide modified-release 60 mg daily, while the insulin group received 16 units of premixed insulin as two divided doses along with medical nutrition therapy. Premeal blood glucose was monitored, and the dose was adjusted accordingly. Glycosylated hemoglobin (HbA1c), lipid profile, and postmeal C-peptide were estimated at baseline and 6 months. Remission was defined as euglycemia off drug for a minimum duration of 1 month.

RESULTS

Baseline and 6-month blood glucose, HbA1c, and lipid profile were comparable between groups. Blood glucose levels normalized in 2-6 weeks in both groups. At 6 months, one of 30 (3.33%) in the gliclazide group and 24 of 30 (80%) in the insulin group were in remission. Ten of 16 (62.5%) in the insulin group and one of 20 (.5%) in the gliclazide group continued to maintain euglycemia off all pharmacological treatment at 12 months. At 6 months, C-peptide increased in the insulin group (3.21+/-1.61 ng/mL at baseline vs. 5.82+/-2.23 ng/mL at 6 months), while it remained unchanged in the gliclazide group (3.4+/-1.87 ng/mL at baseline vs. 3.82+/-1.78 ng/mL at 6 months) (P=0.0003).

CONCLUSIONS

Comparable glycemic control could be achieved with both insulin and oral hypoglycemic agent in newly diagnosed type 2 diabetes subjects. Insulin treatment exceeded gliclazide in the remission (drug-free) rate.

Differential responses of circulating amylin to high-fat vs. high-carbohydrate meal in healthy men

OBJECTIVE

The success of an amylin analogue in weight loss trials has generated interest in amylin as a physiological satiety signal. Little is known about how plasma amylin responds to macronutrients. This study examined the effects of a high-carbohydrate meal (CHO), a high-fat meal (FAT) or a continued fast (FAST) on amylin concentrations and correlations among other satiety hormones and measures of appetite.

DESIGN/PATIENTS

In a randomized, crossover design, 10 healthy males consumed a meal high in carbohydrate or fat or continued fasted.

MEASUREMENTS

Blood samples and subjective hunger scores were obtained at baseline and 30, 90 and 210 min postprandial.

RESULTS

After CHO, amylin, insulin and C-peptide were greater and des-acyl ghrelin lower compared to FAT (P < 0.001). Area under the curve (AUC) was greater for amylin and insulin and lower for des-acyl ghrelin following CHO. Subjective satiety and fullness were higher for CHO and FAT than FAST at 30 and 90 min but only for CHO at 210 min (P < 0.01). Hunger and desire to eat were lower for CHO and FAT than FAST at 30 and 90 min but only for CHO at 210 min (P < 0.005). Amylin was negatively correlated to hunger, desire to eat, and nausea and positively related to satiety and insulin. Des-acyl ghrelin was negatively associated with C-peptide, insulin and GLP-1 and satiety.

CONCLUSIONS

CHO enhances amylin and suppresses des-acyl ghrelin to a greater extent than FAT in healthy men. The mechanisms responsible for these changes and their implications in the physiology of satiety remain to be elucidated.

Increased secretion and expression of amylin in spontaneously diabetic Goto-Kakizaki rats treated with rhGLP-1 (7-36)

AIM

To investigate the effect of recombined human glucagon-like peptide 1 (rhGLP-1 [7-36]) on the secretion and expression of amylin in Goto-Kakizaki (GK) rats.

METHODS

The GK rats were treated with rhGLP-1 (7-36) 56 and 133 mug/kg subcutaneously for 12 weeks. The fasting and post-prandial blood glucose levels were measured. The plasma amylin concentration was measured by ELISA. The transcription levels of amylin and insulin mRNA were evaluated by fluorescent-quantitative- PCR. Immunohistochemistry was utilized to detect the amylin protein. Histological examination was assayed by light microscopy.

RESULTS

Treatment with rhGLP-1 (7-36) caused a significant reduction of post-prandial blood glucose levels in the GK rats (P<0.05). The plasma amylin levels of the GK rats were lower than those of Wistar rats after the glucose administration (P<0.01). Treatment with rhGLP-1 (7-36) exhibited a marked elevation of the glucose-stimulated plasma amylin level (P<0.05) and slight histological amelioration. The amylin expression was augmented in the rhGLP-1 (7-36)-treated GK rat pancreas. Amylin and insulin mRNA were also highly expressed in the treated GK rats (P<0.05). However, the ratio of amylin to insulin mRNA was significantly decreased by treatment with rhGLP-1 (7-36).

CONCLUSION

RhGLP-1 (7-36) stimulates the secretion and expression of amylin, and exerts a beneficial effect on the ratio of amylin to insulin mRNA. These findings suggest that GLP-1 and GLP-1 analogs are ideal candidates for the treatment of type 2 diabetes.

Treatment of type 2 diabetes with combined therapy: what are the pros and cons?

Type 2 diabetes is a progressive syndrome that evolves toward complete insulin deficiency during the patient's life. A stepwise approach for its treatment should be tailored according to the natural course of the disease, including adding insulin when hypoglycemic oral agent failure occurs. Treatment with insulin alone should eventually be considered in a relevant number of cases. Experience has shown the protective effects of insulin on beta-cell survival and function, resulting in more stable metabolic control. On the contrary, treatment with most insulin secretagogues has been associated with increased beta-cell apoptosis, reduced responsiveness to high glucose, and impairment of myocardial function during ischemic conditions. In addition, macrovascular complications are associated with postprandial hyperglycemia, indicating the need for tight glycemic control. Insulin treatment, especially with rapid-acting analogs, has been demonstrated to successfully control postprandial glucose excursions. Finally, a reason for concern with regard to combined therapy is represented by the evidence that polipharmacy reduces compliance to the treatment regimen. This can be particularly relevant in patients with type 2 diabetes usually taking drugs for complications and for concomitant diseases with consequent deterioration not only of metabolic control but also of other conditions. In conclusion, therapy with insulin alone immediately after hypoglycemic oral agent failure may be a useful and safe therapeutic approach in type 2 diabetes.

Six-month multicentric, open-label, randomized trial of twice-daily injections of biphasic insulin aspart 30 versus multiple daily injections of insulin aspart in Japanese type 2 diabetic patients (JDDM 11)

To evaluate glycemic control using convenience-oriented biphasic insulin analog compared with intensified insulin therapy, we conducted a 6-month multicentric, open-label, randomized trial in Japanese insulin-naive patients with type 2 diabetes mellitus. A total of 160 adult patients at 19 centers were randomized into two groups: those who received twice-daily injections of biphasic insulin aspart 30 and those on three-times-daily injections of insulin aspart with or without NPH insulin (multiple daily injections). At 6 months, mean HbA(1c) decreased by approximately 2.5% in both groups. Reduction of HbA(1c) on both regimens was better in patients whose prior therapy before starting the study was only diet and exercise (-5.0%) than in patients who were previously taking oral antidiabetic agents (-1.0%). No incidence of major hypoglycemia was observed in either regimen. These results suggest that convenience-oriented insulin therapy using biphasic insulin analog is as useful as intensified insulin therapy with insulin analog for the treatment of type 2 diabetes mellitus over 6 months. Furthermore, early induction of insulin therapy in individuals hitherto using only diet and exercise may provide good glycemic control. This study suggests that convenience-oriented biphasic insulin aspart 30 might be a useful option for the treatment of type 2 diabetes mellitus, especially for insulin-naive patients over 6 months, although it should be changed to another regimen when expected efficacy is not obtained.

Novel pharmacologic agents for type 2 diabetes

After many decades of relative therapeutic stagnation since the initial discovery of insulin, followed by some modifications on its structure and only having sulfonylureas and biguanides for many years, the last decade has seen a surge in new therapeutic options for the management of diabetes. The results of the United Kingdom Prospective Diabetes Study and Kumamoto study indicate the need for aggressive glycemic control and the slow inexorable clinical deterioration associated with type 2 diabetes overtime. The propensity for weight gain and hypoglycemia are the two major limitations that subcutaneous insulin and sulfonylureas have been particularly prone to. The newer antidiabetic medications and those on the horizon attempt to address these limitations. GLP-1 agonists and the DPP-IV inhibitors exploit the innate incretin system to improve glycemia while promoting satiety and weight management. Like GLP-1 related compounds, pramlintide offers the potential to address postprandial hyperglucagonemia associated with type 2 diabetes only limited by the multiple injections and gastrointestinal side effects. The glitazars offer the hope ofa new approach to diabetes care addressing not just glycemia, but dyslipidemia and other components of the metabolic syndrome, though the side effect profile remains a major unknown. The INGAP peptide represents the holy grail of diabetes care as it offers the potential of a new paradigm: that of islet regeneration and potential for a cure. But at this stage, with no human data available, it remains highly speculative. Beyond these and other novel agents being developed to meet the challenge of the worldwide epidemic of diabetes, the central place of insulin in diabetes care cannot be forgotten. In view of this the continued efforts of improvement in insulin delivery, kinetics and action have spurred such innovations as the various inhaled insulins and new insulin analogues. There is cause for guarded optimism and excitement about the years ahead. There is reason to expect that despite the growing burden of diabetes worldwide, we will be better equipped to manage it and its comorbidities and prevent its onset and possibly even cure it.

Sustained effects of pioglitazone vs. glibenclamide on insulin sensitivity, glycaemic control, and lipid profiles in patients with Type 2 diabetes

AIMS

This study compared the effects of 52 weeks' treatment with pioglitazone, a thiazolidinedione that reduces insulin resistance, and glibenclamide, on insulin sensitivity, glycaemic control, and lipids in patients with Type 2 diabetes.

METHODS

Patients with Type 2 diabetes were randomized to receive either pioglitazone (initially 30 mg QD, n = 91) or micronized glibenclamide (initially 1.75 mg QD, n = 109) as monotherapy. Doses were titrated (to 45 mg for pioglitazone and 10.5 mg for glibenclamide) to achieve glycaemic targets during the next 12 weeks: fasting blood glucose of < or = 7 mmol/l and 1-h postprandial blood glucose of < or = 10 mmol/l. Patients were maintained on the titrated dose for 40 weeks.

RESULTS

Pioglitazone significantly increased insulin sensitivity compared with glibenclamide, as assessed by homeostasis model assessment (17.0% vs. -13.0%; P < 0.001), quantitative insulin sensitivity check index (0.011 vs. -0.007; P < 0.001) and fasting serum insulin (-1.3 pmol/l vs. 23.8 pmol/l; P = 0.007). The glibenclamide group had significantly lower HbA1c than the pioglitazone group after 12 weeks of therapy (7.8% vs. 8.3%, P = 0.015), but significantly higher HbA1c after 52 weeks of therapy (7.8% vs. 7.2%, P = 0.001). Pioglitazone significantly (vs. glibenclamide) increased mean HDL-C (P < 0.001), decreased mean triglycerides (P = 0.019), and decreased mean atherogenic index of plasma (AIP; P = 0.001) and mean total cholesterol/HDL-C (P = 0.004), without significantly elevating mean total cholesterol or mean LDL-C compared with glibenclamide. CONCLUSIONS These data suggest that the effects of pioglitazone are more sustained than those of glibenclamide for improving insulin sensitivity in patients with Type 2 diabetes, and that 52 weeks' treatment with pioglitazone has favourable effects on glycaemic control and lipoprotein profile.

Role of islet amyloid in type 2 diabetes mellitus: consequence or cause?

Type 2 diabetes mellitus (DM2) is characterized metabolically by defects in both insulin secretion and insulin action, resulting in hyperglycemia. Histopathologically, DM2 is characterized by depositions of protein in the pancreatic islets. This 'islet amyloid' is present in >90% of patients with DM2, as well as in monkeys and cats with DM2. The pathogenesis of DM2 is heterogeneous and multifactorial, although insulin resistance seems to be the predominant initiating factor for development of the disease. In the longer term, an insulin secretion defect is also revealed (referred to as 'beta-cell failure'), resulting in clinically manifest diabetes. Recent data, particularly from transgenic mouse studies, indicate that islet amyloidosis is a diabetogenic factor, which is both consequence (of insulin resistance) and cause (of beta-cell failure) of DM2. Available transgenic mouse models with islet amyloid formation in vivo will provide the opportunity to assess the effectiveness of novel anti-amyloidogenic therapies, for which promising results are emerging.

Design of peptide-based inhibitors of human islet amyloid polypeptide fibrillogenesis

Human islet amyloid polypeptide (IAPP) is the major component of amyloid deposits found in the pancreas of over 90% of all cases of type-2 diabetes. We have generated a series of overlapping hexapeptides to target an amyloidogenic region of IAPP (residues 20-29) and examined their effects on fibril assembly. Peptide fragments corresponding to SNNFGA (residues 20-25) and GAILSST (residues 24-29) were strong inhibitors of the beta-sheet transition and amyloid aggregation. Circular dichroism indicated that even at 1:1 molar ratios, these peptides maintained full-length IAPP (1-37) in a largely random coil conformation. Negative stain electron microscopy revealed that co-incubation of these peptides with IAPP resulted in the formation of only semi-fibrous aggregates and loss of the typical high density and morphology of IAPP fibrils. This inhibitory activity, particularly for the SNNFGA sequence, also correlated with a reduction in IAPP-induced cytotoxicity as determined by cell culture studies. In contrast, the peptide NFGAIL (residues 22-27) enhanced IAPP fibril formation. Conversion to the amyloidogenic beta-sheet was immediate and the accompanying fibrils were more dense and complex than IAPP alone. The remaining peptide fragments either had no detectable effects or were only weakly inhibitory. Specificity of peptide activity was illustrated by the fragments, SSNNFG and AILSST. These differed from the most active inhibitors by only a single amino acid residue but delayed the random-to-beta conformational change only when used at higher molar ratios. This study has identified internal IAPP peptide fragments which can regulate fibrillogenesis and may be of therapeutic use for the treatment of type-2 diabetes.

Management of feline diabetes mellitus

Up to one quarter of diabetic cats can be well controlled with oral hypoglycemic drugs, although at least 75% require insulin therapy. Most available insulins provide good clinical control but only moderate glycemic control. Because mild to moderate hyperglycemia is well tolerated by cats receiving insulin but hypoglycemia can be life threatening, conservative insulin dosing is recommended. Clinical signs and water intake indicate whether a dose adjustment is required, but serial blood glucose measurements are usually needed to determine the direction of the adjustment. Starting doses of 0.3 to 0.5 IU/kg administered twice daily (rounded down to the nearest whole unit) are usually safe. Dose adjustments should not exceed 1 IU per cat every 2 to 4 weeks unless clinical hypoglycemia has occurred. Cats with clinical hypoglycemia need to be reassessed to see if they are in remission. If not, a 50% to 75% reduction in dose is advised. Approximately 30% of cats go into diabetic remission 1 to 4 months after an adequate treatment protocol is instituted.

A feline model of experimentally induced islet amyloidosis

The study of the pathogenesis of islet amyloidosis and its relationship to the development and progression of type 2 diabetes mellitus has been hampered by the lack of an experimentally inducible animal model. The domestic cat, by virtue of the fact that it is one of the few species that spontaneously develop a form of diabetes mellitus that closely resembles human type 2 diabetes, including the formation of amyloid deposits derived from islet amyloid polypeptide (IAPP), was considered to be an excellent candidate species in which to attempt to develop a nontransgenic animal model for this disease process. To develop the model, 8 healthy domestic cats were given a 50% pancreatectomy, which was followed by treatment with growth hormone and dexamethasone. Once a stable diabetic state was established, cats were randomly assigned to groups treated with either glipizide or insulin at doses appropriate to control hyperglycemia. Cats were maintained on this treatment regimen for 18 months and then euthanized. Based on light microscopic examination of Congo red-stained sections of pancreas, all cats were negative for the presence of islet amyloid at the time of pancreatectomy. At the end of the study all 4 glipizide-treated cats had islet amyloid deposits, whereas only 1 of 4 insulin-treated cats had detectable amyloid. In addition, the glipizide treated cats had threefold higher basal and fivefold higher glucose-stimulated plasma IAPP concentrations than insulin-treated cats, suggesting an association between elevated IAPP secretion and islet amyloidosis. Blood-glycosylated hemoglobin concentrations were not significantly different between the two treatment groups. This study documents for the first time an inducible model of islet amyloidosis in a nontransgenic animal.

Current understanding of feline diabetes: part 2, treatment

When treating diabetic cats, the primary aim is to control clinical signs without causing clinical hypoglycaemia. Secondary goals are to maximise the chances of attaining diabetic remission and to minimise the risk of complications due to chronic hyperglycaemia. A treatment plan that is convenient for the owner is important for compliance. Underweight or overweight diabetic cats should be fed with the aim of normalising bodyweight. Current evidence suggests that non-obese diabetic cats can be fed ad libitum. The oral hypoglycaemic drug glipizide is well established as a treatment for about a third of diabetic cats, which have residual beta cell function. Preliminary studies on other oral agents such as vanadium salts, metformin, and troglitazone indicate a potential use in some diabetic cats. Insulin treatment remains the treatment of choice for the majority of diabetic cats. Choice of insulin, dose rates and monitoring of treatment are discussed.