Initial management of diabetic ketoacidosis (DKA) often involves administration of regular insulin, and the transition from regular to intermediate or long-acting insulin can be challenging. While some guidelines exist for this, recent developments in the field have altered the diabetes treatment landscape. The objective of this study was to describe insulin prescribing practices of small animal specialists for patients with DKA and to explore the factors influencing the selection of insulin type and dose. An electronic survey involving two clinical case scenarios was distributed to diplomates of American College of Veterinary Internal Medicine (ACVIM) and American College of Veterinary Emergency and Critical Care (ACVECC) in Spring 2025. For the canine case, 76/162 participants (47%) selected insulin lente (Vetsulin® or Caninsulin), with 74/162 (46%) selecting insulin lente administered twice daily (BID). The median dose for insulin lente BID was 0.43 U/kg/injection (range, 0.05-1.29 U/kg/injection). 62 out of 162 respondents (38%) selected insulin NPH (Humulin®-N, Novolin®-N) BID at a median dose of 0.43 U/kg/injection (range, 0.11-2.15 U/kg/injection). For the feline case, 120/151 participants (79%) selected insulin glargine 100 U/ml, with 118/151 (78%) selecting insulin glargine BID. The median dose for insulin glargine BID was 0.17 U/kg/injection (range, 0.04-1.87 U/kg/injection). The survey data describe current prescribing practices and clinical decision-making. As options for novel insulins and diabetic therapies expand, additional studies focused on outcomes related to clinical control, cost efficacy, and quality-of-life for pet and owner are needed.

Clinical studies that compare lente insulin and neutral protamine Hagedorn (NPH) insulin in diabetic dogs are lacking. This is a prospective, randomised, controlled clinical study aimed to compare the efficacy and safety of lente insulin and NPH insulin in diabetic dogs. Thirty client-owned, newly diagnosed diabetic dogs were included. Animals were randomised into two groups and received lente insulin or NPH insulin administered every 12 hours. Follow-up re-evaluations were done at 1, 2, 4, 6, 8 and 12 weeks. At each re-evaluation, a physical exam, blood glucose curve, and serum fructosamine concentrations were performed. At the end of the study, the median insulin dose per injection was 0.61 U/kg (range, 0.34-0.92 U/kg) and 0.49 U/kg (range, 0.23-0.68 U/kg) in the lente and NPH groups, respectively. There was a significant improvement of polyuria and polydipsia and glucose concentrations in both groups. At the end of the study, the glycaemic control was considered good in 9/15 (60 per cent) and 11/15 (73 per cent) in the lente and NPH groups, respectively. These differences were not significant. Lente insulin and NPH insulin were similarly effective in the treatment of dogs with diabetes mellitus.

Objectives The objective was to evaluate a nadir-led protocol for transitioning porcine lente insulin suspension (PLIS)-treated diabetic cats onto human recombinant protamine zinc insulin (PZIR). Methods Recently diagnosed (<5 months) diabetic cats, treated with PLIS q12h for ⩾6 weeks, were recruited. Fructosamine, 24 h blood glucose curve (BGC), quality of life assessment (DIAQoL-pet score) and Diabetic Clinical Score (DCS) were assessed at enrolment (PLIS-treated) and 2, 4 and 12 weeks after transitioning to PZIR (starting dose 0.2-0.7 U/kg q12h). Short duration of insulin action was defined as <9 h. Linear mixed effects modelling assessed for change in fructosamine, mean blood glucose (MBG) during BGCs, DIAQoL-pet score, DCS and q12h insulin dose. McNemar's tests compared the proportion of cats with hypoglycaemia at week 0 (PLIS-treated) and week 4 (PZIR-treated). Results Twenty-two cats were recruited. Median PLIS dose at enrolment was 0.5 U/kg (interquartile range 0.3-0.7 U/kg) q12h, equalling median PZIR starting dose (0.5 U/kg; interquartile range 0.3-0.7 U/kg q12h). Transitioning was followed by significant decreases in fructosamine ( P = 0.00007), insulin dose ( P = 0.02), DCS ( P = 8.1 × 10-8) and DIAQoL-pet score ( P = 0.003), indicating improved quality of life. MBG did not alter significantly ( P = 0.1). Five cats (22.7%) achieved remission. Hypoglycaemia was recorded in 30/190 12 h BGCs (15.8%) and five cats experienced clinical hypoglycaemia. The proportion of cats with hypoglycaemia did not differ between PLIS (week 0) and PZIR (week 4) ( P = 1.0). Duration of action was analysed in 19 cats. Six cats (31.6%) showed short duration of action on PLIS, compared with two cats (10.5%) after 4 weeks on PZIR. All six cats with short PLIS duration showed duration of ⩾9 h on PZIR. Conclusions and relevance Used alongside a low-carbohydrate diet, transitioning to PZIR was associated with significantly improved clinical signs and quality of life, with some cats achieving remission. Transition to PZIR should be considered for cats with short duration of action on PLIS.

Manufacturers of insulin products for diabetes therapy have long sought ways to modify the absorption rate of exogenously administered insulins in an effort to better reproduce the naturally occurring pharmacokinetics of endogenous insulin secretion. Several mechanisms of protraction have been used in pursuit of a basal insulin, for which a low injection frequency would provide tolerable and reproducible glucose control; these mechanisms have met with varying degrees of success. Before the advent of recombinant DNA technology, development focused on modifications to the formulation that increased insulin self-association, such as supplementation with zinc or the development of preformed precipitates using protamine. Indeed, NPH insulin remains widely used today despite a frequent need for a twice-daily dosing and a relatively high incidence of hypoglycaemia. The early insulin analogues used post-injection precipitation (insulin glargine U100) or dimerization and albumin binding (insulin detemir) as methods of increasing therapeutic duration. These products approached a 24-hour glucose-lowering effect with decreased variability in insulin action. Newer basal insulin analogues have used up-concentration in addition to precipitation (insulin glargine U300), and multihexamer formation in addition to albumin binding (insulin degludec), to further increase duration of action and/or decrease the day-to-day variability of the glucose-lowering profile. Clinically, the major advantage of these recent analogues has been a reduction in hypoglycaemia with similar glycated haemoglobin control when compared with earlier products. Future therapies may bring clinical benefits through hepato-preferential insulin receptor binding or very long durations of action, perhaps enabling once-weekly administration and the potential for further clinical benefits.

The discovery of insulin can be considered the milestone of diabetes mellitus history and a great achievement for its treatment. The first insulin available was the regular. Afterwards, Hagedorn added the protamine to the insulin, thus, creating the NPH insulin. In the 1950s an insulin free of protamine was synthesized: the lente insulin. With the advent of molecular biology, synthetic human insulin was synthesized using recombinant DNA technology. Most recently several types of insulin analogues were available, providing the patients with better metabolic control. Type 1 diabetes mellitus treatment includes plain substitution and individualization for short-acting plus long-acting insulin according to the physician's assistance, besides regular practice of physical activities and diet orientations. In type 1 diabetes mellitus the insulin of low variability is the best choice since basal/bolus insulin therapy or continuous subcutaneous insulin infusion pump can mimetize the physiological release of insulin by beta cells.

Paediatric Diabetologists aim to personalize insulin therapy in order to attain good metabolic control and good quality of life. Nowadays this goal may be obtained through many devices: syringes, pens or injectors and by several insulin preparations. In fact besides human "traditional" (regular, NPH, Lente zinc and Ultralente zinc insulins) recently, insulin analogues have been synthesized with different pharmacokinetics: short acting (Lispro and Aspart) and long acting (Glargine, Detemir). Since children with diabetes are, often, totally c-peptide negative, insulin therapy must substitute the absence of insulin production and the successful use of short acting insulin analogues requires optimal association with basal insulin. Insulin therapy regimens are adapted to the life style of children and factors affecting the diabetologist's decision to change the regimen are not only glycaemic profiles, HbAlc and metabolic control but, also, age, school needs, prevention of hypoglycaemia, meals timing etc. and, also, culture of patients and their families, compliance to the therapy, possibility to contact frequently the diabetology team, etc. In conclusion insulin regimens must reflect the life style of the diabetic patient who is educated in the strategy of intensive insulin therapy. Italy is a "long" country and the life styles are different region by region; Italian Paediatric Diabetologists are fanciful and the personalization of insulin therapy is a recent conquest thanks to the new and old insulin preparations.

Diabetes mellitus is a common chronic disorder, which is increasing in prevalence on a global scale. Insulin replacement therapy is required for all people with Type 1 diabetes and for many with Type 2 diabetes, to correct the metabolic abnormalities of these disorders. However, the pharmacokinetics and glucodynamics of available insulins have numerous limitations. Problems include delayed absorption from subcutaneous absorption sites (soluble [regular] insulin), and wide variability of absorption characteristics (insulin isophane suspension [NPH] and insulin lente) that is influenced by the adequacy of resuspension, and by a variable and insufficient duration of action, which usually requires intermediate-acting insulins to be administered twice-daily. All insulin preparations are associated with the common side effect of hypoglycaemia, and encourage weight gain.

Intensification of insulin therapy which maintains long-term near-normoglycaemia (HbA1c<7.0%) strongly protects against onset and/or progression of diabetic microangiopathy in Type 1 diabetes mellitus of adults. Similar intensification of insulin therapy is needed in diabetic children as well, in order to prevent complications a few years after diabetes onset, ie very often in young age. Provided adequate psychosocial support and education are available, children should be treated with multiple daily injections of insulin or, when necessary, with continuous subcutaneous insulin infusion, along with blood glucose monitoring. Insulin regimens may differ from child to child and vary from day to day in the same child, depending on lifestyle and considering all the available insulin preparations. These include the short-acting insulin (both human regular and short-acting insulin analogues), the intermediate-acting insulin (NPH and Lente), as well as the new long-acting insulin analogue glargine. The latter seems a promising candidate to substitute of basal insulin. The concern that intensified insulin therapy increases the risk of hypoglycaemia, as indicated by the Diabetes Control and Complications Trial (DCCT), is no longer tenable. On the contrary, a physiological, flexible insulin regimen better than a fixed insulin regimen, usually the twice daily split-mixed regimen, protects against the risk of hypoglycaemia in relation to food ingestion, physical exercise and sleep. Thus, appropriate education should be delivered at diabetes onset to the child and parents in order to start the strategy of intensified insulin therapy as early as possible.

We report an insulin-treated diabetic patient who suffered, in a 2-month period, three severe anaphylactic reactions immediately after self-administered subcutaneous injections of neutral protamine Hagedorn (NPH) human recombinant-DNA insulin. These reactions consisted of local and systemic symptoms, including dyspnea and hypotension. A simultaneous sensitization to human insulin and to protamine was demonstrated, both by skin tests and by the determination of serum specific IgE. Suspecting protamine allergy, we performed a test dose to human lente insulin with perfect tolerance. After a 1-year follow-up with lente-insulin treatment, no reactions have occurred, despite treatment interruptions. Therefore, protamine IgE-mediated allergy probably caused our patient's reactions. In conclusion, protamine sensitization should be ruled out in any patient with a history of reactions to subcutaneous protamine-containing insulins, even if insulin sensitization is present.

In an infant with transient neonatal diabetes mellitus, control of the blood glucose concentration was attained with ultralente insulin treatment, without any episodes of hypoglycemia. We recommend subcutaneous injection of ultralente insulin, rather than lente or isophane (NPH) insulin, to avoid hypoglycemia during the treatment of transient neonatal diabetes mellitus.

The aim of the study was to analyse the clinical symptoms preceding the final diagnosis of IDDM, some features of the illness at the moment of the diagnosis and variants of treatment. We examined 54 patients, among them 28 males and 26 females. There were 23 and 31 persons between 0-14 and 15-29 years of age, respectively. The data were accumulated using questionnaires. We have shown that the newly diagnosed IDDM cases were characterised by typical clinical symptoms, early detection and 100% hospitalization. Most of the patients or their parents underwent the diabetic education during the patients first stay at hospital. Only monocomponent or human insulins were used in the case of patients between 0-14 years of age. Among the group 15-29 years of age in 13% of patients ordinary insulins (regular, NPH, Lente group) were administered as well. Intensive insulin therapy was used exclusively, but sporadically in the patients 15-29 years of age.