Correlation between HbA1c, purified insulins, diabetic control, and insulin antibodies in diabetic children

Insulin antibodies were determined in sera from 38 children diagnosed as having juvenile diabetes for a duration of 0.7-15.2 years (median = 4.9 years). 8 children were treated with purified porcine insulins from the beginning of their disease, 16 children with bovine insulin NPH alone, and 14 children with non-purified, of whom 9 were later transferred to purified insulins. Serum insulin antibodies were measured by non-specific and specific methods using beef (B) and pork (P) antigens as described by Welborne and Sebriakova, respectively. 12/38 children had insulin binding levels similar to those of normal children, irrespective of the type of insulin used. The concentration of antibodies using radiolabelled B or P insulins as antigens were strongly correlated, by both the non-specific (p less than 0.01) and the specific (p less than 0.01) methods. Children with better score for diabetic control had significantly lower levels of insulin antibodies against B (p less than 0.05) and P (p less than 0.05) than those with poor diabetic control. There was also a significant positive correlation between mean HbA1c concentration and both B and P mean insulin antibody concentration (p less than 0.01). Finally, patients treated with purified porcine insulin had significantly lower levels of antibodies than patients with non-purified bovine insulin (p less than 0.05).     

Transfer from porcine insulin to human insulin in insulin-dependent diabetes mellitus: effects on insulin binding to IgG and glycemic control

Thirty type I diabetic patients who were treated for at least 2 years with a combination of regular and lente monocomponent porcine insulins were allocated in a double-blind study to either continued porcine insulin treatment or a transfer to the corresponding semi-synthetic human insulins. Insulin binding to IgG measured by an immunoelectrophoretic method, was followed at 3-month intervals for 1 year, and did not change after the transfer. The glycemic control, as assessed by hemoglobin A1 levels, tended to deteriorate in the human insulin group during the first 3 months of the trial and then return to the baseline level. It is concluded that a transfer from highly purified porcine insulin to human insulin apparently does not change the insulin binding to IgG in already sensitized patients.     

Human insulin and porcine insulin in the treatment of diabetic children: comparison of metabolic control and insulin antibody production.

Semisynthetic human insulin and highly purified porcine insulin were compared in a double blind crossover study in 21 diabetic children. Glycosylated haemoglobin values at the end of four month treatment periods were higher after treatment with human insulin than after treatment with porcine insulin (mean 15.7% (SD 2.3%) v 14.2% (2.3%); p less than 0.01). Higher fasting blood glucose concentrations occurred during treatment with human insulin than with porcine insulin (mean 12.0 (SD 2.1) v 11.0 (2.4) mmol/1; mean 216 (SD 38) v 198 (43) mg/100 ml; p less than 0.05), but there were no significant differences at other time points during the day. The incidence of hypoglycaemia was similar for both treatment groups. Concentrations of antibody reactive with porcine and human insulins were similar for the two treatment groups, although greater fluctuation was observed in the amount of antibody reactive with human insulin. Semisynthetic human insulin is safe and effective in diabetic children, although further work is needed to devise regimens which achieve optimal blood glucose control.     

Double blind clinical and laboratory study of hypoglycaemia with human and porcine insulin in diabetic patients reporting hypoglycaemia unawareness after transferring to human insulin.

OBJECTIVES--To compare awareness of hypoglycaemia and physiological responses to hypoglycaemia with human and porcine insulin in diabetic patients who reported loss of hypoglycaemia awareness after transferring to human insulin. DESIGN--Double blind randomised crossover study of clinical experience and physiological responses during slow fall hypoglycaemic clamping with porcine and human insulin. SETTING--Clinical investigation unit of teaching hospital recruiting from diabetes clinics of five teaching hospitals and one district general hospital. SUBJECTS--17 patients with insulin dependent diabetes mellitus of more than five years'' duration who had reported altered hypoglycaemia awareness within three months of transferring to human insulin. MAIN OUTCOME MEASURES--Glycaemic control and frequency of hypoglycaemic episodes during two months'' treatment with each insulin. Glucose thresholds for physiological and symptomatic responses during clamping. RESULTS--Glycaemic control did not change with either insulin. 136 hypoglycaemic episodes (eight severe) were reported with human insulin and 149 (nine severe) with porcine insulin (95% confidence interval -4 to 2.5, p = 0.63). 20 episodes of biochemical hypoglycaemia occurred with human insulin versus 18 with porcine insulin (-0.8 to 1, p = 0.78). During controlled hypoglycaemia the mean adrenaline response was 138 nmol/l/240 min for both insulins; neurohormonal responses were triggered at 3.0 (SE 0.2) versus 3.1 (0.2) mmol/l of glucose for adrenaline and 2.5 (0.1) versus 2.5 (0.1) mmol/l for subjective awareness. CONCLUSIONS--These data suggest that human insulin per se does not affect the presentation of hypoglycaemia or the neurohumoral, symptomatic, and cognitive function responses to hypoglycaemia in insulin dependent diabetic patients with a history of hypoglycaemia unawareness.     

Risk of severe hypoglycaemia in insulin treated diabetic patients transferred to human insulin: a case control study.

OBJECTIVE--To examine whether transfer from animal insulin to human insulin is associated with an increased risk of severe hypoglycaemia. DESIGN--Matched case-control study of insulin treated diabetic patients admitted to hospital because of hypoglycaemia during 1984-7, the period when human insulin was introduced into treatment. SETTING--Case admissions and control admissions were obtained from eight public hospitals within the Swiss canton of Berne and a second control group comprised members of the Bernese section of the Swiss Diabetes Association. SUBJECTS--94 patients with insulin treated diabetes with a total of 112 admissions for hypoglycaemia during 1984-7 (case admissions), 182 patients with insulin treated diabetes seen in the same hospitals for reasons other than hypoglycaemia with a total of 225 admissions (control admissions), and 86 insulin treated diabetic patients who were members of the Bernese section of the Swiss Diabetes Association. MAIN OUTCOME MEASURES--Type of insulin used at time of admission, glycaemic control as measured by amount of glycated haemoglobin or glucose concentration; severity of hypoglycaemia. RESULTS--Treatment with human insulin at admission was more common in cases than controls (52/112 (46%) admissions v 77/225 (34%); p = 0.003). 116 out of 129 (90%) of admissions taking human insulin had been transferred from animal insulin, mainly because of non-availability of porcine insulins. The ratio of rate of hypoglycaemia in those taking human insulin to the rate in those taking animal insulin was 2.4 (95% confidence interval 1.3 to 4.4). Other risk factors for hypoglycaemia were a history of hypoglycaemic coma (rate ratio of history to no history 3.8, 2.3 to 6.4) and good glycaemic control (rate ratio of good to poor control 3.9, 1.4 to 7.5). With multivariate analysis the increase in rate ratio associated with use of human insulin rose to 3.0 (1.4 to 6.4). Comparison with the diabetes association controls also showed an increased risk associated with use of human insulin (2.2; 1.1 to 4.8). CONCLUSIONS--Transfer of treatment from animal insulin to human insulin was associated with an increased risk of severe hypoglycaemia. Caution should be exercised when transferring diabetic patients to human insulin. Further studies are required to elucidate why this effect occurs.     

Human insulin: study of safety and efficacy in man.

The safety and efficacy of a new highly purified neutral soluble human insulin produced by conversion of porcine insulin was compared with a highly purified neutral soluble porcine insulin in six normal men. The insulins were administered by subcutaneous injection at a dose of 0.075 U/kg body weight. Somatostatin was infused during the experiment to suppress endogenous insulin secretin. No difference was found in the plasma glucose, insulin, or metabolite responses. Thus the potency, onset, and duration of effect were identical with the two insulins. No short-term side effects to either insulin were observed. Highly purified, semi-synthetic human insulin offers a safe and effective means to explore the possible advantages of homologous human insulin in the management of diabetes mellitus.     

Effect of optimal glycaemic control with continuous subcutaneous insulin infusion on energy expenditure in type I diabetes mellitus.

To assess the role of insulin in the control of body weight energy expenditure was measured by indirect calorimetry in eight patients of normal weight with type I diabetes initially while poorly controlled during conventional insulin treatment and later during optimal glycaemic control achieved by using the continuous subcutaneous insulin infusion pump. Their response to seven days of fat supplementation was also assessed and the results compared with those in eight non-diabetic subjects. After a mean of 5.3 months of continuous subcutaneous insulin infusion the diabetic subjects had gained on average 3.5 kg. In the poorly controlled diabetic state the resting metabolic rate was raised but decreased by a mean of 374 kJ (90 kcal) per 24 hours with optimal glycaemic control. The thermic response to infused noradrenaline was reduced by 59% in the diabetic subjects, was not improved by continuous subcutaneous insulin infusion, but was improved when three of the subjects were given metformin in addition. The diabetic subjects had no abnormality in the thermic response to a meal while taking their usual diabetic diet. During fat supplementation, however, this thermic response was reduced when glycaemic control was poor but not when control was precise. Fat supplementation did not alter the resting metabolic rate or the reduced noradrenergic thermic response in the diabetic subjects. These findings suggest that precise glycaemic control could produce weight gain if energy intake remained unaltered, for diabetic subjects do not compensate for the decrease in metabolic rate by an increase in noradrenergic and dietary thermic responses. Also precise glycaemic control using continuous subcutaneous insulin infusion does not correct all the metabolic abnormalities of diabetes mellitus.     

Autoantibodies against human insulin.

Sera from 680 non-diabetic subjects with suspected autoimmune disease were screened for 13 different antibodies. Of the 582 sera found to contain these antibodies, nine bound insulin in an IgG specific enzyme linked immunosorbent assay (micro ELISA). Four of the sera bound human, porcine, and bovine insulins and five bound exclusively human insulin. "Cold" human, porcine, and bovine insulins each displaced, in a dose dependent manner, the four sera which bound all three insulins, but only human insulin displaced the remaining five, porcine and bovine insulins having little or no effect in concentrations up to 1000 U/1. These observations point to the existence of autoantibodies specifically against human insulin in some subjects with established autoimmunity.     

A radioreceptor assay for pharmaceutical preparations of insulin

A radioreceptor assay has been developed that is suitable for the measurement of the potency of crystalline insulin and pharmaceutical insulin formulations. It utilizes the well characterized and widely available IM-9 human lymphocyte cell line as the source of receptor. Bovine, porcine and human crystalline and formulated insulins have been assayed against the 4th International and European Standards for Insulin and the potencies compared with those obtained by the mouse blood glucose method. Results with bovine insulin were in full correspondence with the in vivo results. Porcine and human insulins were 15-20% more potent by the radioreceptor assay than by the in vivo method when the mixed bovine and porcine insulin 4th International and European Standards were used, but were equivalent when compared with like materials. Average 95% confidence limits for formulated insulins in two assays were +/- 6% of the mean. The coefficient of variation on repeated assay of the same sample was 3.8%. The three dose parallel line radioreceptor assay with appropriate species species standards is a candidate biological test capable of international adoption as an alternative to in vivo animal testing of insulin.     

Reversal of insulin resistance in type I diabetes after treatment with continuous subcutaneous insulin infusion.

Insulin responsiveness was studied with the euglycaemic glucose clamp technique in seven patients with type I diabetes and in six control subjects matched for age and weight. The glucose disposal rate was significantly reduced in the diabetic subjects when they were receiving conventional insulin treatment compared with the control group, showing insulin resistance in the diabetics. The diabetic patients were again studied after eight days of intensified metabolic control achieved with continuous subcutaneous insulin infusion. During the infusion a more physiological insulin regimen was used compared with their regular treatment, less of the total insulin dose being given as continuous infusion and more as bolus doses before meals. The insulin resistance in the diabetics was largely reversed after this improved metabolic control. Dose response studies showed an increased glucose disposal rate at all plasma insulin concentrations, including the maximum insulin concentration, indicating a predominant effect of the continuous infusion regimen at the postreceptor level. The improved insulin effect seen with continuous subcutaneous insulin infusion could be due to the improved metabolic control achieved as well as the more physiological regimen.     

Comparison of human versus porcine insulin in treatment of diabetes in children.

The blood glucose control obtained when using semi-synthetic monocomponent human insulin (insulin A) was compared with that using standard monocomponent porcine insulin (insulin B) in 14 children in a double blind crossover study. At the start of the study age, duration of diabetes, insulin dose, and daily carbohydrate intake were the same in both groups. After a one month run in period of standard treatment with porcine insulin the children were randomly divided into group 1 (three months of insulin A followed by three months of insulin B) and group 2 (three months of insulin B followed by three months of insulin A). During each treatment period blood glucose control was assessed by clinical symptoms, glycosylated haemoglobin, and home blood glucose monitoring. Although a significant difference in the period after lunch during 24 hour blood glucose profiles suggested a shorter onset time and faster peak action time of human insulin, no significant difference in the overall diabetic control was seen between the two types of insulin. There was a trend towards improved blood glucose control (irrespective of insulin) as the trial progressed. No clinical reactions to human insulin occurred, and there was no significant difference in the daily insulin dose between porcine and human insulin.     

When a unit of insulin is not a unit: Detemir dosing and insulin cost in type 2 diabetes mellitus

Background: Increasing acceptance of basal-bolus insulin therapy for the control of diabetes mellitus (DM) has led to newer formulations of basal insulin analogues. The newest one is detemir.Objectives: Clinical evidence suggests that patients with type 2 DM require higher doses of detemir than other basal insulins to achieve equivalent glycemic control. This study examines evidence for greater dosing requirements and the implications of higher doses on the cost of insulin treatment.Methods: We performed a MEDLINE search for randomized, prospective studies comparing detemir with other basal insulins in patients with type 2 DM that were published in English between January 2000 and November 2008. The mean daily doses of basal and bolus insulin and the mean total daily insulin doses were determined. Overall weighted mean doses of the insulins were used to estimate the mean total daily insulin doses required for a 100-kg patient, and published 2008 US retail prices were used to estimate the retail costs of basal-bolus and basal-only insulin regimens.Results: Seven trials involving 3311 patients were identified in the literature search. The mean total daily insulin dose was 0.80 unit/kg for detemir-based regimens and 0.58 unit/kg for comparison regimens. For basal-bolus regimens, the estimated retail cost of the mean total daily insulin dose was $11.24 for detemir-based regimens compared with $8.99 for glargine-based regimens and $6.41 for neutral protamine Hagedorn (NPH)-based insulins. For basal-only regimens, the estimated retail cost of the mean total daily insulin dose was $8.23 for detemir compared with $5.19 for glargine and $2.35 for NPH.Conclusions: It is important for health care providers and patients to know that patients with type 2 DM may require substantially higher doses of detemir than other basal insulins. This should be considered when titrating the dose as well as in cost-benefit analyses of detemir versus other insulins.     

Insulin analogues: action profiles beyond glycaemic control

A variety of studies have documented significant improvements in the treatment of type 1 and 2 diabetes after the introduction of artificial insulins. This review gives an overview of insulin analogues which are currently approved for therapeutical use. Clinical data regarding the efficiency to control blood glucose level as well as improving HbA1c level in comparison to conventional insulin preparations in type 1 and 2 diabetic patients are summarized. Furthermore, special features of insulin analogues regarding their signalling properties are discussed with focus on the proliferative effects of insulin glargine as well as some recent data of insulin detemir.     

Comparative study of binding of Scorpaena porcus scorpion fish insulin and pig insulin by specific muscle plasma membrane receptors

Insulin from the scorpion-fish and porcine insulin have been compared with respect to their capacity to interact with the specific receptors in plasma membrane of skeletal muscle fibers of rats. Both insulins inhibited membrane binding of insulin-125J; the dose of porcine insulin which inhibited binding by 50% was equal to 3.7 nM, that of fish insulin -- to 100 nM. These figures indicated lower affinity of fish insulin to mammalian receptors (4% of the porcine affinity), being in accordance with lower biological activity of fish insulin in diaphragmal test. Other peculiarity of fish insulin was revealed in studies on dissociation of insulin-125J, which was previously bound to isolated diaphragm muscle of the rat. In contrast to mammalian insulin, it was not capable of increasing the dissociation when being added to a solution in doses from 7.10(-11) to 7.10(-9) M. This fact is analysed in term of the "site--site" interactions concept.     

Comparison of the effect of semisynthetic human insulin and porcine insulin on glucose kinetics, plasma free fatty acid and amino acid levels in man

The effect of semisynthetic human insulin on hepatic glucose output, peripheral glucose clearance, plasma levels of C-Peptide, free fatty acids and amino acids was compared with purified pork insulin using the glucose clamp technique. 8 normal overnight-fasted subjects received intravenous infusions of either human or porcine insulin at 20 mU/m2.min(-1) during 120 min achieving plasma insulin levels of approximately equal to 50 mU/l. Plasma glucose levels were maintained at euglycaemia by variable rates of glucose infusion. Hepatic glucose production measured by continuous infusion of 3-(3) H-glucose was similarly suppressed by both insulins to rates near zero. The metabolic clearance rate of glucose increased during infusion of human insulin by 120%, C-peptide levels decreased by 41% and plasma FFA concentrations fell by 74%. The respective changes during infusion of pork insulin were similar, 118%, 48% and 72%. Both insulins decreased the plasma levels of branched-chain amino acids, tyrosine, phenylalanine, methionine, serine and histidine similarly. Thus, the results demonstrate that semisynthetic human and porcine insulin are aequipotent with respect to suppression of hepatic glucose output, stimulation of glucose clearance, inhibition of insulin secretion, lipolysis and proteolysis.     

GLUT4 and UBC9 protein expression is reduced in muscle from type 2 diabetic patients with severe insulin resistance

Aims

Subgroups of patients with type 2 diabetes mellitus demand large insulin doses to maintain euglycemia. These patients are characterized by severe skeletal muscle insulin resistance and the underlying pathology remains unclear. The purpose of this study was to examine protein expression of the principal glucose transporter, GLUT4, and associated proteins in skeletal muscle from type 2 diabetic patients characterized by severe insulin resistance.

Methods

Seven type 2 diabetic patients with severe insulin resistance (mean insulin dose 195 IU/day) were compared with seven age matched type 2 diabetic patients who did not require insulin treatment, and with an age matched healthy control group. Protein expression of GLUT4 and associated proteins was assessed in muscle and fat biopsies using standard western blotting techniques.

Results

GLUT4 protein expression was significantly reduced by ∼30 pct in skeletal muscle tissue from severely insulin resistant type 2 diabetic subjects, compared with both healthy controls and type 2 diabetic subjects that did not require insulin treatment. In fat tissue, GLUT4 protein expression was reduced in both diabetic groups. In skeletal muscle, the reduced GLUT4 expression in severe insulin resistance was associated with decreased ubiquitin-conjugating enzyme 9 (UBC9) expression while expression of GLUT1, TBC1D1 and AS160 was not significantly different among type 2 diabetic patients and matched controls.

Conclusions

Type 2 diabetic patients with severe insulin resistance have reduced expression of GLUT4 in skeletal muscle compared to patients treated with oral antidiabetic drugs alone. GLUT4 protein levels may therefore play a role in the pathology behind type 2 diabetes mellitus among subgroups of patients, and this may explain the heterogeneous response to insulin treatment. This new finding contributes to the understanding of the underlying mechanisms for the development of extreme insulin resistance.     

Blood glucose and free insulin levels after the administration of insulin by conventional syringe or jet injector in insulin treated type 2 diabetics

The levels of blood glucose and free insulin were compared in 20 diabetic subjects (type 2) receiving one dose of a combination of fast-acting and intermediary-acting insulins in the morning by means of a needle syringe or a jet injector (SICIM, Italy), using minimum possible injecting power. A shift to the left in the free insulin profile, consequential to different pharmacokinetic characteristics of insulin when administered by means of a jet injector, was observed, although no significant differences were seen for free insulin levels. Statistically significantly higher blood glucose values (P less than 0.05) were recorded 6 and 9 h after insulin administration by means of a jet injector, as well as statistically significant higher MBG values (P less than 0.05), thus indicating a faster and shorter effect achieved in comparison to that produced by the syringe injected insulin. Conclusions: 1. When switching the method of insulin administration in patients from needle syringe to jet injections the power of the jet injector should be increased (it can be set in three different levels). If that is not possible, because of patient skin characteristics then the dose of intermediary acting insulin should be slightly increased. 2. No local or general side-effects were registered using minimum injecting power of jet injector. 3. The results of the controlled poll have shown that this method of insulin administration is less painful and simpler for patients. The great majority of the patients would like to possess a jet injector.     

New developments in the treatment and monitoring of type 1 diabetes mellitus

In recent years, insulin analogues are the benefits of the use in functional intensive insulin therapy for the treatment of diabetes. Shortacting insulin (lispro, aspart and glulisine) and long-acting insulin (glargine and detemir) have been developed for the management of diabetes. Short-acting insulin analogues are an alternative to regular human insulin before meals. These new short-acting insulin analogues show more rapid onset of activity and a shorter duration of action. As a result of these pharmacokinetic differences, an improved postprandial glycemic control is achieved, without increasing the risk of hypoglycemia. In addition, these insulin analogues can be administered immediately before a meal. The long-acting insulin analogues provide basal insulin levels for 24 h when administered once (glargine) or two (detemir) daily. Compared with previous intermediate- or long-acting conventional insulin, these insulins shows a flat profile of plasma insulin levels . The use of these long-acting insulin analogues appears to be associated with a reduced incidence of hypoglycemia, especially at night. The availability of these new insulin analogues has the potential to significantly improve long-term control over blood glucose in diabetic patients. In recent years more and more frequently the method of multiple daily injections (MDI) of insulin is being replaced by the method of continuous subcutaneous insulin infusion (CSII). It is the most physiological way to administer insulin. In recent years treatment with insulin pumps has been used more frequently in the pediatric patients and in the treatment of diabetes in pregnancy. Use of continuous glucose monitoring systems enables detection of glycemia fluctuations unrevealed by selfmonitoring of blood glucose, such as night hypoglycemias and early postprandial hyperglycemias. Real-time systems allow to reduce HbA1c levels and limit number of excursions. Non-invasive glucose measurement devices are introduced. Fully automated continuous glucose monitoring systems integrated with insulin pumps operating in closed-loop model, requiring no patient assistance, are still being researched. Commercially available systems operate in open-loop model, where the patient has to decide on administration and dose of insulin.     

Preliminary note on anti-insulin antibody formation in diabetics treated with porcine insulin

In the present study, we have tested the sera of sixty five diabetic patients treated with insulin, researching the action of some physiologic and therapeutic factors (sex, age, insulin dose and time of treatment), to production of anti-insulin antibodies. Our results have shown that an important percentage of diabetic patients treated by porcine insulin produce antibodies: 72% of studied patients, concerning chiefly all the women and patients under-fourty years old. However our results have not pointed out any relation between the administered insulin dose versus the anti-insulin antibodies production, in spite of the early production of these antibodies in a great part of the patients.     

Effect of near normoglycaemia for two years on progression of early diabetic retinopathy,nephropathy, and neuropathy: the Oslo study.

Forty five insulin dependent diabetics were randomised to treatment with continuous subcutaneous insulin infusion (CSII), multiple insulin injections (five or six daily), or conventional twice daily insulin injections. Near normoglycaemia was obtained with CSII and multiple injections but not with conventional treatment (p less than 0.01). Hypoglycaemic coma was observed less frequently with CSII than with multiple injections and conventional treatment (p less than 0.001), but blood glucose concentrations below 2.5 mmol/l (45 mg/100 ml) were more common. After two years fewer retinal microaneurysms and haemorrhages had developed in the patients given CSII and multiple injections compared with those given conventional treatment, in whom the number had increased significantly (p less than 0.01). Motor nerve conduction velocity deteriorated in the patients given conventional treatment; in those given CSII it was unchanged during the first year but had improved after two years (p less than 0.01). Glomerular hyperfiltration was reduced with CSII, but no change occurred in urine albumin excretion rates. Long term near normoglycaemia may prevent the progression of early stages of late diabetic complications.