Environmental effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes mellitus

OBJECTIVE

This study aimed to explore the effects of ambient temperature and relative humidity on insulin pharmacodynamics in adults with type 1 diabetes.

MATERIALS AND METHODS

A three-way, cross-over, randomised study was performed in adults with type 1 diabetes mellitus (n = 10). The pharmacodynamics profile of a single dose of short-acting insulin (insulin lispro) was investigated, using a controlled environmental chamber, under three environmental conditions: (a) temperature: 15°C and humidity: 10%; (b) temperature: 30°C and humidity: 10%; and (c) temperature: 30°C and humidity: 60%. A euglycaemic glucose clamp technique ensured constant blood glucose of 100 mg/dL (5.5 mmol/L). The following pharmacodynamic endpoints were calculated: maximum glucose infusion rate (GIR_max ), time to GIR_max (t_GIRmax ), total area under the curve (AUC) for GIR from 0-6 hours (AUC_GIR.0-6h ), and partial AUCs (AUC_GIR.0-1h , AUC_GIR.0-2h and AUC_GIR.2-6h ).

RESULTS

Higher temperature (30°C) under 10% fixed humidity conditions resulted in greater GIR_max (P = 0.04) and a later t_GIR.max (P = 0.049) compared to lower temperature (15°C). Humidity did not affect any pharmacodynamic parameter. When the combined effects of temperature and humidity were explored, t_GIR.max (P = 0.008) occurred earlier, with a lower late insulin pharmacodynamic effect (AUC_GIR.2-6h ; P = 0.017) at a temperature of 15°C and humidity of 10% compared to a temperature of 30°C and humidity of 60%.

CONCLUSIONS

High ambient temperature resulted in a greater insulin peak effect compared to low ambient temperature, with the contribution of high relative humidity apparent only at high ambient temperature. This suggests that patients with type 1 diabetes mellitus who are entering higher environmental temperatures, with or without high humidity, could experience more hypoglycaemic events.

Low within- and between-day variability in exposure to new insulin glargine 300 U/ml

AIMS

To characterize the variability in exposure and metabolic effect of insulin glargine 300 U/ml (Gla-300) at steady state in people with type 1 diabetes (T1DM).

METHODS

A total of 50 participants with T1DM underwent two 24-h euglycaemic clamps in steady-state conditions after six once-daily administrations of 0.4 U/kg Gla-300 in a double-blind, randomized, two-treatment, two-period, crossover clamp study. Participants were randomized to receive Gla-300 as a standard cartridge formulation in the first treatment period, and as a formulation with enhanced stability through polysorbate-20 addition in the second treatment period, or vice versa. This design allowed the assessment of bioequivalence between formulations and, subsequently, within- and between-day variability.

RESULTS

The cumulative exposure and effect of Gla-300 developed linearly over 24 h, and were evenly distributed across 6- and 12-h intervals. Diurnal fluctuation in exposure (within-day variability) was low; the peak-to-trough ratio of insulin concentration profiles was <2, and both the swing and peak-to-trough fluctuation were <1. Day-to-day reproducibility of exposure was high: the between-day within-subject coefficients of variation for total systemic exposure (area under the serum insulin glargine concentration time curve from time 0 to 24 h after dosing) and maximum insulin concentration were 17.4% [95% confidence interval (CI) 15-21] and 33.4% (95% CI 28-41), respectively. Reproducibility of the metabolic effect was lower than that of exposure.

CONCLUSIONS

Gla-300 provides predictable, evenly distributed 24-h coverage as a result of low fluctuation and high reproducibility in insulin exposure, and appears suitable for effective basal insulin use.

Reductions in resistance exercise-induced hyperglycaemic episodes are associated with circulating interleukin-6 in type 1 diabetes

AIMS

To determine the influence of different volumes of resistance exercise on circulating interleukin-6 (IL-6) and to explore the relationships between IL-6 and glycaemia.

METHODS

Eight participants with complication-free type 1 diabetes, whose mean ± SEM age was 38 (6) years, mean ± SEM HbA(1c) concentration was 71 ±11 mmol/mol (8.7 ±1.0%) and mean ± SEM type 1 diabetes duration was 15 ±13 years, attended the research facility after an overnight fast on four separate occasions, having administered their basal insulin the night before (glargine 27.5±3.1U, n=8), but omitted morning rapid-acting insulin. Participants completed either a one-set (14-min), two-set (28-min), or three-set (42-min) resistance exercise trial (eight exercises × 10 repetitions) at 67±3% one-repetition maximum followed by a 60-min recovery, or a resting control trial. Venous blood samples were taken before and after exercise. Data were analysed using repeated-measures ANOVA (P≤0.05).

RESULTS

Whereas IL-6 levels remained similar to baseline levels after one set of resistance exercises (30 min, P=0.287; 60 min, P=0.318), IL-6 levels were > baseline levels at 60 min post-exercise after a two-set exercise trial (2.94 ± 0.94 pg/ml, P=0.002) and doubled at both 30 min (4.01 ± 1.00 pg/ml, P=0.048) and 60 min (4.28 ± 1.25 pg/ml, P=0.084) post-exercise after the three-set resistance exercise trial. Post-exercise blood glucose area under the curve (mmol/l/60 min) was greater after both the one-set (P=0.025) and two-set trials (P=0.008), than after the control trial, but similar between the three-set trial and the control trial (P=0.240). The rise in IL-6 from baseline to peak concentration significantly correlated inversely with blood glucose area under the curve (r=-0.65, P=0.041).

CONCLUSIONS

Circulating IL-6 is increased by resistance exercise in a volume-dependent manner, and resistance exercise-induced increases in IL-6 correlated with reductions in post-exercise hyperglycaemia in type 1 diabetes, suggesting a role for IL-6 in improving post-resistance exercise glycaemic disturbances in type 1 diabetes.

Glargine metabolism over 24 h following its subcutaneous injection in patients with type 2 diabetes mellitus: a dose-response study

BACKGROUND AND AIMS

After subcutaneous injection insulin glargine is rapidly metabolized to M1 and M2. In vitro, both M1 and M2 have metabolic effects and bind to IGF-1R similarly to human insulin, whereas glargine exhibits a higher affinity for the IGF-1R and greater mitogenetic effects. The present study was specifically designed to establish the dose-response metabolism of glargine over 24 h following s.c. injection in T2DM subjects on long-term use of glargine.

METHODS AND RESULTS

Ten subjects with T2DM were studied during 24 h after s.c. injection of 0.4 (therapeutic) and 0.8 (high dose) U/kg of glargine on two separate occasions during euglycaemic clamps (cross-over design). Glargine, M1 and M2 over 24 h period were determined in appropriately processed plasma samples by a specific liquid chromatography-tandem mass spectrometry assay. Plasma M1 concentration (AUC0-24 h) was detected in all subjects and increased by increasing the glargine dose from therapeutic to high dose (p = 0.008). Glargine was detectable in 6 (therapeutic dose) and 9 (high dose) out of the 10 subjects and also increased by increasing the dose (p = 0.031). However, glargine concentration (AUC0-24 h--high dose) represented at most only 9.7% (4.6-15%) of the total amount of insulin measured in the blood. M2 was not detected at all.

CONCLUSION

In T2DM people on long-term use of insulin glargine, even with higher doses (0.8 U/kg), glargine is nearly totally metabolized to the active metabolite M1. Glargine is often detectable in plasma, but its concentration remains well below that needed in vitro to potentiate IGF-1R binding and mitogenesis.

Exposure to excess insulin (glargine) induces type 2 diabetes mellitus in mice fed on a chow diet

We have previously shown that insulin plays an important role in the nutrient-induced insulin resistance. In this study, we tested the hypothesis that chronic exposure to excess long-acting insulin (glargine) can cause typical type 2 diabetes mellitus (T2DM) in normal mice fed on a chow diet. C57BL/6 mice were treated with glargine once a day for 8 weeks, followed by evaluations of food intake, body weight, blood levels of glucose, insulin, lipids, and cytokines, insulin signaling, histology of pancreas, ectopic fat accumulation, oxidative stress level, and cholesterol content in mitochondria in tissues. Cholesterol content in mitochondria and its association with oxidative stress in cultured hepatocytes and β-cells were also examined. Results show that chronic exposure to glargine caused insulin resistance, hyperinsulinemia, and relative insulin deficiency (T2DM). Treatment with excess glargine led to loss of pancreatic islets, ectopic fat accumulation in liver, oxidative stress in liver and pancreas, and increased cholesterol content in mitochondria of liver and pancreas. Prolonged exposure of cultured primary hepatocytes and HIT-TI5 β-cells to insulin induced oxidative stress in a cholesterol synthesis-dependent manner. Together, our results show that chronic exposure to excess insulin can induce typical T2DM in normal mice fed on a chow diet.

Insulin degludec: pharmacokinetics in patients with renal impairment

BACKGROUND

Insulin degludec is a new-generation basal insulin with an ultra-long duration of action. We evaluated the pharmacokinetic properties of insulin degludec in subjects with normal renal function; mild, moderate or severe renal impairment; or end-stage renal disease (ESRD) undergoing hemodialysis.

METHODS

Thirty subjects (n = 6 per group) received a single subcutaneous dose of 0.4 U/kg insulin degludec. Blood samples up to 120 h post-dose and fractionated urine samples were collected.

RESULTS

The ultra-long pharmacokinetic properties of insulin degludec were preserved in subjects with renal impairment, with no statistically significant differences in absorption or clearance, compared with subjects with normal renal function. In subjects with ESRD, pharmacokinetic parameters were similar whether the insulin degludec pharmacokinetic assessment period included hemodialysis or not, and total exposure was comparable to subjects with normal renal function. Simulated mean steady-state pharmacokinetic profiles were comparable between groups.

CONCLUSION

This study indicated dose adjustments due to impaired renal function should not be required for insulin degludec.

Plasma exposure to insulin glargine and its metabolites M1 and M2 after subcutaneous injection of therapeutic and supratherapeutic doses of glargine in subjects with type 1 diabetes

OBJECTIVE

In vivo, after subcutaneous injection, insulin glargine (21(A)-Gly-31(B)-Arg-32(B)-Arg-human insulin) is enzymatically processed into 21(A)-Gly-human insulin (metabolite 1 [M1]). 21(A)-Gly-des-30(B)-Thr-human insulin (metabolite 2 [M2]) is also found. In vitro, glargine exhibits slightly higher affinity, whereas M1 and M2 exhibit lower affinity for IGF-1 receptor, as well as mitogenic properties, versus human insulin. The aim of the study was to quantitate plasma concentrations of glargine, M1, and M2 after subcutaneous injection of glargine in male type 1 diabetic subjects.

RESEARCH DESIGN AND METHODS

Glargine, M1, and M2 were determined in blood samples obtained from 12, 11, and 11 type 1 diabetic subjects who received single subcutaneous doses of 0.3, 0.6, or 1.2 units · kg(-1) glargine in a euglycemic clamp study. Glargine, M1, and M2 were extracted using immunoaffinity columns and quantified by a specific liquid chromatography-tandem mass spectrometry assay. Lower limit of quantification was 0.2 ng · mL(-1) (33 pmol · L(-1)) per analyte.

RESULTS

Plasma M1 concentration increased with increasing dose; geometric mean (percent coefficient of variation) M1-area under the curve between time of dosing and 30 h after dosing (AUC(0-30h)) was 1,261 (66), 2,867 (35), and 4,693 (22) pmol · h · L(-1) at doses of 0.3, 0.6, and 1.2 units · kg(-1), respectively, and correlated with metabolic effect assessed as pharmacodynamics-AUC(0-30h) of the glucose infusion rate following glargine administration (r = 0.74; P < 0.01). Glargine and M2 were detectable in only one-third of subjects and at a few time points.

CONCLUSIONS

After subcutaneous injection of glargine in male subjects with type 1 diabetes, exposure to glargine is marginal, if any, even at supratherapeutic doses. Glargine is rapidly and nearly completely processed to M1 (21(A)-Gly-human insulin), which mediates the metabolic effect of injected glargine.

Insulin glargine: a reevaluation of rodent carcinogenicity findings

The 1995 to 1997 lifetime carcinogenicity studies of insulin glargine in rats and mice were reanalyzed and reassessed for their validity according to current guidelines. In 2-year studies, 50 animals per sex and per group were used. Survival rates between weeks 80 and 90 in female mice and rats were greater than 20 animals in all groups, fulfilling current Food and Drug Administration requirements that enough animals lived long enough to provide adequate exposure to glargine and to be at risk of forming late-developing tumors. Exposure to 5 or 12.5 IU/kg glargine was similar to or 2 to 3 times greater than 5 IU/kg neutral protamine Hagedorn insulin, respectively. Using statistical methods recommended by current guidelines, no significant effect of glargine on mammary gland neoplastic lesions in female rodents was found, confirming earlier results. Thus, both studies can be considered valid according to contemporary standards. Insulin glargine does not present a carcinogenic risk.

Intensification of diabetes treatment with long-acting insulin shows no benefit over other diabetes treatment

BACKGROUND

Control of diabetes is challenging, and frequent treatment changes are needed.

OBJECTIVE

To study the effect of the recommendation to start insulin glargine or insulin determir (long-acting insulin treatment, LAI) at discharge from hospital, on glucose control in the community setting.

METHODS

Included were type II diabetes patients who were referred to and received a consultation from the hospital diabetes clinic during their hosptialization, as part of a routine consultation for diabetes management. During the visit, all patients were recommended long-acting insulin-based treatment, as inpatient treatment and at discharge. Follow-up was done by the primary physician in the community or by a community-based diabetes clinic. Glycosylated hemoglobin, glucose levels and other laboratory tests were obtained from the community health records before hospitalization and 6-12 months later. Medical treatment was ascertained by reviewing the actual usage of prescriptions.

RESULTS

Eighty patients (58% males, mean age 64.1 +/- 12.7 years) were included in the analysis. HbA1c levels were 10.1 +/- 2.4% before admission, but improved significantly at follow-up (8.6 +/- 2.2%, P < 0.001). Seventy-one percent of the patients were taking the LAI treatment and the rest were using non-LAI medications. Changes in diabetes control were similar between the LAI and non-LAL groups (HbA1c was reduced by 1.5 +/- 3.2% and 1.9 +/- 3.1% respectively). The rate of repeated admissions was also similar, averaging at 1.3 admissions for both groups, the minority of which were related to glucose control.

CONCLUSIONS

Insulin glargine or determir-based treatment does not show any superiority over other anti-diabetes treatment. It is our opinion that this treatment should be used as tailored therapy and should not be recommended routinely to all patients.

Ambulatory 24-hour fast using flexible insulin therapy in patients with type 1 diabetes

AIM

Prolonged fasting may be necessary in life for religious, medical and other reasons. For this reason, our study investigated the feasibility and safety of a 24-h fast conducted at home for patients with type 1 diabetes.

RESEARCH DESIGN AND METHODS

Thirty-four patients with type 1 diabetes performed a 24-h complete fast at home. Thirteen patients were treated with multiple insulin injections using either glargine (n=12) or NPH (n=1) as basal insulin. The remaining patients were treated with an insulin pump. All patients received their basal insulin only, which was adjusted to 40% of their total daily dose, and were monitored by either a Gold(®) or Guardian(®) continuous glucose monitoring (CGMS) device. Capillary glucose (SMBG) was targeted at 3.9-7.8 mmol/L, with a standardized protocol for correction of hyper- and hypoglycaemia. Interstitial glucose (IG) profiles were compared with the SMBG values; the IG profiles of patients using glargine or a pump and either of the two CGMS devices were also compared.

RESULTS

All of the patients completed the 24-h fast with no major incident. At the end of the fast, 80% of the IG values were on target. The route by which insulin was delivered made no difference, but there were more IG values on target in patients monitored by the Guardian(®) device. IG was below target in 104 occurrences and above-target in 34. After a mean intake of 10 g of sucrose, below-target IG was corrected within 30 min [range: 15-40]. The mean insulin dose to correct above-target episodes was 1 U.

CONCLUSION

Prolonged fasting is possible at home in patients with type 1 diabetes, provided the basal dose is adjusted. The use of CGMS is not necessary, but offers useful information on the patient's IG profile during the fast.

Pharmacology of a 40 IU/ml porcine lente insulin preparation in diabetic cats: findings during the first week and after 5 or 9 weeks of therapy

The aim of this study was to measure the pharmacokinetics and pharmacodynamics of subcutaneously injected 40 IU/ml porcine lente insulin preparation (Caninsulin, Intervet BV, The Netherlands) in diabetic cats. The pharmacological properties of the insulin in poorly controlled or untreated cats were compared with those after several weeks of treatment, to determine if improved diabetic stability altered the pharmacology of this insulin. In addition, the pharmacological properties of intravenously injected 100 IU/ml regular porcine insulin (Actrapid MC, NovoNordisk, Denmark) were measured. Serial plasma samples were collected after subcutaneous injection of porcine lente insulin from 25 diabetic cats in the first week of admission to a 12-month diabetic treatment trial. Samples were also collected after 4 or 8 weeks of treatment, in those cats which had not achieved diabetic remission by this time. At this time, serial plasma samples were also collected from these cats after intravenous injection of porcine regular insulin. Plasma samples were assayed for glucose, anti-insulin antibodies were extracted using a PEG technique, and samples were assayed for insulin using an RIA kit with low sensitivity for endogenous feline insulin, but high sensitivity for exogenous porcine insulin in feline plasma. Caninsulin injected subcutaneously in diabetic cats led to a peak insulin concentration in plasma after 1.7+/-0.1 h, and a nadir of blood glucose after 4.1+/-0.3 h. Insulin and glucose concentrations returned to baseline within 12 h. There was no significant change in the onset or duration of Caninsulin action between the first week of treatment and 5 or 9 weeks of treatment. Actrapid MC injected intravenously had a peak insulin at 0.36+/-0.03 h, and a nadir of blood glucose at 1.9+/-0.3 h. Insulin and glucose returned to baseline within 6 h. It was concluded that Caninsulin injected subcutaneously has suitable pharmacological properties for the twice-daily treatment of diabetes mellitus in cats. In addition, Actrapid MC insulin injected intravenously has suitable pharmacological properties for injection every 4-6 h in diabetic cats.

The use of human ultralente is limited by great intraindividual variability in overnight plasma insulin profiles

Our objective was to investigate the usefulness of human ultralente insulin as basal substitution overnight in patients with Type 1 diabetes treated with multiple insulin injection therapy by evaluating the free insulin and glucose profiles, the day-to-day variability and the impact of the time of injection.

METHODS

Ten patients with Type 1 diabetes and with good metabolic control (mean HbAlc 6.0%), treated with regular human insulin before breakfast, lunch and dinner and human ultralente (Ultratard) before dinner or at bedtime, were studied. Plasma profiles of blood glucose and free insulin were measured on three occasions from 16.00 h until noon the next day. On two of these occasions Ultratard was injected before dinner and once it was injected at bedtime in randomized order.

RESULTS

Injection of regular insulin before dinner resulted in a high insulin peak during the evening but no insulin peak was found that could be attributed to ultralente. The plasma concentration of free insulin at 03.00 h was 11.0+/-1.9 mU/L and it slowly decreased to 6.4+/-1.4 at 12.00 h after administration of ultralente at 17.00 h. There were no differences in the mean plasma insulin profiles compared to the other occasion when insulin was given at 17.00 h or at 22.00 h. On the other hand, the intra-individual day-to-day variability of mean insulin concentration during the night was considerable, often exceeding 50%. No differences were noted in the mean blood glucose profiles between the three occasions.

CONCLUSION

Human ultralente insulin gives an insulin profile suitable for overnight substitution, but the great day-to-day variability limits its usefulness. It can be injected before dinner or at bedtime without any change in the insulin profile during the night.

Bedtime uncooked cornstarch supplement prevents nocturnal hypoglycaemia in intensively treated type 1 diabetes subjects

OBJECTIVES

The present study tests two interrelated hypotheses: (1) that bedtime ingestion of uncooked cornstarch exerts a lower and delayed nocturnal blood glucose peak compared with a conventional snack; (2) that bedtime carbohydrate supplement, administered as uncooked cornstarch, prevents nocturnal hypoglycaemia without altering metabolic control in intensively treated type 1 diabetes (IDDM) patients.

DESIGN AND SUBJECTS

The above hypotheses were tested separately (1) by pooling and analysing data from two overnight studies of comparable groups of patients with non-insulin dependent diabetes mellitus (NIDDM) (14 and 10 patients, respectively), and (2) by a double-blind, randomized 4-week cross-over study in 12 intensively treated IDDM patients.

SETTING

Sahlgrenska University Hospital, Göteborg. Sweden.

INTERVENTIONS

(1) Ingestion of uncooked cornstarch and wholemeal bread (0.6 g of carbohydrates kg-1 body weight) and carbohydrate-free placebo at 22.00 h. (2) Intake of uncooked cornstarch (0.3 g kg-1 body weight) and carbohydrate-free placebo at 23.00 h.

MAIN OUTCOME MEASURES

(1) Nocturnal glucose and insulin levels; (2) frequency of self-estimated hypoglycaemia (blood glucose [BG] levels < 3.0 mmol L-1) at 03.00 h, HbA1c and fasting lipids.

RESULTS

Bedtime uncooked cornstarch ingestion led to a lower (2.9 +/- 0.5 vs. 5.2 +/- 0.6 mM, P = 0.01) and delayed (4.3 +/- 0.6 vs. 2.0 +/- 0.0 h, P < 0.01) BG peak, compared with a conventional snack, in NIDDM patients. Four weeks of bedtime uncooked cornstarch supplement, as compared with placebo, led to a 70% reduction in the frequency of self-estimated hypoglycaemia at 03.00 h (P < 0.05), without affecting HbA1c or fasting lipids in IDDM patients.

CONCLUSIONS

Uncooked cornstarch, ingested at bedtime, mimicked the nocturnal glucose utilization profile following insulin replacement, with a peak in blood glucose after 4 h. In IDDM patients, bedtime uncooked cornstarch supplement diminished the number of self-estimated hypoglycaemic episodes, without adversely affecting HbA1c and lipid levels. Hence, bedtime uncooked cornstarch ingestion may be feasible to prevent a mid-nocturnal glycaemic decline following insulin replacement in IDDM and, based on the nocturnal blood glucose profile, may also be preferable compared with conventional snacks.

Effect of streptozotocin-induced diabetes on rat brain sulfonylurea binding sites

Both high and low affinity sulfonylurea receptors (SURs) reside on glucose responsive neurons where they influence cell firing and neurotransmitter release via the adenosinetriphosphate (ATP)-sensitive K+ (katp) channel. Here, the effect of diabetes on [3H] glyburide binding to SURs was assessed in male obesity-resistant Sprague-Dawley rats rendered diabetic with streptozotocin (65 mg/kg, i.p.). Additional streptozotocin-treated rats were supplemented with insulin (1.5 U/kg/ day). Streptozotocin reduced plasma insulin to 13% of control associated with hyperglycemia (25.3 +/- 1.7 mmol/l), while insulin lowered plasma glucose (9.56 +/- 1.78 mmol/l) to near control levels (7.65 +/- 0.22 mmol/l). Over 7 days, all streptozotocin-treated rats lost 12% of their initial body wt. while controls gained 1%. Despite equivalent wt. loss, streptozotocin-induced diabetes selectively increased high affinity [3H] glyburide binding in the hypothalamic dorsomedial nuclei (DMN) and ventromedial nuclei (VMN) and lateral area (LH). This was prevented by insulin injections. Low affinity binding was similarly increased in the DMN and VMN, as well as two amygdalar subnuclei but decreased in the substantia nigra, pars compacta. Insulin fully prevented these changes only in the DMN and one amygdalar nucleus and the substantia nigra. Therefore, binding to (SURs) appears to be generally upregulated in the face of hypoinsulinemia with hyperglycemia and this is prevented by insulin treatment. These and other data suggest that this combination of abnormalities in diabetes should have an adverse effect on the glucose sensing capacity of the brain.

Pharmacokinetics of a porcine insulin zinc suspension in diabetic dogs

Ten dogs with naturally occurring diabetes mellitus were injected with a highly purified porcine insulin zinc suspension at a dose according to their expected requirement. Plasma insulin and glucose concentrations were measured at two-hourly intervals over 24 hours following injection. There were either one or two peaks in plasma insulin concentration: one at about four hours (mean 4.3 +/- 1.3 [SD]) and another at about 11 hours (mean 11 +/- 1.85) after the injection. The second insulin peak was seen in only eight dogs. Persistence of elevated plasma insulin concentrations ranged from 14 to 24 hours (mean 17.4 +/- 3.65). These results compare favourably with those published for other intermediate-acting insulin preparations used to treat canine diabetes mellitus and suggest that this preparation has useful properties for the successful management of many canine diabetics.

Treatment of early-morning hyperglycemia in type 1 diabetics with amorphous zinc insulin (Semilente) at bedtime

Fasting hyperglycemia in insulin-dependent diabetic patients (IDDM) treated according to the basal-bolus principle may be due to the fact that currently available neutral protamine Hagedorn (NPH) insulin preparations do not sufficiently meet the increased insulin need in the second part of the night. In the present study, it was investigated whether the amorphous zinc insulin Semilente can be used to control fasting hyperglycemia in IDDM patients. Ten type 1 diabetic patients with persistent fasting hyperglycemia (> 10 mmol/l) participated in the double-blind randomized cross-over trial with 2 10-day treatment periods. Night profiles of blood glucose and free insulin concentrations were determined at the end of each treatment period. Three doses of regular insulin were given before the meals and NPH insulin and Semilente at 10.00 p.m. Nighttime blood glucose and insulin profiles were different under the treatment with Semilente and NPH insulin. Injection of Semilente at bedtime resulted in higher insulin and lower blood glucose values during the second part of the night (p < 0.001 versus Semilente by ANOVA). Semilente injected at bedtime can prevent the early-morning rise in blood glucose in type I diabetic patients.

Response to chronic insulin administration: effect of area postrema ablation

The effects of daily administration of protamine zinc insulin (PZI) on plasma insulin and glucose levels and on food intake and body weight of rats with lesions of the area postrema and adjacent caudal-medial portions of the nucleus of the solitary tract (APX rats) were examined. Prior to insulin treatment, APX rats weighted less and had lower plasma immunoreactive insulin (IRI) levels than nonlesioned controls but did not differ from controls in plasma glucose levels. Five daily injections of 5 U/kg PZI raised plasma IRI and lowered plasma glucose levels similarly for both lesioned and nonlesioned rats. When injected with increasing doses of PZI over a 30-day period, both lesioned and nonlesioned rats showed increases of food intake and rate of weight gain in response to 8 U/kg PZI. These data indicate that APX does not affect either physiological or behavioral responses to chronic peripheral insulin administration.

Comparison of insulin antibody levels during the first 3 years of treatment of adult diabetics with monocomponent porcine lente-insulin and single peak beef NPH insulin

Insulin antibody production was studied in two groups of 9 adult diabetics each, who were never treated before with insulin. One group received Monocomponent porcine lente insulin (MC) and the other group single peak beef NPH insulin, for 3 years. Insulin antibodies were evaluated by antibody-bound immunoreactive insulin (Abl) and by the labelled insulin binding capacity (IBC) which presented a significant correlation best fitted by a logarithmic curve. The patients treated with MC insulin developed significant levels of insulin antibodies, however, at lower levels and appearing later in comparison to those with beef NPH. Only 3 patients did not produce significant levels of insulin antibodies. The highest titers occurred after different lengths of treatment in the two groups of patients. Abl decreased after continuation of treatment particularly in the MC series. While in the MC-treated patients there was some positive correlation between the insulin dose and the level of Abl no significant correlation was found between the diabetes control and insulin antibody titers in both groups of patients.

Human, porcine and bovine ultralente insulin: subcutaneous administration in normal man

Six normal subjects received subcutaneous human, porcine, and bovine ultralente insulin (0.30 U/kg) and diluent (control) in randomized order. Plasma glucose, C-peptide, and insulin were measured for 32 h after injection. From 10 h onward human ultralente produced significantly lower plasma glucose levels (p less than 0.05-0.01) compared to bovine ultralente. Porcine ultralente produced an intermediate hypoglycaemic response up to 16 h and was similar to the bovine insulin from 24-32 h. Estimated exogenous insulin concentration was higher (p less than 0.05-0.001) following human ultralente compared to bovine ultralente between 2 and 22 h after injection. Up to 24 h the porcine preparation led to intermediate insulin levels, but becoming identical to bovine ultralente from 28-32 h. Peak mean exogenous insulin values for human, porcine, and bovine ultralente were 0.054, 0.044, and 0.023 nmol/l at 14, 16, and 18 h, respectively, reaching 0.022, 0.013, and 0.013 nmol/l at 32 h. The different pharmacokinetic behaviour of human and bovine ultralente insulin must be considered when initiating treatment with human ultralente or transferring patients from bovine to human ultralente.

Use of beef ultralente for basal insulin delivery: plasma insulin concentrations after chronic ultralente administration in patients with IDDM

Ultralente has been used as the basal component of intensive insulin therapy programs. To determine the degree to which a single daily subcutaneous injection of beef ultralente provides stable basal insulin concentrations, plasma free insulin concentrations were measured in six insulin-dependent diabetic patients over a 40-h period. All short-acting insulin was withheld during this interval. Each patient had been maintained on a chronic ultralente based program before study. Little if any evidence of a temporal peak in plasma insulin concentrations was observed. Although considerable variation in plasma insulin concentrations was observed in one individual, beef ultralente provided relatively stable plasma insulin concentrations in the group as a whole. Beef ultralente appears to be a reasonable insulin preparation to use as the basal component in an intensive insulin therapy program.