Similar progression of diabetic retinopathy with insulin glargine and neutral protamine Hagedorn (NPH) insulin in patients with type 2 diabetes: a long-term, randomised, open-label study

AIMS/HYPOTHESIS

This long-term study was designed to further characterise the retinal safety profile of insulin glargine and human neutral protamine Hagedorn (NPH) insulin in patients with type 2 diabetes mellitus.

METHODS

An open-label, 5 year, randomised (1:1), multicentre, stratified, parallel-group study conducted in the USA and Canada enrolled individuals with type 2 diabetes and either no or non-proliferative retinopathy (less than severe; Early Treatment Diabetic Retinopathy Study [ETDRS] level less than 53 in both eyes) who were treated with oral hypoglycaemic agents (OHAs) alone, insulin alone or OHAs with insulin for >/=3 months prior to study entry and a baseline HbA(1c) level of 6.0-12.0%. Patients were randomised by the investigator according to the centralised interactive voice response system to receive twice-daily NPH insulin (n = 509) or once-daily basal insulin glargine (n = 515). The investigator was not blinded to the treatment group to which each participant had been assigned. The main objective of this study was to compare the progression of diabetic retinopathy between treatment groups by analysing the percentage of patients with three or more step progression in the ETDRS retinopathy patient-level severity scale after treatment with either basal insulin. Masked, centralised grading of seven-field stereoscopic fundus photographs was used.

RESULTS

Similarly sustained glycaemic control was observed in both the insulin glargine and NPH insulin treatment groups. Despite a slightly greater severity of diabetic retinopathy for the insulin glargine group at baseline, three or more step progression in ETDRS score from baseline to end-of-study was similar between treatment groups (14.2% [53/374] of insulin glargine-treated patients vs 15.7% [57/363] of NPH-treated patients); the difference in the incidence of progression was -1.98% (95% CI -7.02, 3.06%). Other measures of retinopathy-the development of proliferative diabetic retinopathy and progression to clinically significant macular oedema-occurred to a similar degree in both treatment groups. No other safety issues, such as unexpected adverse events for either insulin emerged during the 5 year study. However, NPH insulin treatment was associated with a higher incidence of severe hypoglycaemia compared with insulin glargine.

CONCLUSIONS/INTERPRETATION

This study shows no evidence of a greater risk of the development or progression of diabetic retinopathy with insulin glargine vs NPH insulin treatment in patients with type 2 diabetes mellitus.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00174824

FUNDING

This study was sponsored by sanofi-aventis.

Adding insulin glargine vs. NPH insulin to metformin results in a more efficient postprandial beta-cell protection in individuals with type 2 diabetes

AIM

Postprandial release of intact proinsulin (IP) is an independent marker for beta-cell dysfunction in patients with type 2 diabetes. This open-label, parallel-group, two-arm, pilot study compared the beta-cell protective effect of adding insulin glargine (GLA) vs. NPH insulin to ongoing metformin.

MATERIAL AND METHODS

Overall, 28 insulin-naive type 2 diabetes subjects (mean +/- SD age, 61.5 +/- 6.7 years; diabetes duration, 9.8 +/- 6.5 years; HbA1c, 7.1 +/- 0.5%; BMI, 30.7 +/- 4.3 kg/m(2)) treated with metformin and sulfonylurea were randomized to add once-daily GLA or NPH at bedtime. At baseline and after 3 months, subjects received a standardized breakfast, lunch and dinner, with pre- and postprandial blood sampling to measure plasma IP, total insulin and blood glucose (BG).

RESULTS

Insulin dose after 3 months was comparable in both groups (GLA vs. NPH: 23.6 +/- 13.4 vs. 23.3 +/- 12.7; p = NS ). Both treatments significantly reduced fasting BG levels (GLA: 158 +/- 19 to 121 +/- 23 mg/dl; NPH: 156 +/- 34 to 119 +/- 29 mg/dl; both p < 0.01 vs. baseline). Fasting and postprandial BG levels did not differ between groups. IP levels decreased in both groups (p < 0.05 at all timepoints). Although IP release after breakfast did not differ between treatments, GLA induced a greater reduction in IP release after lunch (p = 0.08) and dinner (p = 0.04). Total plasma insulin levels did not differ between groups.

CONCLUSIONS

Adding basal insulin to metformin reduces postprandial beta-cell load. While GLA and NPH had comparable effects at breakfast, GLA reduces beta-cell stress more effectively at dinner, and with a trend at lunch, most probably because of its longer lasting pharmacodynamic profile.

Assessment of the mixing efficiency of neutral protamine Hagedorn cartridges

Reliable application of neutral protamine Hagedorn (NPH) insulin requires previous resuspension of the suspension by tipping over the cartridge 20 times. This procedure is considered annoying by patients. The goal of this investigation was to assess the efficiency of the mixing procedure when performed less frequently than recommended. Neutral protamine Hagedorn insulin cartridges from five different manufacturers (sanofi-aventis, Lilly, Berlin-Chemie, B. Braun, and Novo Nordisk) were emptied with doses of 28 IU in the morning and the evening over 5 days. While the first dose was obtained after a regular resuspension procedure (20x tipping over), the consecutive doses were obtained after 3, 6, 10, or 20 mixing procedures (12 cartridges per experimental series, two doses/day). Insulin concentrations of doses 1, 2, 6, and 10 were determined by high-pressure liquid chromatography. Between dosing, cartridges were stored at room temperature in a horizontal position. Comparable insulin concentrations were seen in the first correctly prepared doses. Pronounced and substantial deviations from the selected dose were observed with most of the cartridges, in particular when resuspending only 3 and 6 times. Mean absolute percentage deviations when tipping 3 times and maximally observed overdoses were: Insuman basal: 1.1 +/- 1.0%/4 IU, Humulin N: 2.6 +/- 3.4%/19 IU, Berlinsulin H basal: 4.4 +/- 6.0%/26 IU, Insulin B. Braun basal: 10.4 +/- 8.9%/38 IU, and Protaphane: 4.7 +/- 4.1%/19 IU (all p < 0.05 vs Insuman basal). Only one cartridge with three metal mixing bullets (sanofi-aventis) was resuspended efficiently with only a few mixing procedures. All other cartridges with fewer bullets were shown to deliver potentially harmful doses if used for treatment when the mixing procedure was less frequent than demanded in the instructions for use.

Addition of insulin glargine or NPH insulin to metformin monotherapy in poorly controlled type 2 diabetic patients decreases IGF-I bioactivity similarly

AIMS/HYPOTHESIS

The aim of this study was to compare IGF-I bioactivity 36 weeks after the addition of insulin glargine (A21Gly,B31Arg,B32Arg human insulin) or NPH insulin to metformin therapy in type 2 diabetic patients who had poor glucose control under metformin monotherapy.

METHODS

In the Lantus plus Metformin (LANMET) study, 110 poorly controlled insulin-naive type 2 diabetic patients were randomised to receive metformin with either insulin glargine (G+MET) or NPH insulin (NPH+MET). In the present study, IGF-I bioactivity was measured, retrospectively, in 104 out of the 110 initially included LANMET participants before and after 36 weeks of insulin therapy. IGF-I bioactivity was measured using an IGF-I kinase receptor activation assay.

RESULTS

After 36 weeks of insulin therapy, insulin doses were comparable between the G+MET (68 ± 5.7 U/day) and NPH+MET (71 ± 6.2 U/day) groups (p = 0.68). Before insulin therapy, circulating IGF-I bioactivity was similar between the G+MET (134 ± 9 pmol/l) and NPH+MET (135 ± 10 pmol/l) groups (p = 0.83). After 36 weeks, IGF-I bioactivity had decreased significantly (p = 0.001) and did not differ between the G+MET (116 ± 9 pmol/l) and NPH+MET (117 ± 10 pmol/l) groups (p = 0.91). At baseline and after insulin therapy, total IGF-I concentrations were comparable in both groups (baseline: G+MET 13.3 ± 1.0 vs NPH+MET 13.3 ± 1.0 nmol/l, p = 0.97; and 36 weeks: 13.4 ± 1.0 vs 13.1 ± 0.9 nmol/l, p = 0.71). Total IGF-I concentration did not change during insulin therapy (13.3 ± 0.7 vs 13.3 ± 0.7 nmol/l, baseline vs 36 weeks, p = 0.86).

CONCLUSIONS/INTERPRETATION

Addition of insulin glargine or NPH insulin to metformin monotherapy in poorly controlled type 2 diabetic patients decreases serum IGF-I bioactivity in a similar manner.

Impact of patient and treatment characteristics on glycemic control and hypoglycemia in patients with type 2 diabetes initiated to insulin glargine or NPH: A post hoc, pooled, patient-level analysis of 6 randomized controlled trials

BACKGROUND

The goal of this post hoc analysis was to determine key patient and treatment-related factors impacting glycosylated hemoglobin (A1C) and hypoglycemia in patients with uncontrolled type 2 diabetes who were initiated to basal insulin (neutral protamine Hagedorn [NPH] or glargine).

METHODS

Using individual patient-level data pooled from 6 treat-to-target trials, 2600 patients with type 2 diabetes on oral antidiabetic agents initiated to insulin glargine or NPH and treated for 24 to 36 weeks were analyzed.

RESULTS

Both treatments led to significant reduction in A1C levels compared with baseline, with no differences between treatment groups (mean ± standard deviation; glargine: -1.32 ± 1.2% vs NPH: -1.26 ± 1.2%; P = 0.15), with greater reduction in the BMI ≥30 kg/m group than in the BMI <30 kg/m group. Glargine reduced A1C significantly more than NPH in the BMI <30 kg/m group (-1.30 ± 1.18% vs -1.14 ± 1.22, respectively; P = 0.008), but not in the BMI ≥ 30 kg/m group (-1.37 ± 1.19 vs -1.48 ± 1.22, respectively; P = 0.18). Similar proportions of patients achieved A1C target of <7% (glargine 30.6%, NPH 29.1%; P = 0.39). Incidence of severe and severe nocturnal hypoglycemia was significantly lower in glargine versus NPH-treated patients (2.0% vs 3.9%; P = 0.04, and 0.7% vs 2.1%; P = 0.002, respectively), and occurred primarily in the BMI <30 kg/m group.

CONCLUSIONS

Initiation of basal insulin is highly effective in lowering A1C after oral antidiabetic agent failure. Glargine decreases A1C more than NPH in nonobese patients, and reduces the risk for severe and severe nocturnal hypoglycemia versus NPH both in obese and nonobese patients, but more so in nonobese patients. Thus, it is the nonobese patients who may benefit more from initiation of basal insulin as glargine than NPH.

Treatment satisfaction and quality-of-life between type 2 diabetes patients initiating long- vs. intermediate-acting basal insulin therapy in combination with oral hypoglycemic agents--a randomized, prospective, crossover, open clinical trial

BACKGROUND

Pharmacological and clinical differences between insulin glargine and NPH insulin may translate into differences in patient reported outcomes, but existing data are equivocal.

METHODS

In this 48-week, open-label, randomized, multi-center, crossover phase IV trial, insulin naïve type 2 diabetes patients with blood glucose not at target on oral hypoglycemic agents had basal insulin added to their treatment regimen. A total of 343 patients were randomized to either receive insulin glargine (n = 176; sequence A) or neutral protamine Hagedorn (NPH) insulin (n = 167; sequence B) in period 1 (weeks 1-24) and vice versa in period 2 (weeks 25-48). The primary objective was to assess patient reported outcomes using a composite Diabetes Related Quality of Life (DRQoL) score based on an unweighted Insulin Treatment Experience Questionnaire (ITEQ) score, a Problem Areas in Diabetes (PAID) questionnaire score, and the mental health score in the Short Form (SF)-12® Health Survey, analyzed by analysis of covariance (ANCOVA).

RESULTS

Patients (mean age 62.3 ± 9.0; 39.5 % female) had a mean diabetes duration of 9.6 ± 5.9 years, a mean baseline HbA1c of 8.15 ± 0.72 %, and a mean fasting blood glucose (FBG) level of 9.37 ± 2.19 mmol/L. A total of 229 patients were available for primary endpoint evaluation (modified intention to treat population). Combining all data from both periods for each insulin treatment, on a 0-100 scale, the mean DRQoL score was 69.6 (±9.04) with insulin glargine and 70.0 (±9.40) with NPH insulin. Neither an effect of treatment with insulin glargine vs NPH insulin (p = 0.31) nor a period effect (p = 0.96), nor a sequence effect (p = 0.76) was observed using ANCOVA.

CONCLUSIONS

The results show that in a patient population with sub-optimal glycemic control at baseline, and a low target achievement rate together with a low rate of hypoglycemia, differences in the patient reported outcomes evaluated in this study were negligible between insulin glargine and NPH insulin.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT00941369.

Cost Effectiveness of Insulin Glargine versus Neutral Protamin Hagedorn Insulin in the Treatment of Type 2 Diabetes Patients in Turkey

Background: Type 2 diabetes mellitus (T2DM) poses a significant burden on population well being and healthcare expenditure in Turkey, with disease prevalence continuing to increase. Insulin treatment is necessary for patients failing to achieve glycaemic control with lifestyle modification or oral antidiabetic drugs. While neutral protamin Hagedorn (NPH) insulin has been traditionally prescribed for insulin introduction, insulin glargine has been shown to reduce glycated hemoglobin (HbA1c) with a more favourable hypoglycaemic profile. Objective: To evaluate the cost-effectiveness of insulin glargine compared to NPH insulin in patients with T2DM in Turkey, from a Social Security Institution perspective. Methods: A previously published discrete event simulation model of T2DM progression was utilised to characterise the cost-effectiveness of insulin glargine in a Turkish population given the benefits observed in clinical practice. Improvements in glycaemic control have been incorporated using data from The Health Improvement Network (THIN) database in the United Kingdom, combined with meta-regression results describing the relationship between hypoglycaemia and glycaemic control. Outcomes were evaluated over a 40-year horizon, and costs and benefits discounted at an annual rate of 3.5%. Results are reported in Turksih lira (TL), 2012. Results: Over a lifetime, the Incremental Cost-effectiveness Ratio (ICER) of insulin glargine compared to NPH was 40,101 TL per Quality-adjusted Life Year (QALY). Almost 52 hypoglycaemic events per patient were avoided with the use of insulin glargine compared to NPH, at an incremental lifetime cost of 7,140 TL per patient. The cost-effectiveness of insulin glargine is reduced when modelling only those benefits considered in the trial setting, while the cost-effectiveness profile can be expected to further improve in patients with higher HbA1c levels at baseline. Conclusion: It is difficult to interpret the results of modelling as there is no official cost-effectiveness threshold in Turkey. However, the results may be evaluated using thresholds derived according to methodology proposed by the World Health Organisation (WHO). Insulin glargine is expected to be costeffective compared to NPH insulin, with an ICER below three times the estimated gross domestic product (GDP) per capita; 56,850 TL.