The effect of insulin lispro on glycemic control in a large patient cohort

Predicting the effectiveness of insulin pump therapy on glycemic control in clinical practice: a retrospective study of patients with type 1 diabetes from 10 outpatient diabetes clinics in Sweden over 5 years

BACKGROUND

Multicenter long-term studies of predictors for the effectiveness of continuous subcutaneous insulin infusion (CSII) in clinical practice are lacking. We hypothesized that there are substantially greater reductions in hemoglobin A1c (HbA1c) in patients with poor glycemic control and that other predictors may also exist.

SUBJECTS AND METHODS

We used data from 10 outpatient diabetic clinics in Sweden and studied CSII treatment over 5 years. Patients with HbA1c values available ≤ 6 months before starting CSII and at 5 years were included (n = 272, 82% of CSII patients) along with 2,437 contemporaneous controls on multiple daily insulin injections (MDI). Baseline variables evaluated were age, sex, diabetes duration, insulin dose, body mass index (BMI), HbA1c at baseline, and outpatient clinical care unit.

RESULTS

At 5 years, significantly greater reductions in HbA1c by CSII compared with MDI were found for patients with higher baseline HbA1c (P = 0.032) and lower baseline BMI (P = 0.013). For baseline HbA1c levels of 7.0%, 8.0%, and 9.0% and a BMI of 25 kg/m(2), the reduction in HbA1c level by CSII was 0.08% (difference not significant), 0.16% (95% confidence interval, 0.03-0.29%), and 0.25% (95% confidence interval, 0.11-0.39%), respectively. Corresponding analyses for the change in HbA1c level from start to 1 and 2 years revealed a significant interaction of insulin pump therapy only with baseline HbA1c levels (P < 0.001 and P = 0.030, respectively). The interaction term between outpatient clinical care unit and CSII treatment was statistically significant for some care units, with some care units demonstrating a benefit from CSII and others demonstrating a detriment.

CONCLUSIONS

Patients with high HbA1c levels have a greater probability of improved HbA1c after initiating pump therapy, but effects remain relatively modest even for patients with poor control. Factors predicting successful insulin pump use need further study.

Insulin pump-long-term effects on glycemic control: an observational study at 10 diabetes clinics in Sweden

AIM

This study examined long-term effects of continuous subcutaneous insulin infusion (CSII) in clinical practice on glycemic control in patients with type 1 diabetes.

SUBJECTS AND METHODS

We evaluated all type 1 diabetes patients at 10 diabetes outpatient clinics in Sweden who had been treated with CSII for at least 5.5 years and had valid glycated hemoglobin (HbA1c) data before starting pump use and at 5 years ± 6 months. Controls treated with multiple daily insulin injections (MDI) over a time-matched period were also evaluated.

RESULTS

There were 331 patients treated with CSII at least 5.5 years at the 10 clinics. Of these, 272 (82%) fulfilled the inclusion criteria. Patients treated with CSII were younger than those treated with MDI (mean age, 38.6 vs. 45.6 years; P<0.001), more were women (56% vs. 43%; P<0.001), and diabetes duration was shorter (mean, 15.1 years vs. 20.1 years; P<0.001). After adjusting for variables differing at baseline and influencing the change in HbA1c over the study period, the reduction in HbA1c remained statistically significant at 5 years and was estimated to be 0.20% (95% confidence interval [CI] 0.07-0.32) (2.17 mmol/mol [95% CI 0.81-3.53]) (P=0.002). The corresponding adjusted reduction at years 1 and 2 was 0.42% (95% CI 0.31-0.53) (4.59 mmol/mol [95% CI 3.41-5.77]) (P<0.001) and 0.43% (95% CI 0.31-0.55) (4.71 mmol/mol [95% CI 3.38-6.04]) (P<0.001), respectively. The effect of insulin pump use versus controls on HbA1c decreased significantly with time (P<0.001).

CONCLUSIONS

Use of CSII in clinical practice in Sweden is associated with an approximately 0.2% (2 mmol/mol) reduction in HbA1c after 5 years.

Availability of insulin pump therapy in clinical practice

AIM

To examine the availability of insulin pump therapy in patients with Type 1 diabetes.

METHODS

Patients using insulin pumps among a cohort of 7224 patients with Type 1 diabetes were studied.

RESULTS

In logistic regression, used to evaluate variables not changing over time among the total cohort, use of insulin pumps varied by outpatient clinic (P<0.001) and sex (P<0.001). Cox regression analysis in 5854 patients with detailed patient data prior to use of an insulin pump showed higher HbA(1c) (P<0.0001), lower creatinine (P=0.002), high and low insulin doses (P<0.0001), younger age (P<0.0001) and female sex (P<0.0001) to be associated with use of an insulin pump. Women were 1.5-fold more likely to start using an insulin pump (hazard ratio 1.52, 95% confidence interval 1.29-1.79) and patients in the 20- to 30-years age range were more than twice as likely to begin use of an insulin pump than patients aged 40-50 years (hazard ratio 8.63, 95% confidence interval 5.91-12.59 and hazard ratio 3.98, 95% confidence interval 2.80-5.64, respectively). A 10-μmol/l higher level of creatinine was associated with a hazard ratio of 0.56 (95% confidence interval 0.39-0.81) of starting use of an insulin pump.

CONCLUSIONS

At 10 hospital outpatient clinics in Sweden, use of insulin pumps therapy varied by clinic. A higher proportion of women began using insulin pumps. Younger patients and patients with fewer complications were also more likely to start using an insulin pump. Further research is needed to confirm these findings in other geographical regions and to understand whether the availability of insulin pumps today is optimized.

The relationship between the exposure time of insulin glargine and risk of breast and prostate cancer: an observational study of the time-dependent effects of antidiabetic treatments in patients with diabetes

AIMS

To elucidate methodological questions in assessing the relationship between insulin treatment and cancer, since the risk of tumour growth generally increases with longer exposure time and higher dose of a growth promoting substance.

METHODS

Continuous hazard functions for risk of breast and prostate cancer were estimated in relation to exposure of insulin glargine among diabetic patients included in the record system, Diab-Base, as well as in the general population in Sweden.

RESULTS

In 7942 female diabetic patients, mean follow-up 7.0 years, 2014 patients initiated insulin glargine with a mean follow-up of 3.5 years. Among 11,613 men, mean follow-up 6.9 years, 2760 had a mean follow-up with glargine of 3.4 years. Risk of prostate cancer decreased significantly with longer exposure to insulin glargine (p=0.032), although average risk versus non-glargine was non-significantly higher (HR 1.37, 95% CI 0.78-2.39). The breast cancer risk did not change with longer exposure to insulin glargine (p=0.35) and the mean risk was similar for glargine and non-glargine (p=0.12). With higher dose of insulin glargine, there was an increase in risk of prostate (p=0.037) and breast cancer (p=0.019). In diabetics, the mean risk of prostate cancer was decreased (HR 0.68, 95% CI 0.59-0.79) but similar for breast cancer (HR 0.95, 95% CI 0.78-1.14) compared to the general population and did not change with longer diabetes duration (p=0.68 and p=0.53 respectively).

CONCLUSIONS

Analysing continuous hazard functions for cancer risk in relation to exposure time to an antidiabetic agent is an important complementary tool in diabetes and cancer research.

14-day in vitro chemical stability of insulin lispro in the MiniMed Paradigm pump

BACKGROUND

Insulin lispro was subjected to a simulated in-use study in the Medtronic MiniMed Paradigm(®) pump system (Medtronic, Northridge, CA) under stressed conditions over 14 days.

METHODS

Basal and bolus insulin doses were delivered under conditions of elevated temperature (37°C) and continuous shaking over 14 days. The simulation included a study arm with infusion set changes every 3 days and an arm with no infusion set changes over the entire study period. Analyses were performed on samples pumped through the infusion system and on samples retained in the pump reservoir.

RESULTS

Results met U.S. Pharmacopeia criteria for insulin lispro potency through the entire testing period. No precipitation was observed on visual inspection, and no occlusion alarms were noted.

CONCLUSIONS

Insulin lispro demonstrated appropriate physicochemical stability for up to 14 days in the MiniMed Paradigm pump system.

Effect on glycemic control by short- and long-term use of continuous glucose monitoring in clinical practice

BACKGROUND

In Sweden, patients with diabetes mellitus frequently receive short-term (<3 months) continuous glucose monitoring (CGM) to study glucose patterns or long-term CGM to treat poor glycemic control or severe hypoglycemia. The effects of CGM on glycemic control in clinical practice in relation to indication and duration of use has not been completely studied.

METHODS

Patients with diabetes, among which 99% were diagnosed as type 1, receiving CGM at 10 outpatient clinics in Sweden were studied retrospectively. Long-term use of CGM was defined as ≥ 3 months use of CGM and short-term as <3 months. A control group matched on start date and date of latest value 3 months after the start was selected for both long- and short-term groups.

RESULTS

In 34 long-term users of CGM, over a mean follow-up of 1.1 years, the adjusted mean difference of hemoglobin A1c (HbA1c) compared with controls (n = 408) was -0.76 (95% confidence interval -1.17; -0.33, p < .001). Long-term users with indications for high HbA1c (n = 15) had a reduction of 1.2% in HbA1c from 10.1 to 8.9% (p = .003), whereas patients with hypoglycemia as their indication (n = 16) decreased by 0.3% (p = .17). Nonsevere hypoglycemic events decreased in long-term users within the same follow-up period (p = .004). Short-term users showed no statistically significant improvement in HbA1c compared with controls at 1.1 years (n = 41), p = .85 or at 2.6 years (n = 43), p = .19.

CONCLUSION

Long-term CGM use was associated with improved glycemic control in clinical practice and a reduction in nonsevere hypoglycemic events, whereas short-term use had no effect on HbA1c. The effect on glycemic control varied by indication.

Are analogue insulins superior to human insulin in clinical practice?

Insulin analogues were designed to provide more physiologic pharmacokinetic and pharmacodynamic properties compared with human insulin. This article examines the literature over a 2-year period, focusing on studies directly comparing analogue and human insulin in controlled clinical trials and large observational studies documenting the introduction of, or change to, analogue insulin in clinical practice. Findings indicate that analogues provide objective benefits that include improved glycemic control, lower risk of hypoglycemia, lower glucose variability, and (for insulin detemir) reduced weight gain. Recent data with analogues also explore their safety and efficacy in special patient groups such as children and adolescents. These data complement increasing evidence that analogues offer improved acceptability and accessibility to people with diabetes.

The true value of HbA1c as a predictor of diabetic complications: simulations of HbA1c variables

Aim

The updated mean HbA1c has been used in risk estimates of diabetic complications, but it does not take into account the temporal relationship between HbA1c and diabetic complications. We studied whether the updated mean HbA1c underestimated the risk of diabetic complications.

Method

Continuous HbA1c curves for 10,000 hypothetical diabetes patients were simulated over an average of 7 years. Simulations were based on HbA1c values encountered in clinical practice. We assumed that each short time interval of the continuous HbA1c curves had a long-lasting effect on diabetic complications, as evidenced by earlier studies. We tested several different HbA1c variables including various profiles, e.g. different duration, of such a long-lasting effect. The predictive power of these variables was compared with that of the updated mean HbA1c.

Results

The predictive power of the constructed HbA1c variables differed considerably compared to that of the updated mean HbA1c. The risk increase per standard deviation could be almost 100% higher for a constructed predictor than the updated mean HbA1c.

Conclusions

The importance of good glycemic control in preventing diabetic complications could have been underestimated in earlier hallmark studies by not taking the time-dependent effect of HbA1c into account.