Blood glucose control on Sunday in IDDM patients: intensified conventional insulin therapy versus continuous subcutaneous insulin infusion

Insulin pump therapy in adults

Restoration of the physiological insulin secretion is a current medical challenge and a dream for patients with Diabetes Mellitus. Continuous insulin therapy using pumps was the first step to the development of artificial pancreas. The aim of diabetes treatment is to achieve strict glycemic control in order to avoid the development of long-term diabetic complications while reducing the frequency of hypoglycemic episodes. Continuous subcutaneous insulin infusion (CSII) using an external pump, offers both a better blood glucose stability as compared to multiple daily injections and a broader flexibility in life mode, and reduces the frequency of severe hypoglycemia. The advantages of the insulin pump (consistency of basal delivery, adjustable basal rates, and low insulin depots allowing the reduction of glycemic variability) have contributed to its reported superiority compared with multiple daily injections (MDI). However, experience with CSII indicates that candidates for insulin pump therapy must be carefully selected and strongly motivated to improve their glucose control. Finally, the use of CSII in patients with Diabetes Mellitus type 2 now appears to be a good alternative to the ineffective MDI regimens observed in some of these patients.

Continuous subcutaneous insulin infusion (CSII) versus multiple insulin injections for type 1 diabetes mellitus

BACKGROUND

Type 1 diabetes is a metabolic disorder resulting from a defect in insulin secretion. Onset of type 1 diabetes mellitus may occur at any age and it is one of the most common chronic diseases of childhood and adolescence. Since there are no interventions known to prevent onset, it is vital that effective treatment regimes are available. Glycaemic control is maintained by replacement of insulin and may be in the form of 'conventional' insulin therapy (multiple injections per day) or continuous subcutaneous insulin infusion (CSII).

OBJECTIVES

To assess the effects of CSII compared to multiple insulin injections (MI) in people with type 1 diabetes mellitus.

SEARCH STRATEGY

Studies were obtained from electronic searches of The Cochrane Library, MEDLINE, EMBASE and CINAHL.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials comparing CSII with three or more insulin injections per day (MI) in people with type 1 diabetes mellitus.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted characteristics of included studies. Authors contacted study investigators to obtain missing information. Generic inverse variance meta-analyses using a random-effects model were performed.

MAIN RESULTS

Twenty three studies randomised 976 participants with type 1 diabetes to either intervention. There was a statistically significant difference in glycosylated haemoglobin A1c (HbA1c) favouring CSII (weighted mean difference -0.3% (95% confidence interval -0.1 to -0.4). There were no obvious differences between the interventions for non-severe hypoglycaemia, but severe hypoglycaemia appeared to be reduced in those using CSII. Quality of life measures suggest that CSII is preferred over MI. No significant difference was found for weight. Adverse events were not well reported, no information is available on mortality, morbidity and costs.

AUTHORS' CONCLUSIONS

There is some evidence to suggest that CSII may be better than MI for glycaemic control in people with type 1 diabetes. Non-severe hypoglycaemic events do not appear to be reduced with CSII. There is insufficient evidence regarding adverse events, mortality, morbidity and costs.

Treatment of diabetes mellitus using an external insulin pump: the state of the art

The aim of diabetes treatment is to achieve tight glucose control to avoid the development of chronic diabetic complications while reducing the frequency of hypoglycaemic episodes. Continuous subcutaneous insulin infusion (CSII) using an external pump is an intensive diabetes therapy recognized to improve metabolic control and glycaemic instability, and to reduce the frequency of severe hypoglycaemia. For years, the theoretical advantages of the insulin pump (constancy of basal delivery, adjustable basal rates, and low insulin depots allowing the reduction of glycaemic variability) have contributed to its reported superiority compared with multiple daily injections (MDI). However, insulin pump therapy is now challenged by new MDI regimens based on long-acting insulin analogues that could replace the use of CSII. As a consequence, health professionals now have to determine which patients are likely to benefit the most from CSII. Recently, several studies reported that children and adolescents, and patients whose blood glucose imbalance was initially the most pronounced with basal-bolus regimens, would particularly benefit from CSII. Other indications were also proposed in marginal clinical situations with highly selected patients in whom a significant improvement of blood glucose was demonstrated. Finally, the use of CSII in type 2 diabetic patients now appears to be a good alternative to the ineffective MDI regimens observed in some of these patients. However, past experience with CSII indicates that candidates for insulin pump therapy must be carefully selected and strongly motivated to improve their glucose control. Use of CSII also requires strict medical supervision by physicians and a regular programme of patient education by paramedical teams, to ensure optimal responsible use of this technique by healthcare professionals.

Insulin pump therapy: a meta-analysis

OBJECTIVE

To conduct a meta-analysis of the metabolic and psychosocial impact of continuous subcutaneous insulin infusion (CSII) therapy on adults, adolescents, and children.

RESEARCH DESIGN AND METHODS

Studies were identified and data regarding study design, year of publication, sample size, patient's age, diabetes duration, and duration of CSII therapy were collected. Means and SDs for glycohemoglobin, blood glucose, insulin dosages, and body weight for CSII and comparison conditions were subjected to meta-analytic procedures. Data regarding pump complications and psychosocial functioning were reviewed descriptively.

RESULTS

A total of 52 studies, consisting of 1,547 patients, were included in the meta-analysis. Results indicate that CSII therapy is associated with significant improvements in glycemic control (decreased glycohemoglobin and mean blood glucose). A descriptive review of potential complications of CSII use (e.g., hypoglycemia, diabetic ketoacidosis [DKA], pump malfunction, and site infections) suggests a decreased frequency of hypoglycemic episodes but an increased frequency of DKA in studies published before 1993.

CONCLUSIONS

CSII therapy is associated with improved glycemic control compared with traditional insulin therapies (conventional therapy and multiple daily injections) and does not appear to be associated with significant adverse outcomes. Additional studies are needed to further examine the relative risks of CSII therapy, including the potential psychosocial impact of this technologically advanced therapy.

The benefits of metformin therapy during continuous subcutaneous insulin infusion treatment of type 1 diabetic patients

OBJECTIVE

This study was designed to assess the insulin-sparing effect of oral administration of metformin along with a continuous subcutaneous insulin infusion (CSII) for the treatment of type 1 diabetic patients.

RESEARCH DESIGN AND METHODS

A total of 62 patients (25 women and 37 men) were studied in a monocenter, randomized, double-blind placebo-controlled study, comparing metformin (850 mg b.i.d.) with placebo in association with CSII during a 6-month period.

RESULTS

Treatment with metformin was associated with a reduction in daily insulin requirements between V0 and V6 of -4.3 +/- 9.9 units (-7.8 +/- 18%) compared with an increase with placebo treatment of 1.7 +/- 8.3 units (2.8 +/- 12.7%) (P = 0.0043). A decrease in basal requirement of insulin was also observed in patients treated with metformin of -2.6 +/- 3.2 units (-7.9 +/- 23.8%) compared with an increase with placebo treatment of 1.9 +/- 5.7 units (8.8 +/- 27.1%) (P = 0.023). HbA(1c) remained unchanged in treatment with metformin and placebo between V0 and V6. The number of hypoglycemic events (<60 mg/dl) was similar in both groups. Significant reductions of total cholesterol (P = 0.04) and LDL cholesterol (P = 0.05) were observed in patients treated with metformin. Gastrointestinal events, including diarrhea and abdominal pain, were reported in three patients in the metformin group who discontinued the trial. Mild or moderate gastrointestinal side effects were also reported in eight patients treated with metformin and two patients treated with placebo (P = 0.069).

CONCLUSIONS

Metformin was found to be a safe insulin-sparing agent, when used in combination with CSII for the treatment of type 1 diabetes.

Comparison of metabolic deterioration between insulin analog and regular insulin after a 5-hour interruption of a continuous subcutaneous insulin infusion in type 1 diabetic patients

An interruption of continuous sc insulin infusion (CSII) of the insulin analog lispro should result in a more rapid metabolic deterioration of type 1 diabetic patients because of its pharmacokinetic characteristics. We analyzed the metabolic changes occurring during a 5-h interruption of CSII and the 5 h after restarting the pump in 10 type 1 diabetic patients. The study was a randomized, cross-over, open label design comparing insulin analog [Lispro (LP)] and regular insulin [Velosuline (VE)]. Plasma glucose, free insulin, glucagon, betahydroxybutyrate (beta-OHB), and nonesterified fatty acids (NEFA) were measured every hour from 0700 h (time zero) to 1700 h (600 min). After stopping CSII, the plasma glucose level was significantly higher in the LP group than in the VE group (P < 0.05-0.01). The plasma free insulin level decreased significantly with the two treatments, but was significantly lower with LP than with VE (P < 0.05-0.01). Plasma NEFA increased more rapidly and was significantly higher in the LP group than in the VE group (P < 0.01-0.05). Plasma beta-OHB increased earlier with LP, but was not statistically different between the treatments. After restarting the pump, plasma glucose decreased with LP, but continued to increase with VE, and the plasma free insulin peak occurred earlier and was greater with LP than with VE (P < 0.05). Plasma NEFA and beta-OHB levels decreased significantly with the two treatments, but more dramatically with LP treatment. Thus, a short interruption of Lispro in CSII is associated with an earlier, greater metabolic deterioration, but Lispro corrected this metabolic deterioration more effectively.