Summary of ‘Continuous subcutaneous insulin infusion (CSII) versus multiple insulin injections for type 1 diabetes mellitus’

Authors


Abstract

This is a summary of a Cochrane review, published in this issue of EBCH, first published as: Misso ML, Egberts KJ, Page M, O'Connor D, Shaw J. Continuous subcutaneous insulin infusion (CSII) versus multiple insulin injections for type 1 diabetes mellitus. Cochrane Database of Systematic Reviews 2010, Issue 1. Art. No.: CD005103. DOI: 10.1002/14651858.CD005103.pub2. Copyright © 2010 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. The Cochrane Collaboration

Objectives

  • This review aims to assess the effects of continuous subcutaneous insulin infusion (CSII) compared to multiple insulin injections (MI) in people with type 1 diabetes mellitus.

Relevance

  • Type 1 diabetes results from a defect in insulin secretion. A consequence of this is chronic hyperglycaemia. Long-term complications include retinopathy, nephropathy and neuropathy. Also, cardiovascular disease risk is increased.

  • The onset of type 1 diabetes may occur at any age and it is one of the most common chronic diseases of childhood and adolescence. Based on young onset patients, the incidence of this disease worldwide varies from 0.1 to 37.4 per 100,000.

  • Life-long insulin replacement and monitoring of blood glucose levels are required.

  • Glycaemic control is maintained by replacement of insulin. Insulin is administered subcutaneously and is absorbed into the bloodstream. Here, complexes are formed enabling binding to the insulin receptor for activation of glucose uptake into the muscle.

  • Insulin therapy may be in the form of MI (2 to 4 injections per day) or CSII. With CSII insulin is typically administered by a pump programmed to deliver basal rates to match the individual's needs; bolus doses are activated by the individual to cover meals and correct hyperglycaemia.

  • Insulin pumps are worn externally and insulin is delivered from the pump via insertion of a catheter into the subcutaneous tissue of the abdominal wall.

  • CSII may provide a more efficient mode of insulin delivery to the bloodstream, minimize the risk of hypoglycaemic events and may be more beneficial to those who find it difficult to adhere to MI.

Participants

  • This review included 23 studies with 976 participants. Seven of the 23 studies were performed in participants under 18 years of age, with a total of 205 participants in this subgroup.

Comparison

  • CSII compared to multiple insulin injections.

Results

  • All studies assessed CSII vs MI. Results showed that CSII led to a significant decrease in the following outcomes:

    • HbA1c levels (MD: − 0.29; 95% CI: − 0.52, − 0.06)

    • Daily mean blood glucose levels (MD: − 15.26; 95% CI: − 23.37, − 7.14)

    • Fasting blood glucose levels (MD: − 14.02; 95% CI: − 24.42, − 3.61)

    • Daily insulin requirement (U) (MD: − 6.98; 95% CI: − 10.77, − 3.19)

    • Daily insulin requirement for weight (U/kg) (MD: − 0.12; 95% CI: − 0.19, − 0.05)

    • Severe hypoglycaemic events (numeric data not provided)

  • There was no difference between groups for measures of post prandial blood glucose levels (MD: − 4.44; 95% CI: − 10.91, 2.03), body weight (MD: − 0.37; 95% CI: − 1.98, 1.25) or non-severe hypoglycaemic events (numeric data not provided).

  • Subgroup analysis was performed for children (≤18 years). Two outcomes remained significant in favour of CSII: HbA1c levels (MD: − 0.20; 95% CI: − 0.40, − 0.03) and daily insulin requirement (U/kg) (MD: − 0.16; 95% CI: − 0.31, − 0.01).

  • Quality of life was reported in 15 studies (overall unclear risk of bias) using different scales. Authors found the data was not appropriate to conduct a meta-analysis. Many of the studies used validated questionnaires and found that CSII was preferred over MI for treatment satisfaction, quality of life and perception of better general and mental health. Often, participants randomized to CSII preferred to continue with CSII at study completion rather than return to MI.

Implications

  • It may be beneficial to use CSII over MI for improving glycaemic control and improving health-related quality of life in people with type 1 diabetes.

  • Outcomes measured are short-term and biological; more evidence is required regarding long-term outcomes, adverse events, diabetes late complications, mortality and cost—all important factors in deciding which treatment is best in practice.

How Recent is the Evidence

  • Databases were searched up to July 2009.

Research Gaps

  • Further large RCTs studies are required to determine the effect of CSII and MI on outcomes such as hypoglycaemia, mortality, diabetes late complications and other adverse effects, for an extended period of time, using validated scales. Cost effectiveness analysis is warranted.

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