A new approach to improved metabolic control in diabetics: continuous subcutaneous insulin infusion

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.

Adsorption of insulin to the surface of peritoneal dialysis solution containers

Continuous ambulatory peritoneal dialysis (CAPD) is becoming widely used in diabetics with end-stage renal disease. One of the proposed advantages of this technique is the ability to administer insulin intraperitoneally. The administration of insulin by this route provides acceptable plasma glucose control with no need for subcutaneous injections. Because adsorption of insulin to glass and polyvinyl chloride (PVC) surfaces is known to occur with intravenous fluid systems, this study was conducted to measure insulin adsorption to dialysis fluid systems. The effects of time, temperature, heparin concentration, dextrose concentration, and insulin concentration in 2-L glass and PVC dialysis solution containers were studied. While all factors significantly affected adsorption to the PVC containers, the effects of heparin and dextrose were considered to be clinically unimportant. The percentage of insulin adsorbed to the PVC surface increased with increasing time and temperature and decreased with increasing insulin concentrations. Under the conditions studied, 7.1% to 9.6% of insulin added to PVC containers was lost within the first minute. Since 15 to 30 minutes is required by most CAPD patients to prepare and instill the dialysate, 10% to 20% of added insulin may be adsorbed to the PVC bad. The adsorption of insulin to the glass surfaces was rapid with 39.6% to 42.8% being lost within the first minute. All factors studied significantly affected adsorption to the glass, but the effects of time, temperature, dextrose, and heparin were considered to be of minor clinical importance.(ABSTRACT TRUNCATED AT 250 WORDS)