A Cochrane review [Abstract] 1 included 23 studies with a total of 976 subjects with type 1 diabetes. Studies compared continuous insulin infusion (CSII) with three or more insulin injections per day (MI) in people with type 1 diabetes mellitus; 7 of the studies were performed in participants under 18 years of age. There was a statistically significant difference in glycosylated haemoglobin A1c (HbA1c) favouring CSII (WMD -0.3%, 95% CI -0.1 to -0.4%, statistical heterogeneity I2 =50%; 20 studies). 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.
Another systematic review and meta-analysis 2 included 25 RCTs. A reduction in glycosylated hemoglobin was found in patients treated with continuous subcutaneous insulin infusion compared to multiple daily injections (mean difference 0.37; 95 % confidence interval, 0.24-0.51). This effect was demonstrated in both children and adults. There was no significant difference in minor or severe hypoglycemic events. Continuous infusion was associated with lower incidence of nocturnal hypoglycemia. There was no significant difference in the time spent in hypoglycemia.
Another meta-analysis 3 comparied CSII with traditional MI in type 1 diabetes. In trials with rapid-acting analogue the advantage of CSII was significantly smaller than in trials with regular human insulin (HbA1c difference - 0.29, 95% CI - 0.46 to - 0.13 vs - 1.93, 95% CI - 1.84 to - 0.42%; p = 0.02). Different rapid-acting analogues (lispro and aspart) provided similar results. With respect to severe hypoglycemia, CSII did not produce a significant reduction of risk in comparison with MI. Conversely, CSII was associated with a significant increase in the incidence of reported diabetic ketoacidosis.
Comment: The quality of evidence is downgraded by study quality (unclear allocation concealment).
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