Two-Year Experience with Continuous Subcutaneous Insulin Infusion in Relation to Retinopathy and Neuropathy

Abstract

Thirty patients with insulin-dependent diabetes mellitus (IDDM) who had advanced background retinopathy were randomized to unchanged conventional treatment (UCT) or to continuous subcutaneous insulin infusion (CSII). They were followed prospectively for 2 yr. The mean blood glucose and hemoglobin A1C (HbA1C) were significantly lower in the CSII group than in the UCT group. The mean blood glucose and HbA1C did not change from the first to the second year in either of the treatment groups in spite of less frequent home-monitoring of blood glucose and less frequent outpatient visits during the second year. Four patients in the CSII group and five in the UCT group developed proliferative retinopathy. However, a marginally significant trend was found toward more frequent improvement of retinal morphology in the CSII group (47%) than in the UCT group (13%). Beat-to-beat variation was found to deteriorate significantly with UCT compared with a nonsignificant improvement with CSII therapy. Vibration sense was unchanged in both treatment groups. It is concluded that near-normal blood glucose levels can be maintained with CSII therapy in spite of less frequent home-monitoring of blood glucose and outpatient visits. Furthermore, established background retinopathy may progress to proliferative retinopathy in spite of 2 yr of near-normal blood glucose levels. However, a marginally significant trend toward more frequent improvement of retinal morphology was found among CSII-treated patients compared with conventionally treated patients. Large-scale, prospective, randomized studies are needed to confirm these results.

Diabetic retinopathy

“…This phenomenon was reported in some early intervention studies of intensified insulin treatment [83,84,85], confirmed by the DCCT [89] and also described in patients with Type II diabetes after starting insulin to improve control [90]. Early worsening was observed in moderate to severe NPDR within 6 to 12 months of rapidly improving control but appeared to be selflimiting.…”

“…The notion that higher chronic blood concentrations of glucose result in more frequent and severe microvascular damage is perhaps intuitive and was supported by prospective observational studies [51,82] and small intervention trials [83,84,85,86]. However, the role played by other factors could not be put into perspective until two major long-term intervention trials were published.…”

Long-term progression of retinopathy after initiation of insulin therapy in Type�2 diabetes: an observational study

“…This was reported in several large studies [1,2,3,4] and was confirmed in the Diabetes Control and Complications Trial (DCCT) [5,6,7]. The DCCT study showed deterioration of retinopathy in patients with Type 1 diabetes during the first 3 to 12 months with intensive therapy, followed by a beneficial effect, which increased in magnitude over time.…”

Blood glucose control and microvascular complications ? what do we do now?

“…In the long term glycaemic control was monitored by HbAlc measurements. This made it possible to test the hypothesis that nearnormoglycaemia retarded the progression of late complications and led to several trials in the early [2][3][4][5][20][21][22][23] which aimed at secondary prevention, as the study populations already had variable degrees of complications.…”

“…[1]. This statement was based on the results from several Scandinavian trials which started 10-12 years ago [1][2][3][4][5][6][7]. Since then further evidence has strengthened the basis of the above conclusion, particularly results from the Stockholm study [8] and the Diabetes Control and Complications Trial (DCCT) [9].…”