We studied short-term changes in plasma lipid levels in type I diabetics treated with either a conventional insulin regimen or continuous subcutaneous insulin infusion. Mean plasma glucose dropped from 260 ± 18 to 134 ± 8 mg/dl when conventional treatment was used and from 194 ± 18 to 108 ± 8 mg/dl with CSII. Both forms of therapy were associated with a significant fall in plasma triglyceride levels. However, only CSII treatment produced significant changes in total plasma cholesterol and LDL cholesterol levels. Total cholesterol fell from 195 ± 17 mg/dl to 161 ± 11 mg/dl and LDL cholesterol fell from 129 ± 13 mg/dl to 102 ± 9 mg/dl.
We conclude that improved diabetic control by any method is effective in lowering plasma triglyceride levels, but it requires almost perfect metabolic control to affect plasma cholesterol and LDL cholesterol levels. The changes in plasma lipid and lipoprotein achieved with CSII may favorably alter the prediction for the development of premature atherosclerosis in our patients.