Intravenous insulin does not affect diabetic post-PCI inflammatory markers
MedWire News: Intravenous (iv) insulin does not prevent rises in inflammatory or oxidative stress markers after percutaneous coronary intervention (PCI) in patients with diabetes compared with standard insulin treatment, study findings suggest.
Diabetic patients who have undergone PCI are usually managed with insulin administered subcutaneously, which generally fails to attain plasma glucose targets, note the researchers from Hospital de Clínicas de Porto Alegre in Brazil.
They examined the value of iv insulin in an open-label, randomized trial in 70 patients with diabetes and stable coronary artery disease who had a mean age of 60.5 years and had undergone angioplasty with bare metal stent implantation.
Participants were randomly assigned to a standard approach, where hyperglycemia was managed with subcutaneous regular insulin as needed with a target of 250 mg/dl or less, or to 24 hours of continuous iv insulin infusion, targeting glucose levels of 80 to 100 mg/dl in premeal periods and lower than 140 mg/dl in random glucose measurements.
Blood samples were collected immediately after PCI and again 24 hours later.
At 24 hours after PCI, mean glycemia was significantly lower and insulinemia higher among patients receiving iv versus subcutaneous insulin, report Beatriz D'Agord Schaan and co-workers in the Journal of Clinical Endocrinology and Metabolism.
Levels of the inflammatory marker C-reactive protein doubled in the 24 hours after PCI in both groups, and interleukin-6 levels doubled with iv-insulin and tripled with standard treatment, but differences between the groups were not statistically significant.
Endothelin 1 levels were approximately 30% higher 24 hours after PCI compared with immediately after the procedure in both groups, with no significantly between-group differences.
The treatment groups also did not significantly differ in protein oxidation, with the plasma carbonyl content not significantly changing in either group in the 24 hours after PCI and total serum antioxidant status rising in both.
The authors conclude that despite the fact that "continuous iv insulin effectively increased insulin levels and prevented hyperglycemia, a clear rise in inflammatory markers was observed after PCI."
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By Anita Wilkinson