Spurious Elevation of Glucose Concentration during Administration of High Dose of Ascorbic Acid in a Patient with Type 2 Diabetes on Hemodialysis

Abstract

We describe herein a case of life-threatening hypoglycemia due to spurious elevation of glucose concentration during the administration of ascorbic acid in a type 2 diabetic patient. A 31-year-old female was admitted for proliferative diabetic retinopathy treatment and prescribed high dose ascorbic acid. During hospitalization, she suddenly lost her consciousness and her glucose concentration was 291 mg/dL, measured using self-monitoring blood glucose (SMBG) device, while venous blood glucose concentration was 12 mg/dL. After intravenous injection of 50% glucose solution, the patient became alert. We reasoned that glucose measurement by SMBG device was interfered by ascorbic acid. Physicians should be aware of this interference; high dose ascorbic acid may cause spurious elevation of glucose concentration when measuring with SMBG devices.

Accuracy of Point‐of‐Care Blood Glucose Level Measurements in Critically Ill Patients with Sepsis Receiving High‐Dose Intravenous Vitamin C

“…The degree of vitamin C interference on POC BG testing may be influenced by vitamin C concentrations. Data from two case reports, not including burn patients, suggest that artifact is possible with vitamin C concentrations exceeding 340 µg/ml . In these cases, the dose of vitamin C administered was 10 g or higher.…”

“…Multiple cases of inaccurate POC BG level measurements in patients receiving high‐dose IV vitamin C were reported, but none of these patients had sepsis. The indications for vitamin C in these studies included malignancy, diabetic retinopathy, and burn resuscitation.…”

“…The indications for vitamin C in these studies included malignancy, diabetic retinopathy, and burn resuscitation. The lowest reported dose of IV vitamin C to affect POC BG level measurements was 10 g/day, resulting in a POC BG level of 291 mg/dl and a simultaneous venous BG level of 12 mg/dl . Two studies describing this phenomenon were published in the burn literature.…”

“…Additionally, a case series involving seven burn patients reported a difference in POC BG and laboratory BG levels ranging from 10–200 mg/dl . In some cases, the interference appeared to continue well beyond the discontinuation of vitamin C therapy …”

“…Another potential confounder with vitamin C is its potential to interfere with point‐of‐care (POC) glucose testing and associated interventions to maintain glycemic control. Literature involving 15 patients in a variety of settings (burns, cancer, diabetes mellitus) receiving IV vitamin C in doses of 10 g/day or higher described artifactually high POC blood glucose (BG) level measurements ranging from 10–280 mg/dl above laboratory test results . Unpublished data suggest that this degree of artifact is not apparent with vitamin C doses used in patients with sepsis .…”