Diabetes, Metabolic Syndrome and Obesity: Targets and Therapy (Nov 2022)

Diabetes Complications and Related Comorbidities Impair the Accuracy of FreeStyle Libre, a Flash Continuous Glucose Monitoring System, in Patients with Type 2 Diabetes

  • Wen X,
  • Zeng N,
  • Zhang N,
  • Ou T,
  • Li X,
  • Li X,
  • Li W,
  • Xu K,
  • Du T

Journal volume & issue
Vol. Volume 15
pp. 3437 – 3445


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Xiaofang Wen,1,* Nan Zeng,1,* Ningbo Zhang,1,2,* Tingting Ou,1 Xiaowei Li,1 Xiaoying Li,1 Wangen Li,1 Kang Xu,3 Tao Du1 1Department of Endocrinology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, People’s Republic of China; 2Department of Endocrinology, Peking University Shenzhen Hospital, Shenzhen, 518036, People’s Republic of China; 3Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, 510120, People’s Republic of China*These authors contributed equally to this workCorrespondence: Tao Du; Kang Xu, Email [email protected]; [email protected]: Although flash continuous glucose monitoring systems (FCGM) accuracy has been extensively studied in diabetes, its accuracy is still not fully evaluated in type 2 diabetes (T2D) patients in real-world settings. In the present study, we aim to assess the effects of diabetes complications and related comorbidities on FCGM accuracy in T2D patients with diabetes complications and related comorbidities in the real world.Methods: FCGM data were collected at eight-time points daily (3 AM, 7 AM, 9 AM, 11 AM, 1 PM, 5 PM, 7 PM, and 9 PM) from 742 patients with T2D and compared with simultaneous fingertip capillary blood glucose (reference blood glucose, REF), and the difference was evaluated using Parkes error grid (PEG), surveillance error grid (SEG), and logistic regression analysis.Results: In total, 25,579 FCGM/REF data pairs were included in the study. The FCGM values were lower than the paired REF values in 75% of the pairs. The maximum bias (− 23.0%) and maximum mean absolute relative difference (24.5%) were observed at 3 AM among eight-time points. SEG analysis also demonstrated the highest percentage of paired readings in moderate and great risk zone (C and D) at 3 AM than PEG analysis (7.33% vs 0.43%, P< 0.001). According to the SEG classification, hypoglycemia, infection, diabetic foot, diabetic ketoacidosis, and hypertension were independent risk factors that impaired FCGM accuracy in patients.Conclusion: FCGM commonly underestimates blood glucose levels. Compared with PEG, SEG analysis seems more conducive to the analysis of FCGM performance. The present data highlights the impairment of diabetes complications and related comorbidities on the FCGM accuracy in T2D patients.Keywords: flash continuous glucose monitoring system, type 2 diabetes, surveillance error grid, Parkes error grid, diabetes complications