Observational Study
Copyright ©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Jun 15, 2024; 15(6): 1254-1262
Published online Jun 15, 2024. doi: 10.4239/wjd.v15.i6.1254
Accuracy of FreeStyle Libre flash glucose monitoring in patients with type 2 diabetes who migrated from highlands to plains
Zeng-Mei Sun, Yuan-Ze Du, Su-Yuan Wang, Shu-Yao Sun, Yan Ye, Xue-Ping Sun, Ming-Xia Li, Hua He, Wun-Chun Long, Cheng-Hui Zhang, Xuan-Yu Yao, Wu-Yi Fan, Ling Wang, Yun-Hong Wu
Zeng-Mei Sun, Yun-Hong Wu, Department of Endocrinology and Metabolism, Hospital of the People's Government of the Tibet Autonomous Region in Chengdu, Chengdu 614000, Sichuan Province, China
Yuan-Ze Du, Department of Nursing, Hospital of Chengdu Office of the People's Government of Tibet Autonomous Region, Chengdu 610041, Sichuan Province, China
Su-Yuan Wang, Shu-Yao Sun, Yan Ye, Xue-Ping Sun, Ming-Xia Li, Hua He, Wun-Chun Long, Cheng-Hui Zhang, Xuan-Yu Yao, Wu-Yi Fan, Ling Wang, Department of Endocrinology, Hospital of Chengdu Office of the People's Government of Tibet Autonomous Region, Chengdu 610041, Sichuan Province, China
Co-first authors: Zeng-Mei Sun and Yuan-Ze Du.
Author contributions: Sun ZM, Wang SY, and Wu YH conceived and designed the study protocol; Sun SY, Li MX, He H, and Zhang CH performed the literature search; Du YZ, Ye Y, Long WC, Fan WY, and Wang L were involved in the data collection; Sun ZM and Du YZ performed the data analysis, and drafted the original manuscript. Sun ZM and Du YZ contributed equally to this work as co-first authors. They are designated as co-first authors as the lead investigators of this work. They took the lead in managing the data collection and data analysis processes and collaborated on the final manuscript and completed revisions. Their contributions were equally significant. Therefore, we believe that designating Sun ZM and Du YZ as co-first authors is fitting for our manuscript. Furthermore, Wu YH, who has a rich academic background, guided the entire process of this work, and is designated as the corresponding author.
Supported by Health and Family Planning Project of Sichuan Province, No. 17PJ069; Tibet Autonomous Region Science and Technology Program, No. XZ202303ZY0011G.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Hospital of Chengdu Office of the People's Government of the TAR, China.
Informed consent statement: All study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
Data sharing statement: The datasets generated and analyzed during the study are not publicly available due to the regulations of the hospital. Readers of the article need to discuss with our hospital before the release of the datasets.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Yun-Hong Wu, Doctor, PhD, Chief Doctor, Chief Physician, Professor, Department of Endocrinology and Metabolism, Hospital of the People's Government of the Tibet Autonomous Region in Chengdu, No. 20 Ximianqiao Hengjie, Wuhou District, Chengdu 614000, Sichuan Province, China. wu_yunhong@163.com
Received: December 15, 2023
Revised: February 2, 2024
Accepted: March 19, 2024
Published online: June 15, 2024
Processing time: 179 Days and 6.3 Hours
Abstract
BACKGROUND

The FreeStyle Libre flash glucose monitoring (FGM) system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose. Due to its increased usage in clinics, the number of studies investigating its accuracy has increased. However, its accuracy has not been investigated in highland popu-lations in China.

AIM

To evaluate measurements recorded using the FreeStyle Libre FGM system compared with capillary blood glucose measured using the enzyme electrode method in patients with type 2 diabetes (T2D) who had migrated within 3 mo from highlands to plains.

METHODS

Overall, 68 patients with T2D, selected from those who had recently migrated from highlands to plains (within 3 mo), were hospitalized at the Department of Endocrinology from August to October 2017 and underwent continuous glucose monitoring (CGM) with the FreeStyle Libre FGM system for 14 d. Throughout the study period, fingertip capillary blood glucose was measured daily using the enzyme electrode method (Super GL, China), and blood glucose levels were read from the scanning probe during fasting and 2 h after all three meals. Moreover, the time interval between reading the data from the scanning probe and collecting fingertip capillary blood was controlled to < 5 min. The accuracy of the FGM system was evaluated according to the CGM guidelines. Subsequently, the factors influencing the mean absolute relative difference (MARD) of this system were analyzed by a multiple linear regression method.

RESULTS

Pearson’s correlation analysis showed that the fingertip and scanned glucose levels were positively correlated (R = 0.86, P = 0.00). The aggregated MARD of scanned glucose was 14.28 ± 13.40%. Parker's error analysis showed that 99.30% of the data pairs were located in areas A and B. According to the probe wear time of the FreeStyle Libre FGM system, MARD1 d and MARD2–14 d were 16.55% and 14.35%, respectively (t = 1.23, P = 0.22). Multiple stepwise regression analysis showed that MARD did not correlate with blood glucose when the largest amplitude of glycemic excursion (LAGE) was < 5.80 mmol/L but negatively correlated with blood glucose when the LAGE was ≥ 5.80 mmol/L.

CONCLUSION

The FreeStyle Libre FGM system has good accuracy in patients with T2D who had recently migrated from highlands to plains. This system might be ideal for avoiding the effects of high hematocrit on blood glucose monitoring in populations that recently migrated to plains. MARD is mainly influenced by glucose levels and fluctuations, and the accuracy of the system is higher when the blood glucose fluctuation is small. In case of higher blood glucose level fluctuations, deviation in the scanned glucose levels is the highest at extremely low blood glucose levels.

Keywords: Type 2 diabetes; Flash glucose monitoring; Accuracy; Continuous glucose monitor; High altitude

Core Tip: Although blood glucose monitoring is the standard and most established approach for informing diabetes therapy, continuous glucose monitoring has seen a rapid increase in the number of users in recent years. Abnormal glucose metabolism in highland populations is a major health concern worldwide. This study focused on the accuracy of the FreeStyle Libre FGM system in highland populations.