Accuracy of FreeStyle Libre flash glucose monitoring in patients with type 2 diabetes who migrated from highlands to plains.

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.

[Change of Hepcidin in Patients with Iron Overload at the Tibet Plateau].

OBJECTIVE: To explore the possible etiological factors of iron overload through detecting plasma hepcidin level of adult males at Tibet plateau. METHODS: 81 Tibetan male adult patients hospitalized in our department during January 2017 - December 2018 were selected, and divided into iron overload group and non-iron overload group. The difference in serum ferritin, serum iron, total iron binding capacity, hemoglobin, HBSAg, ALT, AST, albumin, creatinine and hepcidin of patients in each group were tested. To analyze the differences between groups. The regression analysis was applied to analyze the relationship between laboratory index and hepcidin. RESULTS: The plasma hepcidin of iron overload group was significantly higher than that of the non-iron overload group [93.69 (65.57-133.92) ng/ml vs 63.93 (40.01-90.65) ng/ml] (P=0.005). And there was a positive correlation between plasma hepcidin and ferritin (ß=0.03 ng/ml，95%CI 0.01-0.05) (P<0.01) and BMI (ß=5.71 ng/ml，95%CI 0.54-10.88) (P<0.05）. CONCLUSION: Iron overload at Tibet plateau can not be attributed to hepcidin deficiency in Tibetan adult male patients. Iron metabolism disorders in Tibetan population may be associated with metabolic syndrome.

Serum Ferritin Independently Predicts the Incidence of Chronic Kidney Disease in Patients with Type 2 Diabetes Mellitus.

AIM: This study aimed to determine whether serum ferritin (SF) is an independent risk factor of the incidence of chronic kidney disease (CKD) and rapid renal function decline (RFD) in male Tibetan patients with type 2 diabetes mellitus (T2DM). METHODS: We performed a retrospective cohort study that included 191 male Tibetan patients with T2DM without CKD. Patients were divided into three groups according to the level of SF. The following outcomes were measured: cumulative incidence of chronic kidney disease [i.e. estimated glomerular filtration rate (eGFR) <60 mL/min per 1.73 m2 and/or urinary albumin/creatine ratio (ACR) ≥30 mg/g] and RFD (i.e. decrease in eGFR of ≥25% from baseline or a decline rate of ≥3 mL/min per 1.73 m2 annually). RESULTS: In total, over a median follow-up period of 23 months, 30 (15.7%) and 89 patients (46.6%) developed CKD and RFD. In multivariable Cox models, a 100 ng/mL increment in SF was associated with a 1.12-fold (95% CI: 1.02-1.24) higher adjusted risk for incidence of CKD. The adjusted-HR of CKD was 1.31 (95% CI: 0.38-4.53) and 2.92 (95% CI: 0.87-9.77) for those in tertile 2 and tertile 3, respectively, compared with the patients in tertile 1. However, SF was not significantly associated with RFD (adjusted-HR: 1.06, 95% CI: 0.99-1.14). CONCLUSION: Serum ferritin independently predicts the incidence of CKD in male Tibetan patients with T2DM. High levels of serum ferritin may play a role in the pathogenesis leading to the development of CKD in T2DM.

[Analysis of HFE and Non-HFE Mutations in a Tibet Cohort with Iron Overload].

OBJECTIVE: The explore the molecular basis of iron-overload in Tibet nationality population of Tibet. METHODS: The inpatients with iron-overload in our department from Dec. 1st 2014 to Jul.31st 2016 were enrolled in this study. Abdominal MRI and the mutation sites C282Y and H63D in HFE exon were examined. For HFE mutation-negative patients, the non-HFE mutation was detected, including 5 HJV mutations of G320V, p.Q312X, p.D249H, p.I281T, p.C321X and 2 TFR2 mutations: (Y250X, I238M), and 2 SLC40A1 mutations: (V162del, N144H). RESULTS: Among 113 iron overload patients, only one showed homozygous p.H63D mutation, and one showed heterozygosis p.H63D mutation. In 73 patients accepted non-HFE gene detection, only one was heterozygosis p.D249N mutation in HJV, and one was heterozygosis p.I238M mutation in TFR2. CONCLUSION: Currently, the pathogenic gene for Tibetan iron-overload has not yet been found.