Evaluation of the relationship between glycated hemoglobin A1c and mean glucose levels derived from the professional continuous flash glucose monitoring system

Abstract

Previously, we reported that short-term continuous glucose monitoring (CGM) with the professional iPro2 © CGM device is a good clinical indicator of glycated hemoglobin (HbA1c) levels. However, there was no significant correlation between CGM and HbA1c levels when HbA1c levels were >8.0%. To further investigate this issue, we performed a similar study using the FreeStyle Libre Pro © , a newer device that does not require glucose calibration and allows patients to be examined for up to 14 days. Fifty-nine patients (68% women, 32% men) were examined. Twenty-eight and 31 patients presented with type 1 and type 2 diabetes, respectively. Clinically assessed HbA1c levels were compared to blood glucose levels determined by the FreeStyle Libre Pro © for up to 14 days (10.7 ± 3.7 days). We found a significant correlation between HbA1c and CGM levels even when HbA1c levels were >8.0%. Additionally, the correlation between HbA1c and average glucose was identified with the modern CGM and was found to deviate substantially from the new suggested formula. More importantly, we found a more robust correlation between HbA1c and CGM levels in patients with type 2 diabetes. Overestimation or underestimation of blood glucose levels through CGM might increase the risks of inappropriate clinical treatment of diabetes patients. Our results indicate the need for proper CGM data interpretation individualized for each patient to better assist the determination of customized treatments for patients.

Glucose patterns following alcohol and illicit drug use in young adults with type 1 diabetes: A flash glucose monitoring study

“…However, our data showed a weakening of the relationship between HbA1c and a range of glucose parameters on SUEDs versus non‐SUEDs. In most studies from the literature, a linear relationship exists between HbA1c and glycaemic control parameters such as mean SG and time out of range 24,25 . We found that HbA1c was less closely associated with mean SG, time out of range (SG < 3.9 and >10 mmol/L) and time with SG > 10 mmol/L on days when substances were used.…”

“…In most studies from the literature, a linear relationship exists between HbA1c and glycaemic control parameters such as mean SG and time out of range. 24,25 We found that HbA1c was less closely associated with mean SG, time out of range (SG < 3.9 and >10 mmol/L) and time with SG > 10 mmol/L on days when substances were used. Also, a dose-dependent effect was observed for those days when alcohol alone was consumed.…”

To What Extent Is HbA1c Associated with Glycemic Variability in Patients with Type 1 Diabetes? A Retrospective, Noninterventional Study

“…This observation emphasizes that the measurement of DM management, with respect to the glycemic control, should not be focused only on the mean of the glycemic values but also on the dispersion of those values around the average. This association is supported by several articles [42][43][44]. A recent study that included over 600 young patients with T1DM showed a positive correlation between SD and HbA1c, indicating that a higher HbA1c leads to poorer glycemic control [42].…”

Role of Flash Glucose Monitoring System Combined With Insulin Pump in Blood Glucose Treatment of Patients with Type 2 Diabetes Mellitus

“…Type 2 diabetes mellitus is more common in the elderly. With the increase of the elderly population in recent years, the incidence rate of type 2 diabetes mellitus exhibits an upward trend, so it has become a public health problem endangering people's health [12] . In clinical practice, the pathogenesis of type 2 diabetes mellitus is not completely clear and there is still a lack of means to cure type 2 diabetes mellitus.…”