New Indices for Predicting Glycaemic Variability

Abstract

Blood glucose variability is known to be associated with increased risk of long-term complications. Reliable indices for predicting hyperglycaemic and hypoglycaemic fluctuations are therefore needed. Glycaemic standard deviation (SD) obtained by continuous glucose monitoring correlates closely with nine previously described glycaemic variability formulas. Here, new indices predictive of glycaemic variability were developed, which can be calculated from laboratory measures based on a single blood draw. The indices included the glycated albumin (GA) to HbA1c ratio (GA/A1c ratio) and the fasting C-peptide immunoreactivity (FCPR) to fasting plasma glucose (FPG) ratio (FCPR index). Predictive values of these indices were assessed in 100 adults with diabetes. GA/A1c ratio and FCPR index showed close associations with glycaemic SD in addition to the nine existing glucose variability formulas. Subjects with a GA/A1c ratio ≥2.8 and FCPR index <3.0 showed the greatest SD and longest durations of hypoglycaemia, while those with a GA/A1c ratio <2.8 and FCPR index ≥3.0 had smaller SDs and little sign of hypoglycaemia. In adults with diabetes, a high GA/A1c ratio and low FCPR index value reflect higher glycaemic excursions, irrespective of diabetes type. Simultaneous measurements of GA, HbA1c, FPG and FCPR may help to identify a group of patients who warrant closer monitoring in relation to glycaemic variability and hypoglycaemia.

The ratio of glycated albumin to hemoglobin A1c measured in IFCC units accurately represents the glycation gap

“…The GA/A1C ratio may thus reflect worsening or improving fluctuations in glycemic control over the short term [21,22]. Some previous authors have argued that a high GA/A1C ratio is associated with postprandial glucose excursion, early progression to insulin therapy in type 2 diabetes, or other events [35,36]. A high G-gap, corresponding to a low GA/ A1C ratio in the present study, has been reported to be a predictive indicator of diabetic complications, especially diabetic nephropathy [3][4][5]7].…”

Lower beta cell function relates to sustained higher glycated albumin to glycated hemoglobin ratio in Japanese patients with type 2 diabetes

“…Recent studies suggest that the effect of treatment strategy on glycemic variability is relatively small [9,10,33,34]. Whether this was due to insufficient control of glycemic variability with current therapy or to other factors affecting GA/HbA1c should be addressed in future prospective studies.…”

“…It has been shown that GA and GA/HbA1c are more sensitively correlated with postprandial glucose excursion than is HbA1c [6,7,8,9]. Thus, not only HbA1c but also GA and GA/HbA1c are expected to be important markers for the development of diabetic complications [24].…”

Evaluation of Glycemic Variability in Well-Controlled Type 2 Diabetes Mellitus

“…Because GA levels increase as blood glucose levels rise 33 and the rate of GA level increase is 10 times faster than that of hemoglobin, 34 serum GA levels may also be affected by temporary blood glucose spikes. 35 However, the exact reasons why FA and GA are related to daily glycemic excursions remain unclear. 36 FA assays are cheap and fast and can be performed in routine laboratories; however, they are currently underutilized.…”