Does glucose still have a role in the monitoring and management of diabetes?

Abstract

Introduction:  Since time immemorial glucose has been used as front line biomarker in the management of diabetes. Glucose has probably the highest number analytical methods developed in an attempt to optimally monitor and manage diabetes. Most of these analytical methods are in-cooperated in Point-of-Care Testing (POCT) devices and central laboratory analysers. Therefore, most healthcare facilities in South Africa depend on the results of random glucose from glucometer POCT devices. Since the introduction of glycated Haemoglobin (HbA1c), which is now accepted as a better diagnostic and monitoring biomarker for diabetes, the aim of the study was to determine if glucose measurement still has a role in the monitoring and management of diabetes.

Design: A comparative study between glucose and HbA1c was conducted at an academic hospital diabetes outpatients' clinic. Based on the clinic's protocol, patients had random capillary finger prick blood for both glucose and HbA1c tested on site by a medical laboratory scientist before consultation with the attending clinicians.

Results: Ninety one percent of the 171 patients had abnormal HbA1c results and 41.5% (70 of the171) patients had abnormal random blood glucose levels. Bland-Altman scatter plot analysis had a mean glucose concentration of 1.984, with limits of acceptance of -5.527 and 9.495. An agreement of 42.7% was calculated. Spearman's correlation was also performed and revealed a statistically moderate correlation between random capillary glucose and HbA1c (r = 0.60, p=< 0.001).

Conclusion:  There is a low-to-moderate correlation between HbA1c and random glucose levels. Therefore, the age old measurement of glucose has lost its central role in the management and monitoring of patients with diabetes.