Area under the curve of glucose : an accurate indicator of glucose control in type 2 diabetic patients

Abstract

Relationships between the area under the curve of glucose (AUC glucose), self-monitored blood glucose (SMBG) levels and hemoglobin A1c(A!C) in type 2 diabetes patients were studied. Within 2 weeks patients did SMBG four times a day for each meal twice on different days; immediately before meal (“0 h” or pre meal), 1, 2 and 4 hour(h) after meal. SMBG level at each time point was reported as mean level from two measurements. A1C was measured 2 months later. AUC glucose for each meal were calculated from SMBG between 0-1 h, 1-2 h, and 2-4 h. Relationships between AUC glucose, SMBG level and A1C were done by using Pearson correlation. Sixty-four patients at the Police General Hospital, Bangkok were studied. The sum of AUC glucose 3 meals was strongly correlated with A1C (r=0.746, p< 0.01). AUC glucose of lunch meal and 2-4 hour post lunch were strongly correlated with A1C (r=0.759 and r= 0.727, p< 0.01) in insulin combined with oral agent users (N=25). In oral agent users (N= 39) AUC glucose of dinner meal and 0-1 hour after dinner correlated with A1C (r =0.680 and r=0.707, p<0.01). The mean SMBG levels of 3 meal and of pre breakfast were correlated with A1C [ r= 0.766, and r=0.689, p< 0.01 (N=64) ; r = 0.786 and r=0.638, p <0.01(N=25) and r=0.695,and r=0.652, p<0.01(N=39)] . SMBG level at 4 hour post lunch was also correlated with A1C (r=0.671, p<0.01)(N=64). This same relationship was also found with the insulin combined with oral user group (r=0.725, p< 0.01) (N=25). For oral agent users, A1C was correlated with SMBG level before dinner (r=0.628, p <0.01) (N=39). AUC glucose and SMBG level can be used as indicators of glucose control. Besides pre breakfast SMBG level at 4 hour post lunch and pre dinner are recommended for insulin combined users and oral agent users, respectively.