Utility of casual postprandial glucose levels in type 2 diabetes management.
OBJECTIVE
Because readily available glycemic indicators are needed to guide clinical decision-making for intensification of diabetes therapy, our goals were to define the relationship between casual postprandial plasma glucose (cPPG) levels and HbA(1c) in patients with type 2 diabetes and to determine the predictive characteristics of a convenient glucose cutoff.


METHODS
We examined the relationship between cPPG levels (1-4 h post meal) and HbA(1c) levels in 1,827 unique patients who had both determinations during a single office visit.


RESULTS
The population studied was predominantly African American and middle-aged, with average cPPG of 201 mg/dl and HbA(1c) of 8.4%. The prevalence of HbA(1c) > or = 7.0% was 67% and HbA(1c) >6.5% was 77%. Overall, cPPG and HbA(1c) were linearly correlated (r = 0.63, P < 0.001). The correlation between cPPG and HbA(1c) was strongest in patients treated with diet alone (n = 348, r = 0.75, P < 0.001) and weaker but still highly significant for patients treated with oral agents (n = 610, r = 0.64, P < 0.001) or insulin (n = 869, r = 0.56, P < 0.001). A cutoff cPPG >150 mg/dl predicted an HbA(1c) level > or = 7.0% in the whole group, with a sensitivity of 78%, a specificity of 62%, and an 80% positive predictive value. The same cPPG cutoff of 150 mg/dl predicted an HbA(1c) level >6.5%, with a sensitivity of 74%, a specificity of 66%, and an 88% positive predictive value.


CONCLUSIONS
When rapid-turnaround HbA(1c) determinations are not available, a single cPPG level >150 mg/dl may be used during a clinic visit to identify most inadequately controlled patients and allow timely intensification of therapy.
El-Kebbi
Imad M
IM
Division of Endocrinology and Metabolism, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia 30303, USA. ielkebb@emory.edu
Ziemer
David C
DC
Cook
Curtiss B
CB
Gallina
Daniel L
DL
Barnes
Catherine S
CS
Phillips
Lawrence S
LS
D044383:Black People; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D003927:Diet, Diabetic; D005260:Female; D005845:Georgia; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D007004:Hypoglycemic Agents / Q000145:classification / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D001741:Black or African American
D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents