this was a prospective study at three large swiss hospitals assessing the impact of strategies to improve postprandial glucose by optimizing the combination of oral antidiabetes drugs and/or insulin according to a prespecified scheme ( 5 ) .
included patients had type 2 diabetes 6 months with a1c between 7.0 and 12.0% . patients with renal insufficiency or proteinuria were excluded .
written consent was obtained , and the study was approved by the local ethics committees .
patients regularly monitored their blood glucose levels before and 2 h after main meals ( glucotrend premium ; roche diagnostics , mannheim , germany ) , and 1,5-ag was measured at each time point in a central laboratory ( lana 1.5 auto liquid reagent ; interbiotech , tokyo , japan ; automated on a hitachi 917 analyzer , coefficient of variation 5.2% ) .
postprandial glucose values were included in the analysis if measured between 110 and 130 min after the corresponding preprandial measurement .
the models were adjusted for age , sex , treatment modalities , time in study , and time of day .
1,5-ag measurements were examined for correlations with postprandial glucose values taken over the following prespecified preceding time periods : 3 days , 1 week , then weekly up to 12 weeks .
all analyses were performed using stata 10.0 ( stata , college station , tx ) .
all 55 patients ( 19 women and 36 men ) contributed to the present analysis .
the average number of self - measurements of blood glucose per patient and year were 405  224 ( fasting / preprandial ) and 230  122 ( postprandial ) .
mean fasting / preprandial glucose was 155  48 mg / dl at the beginning and 133  46 mg / dl at the end of the study , and corresponding values for postprandial glucose were 172  55 and 162  53 mg / dl .
mean a1c was 8.7  1.3% at baseline and 7.7  1.0% at study end .
mean 1,5-ag was 4.2  3.5 g / ml at baseline and 6.4  3.5 g / ml at study end .
a1c and 1,5-ag were negatively correlated ( r = 0.42 , p < 0.001 ) . the correlation coefficient of postprandial glucose values with 1,5-ag varied across the prespecified time periods preceding the measurement of 1,5-ag ( fig .
1 ) : 0.34 ( p < 0.05 ) for 3 days , 0.38 ( p <
0.001 ) for 1 week , and 0.40 ( p < 0.001 ) for 2 weeks . afterward , the strength of the correlation decreased ( p < 0.001 for all remaining correlations ) .
the association of fasting / preprandial glucose and 1,5-ag was lower ( 0.19 to 0.23 , p < 0.001 for all correlations ) and did not reveal a time dependency ( fig .
1 ) . adjusting analyses for age , sex , treatment modalities , time in study , and time of day did not change the observed time dependency ( data not shown ) .
time - specific correlation coefficients were 0.260.28 for a1c with fasting / preprandial and 0.220.30 for a1c with postprandial glucose , without evidence of a time dependency .
the present study is the first to longitudinally assess the association of 1,5-ag with 2-h postprandial glucose values in diabetic patients followed over 12 months in an outpatient setting . although correlations were moderate ( < 0.5 in magnitude ) , 1,5-ag best reflected 2-h postprandial glucose values in the 2 preceding weeks .
correlations were weaker for a1c with fasting / preprandial as well as with postprandial glucose . a comparable
albeit slightly stronger correlation of 1,5-ag with postprandial glucose in a population of type 1 and 2 diabetic patients was recently reported . of note ,
dungan et al . ( 1 ) used a continuous glucose monitoring system to measure the area under the curve for glucose levels exceeding 180 mg / dl , while the present study was based on self - measured glucose values .
the lower number of postprandial compared with preprandial values reflects the difficulty to motivate patients for additional measurements and substantiates the role of 1,5-ag as a substitute for postprandial glucose measurements , complementing the widely used a1c and fructosamine measurements .
a recent cross - sectional study in prediabetic japanese patients found a higher correlation with 2-h postprandial glucose ( 3 ) .
it is noteworthy that 1,5-ag is subject to urinary excretion followed by almost complete reabsorption , which is competitively inhibited by glucose if the renal threshold for glucosuria is exceeded ( 6 ) .
while glucosuria in prediabetic individuals mainly occurs in the context of carbohydrate loading , diabetic patients may reveal increased glucose values independently of meals .
moreover , differences in absolute levels of 1,5-ag between asian and caucasian individuals have been previously reported ( 7 ) . in conclusion
, this longitudinal study in an outpatient setting shows that 1,5-ag best reflects 2-h postprandial glucose values in the 2 preceding weeks .
 objective  to assess the association of 1,5-anhydroglucitol ( 1,5-ag ) with 2-h postprandial glucose values in type 2 diabetic patients followed over 12 months in an outpatient setting.research design and methods  in 55 patients , we examined self - measured postprandial blood glucose values for correlations with 1,5-ag values over prespecified preceding time periods ( 3 days , 1 week , and weekly up to 12 weeks).results  the correlation coefficients for postprandial glucose values were 0.34 ( p < 0.05 ) for 3 days , 0.38 ( p < 
 0.001 ) for 1 week , and 0.40 ( p < 
 0.001 ) for 2 weeks preceding the measurement of 1,5-ag . 
 correlations declined for time periods > 2 weeks before measurement of 1,5-ag . 
 the correlation was lower with fasting / preprandial plasma glucose levels . 
 there was no time dependency for the correlation between a1c and fasting or postprandial glucose.conclusions1,5-ag best reflected the 2-h postprandial glucose values of the 2 previous weeks . 
RESEARCH DESIGN AND METHODS
RESULTS
CONCLUSIONS