with attention to the role of diet or medical nutritional therapy on chronic disease , the dietary pattern approach , which involves diet quality indices , has been suggested as a powerful tool because of the complexity of diets [ 1 - 3 ] . in recent decades , several indices have been developed and validated , including the diet quality index ( dqi ) , healthy eating index ( hei ) , mediterranean diet score , healthy diet indicator ( hdi ; based on the world health organization dietary guidelines ) , alternate hei ( ahei ; including american dietary guidelines ) , and dqi - international ( dqi - i ; developed for worldwide national dietary guidelines ) .
the diet quality indices may be used as a quick assessment to evaluate compliance to healthy dietary guidelines and dietary changes after diet education .
there have been several studies that have shown an association between diet quality indices and chronic diseases , especially cancer and cardiovascular diseases .
some research has also demonstrated an association of diet quality indices with obesity and diabetes [ 12 - 15 ] .
however , there have been few studies assessing the relationship between diet quality indices and glycemic control , and on which indices might serve as an appropriate tool to assess diet quality in patients with type 2 diabetes following diet education . in this study
, we tried to determine the relationship between the diet quality indices including hdi , ahei , and dqi - i , and glycemic indices in korean patients with type 2 diabetes , independent of adiposity and energy intake .
then , we also tried to determine which indices were appropriate for assessment of diet quality after dietary education in patients with type 2 diabetes .
subjects were 110 consecutive korean outpatients with type 2 diabetes who visited 2 university hospitals from april 2004 to november 2006 and who were enrolled in a study to evaluate the effectiveness of the medical nutrition therapy ( mnt ) .
briefly , subjects were patients with newly diagnosed type 2 diabetes or patients who had been diagnosed with type 2 diabetes for fewer than 5 years but did not have acute and/or chronic complications . at the time of enrollment ,
height was measured to the nearest centimeter while the subjects were barefoot , and body weight was measured to the nearest 0.1 kg using a digital scale while the subjects wore light clothing .
then , body mass index ( bmi ) was calculated by determining the ratio between weight and height squared ( kg / m ) .
the waist circumference was taken at the narrowest point between the lower costal margin and the superior iliac crest , and the hip circumference was measured at the horizontal level between the symphysis pubis and the greater gluteal protuberance that yielded the maximum measurement .
blood pressure was recorded using a mercury sphygmomanometer twice in a sitting position after subjects had been in a relaxed state for at least 10 minutes .
hypertension was defined as 2 consecutive systolic / diastolic blood pressure measurements > 140/90 mmhg or current treatment with antihypertensive medication .
fasting plasma glucose ( fpg ) , 2-hour postprandial glucose ( pp2 ) concentration , and lipid profile levels were analyzed enzymatically , using an autoanalyzer ( hitachi 760 - 210 , hitachi ltd . ,
( hba1c ) was determined using high - performance liquid chromatography ( hlc-723 g8 , tosoh , tokyo , japan ) .
the dqi - i focused on 4 major aspects : variety ( 0 - 20 points ) , adequacy ( 0 - 40 points ) , moderation ( 0 - 30 points ) , and overall balance ( 0 - 10 points ) .
the scores for all 4 categories were totaled , from 0 to 100 ( 0 being the worst and 100 the best possible scores ) . for the variety and adequacy categories , we used the us exchange list serving size definition   for cross - national comparative work .
the adequacy of intakes for iron , calcium , and vitamin c were examined on the basis of the percentage attainment of the dietary reference intakes in korea .
the hdi was calculated as the sum of dichotomous variables on the basis of 9 items : saturated fatty acids ; polyunsaturated fatty acids ; protein ; complex carbohydrates ; dietary fiber ; fruits and vegetables ; legumes , nuts , and seeds ; mono- and di - saccharides ; and cholesterol ( range 0 - 9 , 0 being the worst and 9 the best possible scores ) . scoring for the ahei was based on intake levels of 9 components : fruits , vegetables , ratio of white to red meat , trans fats , ratio of polyunsaturated to saturated fat , cereal fiber , nuts and soy , moderate amounts of alcohol , and multivitamins over a long period .
each component contributed 0 to 10 points , with 10 indicating that recommendations were met and 0 indicating the poorest dietary behavior .
intermediate intakes were scored proportionally between 0 and 10 , except for the multivitamin component , which was assigned a score of either 2.5 or 7.5 to avoid overweighting of this binary variable .
component scores for ahei were totaled , ranging from 2.5 ( worst ) to 87.5 ( best ) . in our study , the duration of multivitamin use was not measured , because this information was not collected . therefore , the maximum possible ahei score was 82.5 .
we used spss version 10.0 ( spss , chicago , il , usa ) for statistical analysis .
partial correlation coefficients were used to assess the association of the 3 indices of dietary pattern analysis with glycemic indices .
subjects were 110 consecutive korean outpatients with type 2 diabetes who visited 2 university hospitals from april 2004 to november 2006 and who were enrolled in a study to evaluate the effectiveness of the medical nutrition therapy ( mnt ) .
briefly , subjects were patients with newly diagnosed type 2 diabetes or patients who had been diagnosed with type 2 diabetes for fewer than 5 years but did not have acute and/or chronic complications . at the time of enrollment ,
height was measured to the nearest centimeter while the subjects were barefoot , and body weight was measured to the nearest 0.1 kg using a digital scale while the subjects wore light clothing .
then , body mass index ( bmi ) was calculated by determining the ratio between weight and height squared ( kg / m ) .
the waist circumference was taken at the narrowest point between the lower costal margin and the superior iliac crest , and the hip circumference was measured at the horizontal level between the symphysis pubis and the greater gluteal protuberance that yielded the maximum measurement .
blood pressure was recorded using a mercury sphygmomanometer twice in a sitting position after subjects had been in a relaxed state for at least 10 minutes .
hypertension was defined as 2 consecutive systolic / diastolic blood pressure measurements > 140/90 mmhg or current treatment with antihypertensive medication .
fasting plasma glucose ( fpg ) , 2-hour postprandial glucose ( pp2 ) concentration , and lipid profile levels were analyzed enzymatically , using an autoanalyzer ( hitachi 760 - 210 , hitachi ltd . ,
( hba1c ) was determined using high - performance liquid chromatography ( hlc-723 g8 , tosoh , tokyo , japan ) .
the dqi - i focused on 4 major aspects : variety ( 0 - 20 points ) , adequacy ( 0 - 40 points ) , moderation ( 0 - 30 points ) , and overall balance ( 0 - 10 points ) . the scores for all 4 categories were totaled , from 0 to 100 ( 0 being the worst and 100 the best possible scores ) . for the variety and adequacy categories , we used the us exchange list serving size definition   for cross - national comparative work .
the adequacy of intakes for iron , calcium , and vitamin c were examined on the basis of the percentage attainment of the dietary reference intakes in korea .
the hdi was calculated as the sum of dichotomous variables on the basis of 9 items : saturated fatty acids ; polyunsaturated fatty acids ; protein ; complex carbohydrates ; dietary fiber ; fruits and vegetables ; legumes , nuts , and seeds ; mono- and di - saccharides ; and cholesterol ( range 0 - 9 , 0 being the worst and 9 the best possible scores ) . scoring for the ahei was based on intake levels of 9 components : fruits , vegetables , ratio of white to red meat , trans fats , ratio of polyunsaturated to saturated fat , cereal fiber , nuts and soy , moderate amounts of alcohol , and multivitamins over a long period .
each component contributed 0 to 10 points , with 10 indicating that recommendations were met and 0 indicating the poorest dietary behavior .
intermediate intakes were scored proportionally between 0 and 10 , except for the multivitamin component , which was assigned a score of either 2.5 or 7.5 to avoid overweighting of this binary variable .
component scores for ahei were totaled , ranging from 2.5 ( worst ) to 87.5 ( best ) . in our study , the duration of multivitamin use was not measured , because this information was not collected . therefore , the maximum possible ahei score was 82.5 .
we used spss version 10.0 ( spss , chicago , il , usa ) for statistical analysis .
partial correlation coefficients were used to assess the association of the 3 indices of dietary pattern analysis with glycemic indices .
the mean age , bmi , and diabetes duration of subjects were 54.6  8.9 years , 25.4  2.8 kg / m , and 1.6  1.5 years , respectively ( table 1 ) .
the percentages of subjects with hypertension , who regularly exercised , who currently smoked , and who consumed alcohol were 17.3% , 64.6% , 15.5% , and 28.2% , respectively .
forty subjects ( 36.4% ) were treated with oral hypoglycemic agents , but none was on insulin therapy .
the mean fpg , pp2 , and hba1c of subjects were 142.6  33.6 mg / dl , 218.7  78.5 mg / dl , and 7.3  1.2% , respectively .
the average intakes of energy , carbohydrate , and fat in these subjects were 1935  492 kcal / day , 277  78 g / day , and 51  22 g / day , respectively ( table 2 ) .
the average scores for dqi - i , hdi , and ahei in this study were 68.9  8.2 ( table 3 ) , 5.0  1.3 ( table 4 ) , and 39.4  8.9 ( table 5 ) . in the dqi - i ,
the score of overall - balance aspect was the lowest of the 4 aspects ( 2.4  2.6 ; 24% of the total score of aspect ) .
however , the variety aspect demonstrated the highest score ( 16.5  2.6 ; 82% of the total score of aspect ) , closely followed by the adequacy aspect ( 32.5  4.7 ; 81% of the total score of aspect ) . in the hdi , the score for saturated fatty acid ( 1.0  0.20 ) was the highest , followed by oligosaccharides ( 0.9  0.3 ) , polyunsaturated fatty acids ( 0.8  0.4 ) , and polysaccharides ( 0.7  0.5 ) . in the ahei ,
the score for trans - fat was the highest ( 10.0  0.2 ) , followed by polyunsaturated fatty acids : saturated fatty acids ( 10.0  0.2 ) , vegetables ( 7.2  2.5 ) , and nuts and soy proteins ( 5.5  4.7 ) .
after adjustment for age , the dqi - i and ahei scores did not correlate with hba1c , while the hdi score showed a significant negative correlation with hba1c ( table 6 ) .
however , the dqi - i , ahei , and hdi scores had a significant negative correlation with fpg and pp2 .
when age , bmi , and energy intake were adjusted for , the dqi - i and hdi scores had a significant negative correlation with hba1c .
this study focused on assessing the association between dietary quality indices and glycemic indices in korean patients with type 2 diabetes .
we found that the dqi - i and hdi had a significant negative correlation with hba1c , fpg , and pp2 , but the ahei did not have a significant negative correlation with hba1c .
a few studies have shown an association between glycemic status and the dqi - i and hdi in patients with diabetes .
however , similar to our study , the dietary guideline index , which assessed compliance with established dietary guidelines , was inversely associated with glycemic indices in type 2 diabetes .
interestingly , our results showed that the total scores of the dqi - i and hdi had an association with glycemic indices , but each component of the dqi - i and hdi did not .
consistent with our findings , the multiple food groups characterized as the 4-principle component analysis dietary pattern score and a priori -defined low - diabetes - risk food pattern score were associated with lower risk of type 2 diabetes , but individual food groups were not independently associated .
this observation suggests that dietary pattern indices are a better approach to assess diet quality for diabetes than traditional approach of using single - nutrient or food group exposures .
several studies have shown an association between eating patterns according to the ahei and risk of type 2 diabetes .
contrary to our findings , higher scores on the ahei were reported to be associated with a lower risk of type 2 diabetes ( comparing the top to the bottom quintile : 0.64 ( [ 95% confidence interval , 0.58 - 0.71 ] , ptrend < .0001 ) , and the ahei score was negatively correlated with change in hba1c level ( r = -0.024 , p < 0.05 ) .
a limitation of this study was that the 3 dietary pattern indices were derived from one - day dietary intake data obtained by the 24-hour recall method , which may not reflect the ordinary diet of the subjects .
however , 24-hour recall data maybe a stronger predictor of more recent diet than distant diet for type 2 diabetes , and the timing of food frequency questionnaires may not capture short - term improvement .
this might explain why a correlation was observed between the 3 dietary quality indices and fpg and pp2 , but not between ahei and hba1c . additionally , our data were cross - sectional , thereby precluding the determination of causality .
taken together , these findings suggest the need for longitudinal research to examine in more detail the relationship between diet quality and glycemic changes in type 2 diabetes .
in addition , for the variety and adequacy aspects for some of the components of the dqi - i , we used the us food guide pyramid serving size definitions to assess food group intake on the basis of how the number of servings consumed compared with the recommendations .
this study examined whether dietary quality indices are appropriate to assess diet quality and predict adherence to dietary recommendations in korean patients with type 2 diabetes .
further research is needed to examine the long - term dietary and glycemic changes in patients with diabetes following nutrition education .
the dqi - i and hdi may be useful tools in assessing diet quality and adherence to dietary recommendations in patients with type 2 diabetes . future research is required to determine whether dietary quality indices have predictive validity for dietary and glycemic changes after diet education in a clinical care setting .
 the present study was performed to evaluate the relationship between dietary quality indices including the diet quality index - international ( dqi - i ) , alternate healthy eating index ( ahei ) , and healthy diet indicator ( hdi ) and glycemic status in korean patients with type 2 diabetes . 
 a total of 110 consecutive outpatients with type 2 diabetes who visited 2 university hospitals in seoul and seongnam from april 2004 to november 2006 were enrolled as subjects . at the time of enrollment , anthropometric parameters , dietary habits , experience of exercise , and metabolic parameters 
 were obtained . 
 experienced registered dietitians collected one - day dietary intake using the 24-hour recall method . 
 the mean scores for dqi - i , ahei , and hdi were 68.9  8.2 , 39.4  8.9 , and 5.0  1.3 , respectively . 
 after adjustment for age , body mass index , and energy intake , dqi - i and hdi were found to have a significant correlation with hemoglobin a1c ( hba1c ) ( r = -0.21 , p < 0.05 ; r = -0.28 , p < 0.05 ) , fasting plasma glucose ( r = -0.21 , p < 0.05 ; r = -0.23 , p < 0.05 ) , and postprandial 2-h glucose ( r = -0.30 , p < 0.05 ; r = -0.26 , p < 0.05 , respectively ) . 
 however , ahei did not have a significant correlation with hba1c . in conclusion , 
 the dqi - i and hdi may be useful tools in assessing diet quality and adherence to dietary recommendations in korean patients with type 2 diabetes . 
 future research is required to determine whether the dietary quality indices have predictive validity for dietary and glycemic changes following diet education in a clinical setting . 
Introduction
Materials and Methods
Subjects and design
Application of the DQI-I, HDI, and AHEI to the datasets
Statistical analysis
Results
Discussion
Conclusion