we used two samples , a sample from the nhanes 19881994 and a sample from the nhanes 19992008 . the nhanes used a stratified , multistage probability - sampling frame and represented the civilian , noninstitutionalized u.s . we limited our nhanes 19881994 sample to 1,503 of these respondents who reported having been diagnosed with diabetes . in the nhanes 19992008 , 26,246 individuals aged 20 years were interviewed , and we limited our nhanes 19992008 sample to 2,802 of these respondents who reported having been diagnosed with diabetes . among those who reported having diabetes , we further limited nhanes 19881994 and nhanes 19992008 samples to those who had information regarding all four cvd risk factors ( blood glucose , blood pressure , lipids , and current smoking ) . blood glucose , blood pressure , and lipid information are available only for those nhanes respondents who participated in the medical examination portion of the survey , which included a blood draw . these sample restrictions yielded 1,149 respondents in the nhanes 19881994 sample and 2,056 respondents in the nhanes 19992008 sample . after excluding respondents with missing sociodemographic characteristics used in the analysis , our final analysis samples included 1,065 respondents from the nhanes 19881994 and 1,872 respondents from the nhanes 19992008 . the main racial / ethnic comparisons made were between african americans versus non - latino whites and mexican - americans versus non - latino whites . latinos from countries of origin other than mexico are included in the  other  race / ethnicity category . the age- and sex - adjusted proportion of respondents with nonmissing information on control of cvd risk factors decreased from 93.7% in the nhanes 19881994 to 81.1% in the nhanes 19992008 . we tested for differences in observed characteristics between those included in the sample and those excluded from the sample because of missing data . in both the nhanes 19881994 and the nhanes 19992008 , in addition , in the nhanes 19992008 , those with less than a high - school education were overrepresented among missing cases . when we ran a probit regression model with missing from sample  as the dependent variable , we found that in both the nhanes 19881994 and in the nhanes 19992008 , the only statistically significant predictor of being missing from the sample was african american race . we emphasize , however , that there is no statistically significant difference in the estimated coefficient on african american race in the nhanes 19881994 versus the nhanes 19992008 , suggesting that the possible bias resulting from excluding observations with incomplete information is likely to be minimal . have you ever been told by a doctor or health professional that you have diabetes or sugar diabetes ?  we did not consider respondents who reported having gestational diabetes to have diagnosed diabetes . when we estimated the prevalence rates of diagnosed diabetes , we used all respondents from the nhanes 19881994 and the nhanes 19992008 samples who provided a response to this question . to define poor control of blood glucose and blood pressure we defined poor glycemic control using a binary indicator of having an hba1c 7% . to define poor blood pressure control , we used a binary indicator of having a systolic blood pressure 130 mmhg or diastolic blood pressure 80 mmhg . for this sample , we used the average of the second and third readings . in the nhanes 19992008 , thus , for this sample , we used the average of the second and third readings when they were both available , and we used the average of the third and fourth measure or the average of the second and fourth measure of blood pressure in 193 case subjects for whom the second or third measure of blood pressure was missing and a fourth measure was available . we defined a dichotomous indicator of current smoking , which equaled 1 if a respondent reported  yes  to the question ,  have you smoked at least 100 cigarettes in your entire life ?  and did not answer  not at all  to the question ,  do you now smoke cigarettes   in the nhanes 19992008 . in the nhanes 19881994 , we defined a current smoker as someone who reported  yes  to both do you smoke cigarettes now ?  to measure lipid control , we used the total cholesterol level , which follows the adult treatment panel iii guidelines , instead of ldl cholesterol , as suggested by the ada in 2009 , because of the small sample sizes with available ldl cholesterol information in the nhanes ( n = 335 in the nhanes 19881994 , n = 785 in the nhanes 19992008 ) . the small sample sizes resulted from the ldl cholesterol measurement only being available for those who were assigned a nhanes medical examination scheduled in the morning . we used a binary indicator for total cholesterol of 200 mg / dl as an indicator for poor lipid control . initially , we examined trends in the prevalence of diagnosed diabetes and the sociodemographic characteristics of the diagnosed diabetic populations in the nhanes 19881994 and the nhanes 19992008 samples . we reported age- and sex - adjusted as well as unadjusted prevalence rates of diagnosed diabetes ( table 1 ) . census population , using sex and age ( 5-year age categories for those aged 2079 years and a category for those aged 80 years ) . we then examined sample characteristics of the population with diagnosed diabetes in the nhanes 19881994 and the nhanes 19992008 ( table 2 ) and , in table 3 , estimated the rates of poor control of cvd risk factors in the nhanes 19881994 and the nhanes 19992008 samples and by racial / ethnic and education groups . in tables 23 , the nhanes 19881994 percentages were standardized according to the nhanes 19992008 population of individuals with diagnosed diabetes , using age - sex groups and their corresponding weights ( 12 ) . we compared the rates of poor control of cvd risk factors between the nhanes 19881994 and the nhanes 19992008 ( table 3 ) ( 20 ) . prevalence rates of diagnosed diabetes among adults aged 20 years sample characteristics of adults with diagnosed diabetes poor control of risk factors among adults with diagnosed diabetes we used logistic models estimated with survey weights to test for racial / ethnic- and education - related disparities in poorly controlled risk factors for cvd among individuals with diagnosed diabetes ( table 4 ) . the models included controls for race / ethnicity ( african american , mexican american , other race / ethnicity versus non - latino whites ) , age categories ( 5-year age categories for those aged 2079 years and a category for those aged 80 years ) , sex ( female vs. male ) , marital status ( married vs. not married ) , years since diagnosis of diabetes ( 25 , 610 , 1115 , and 16 years vs. 01 years ) , obesity ( bmi 2529 kg / m [ overweight ] , bmi 30 kg / m [ obese ] vs. bmi < 25 kg / m [ normal ] ) , access to routine care ( has routine access vs. does not have routine access ) , health insurance type ( public , public and private , or uninsured vs. private only ) , and indicators for survey year . all analyses in this article were performed using stata software , version 11.1 ( statacorp , college station , tx ) . poorly controlled cvd risk factors among adults with diagnosed diabetes in nhanes 19881994 and nhanes 19992008 we used two samples , a sample from the nhanes 19881994 and a sample from the nhanes 19992008 . the nhanes used a stratified , multistage probability - sampling frame and represented the civilian , noninstitutionalized u.s . we limited our nhanes 19881994 sample to 1,503 of these respondents who reported having been diagnosed with diabetes . in the nhanes 19992008 , 26,246 individuals aged 20 years were interviewed , and we limited our nhanes 19992008 sample to 2,802 of these respondents who reported having been diagnosed with diabetes . among those who reported having diabetes , we further limited nhanes 19881994 and nhanes 19992008 samples to those who had information regarding all four cvd risk factors ( blood glucose , blood pressure , lipids , and current smoking ) . blood glucose , blood pressure , and lipid information are available only for those nhanes respondents who participated in the medical examination portion of the survey , which included a blood draw . these sample restrictions yielded 1,149 respondents in the nhanes 19881994 sample and 2,056 respondents in the nhanes 19992008 sample . after excluding respondents with missing sociodemographic characteristics used in the analysis , our final analysis samples included 1,065 respondents from the nhanes 19881994 and 1,872 respondents from the nhanes 19992008 . the main racial / ethnic comparisons made were between african americans versus non - latino whites and mexican - americans versus non - latino whites . latinos from countries of origin other than mexico are included in the  other  race / ethnicity category . the age- and sex - adjusted proportion of respondents with nonmissing information on control of cvd risk factors decreased from 93.7% in the nhanes 19881994 to 81.1% in the nhanes 19992008 . we tested for differences in observed characteristics between those included in the sample and those excluded from the sample because of missing data . in both the nhanes 19881994 and the nhanes 19992008 , in addition , in the nhanes 19992008 , those with less than a high - school education were overrepresented among missing cases . when we ran a probit regression model with missing from sample  as the dependent variable , we found that in both the nhanes 19881994 and in the nhanes 19992008 , the only statistically significant predictor of being missing from the sample was african american race . we emphasize , however , that there is no statistically significant difference in the estimated coefficient on african american race in the nhanes 19881994 versus the nhanes 19992008 , suggesting that the possible bias resulting from excluding observations with incomplete information is likely to be minimal . have you ever been told by a doctor or health professional that you have diabetes or sugar diabetes ?  we did not consider respondents who reported having gestational diabetes to have diagnosed diabetes . when we estimated the prevalence rates of diagnosed diabetes , we used all respondents from the nhanes 19881994 and the nhanes 19992008 samples who provided a response to this question . to define poor control of blood glucose and blood pressure we defined poor glycemic control using a binary indicator of having an hba1c 7% . to define poor blood pressure control , we used a binary indicator of having a systolic blood pressure 130 mmhg or diastolic blood pressure 80 mmhg . the nhanes 19881994 medical examination included three readings of systolic and diastolic blood pressure . for this sample , we used the average of the second and third readings . in the nhanes 19992008 , thus , for this sample , we used the average of the second and third readings when they were both available , and we used the average of the third and fourth measure or the average of the second and fourth measure of blood pressure in 193 case subjects for whom the second or third measure of blood pressure was missing and a fourth measure was available . we defined a dichotomous indicator of current smoking , which equaled 1 if a respondent reported  yes  to the question ,  have you smoked at least 100 cigarettes in your entire life ?  and did not answer  not at all  to the question ,  do you now smoke cigarettes   in the nhanes 19992008 . in the nhanes 19881994 , we defined a current smoker as someone who reported  yes  to both to measure lipid control , we used the total cholesterol level , which follows the adult treatment panel iii guidelines , instead of ldl cholesterol , as suggested by the ada in 2009 , because of the small sample sizes with available ldl cholesterol information in the nhanes ( n = 335 in the nhanes 19881994 , n = 785 in the nhanes 19992008 ) . the small sample sizes resulted from the ldl cholesterol measurement only being available for those who were assigned a nhanes medical examination scheduled in the morning . we used a binary indicator for total cholesterol of 200 mg / dl as an indicator for poor lipid control . initially , we examined trends in the prevalence of diagnosed diabetes and the sociodemographic characteristics of the diagnosed diabetic populations in the nhanes 19881994 and the nhanes 19992008 samples . we reported age- and sex - adjusted as well as unadjusted prevalence rates of diagnosed diabetes ( table 1 ) . census population , using sex and age ( 5-year age categories for those aged 2079 years and a category for those aged 80 years ) . we then examined sample characteristics of the population with diagnosed diabetes in the nhanes 19881994 and the nhanes 19992008 ( table 2 ) and , in table 3 , estimated the rates of poor control of cvd risk factors in the nhanes 19881994 and the nhanes 19992008 samples and by racial / ethnic and education groups . in tables 23 , the nhanes 19881994 percentages were standardized according to the nhanes 19992008 population of individuals with diagnosed diabetes , using age - sex groups and their corresponding weights ( 12 ) . we compared the rates of poor control of cvd risk factors between the nhanes 19881994 and the nhanes 19992008 ( table 3 ) ( 20 ) . prevalence rates of diagnosed diabetes among adults aged 20 years sample characteristics of adults with diagnosed diabetes poor control of risk factors among adults with diagnosed diabetes we used logistic models estimated with survey weights to test for racial / ethnic- and education - related disparities in poorly controlled risk factors for cvd among individuals with diagnosed diabetes ( table 4 ) . the models included controls for race / ethnicity ( african american , mexican american , other race / ethnicity versus non - latino whites ) , age categories ( 5-year age categories for those aged 2079 years and a category for those aged 80 years ) , sex ( female vs. male ) , marital status ( married vs. not married ) , years since diagnosis of diabetes ( 25 , 610 , 1115 , and 16 years vs. 01 years ) , obesity ( bmi 2529 kg / m [ overweight ] , bmi 30 kg / m [ obese ] vs. bmi < 25 kg / m [ normal ] ) , access to routine care ( has routine access vs. does not have routine access ) , health insurance type ( public , public and private , or uninsured vs. private only ) , and indicators for survey year . all analyses in this article were performed using stata software , version 11.1 ( statacorp , college station , tx ) . poorly controlled cvd risk factors among adults with diagnosed diabetes in nhanes 19881994 and nhanes 19992008 as others have reported ( 2,21 ) , the prevalence of diagnosed diabetes has increased appreciably over time ( table 1 ) . the age- and sex - standardized prevalence rate of diagnosed diabetes in the nhanes 19992008 was 7.4% , whereas it was 5.3% in the nhanes 19881994 ( p < 0.001 ) . the unadjusted prevalence of diagnosed diabetes shows the same pattern , increasing from 5.1% in the nhanes 19881994 to 7.5% in the nhanes 19992008 ( p < 0.001 ) , which is consistent with previous research ( 22 ) . between the nhanes 19881994 and the nhanes 19992008 , the incidence of diabetes ( diagnosed and undiagnosed ) increased from 7.9 to 10.1% ( results not shown ) . we found that among those with diabetes ( diagnosed and undiagnosed ) , the rate of undiagnosed diabetes decreased from 38.2 to 28.4% ( results not shown ) , suggesting that diagnosis has improved over time . one of the most significant changes in the characteristics of the population with diagnosed diabetes between the nhanes 19881994 and the nhanes 19992008 is the race / ethnicity distribution . table 2 shows the increases over time in the proportions of mexican americans ( from 5.9 to 8.0% , p = 0.10 ) and individuals from the  other  race / ethnicity group ( from 6.0 to 12.2% , p = 0.002 ) in the population with diagnosed diabetes , whereas the proportion of non - latino whites declined ( from 73.6 to 65.3% , p = 0.009 ) . for african americans , there is no statistically significant change between the nhanes 19881994 and the nhanes 19992008 ( table 2 ) . the age distribution of the population with diagnosed diabetes also changed between the nhanes 19881994 and the nhanes 19992008 ( table 2 ) . the proportion of middle - aged individuals increased over time ( aged 4059 years , from 34.5 to 41.6% , p = 0.01 ) , whereas the proportion of elderly individuals declined ( aged 60 years , from 55.6 to 49.5% , p = 0.03 ) . this trend may have resulted from an earlier diagnosis of diabetes and/or an earlier onset of diabetes in recent years . in fact , we found that mean age at the time of diabetes diagnosis is higher in the nhanes 19881994 than in the nhanes 19992008 ( aged 49.3 vs. 46.8 years , p < 0.001 ) , and the number of years since diabetes was diagnosed was 9.1 years in the nhanes 19881994 versus 11.4 years in the nhanes 19992008 ( p < 0.001 ) . in addition , the education profile of individuals with diagnosed diabetes changed remarkably between the nhanes 19881994 and the nhanes 19992008 ( table 2 ) . the proportion of high - school dropouts among individuals with diagnosed diabetes decreased from 41.9 to 29.9% ( p = 0.001 ) , whereas the percentage with some postsecondary education increased from 27.1 to 44.4% ( p < 0.001 ) . to some extent , this change resulted from an increasing level of education in the population as a whole . between the nhanes 19881994 and the nhanes 19992008 , the age- and sex - standardized percentage of nhanes respondents aged 20 years with at least some postsecondary education rose from 27.1% in the nhanes 19881994 to 44.4% in the nhanes 19992008 ( p < 0.001 ) . finally , the population with diagnosed diabetes has become more obese over time , with obesity levels increasing from 43.2% in the nhanes 19881994 to 54.8% in the nhanes 19992008 ( p < 0.001 ) . the percentage of people who were either obese or overweight also increased between the nhanes 19881994 ( 81.3% ) and the nhanes 19992008 ( 84.2% ) . our findings suggest that control of cvd risk factors among individuals with diagnosed diabetes has improved markedly over the past two decades ( table 3 ) . the percentage of those with diagnosed diabetes not achieving glycemic control ( hba1c > 7% ) was 50.0% in the nhanes 19992008 , an improvement from the nhanes 19881994 , when 57.7% of people with diagnosed diabetes did not meet this target ( p = 0.008 ) . the percentage of individuals with diagnosed diabetes who do not achieve blood pressure control ( 130/80 mmhg ) decreased from 60.8% in the nhanes 19881994 to 53.5% in the nhanes 19992008 ( p = 0.01 ) . the percentage of people with diagnosed diabetes who did not have total cholesterol < 200 mg / dl also significantly fell from 67.1% in the nhanes 19881994 to 41.3% in the nhanes 19992008 . rates of current smoking among individuals with diagnosed diabetes , however , did not change between the nhanes 19881994 ( 17.5% ) and the nhanes 19992008 our analyses show a trend of improvement not only in the control of each risk factor individually but also in the number of controlled risk factors . in the nhanes 19881994 , only 5.2% of those with diagnosed diabetes had control of all of the four risk factors we examined . in the nhanes 19992008 , however , 13.6% of individuals with diagnosed diabetes had control of all four risk factors ( p < 0.001 ) ( results not shown ) . in addition , the percentage of people with diagnosed diabetes who had control of three of four risk factors increased from 24.1 to 31.0% ( p = 0.003 ) between the nhanes 19881994 and the nhanes 19992008 . nevertheless , in the nhanes 19992008 , more than one - half of the population with diagnosed diabetes ( 54.4% ) still had more than two uncontrolled risk factors ( results not shown ) . in the nhanes 19881994 , there were no statistically significant racial / ethnic or education - related disparities in glycemic control among individuals with diagnosed diabetes , although some of the cis were wide ( table 4 , blood glucose column ) . in the nhanes 19992008 , however , we found that african americans and mexican americans with diagnosed diabetes were ~50% more likely than non - latino whites with diagnosed diabetes to be in poor glycemic control ( african american vs. non - mexican white : odds ratio 1.52 [ 95% ci 1.142.03 ] ; mexican vs. non - mexican white : 1.53 [ 1.152.04 ] ) . also , in the nhanes 19992008 , we found that individuals with postsecondary education were less likely to be in poor glycemic control compared with those without postsecondary education ( 0.65 [ 0.480.89 ] ) . in summary , our results indicate that although glycemic control has improved in the population of individuals with diagnosed diabetes at large , these improvements may have been , to some extent , concentrated among non - latino white and more - educated individuals , such that new health disparities have emerged . these racial / ethnic- and education - related disparities in glycemic control persisted when we limited the sample to the most recent two waves of the nhanes ( 20052006 and 20072008 ) ( results not shown ) . in these models , we tried including covariates that may have captured quality - of - care mechanisms of disparities , specifically whether the respondent had seen a diabetes specialist in the past year , whether the respondent usually saw a particular doctor for diabetes , and whether the respondent checked his or her own blood glucose level . after these covariates were included , both racial / ethnic - related disparities and education - related disparities were not changed appreciably , suggesting that these mechanisms ( if they indeed were capturing quality of care ) did not explain the disparities we observed in recent years . however , we interpreted these findings with caution because the additional covariates included may have captured the severity of disease instead of or in addition to quality of care . in that case , there may have been a reverse - causality problem , with poor control of diabetes driving severity instead of the other way around . we did not find racial / ethnic differences in blood pressure control among individuals with diagnosed diabetes in either the nhanes 19881994 or the nhanes 19992008 ( table 4 , blood pressure column ) . individuals with diagnosed diabetes who had some postsecondary education were less likely than those without postsecondary education to be in poor control of blood pressure , but this association was statistically significant only in the nhanes 19992008 data . there were no racial / ethnic disparities in total cholesterol control among individuals with diagnosed diabetes in either the nhanes 19881994 or the nhanes 19992008 ( table 4 , total cholesterol column ) . the association between postsecondary education and control of cholesterol approached statistical significance in the nhanes 19881994 but essentially disappeared by the nhanes 19992008 . in the case of smoking , postsecondary education and mexican american ethnicity were associated with a lower risk of smoking in the nhanes 19992008 ( table 4 , current smoking column ; mexican american vs. non - latino whites : odds ratio 0.66 [ 95% ci = 0.440.97 ] ; postsecondary education vs. no postsecondary education : 0.63 [ 0.420.95 ] ) . we did not find these odds ratios in the nhanes 19881994 ; surprisingly , having 12 years of education ( compared with < 12 years ) is associated with a higher risk of smoking in the nhanes 19881994 , although the ci is very wide for this estimate ( table 4 , current smoking column ; 2.34 [ 1.124.87 ] ) . the models in table 4 focus on poor control of cvd risk factors only among individuals with diagnosed diabetes . recent work shows education - related disparities in the likelihood of having undiagnosed diabetes in the nhanes 19992002 and african american vs. non - latino white disparities in undiagnosed diabetes in the nhanes 19881994 ( 23 ) . thus , as a sensitivity check , we examined whether our results on disparities were affected if we considered undiagnosed cases . we reestimated all of the models in table 4 , including individuals with undiagnosed diabetes . the only significant change was that including undiagnosed individuals in the blood pressure control models caused african american / non - latino white disparities to grow somewhat larger , reaching statistical significance ( results not shown ) . as others have reported ( 2,21 ) , the prevalence of diagnosed diabetes has increased appreciably over time ( table 1 ) . the age- and sex - standardized prevalence rate of diagnosed diabetes in the nhanes 19992008 was 7.4% , whereas it was 5.3% in the nhanes 19881994 ( p < 0.001 ) . the unadjusted prevalence of diagnosed diabetes shows the same pattern , increasing from 5.1% in the nhanes 19881994 to 7.5% in the nhanes 19992008 ( p < 0.001 ) , which is consistent with previous research ( 22 ) . between the nhanes 19881994 and the nhanes 19992008 , the incidence of diabetes ( diagnosed and undiagnosed ) increased from 7.9 to 10.1% ( results not shown ) . we found that among those with diabetes ( diagnosed and undiagnosed ) , the rate of undiagnosed diabetes decreased from 38.2 to 28.4% ( results not shown ) , suggesting that diagnosis has improved over time . one of the most significant changes in the characteristics of the population with diagnosed diabetes between the nhanes 19881994 and the nhanes 19992008 is the race / ethnicity distribution . table 2 shows the increases over time in the proportions of mexican americans ( from 5.9 to 8.0% , p = 0.10 ) and individuals from the  other  race / ethnicity group ( from 6.0 to 12.2% , p = 0.002 ) in the population with diagnosed diabetes , whereas the proportion of non - latino whites declined ( from 73.6 to 65.3% , p = 0.009 ) . for african americans , there is no statistically significant change between the nhanes 19881994 and the nhanes 19992008 ( table 2 ) . the age distribution of the population with diagnosed diabetes also changed between the nhanes 19881994 and the nhanes 19992008 ( table 2 ) . the proportion of middle - aged individuals increased over time ( aged 4059 years , from 34.5 to 41.6% , p = 0.01 ) , whereas the proportion of elderly individuals declined ( aged 60 years , from 55.6 to 49.5% , p = 0.03 ) . this trend may have resulted from an earlier diagnosis of diabetes and/or an earlier onset of diabetes in recent years . in fact , we found that mean age at the time of diabetes diagnosis is higher in the nhanes 19881994 than in the nhanes 19992008 ( aged 49.3 vs. 46.8 years , p < 0.001 ) , and the number of years since diabetes was diagnosed was 9.1 years in the nhanes 19881994 versus 11.4 years in the nhanes 19992008 ( p < 0.001 ) . in addition , the education profile of individuals with diagnosed diabetes changed remarkably between the nhanes 19881994 and the nhanes 19992008 ( table 2 ) . the proportion of high - school dropouts among individuals with diagnosed diabetes decreased from 41.9 to 29.9% ( p = 0.001 ) , whereas the percentage with some postsecondary education increased from 27.1 to 44.4% ( p < 0.001 ) . to some extent , this change resulted from an increasing level of education in the population as a whole . between the nhanes 19881994 and the nhanes 19992008 , the age- and sex - standardized percentage of nhanes respondents aged 20 years with at least some postsecondary education rose from 27.1% in the nhanes 19881994 to 44.4% in the nhanes 19992008 ( p < 0.001 ) . finally , the population with diagnosed diabetes has become more obese over time , with obesity levels increasing from 43.2% in the nhanes 19881994 to 54.8% in the nhanes 19992008 ( p < 0.001 ) . the percentage of people who were either obese or overweight also increased between the nhanes 19881994 ( 81.3% ) and the nhanes 19992008 ( 84.2% ) . our findings suggest that control of cvd risk factors among individuals with diagnosed diabetes has improved markedly over the past two decades ( table 3 ) . the percentage of those with diagnosed diabetes not achieving glycemic control ( hba1c > 7% ) was 50.0% in the nhanes 19992008 , an improvement from the nhanes 19881994 , when 57.7% of people with diagnosed diabetes did not meet this target ( p = 0.008 ) . the percentage of individuals with diagnosed diabetes who do not achieve blood pressure control ( 130/80 mmhg ) decreased from 60.8% in the nhanes 19881994 to 53.5% in the nhanes 19992008 ( p = 0.01 ) . the percentage of people with diagnosed diabetes who did not have total cholesterol < 200 mg / dl also significantly fell from 67.1% in the nhanes 19881994 to 41.3% in the nhanes 19992008 . rates of current smoking among individuals with diagnosed diabetes , however , did not change between the nhanes 19881994 ( 17.5% ) and the nhanes 19992008 ( 18.1% , p = 0.81 ) . of note , our analyses show a trend of improvement not only in the control of each risk factor individually but also in the number of controlled risk factors . in the nhanes 19881994 , only 5.2% of those with diagnosed diabetes had control of all of the four risk factors we examined . in the nhanes 19992008 , however , 13.6% of individuals with diagnosed diabetes had control of all four risk factors ( p < 0.001 ) ( results not shown ) . in addition , the percentage of people with diagnosed diabetes who had control of three of four risk factors increased from 24.1 to 31.0% ( p = 0.003 ) between the nhanes 19881994 and the nhanes 19992008 . nevertheless , in the nhanes 19992008 , more than one - half of the population with diagnosed diabetes ( 54.4% ) still had more than two uncontrolled risk factors ( results not shown ) . in the nhanes 19881994 , there were no statistically significant racial / ethnic or education - related disparities in glycemic control among individuals with diagnosed diabetes , although some of the cis were wide ( table 4 , blood glucose column ) . in the nhanes 19992008 , however , we found that african americans and mexican americans with diagnosed diabetes were ~50% more likely than non - latino whites with diagnosed diabetes to be in poor glycemic control ( african american vs. non - mexican white : odds ratio 1.52 [ 95% ci 1.142.03 ] ; mexican vs. non - mexican white : 1.53 [ 1.152.04 ] ) . also , in the nhanes 19992008 , we found that individuals with postsecondary education were less likely to be in poor glycemic control compared with those without postsecondary education ( 0.65 [ 0.480.89 ] ) . in summary , our results indicate that although glycemic control has improved in the population of individuals with diagnosed diabetes at large , these improvements may have been , to some extent , concentrated among non - latino white and more - educated individuals , such that new health disparities have emerged . these racial / ethnic- and education - related disparities in glycemic control persisted when we limited the sample to the most recent two waves of the nhanes ( 20052006 and 20072008 ) ( results not shown ) . in these models , we tried including covariates that may have captured quality - of - care mechanisms of disparities , specifically whether the respondent had seen a diabetes specialist in the past year , whether the respondent usually saw a particular doctor for diabetes , and whether the respondent checked his or her own blood glucose level . after these covariates were included , both racial / ethnic - related disparities and education - related disparities were not changed appreciably , suggesting that these mechanisms ( if they indeed were capturing quality of care ) did not explain the disparities we observed in recent years . however , we interpreted these findings with caution because the additional covariates included may have captured the severity of disease instead of or in addition to quality of care . in that case , there may have been a reverse - causality problem , with poor control of diabetes driving severity instead of the other way around . we did not find racial / ethnic differences in blood pressure control among individuals with diagnosed diabetes in either the nhanes 19881994 or the nhanes 19992008 ( table 4 , blood pressure column ) . individuals with diagnosed diabetes who had some postsecondary education were less likely than those without postsecondary education to be in poor control of blood pressure , but this association was statistically significant only in the nhanes 19992008 data . there were no racial / ethnic disparities in total cholesterol control among individuals with diagnosed diabetes in either the nhanes 19881994 or the nhanes 19992008 ( table 4 , total cholesterol column ) . the association between postsecondary education and control of cholesterol approached statistical significance in the nhanes 19881994 but essentially disappeared by the nhanes 19992008 . in the case of smoking , postsecondary education and mexican american ethnicity were associated with a lower risk of smoking in the nhanes 19992008 ( table 4 , current smoking column ; mexican american vs. non - latino whites : odds ratio 0.66 [ 95% ci = 0.440.97 ] ; postsecondary education vs. no postsecondary education : 0.63 [ 0.420.95 ] ) . we did not find these odds ratios in the nhanes 19881994 ; surprisingly , having 12 years of education ( compared with < 12 years ) is associated with a higher risk of smoking in the nhanes 19881994 , although the ci is very wide for this estimate ( table 4 , current smoking column ; 2.34 [ 1.124.87 ] ) . the models in table 4 focus on poor control of cvd risk factors only among individuals with diagnosed diabetes . recent work shows education - related disparities in the likelihood of having undiagnosed diabetes in the nhanes 19992002 and african american vs. non - latino white disparities in undiagnosed diabetes in the nhanes 19881994 ( 23 ) . thus , as a sensitivity check , we examined whether our results on disparities were affected if we considered undiagnosed cases . we reestimated all of the models in table 4 , including individuals with undiagnosed diabetes . the only significant change was that including undiagnosed individuals in the blood pressure control models caused african american / non - latino white disparities to grow somewhat larger , reaching statistical significance ( results not shown ) . in the newly released healthy people 2020 , three objectives in the area of diabetes are to improve glycemic , lipid , and blood pressure control among individuals with diagnosed disease ( 24 ) . these objectives reflect mounting evidence that the control of these risk factors prevents cvd complications and mortality among people with diabetes ( 7,25,26 ) . our results show favorable trends in all of these areas except smoking rates . between the nhanes 19881994 and the nhanes 19992008 , the proportion of individuals with diagnosed diabetes with poor glycemic , blood pressure , and lipid control fell by 13 , 12 , and 38% , respectively . the prevalence of current smoking among individuals with diagnosed diabetes , however , remained stable during the time period we examined . our results suggest that , in some areas , improvements in the control of cvd risk factors seem to have benefitted all racial / ethnic and education groups . in the case of cholesterol levels , for example , all racial / ethnic and education groups experienced significant improvements in control between the nhanes 19881994 and the nhanes 19992008 . in fact , we found no evidence of racial / ethnic- or education - related disparities in poor control of cholesterol in either the nhanes 19881994 or the nhanes 19992008 . in addition , there were no racial / ethnic disparities in blood pressure control in the nhanes 19881994 or the nhanes 19992008 . however , in the case of glycemic control , improvements over time may have been driven by improvements among more educated individuals with diabetes and , to some extent , by improvements among non - latino whites . rates of poor glycemic control fell by 20% among those with > 12 years of education between the nhanes 19881994 and the nhanes 19992008 , but rates of glycemic control remained stable during this time period among those with less than a high - school education . results from our regression analysis , which includes controls for a number of confounding factors , suggest that african americans and mexican americans with diagnosed diabetes in the nhanes 19992008 were 50% more likely to have poor glycemic control than non - latino whites with diagnosed diabetes . moreover , in the nhanes 19992008 , individuals with diabetes who had at least some college education were less likely to have uncontrolled blood pressure than those without any college education , controlling for other factors . this association existed in the nhanes 19881994 as well , but it was not statistically significant . it also is notable that smoking rates among individuals with diagnosed diabetes have not improved over time and remain high in some subgroups ; in the nhanes 19992008 , 22% of individuals with diagnosed diabetes without a high - school education were current smokers . this high rate of smoking among the least educated individuals with diabetes is consistent with other data ( 27 ) . in summary , our findings show that important progress has been made in reducing cvd risk factors among individuals with diagnosed diabetes over the past decade , but this progress , in some cases , has been uneven across sociodemographic groups . there are several potential reasons why improvements in glycemic control may have been concentrated among non - latino white and more educated populations . first , some groups may have better access than other groups to the type of integrated , comprehensive medical care that individuals with diabetes need in order to successfully manage their illness . although we adjusted for insurance status and access to routine care in our main regression models , as well as experimented with models based on the latest two waves of the nhanes that included more extensive covariates , there still may exist unmeasured aspects of quality and access that are correlated with race / ethnicity and education . second , individuals with diabetes who are more educated may have been better able to obtain and understand new information related to diabetes treatment compared with individuals with diabetes who are less educated . in our sample limited to the 20052008 nhanes , 44% of individuals with diagnosed diabetes with more than a high - school education reported that their doctor recommended that they maintain an hba1c < 7% ( the recommended level ) , whereas only 12% of respondents with less than a high - school education reported that their doctors recommended this level . there also is evidence that people who are more educated adopt medical technologies more rapidly than people who are less educated ( 28 ) . third , culture and language may play a role in diabetes management practices , and these factors may underlie racial / ethnic disparities in outcomes ( 11 ) . although the mechanisms through which sociodemographic characteristics affect control of cvd risk factors are unclear , our findings underscore the need to remediate these emerging racial / ethnic- and education - related disparities in this area of health care . moreover , although our findings show marked improvements in the control of cvd risk factors among individuals with diabetes , it also is true that only a small group ( 13.6% ) of individuals with diagnosed diabetes in the nhanes 19992008 had control of all four cvd risk factors we examined . continued public health efforts need to be made to address the large majority of individuals with diagnosed diabetes with uncontrolled risk factors for cvd .
objectivethere is limited information on whether recent improvements in the control of cardiovascular disease ( cvd ) risk factors among individuals with diabetes have been concentrated in particular sociodemographic groups . 
 this article estimates racial / ethnic- and education - related disparities and examines trends in uncontrolled cvd risk factors among adults with diabetes . 
 the main racial / ethnic comparisons made are with african americans versus non - latino whites and mexican americans versus non - latino whites.research design and methodsthe analysis samples include adults aged 20 years from the national health and nutrition examination survey ( nhanes ) 19881994 and the nhanes 19992008 who self - reported having diabetes ( n 
 = 1,065 , nhanes 19881994 ; n = 1,872 , nhanes 19992008 ) . by use of logistic regression models 
 , we examined the correlates of binary indicators measuring 1 ) high blood glucose , 2 ) high blood pressure , 3 ) high cholesterol , and 4 ) smoking.resultscontrol of blood glucose , blood pressure , and cholesterol improved among individuals with diabetes between the nhanes 19881994 and the nhanes 19992008 , but there was no change in smoking prevalence . 
 in the nhanes 19992008 , racial / ethnic minorities and individuals without some college education were more likely to have poorly controlled blood glucose compared with non - latino whites and those with some college education . 
 in addition , individuals with diabetes who had at least some college education were less likely to smoke and had better blood pressure control compared with individuals with diabetes without at least some college education.conclusionstrends in cvd risk factors among individuals with diabetes improved over the past 2 decades , but racial / ethnic- and education - related disparities have emerged in some areas .