Catherine C. Cowie

Prevalence of Diabetes, Impaired Fasting Glucose, and Impaired Glucose Tolerance in U.S. Adults: The Third National Health and Nutrition Examination Survey, 1988–1994

OBJECTIVE To evaluate the prevalence and time trends for diagnosed and undiagnosed diabetes, impaired fasting glucose, and impaired glucose tolerance in U.S. adults by age, sex, and race or ethnic group, based on data from the Third National Health and Nutrition Examination Survey, 1988–1994 (NHANES 111) and prior Health and Nutrition Examination Surveys (HANESs). RESEARCH DESIGN AND METHODS NHANES III contained a probability sample of 18,825 U.S. adults ≥20 years of age who were interviewed to ascertain a medical history of diagnosed diabetes, a subsample of 6,587 adults for whom fasting plasma glucose values were obtained, and a subsample of 2,844 adults between 40 and 74 years of age who received an oral glucose tolerance test. The Second National Health and Nutrition Examination Survey, 1976–1980, and Hispanic HANES used similar procedures to ascertain diabetes. Prevalence was calculated using the 1997 American Diabetes Association fasting plasma glucose criteria and the 1980–1985 World Health Organization (WHO) oral glucose tolerance test criteria. RESULTS Prevalence of diagnosed diabetes in 1988–1994 was estimated to be 5.1% for U.S. adults ≥20 years of age (10.2 million people when extrapolated to the 1997 U.S. population). Using American Diabetes Association criteria, the prevalence of undiagnosed diabetes (fasting plasma glucose ≥126 mg/dl) was 2.7% (5.4 million), and the prevalence of impaired fasting glucose (110 to <126 mg/dl) was 6.9% (13.4 million). There were similar rates of diabetes for men and women, but the rates for non-Hispanic blacks and Mexican-Americans were 1.6 and 1.9 times the rate for non-Hispanic whites. Based on American Diabetes Association criteria, prevalence of diabetes (diagnosed plus undiagnosed) in the total population of people who were 40–74 years of age increased from 8.9% in the period 1976–1980 to 12.3% by 1988–1994. A similar increase was found when WHO criteria were applied (11.4 and 14.3%). CONCLUSIONS The high rates of abnormal fasting and postchallenge glucose found in NHANES III, together with the increasing frequency of obesity and sedentary lifestyles in the population, make it likely that diabetes will continue to be a major health problem in the U.S

Prevalence of Diabetes and Impaired Fasting Glucose in Adults in the U.S. Population National Health and Nutrition Examination Survey 1999–2002

OBJECTIVE—The purpose of this study was to examine the prevalences of diagnosed and undiagnosed diabetes, and impaired fasting glucose (IFG) in U.S. adults during 1999–2002, and compare prevalences to those in 1988–1994. RESEARCH DESIGN AND METHODS—The National Health and Nutrition Examination Survey (NHANES) contains a probability sample of adults aged ≥20 years. In the NHANES 1999–2002, 4,761 adults were classified on glycemic status using standard criteria, based on an interview for diagnosed diabetes and fasting plasma glucose measured in a subsample. RESULTS—The crude prevalence of total diabetes in 1999–2002 was 9.3% (19.3 million, 2002 U.S. population), consisting of 6.5% diagnosed and 2.8% undiagnosed. An additional 26.0% had IFG, totaling 35.3% (73.3 million) with either diabetes or IFG. The prevalence of total diabetes rose with age, reaching 21.6% for those aged ≥65 years. The prevalence of diagnosed diabetes was twice as high in non-Hispanic blacks and Mexican Americans compared with non-Hispanic whites (both P < 0.00001), whereas the prevalence of undiagnosed diabetes was similar by race/ethnicity, adjusted for age and sex. The prevalence of diagnosed diabetes was similar by sex, but prevalences of undiagnosed diabetes and IFG were significantly higher in men. The crude prevalence of diagnosed diabetes rose significantly from 5.1% in 1988–1994 to 6.5% in 1999–2002, but the crude prevalences were stable for undiagnosed diabetes (from 2.7 to 2.8%) and IFG (from 24.7 to 26.0%). Results were similar after adjustment for age and sex. CONCLUSIONS—Although the prevalence of diagnosed diabetes has increased significantly over the last decade, the prevalences of undiagnosed diabetes and IFG have remained relatively stable. Minority groups remain disproportionately affected.

Full Accounting of Diabetes and Pre-Diabetes in the U.S. Population in 1988–1994 and 2005–2006

OBJECTIVE—We examined the prevalences of diagnosed diabetes, and undiagnosed diabetes and pre-diabetes using fasting and 2-h oral glucose tolerance test values, in the U.S. during 2005–2006. We then compared the prevalences of these conditions with those in 1988–1994. RESEARCH DESIGN AND METHODS—In 2005–2006, the National Health and Nutrition Examination Survey included a probability sample of 7,267 people aged ≥12 years. Participants were classified according to glycemic status by interview for diagnosed diabetes and by fasting and 2-h glucoses measured in subsamples. RESULTS—In 2005–2006, the crude prevalence of total diabetes in people aged ≥20 years was 12.9%, of which ∼40% was undiagnosed. In people aged ≥20 years, the crude prevalence of impaired fasting glucose was 25.7% and of impaired glucose tolerance was 13.8%, with almost 30% having either. Over 40% of individuals had diabetes or pre-diabetes. Almost one-third of the elderly had diabetes, and three-quarters had diabetes or pre-diabetes. Compared with non-Hispanic whites, age- and sex-standardized prevalence of diagnosed diabetes was approximately twice as high in non-Hispanic blacks (P < 0.0001) and Mexican Americans (P = 0.0001), whereas undiagnosed diabetes was not higher. Crude prevalence of diagnosed diabetes in people aged ≥20 years rose from 5.1% in 1988–1994 to 7.7% in 2005–2006 (P = 0.0001); this was significant after accounting for differences in age and sex, particularly in non-Hispanic blacks. Prevalences of undiagnosed diabetes and pre-diabetes were generally stable, although the proportion of total diabetes that was undiagnosed decreased in Mexican Americans. CONCLUSIONS—Over 40% of people aged ≥20 years have hyperglycemic conditions, and prevalence is higher in minorities. Diagnosed diabetes has increased over time, but other conditions have been relatively stable.

Prevalence of and Trends in Diabetes Among Adults in the United States, 1988-2012

IMPORTANCE Previous studies have shown increasing prevalence of diabetes in the United States. New US data are available to estimate prevalence of and trends in diabetes. OBJECTIVE To estimate the recent prevalence and update US trends in total diabetes, diagnosed diabetes, and undiagnosed diabetes using National Health and Nutrition Examination Survey (NHANES) data. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional surveys conducted between 1988-1994 and 1999-2012 of nationally representative samples of the civilian, noninstitutionalized US population; 2781 adults from 2011-2012 were used to estimate recent prevalence and an additional 23,634 adults from 1988-2010 were used to estimate trends. MAIN OUTCOMES AND MEASURES The prevalence of diabetes was defined using a previous diagnosis of diabetes or, if diabetes was not previously diagnosed, by (1) a hemoglobin A1c level of 6.5% or greater or a fasting plasma glucose (FPG) level of 126 mg/dL or greater (hemoglobin A1c or FPG definition) or (2) additionally including 2-hour plasma glucose (2-hour PG) level of 200 mg/dL or greater (hemoglobin A1c, FPG, or 2-hour PG definition). Prediabetes was defined as a hemoglobin A1c level of 5.7% to 6.4%, an FPG level of 100 mg/dL to 125 mg/dL, or a 2-hour PG level of 140 mg/dL to 199 mg/dL. RESULTS In the overall 2011-2012 population, the unadjusted prevalence (using the hemoglobin A1c, FPG, or 2-hour PG definitions for diabetes and prediabetes) was 14.3% (95% CI, 12.2%-16.8%) for total diabetes, 9.1% (95% CI, 7.8%-10.6%) for diagnosed diabetes, 5.2% (95% CI, 4.0%-6.9%) for undiagnosed diabetes, and 38.0% (95% CI, 34.7%-41.3%) for prediabetes; among those with diabetes, 36.4% (95% CI, 30.5%-42.7%) were undiagnosed. The unadjusted prevalence of total diabetes (using the hemoglobin A1c or FPG definition) was 12.3% (95% CI, 10.8%-14.1%); among those with diabetes, 25.2% (95% CI, 21.1%-29.8%) were undiagnosed. Compared with non-Hispanic white participants (11.3% [95% CI, 9.0%-14.1%]), the age-standardized prevalence of total diabetes (using the hemoglobin A1c, FPG, or 2-hour PG definition) was higher among non-Hispanic black participants (21.8% [95% CI, 17.7%-26.7%]; P < .001), non-Hispanic Asian participants (20.6% [95% CI, 15.0%-27.6%]; P = .007), and Hispanic participants (22.6% [95% CI, 18.4%-27.5%]; P < .001). The age-standardized percentage of cases that were undiagnosed was higher among non-Hispanic Asian participants (50.9% [95% CI, 38.3%-63.4%]; P = .004) and Hispanic participants (49.0% [95% CI, 40.8%-57.2%]; P = .02) than all other racial/ethnic groups. The age-standardized prevalence of total diabetes (using the hemoglobin A1c or FPG definition) increased from 9.8% (95% CI, 8.9%-10.6%) in 1988-1994 to 10.8% (95% CI, 9.5%-12.0%) in 2001-2002 to 12.4% (95% CI, 10.8%-14.2%) in 2011-2012 (P < .001 for trend) and increased significantly in every age group, in both sexes, in every racial/ethnic group, by all education levels, and in all poverty income ratio tertiles. CONCLUSIONS AND RELEVANCE In 2011-2012, the estimated prevalence of diabetes was 12% to 14% among US adults, depending on the criteria used, with a higher prevalence among participants who were non-Hispanic black, non-Hispanic Asian, and Hispanic. Between 1988-1994 and 2011-2012, the prevalence of diabetes increased in the overall population and in all subgroups evaluated.

Prevalence of Diabetes and High Risk for Diabetes Using A1C Criteria in the U.S. Population in 1988–2006

OBJECTIVE We examined prevalences of previously diagnosed diabetes and undiagnosed diabetes and high risk for diabetes using recently suggested A1C criteria in the U.S. during 2003–2006. We compared these prevalences to those in earlier surveys and those using glucose criteria. RESEARCH DESIGN AND METHODS In 2003–2006, the National Health and Nutrition Examination Survey included a probability sample of 14,611 individuals aged ≥12 years. Participants were classified on glycemic status by interview for diagnosed diabetes and by A1C, fasting, and 2-h glucose challenge values measured in subsamples. RESULTS Using A1C criteria, the crude prevalence of total diabetes in adults aged ≥20 years was 9.6% (20.4 million), of which 19.0% was undiagnosed (7.8% diagnosed, 1.8% undiagnosed using A1C ≥6.5%). Another 3.5% of adults (7.4 million) were at high risk for diabetes (A1C 6.0 to <6.5%). Prevalences were disproportionately high in the elderly. Age-/sex-standardized prevalence was more than two times higher in non-Hispanic blacks and Mexican Americans versus non-Hispanic whites for diagnosed, undiagnosed, and total diabetes (P < 0.003); standardized prevalence at high risk for diabetes was more than two times higher in non-Hispanic blacks versus non-Hispanic whites and Mexican Americans (P < 0.00001). Since 1988–1994, diagnosed diabetes generally increased, while the percent of diabetes that was undiagnosed and the percent at high risk of diabetes generally decreased. Using A1C criteria, prevalences of undiagnosed diabetes and high risk of diabetes were one-third that and one-tenth that, respectively, using glucose criteria. CONCLUSIONS Although A1C detects much lower prevalences than glucose criteria, hyperglycemic conditions remain high in the U.S., and elderly and minority groups are disproportionately affected.

Achievement of Goals in U.S. Diabetes Care, 1999–2010

BACKGROUND Tracking national progress in diabetes care may aid in the evaluation of past efforts and identify residual gaps in care. METHODS We analyzed data for adults with self-reported diabetes from the National Health and Nutrition Examination Survey and the Behavioral Risk Factor Surveillance System to examine risk-factor control, preventive practices, and risk scores for coronary heart disease over the 1999-2010 period. RESULTS From 1999 through 2010, the weighted proportion of survey participants who met recommended goals for diabetes care increased, by 7.9 percentage points (95% confidence interval [CI], 0.8 to 15.0) for glycemic control (glycated hemoglobin level <7.0%), 9.4 percentage points (95% CI, 3.0 to 15.8) for individualized glycemic targets, 11.7 percentage points (95% CI, 5.7 to 17.7) for blood pressure (target, <130/80 mm Hg), and 20.8 percentage points (95% CI, 11.6 to 30.0) for lipid levels (target level of low-density lipoprotein [LDL] cholesterol, <100 mg per deciliter [2.6 mmol per liter]). Tobacco use did not change significantly, but the 10-year probability of coronary heart disease decreased by 2.8 to 3.7 percentage points. However, 33.4 to 48.7% of persons with diabetes still did not meet the targets for glycemic control, blood pressure, or LDL cholesterol level. Only 14.3% met the targets for all three of these measures and for tobacco use. Adherence to the recommendations for annual eye and dental examinations was unchanged, but annual lipid-level measurement and foot examination increased by 5.5 percentage points (95% CI, 1.6 to 9.4) and 6.8 percentage points (95% CI, 4.8 to 8.8), respectively. Annual vaccination for influenza and receipt of pneumococcal vaccination for participants 65 years of age or older rose by 4.5 percentage points (95% CI, 0.8 to 8.2) and 6.9 percentage points (95% CI, 3.4 to 10.4), respectively, and daily glucose monitoring increased by 12.7 percentage points (95% CI, 10.3 to 15.1). CONCLUSIONS Although there were improvements in risk-factor control and adherence to preventive practices from 1999 to 2010, tobacco use remained high, and almost half of U.S. adults with diabetes did not meet the recommended goals for diabetes care.

Disparities in Incidence of Diabetic End-Stage Renal Disease According to Race and Type of Diabetes

The incidence of end-stage renal disease in patients with diabetes mellitus is reportedly higher among blacks than among whites. This finding may be explained by the greater prevalence of diabetes among blacks. The relation of the type of diabetes to the risk of diabetic end-stage renal disease is largely unstudied. We addressed these issues in a study of all the black and white diabetic patients with end-stage renal disease (470 blacks and 861 whites) reported to the Michigan Kidney Registry who began treatment during 1974 through 1983. We also reviewed the medical records of a subpopulation of such patients (284 blacks and 310 whites) who were less than 65 years of age at the start of treatment for end-stage renal disease to determine what type of diabetes they had. In this study, we made use of national data on the prevalence of diabetes. We found that the incidence of diabetic end-stage renal disease was 2.6-fold higher (P less than or equal to 0.0001) among blacks after we adjusted for the higher prevalence of diabetes among blacks, with the excess risk occurring predominantly among blacks with non-insulin-dependent diabetes mellitus (NIDDM). Most black patients with diabetic end-stage renal disease had NIDDM (77 percent), whereas most white patients with diabetic end-stage renal disease had insulin-dependent diabetes mellitus (IDDM) (58 percent) (P less than or equal to 0.0005 for the difference between the races). For both races combined, the risk of diabetic end-stage renal disease during the 10-year period we studied was markedly greater for patients with IDDM (5.8 percent) than for those with NIDDM (0.5 percent). Our results indicate an increased risk of diabetic end-stage renal disease among blacks as compared with whites, particularly blacks with NIDDM. Although the risk of diabetic end-stage renal disease is higher in patients with IDDM, the majority of patients with diabetic end-stage renal disease in the population we studied had NIDDM.

The Prevalence of Meeting A1C, Blood Pressure, and LDL Goals Among People With Diabetes, 1988–2010

OBJECTIVE To determine the prevalence of people with diabetes who meet hemoglobin A1c (A1C), blood pressure (BP), and LDL cholesterol (ABC) recommendations and their current statin use, factors associated with goal achievement, and changes in the proportion achieving goals between 1988 and 2010. RESEARCH DESIGN AND METHODS Data were cross-sectional from the National Health and Nutrition Examination Surveys (NHANES) from 1988–1994, 1999–2002, 2003–2006, and 2007–2010. Participants were 4,926 adults aged ≥20 years who self-reported a previous diagnosis of diabetes and completed the household interview and physical examination (n = 1,558 for valid LDL levels). Main outcome measures were A1C, BP, and LDL cholesterol, in accordance with the American Diabetes Association recommendations, and current use of statins. RESULTS In 2007–2010, 52.5% of people with diabetes achieved A1C <7.0% (<53 mmol/mol), 51.1% achieved BP <130/80 mmHg, 56.2% achieved LDL <100 mg/dL, and 18.8% achieved all three ABCs. These levels of control were significant improvements from 1988 to 1994 (all P < 0.05). Statin use significantly increased between 1988–1994 (4.2%) and 2007–2010 (51.4%, P < 0.01). Compared with non-Hispanic whites, Mexican Americans were less likely to meet A1C and LDL goals (P < 0.03), and non-Hispanic blacks were less likely to meet BP and LDL goals (P < 0.02). Compared with non-Hispanic blacks, Mexican Americans were less likely to meet A1C goals (P < 0.01). Younger individuals were less likely to meet A1C and LDL goals. CONCLUSIONS Despite significant improvement during the past decade, achieving the ABC goals remains suboptimal among adults with diabetes, particularly in some minority groups. Substantial opportunity exists to further improve diabetes control and, thus, to reduce diabetes-related morbidity and mortality.

Mortality Trends in Men and Women with Diabetes, 1971 to 2000

Context Whether the mortality reductions observed over recent decades in the United States have been similar among diabetic and nondiabetic persons is unknown. Contribution The 19712000 National Health and Nutrition Examination Surveys and vital statistics data reveal higher mortality in the diabetic population than in the nondiabetic population. Over this period, diabetic men experienced mortality reductions that paralleled those of nondiabetic men. However, mortality rates in women have not changed, and the mortality difference between diabetic and nondiabetic women more than doubled. Implications Mortality among diabetic women does not reflect improvements in the care of diabetes and other cardiovascular risk factors. Understanding the sex differences in diabetes outcomes should be a research priority. The Editors The decrease in cardiovascular disease (CVD) mortality rates and the accompanying increases in overall longevity are major public health successes in the United States over the past 40 years (1). These have been attributed to decreases in CVD risk factors, as well as advances in medical management and revascularization, among persons with diagnosed CVD (2, 3). Aggressive management of CVD risk factors has been shown to be particularly effective among persons with diabetes, and implementation of these findings into practice along with aggressive diabetes care should, in theory, result in increased longevity among persons with diabetes (49). The quality of diabetes care and levels of certain CVD risk factors have improved among the U.S. population with diagnosed diabetes (10, 11). Whether reductions in mortality have occurred among persons with diabetes, however, remains unclear. Although regional studies of persons with diabetes suggest that rates of all-cause mortality and cardiovascular complications have declined in recent decades (1215), the only nationally representative study to examine trends in mortality rates of adults with diabetes found no improvement between 1971 and 1992 (16). However, no national studies of mortality trends of the U.S. diabetic population have extended through the 1990s, a period of major advances in clinical diabetes management, leaving the question of whether longevity in this population has improved (4, 11, 17). Thus, we assembled data from 3 consecutive nationally representative cohorts to assess whether all-cause and CVD mortality have declined among the U.S. population with diabetes and whether the disparity in mortality rates between persons with and without diabetes has decreased. Methods Study Design and Population The National Health and Nutrition Examination Survey (NHANES) is a series of independent, nationally representative health surveys of the U.S. noninstitutionalized population conducted from 1971 to 1975 (NHANES I), 1976 to 1980 (NHANES II), and 1988 to 1994 (NHANES III) (1820). Each survey used a stratified, multistage probability design that sampled, interviewed, and examined participants to determine their health status. Sampling approaches, interview, and examination methods were standardized across surveys, and data were linked to death certificate data (21). To minimize bias from differential follow-up, we limited follow-up to 12.2 years, which was the maximum period for the survey with the shortest follow-up (NHANES III). Thus, the follow-up years for the 3 survey cohorts were 1971 to 1986, 1976 to 1992, and 1988 to 2000. Overall, 28043 persons, 27801 persons, and 39695 persons were selected for NHANES I, II, and III, respectively, and 75% (20749 persons), 73% (20322 persons), and 78% (30818 persons) were examined. We restricted our analyses to adults age 35 to 74 years who were examined at baseline. These groups included 8654 (80%), 8213 (76%), and 9399 (90%) persons from each of the 3 cohorts. After excluding persons without information on diabetes (7, 3, and 12 persons) or death (176, 5, and 6 persons), we were left with 8471, 8205, and 9381 persons in the primary analyses. Previous analyses have indicated little bias due to nonresponse (22, 23). Measurements Demographic characteristics, self-reported diabetes status, duration of disease, insulin use, and history of CVD (heart attack, heart failure, or stroke) were determined by interview. Weight and height were measured and were used to calculate body mass index (BMI). Underlying causes of death were classified according to the International Classification of Diseases, Ninth Revision, with CVD coded as 390 to 448. Statistical Analysis We completed mortality rates as the number of deaths divided by the sum of person-years and standardized by age and sex to the 2000 U.S. population. We examined changes in absolute standardized mortality rates over time by using t tests. We also used proportional hazards models to estimate the hazard rate ratios for the NHANES II and III cohorts compared with the NHANES I cohort among the diabetic and nondiabetic populations, with primary models controlling for age, sex, and race or ethnicity and additional models controlling for duration of diabetes and prevalent CVD. We also examined 2-way interactions of survey among persons with diabetes with each of the covariates mentioned above. We assessed the validity of the proportional hazards assumption by adding time-dependent variables to the model (that is, the interaction of age, sex, or race or ethnicity and the logarithm of follow-up duration). Because this assumption was not met across sex, we fit models separately by sex. Mortality rate estimation and proportional hazards regression incorporated survey weights such that results are representative of the U.S. noninstitutionalized population and account for the stratified, clustered design and the unequal probabilities of selection from oversampling and nonresponse (24). We combined data across the 3 surveys for regression analyses, using the original survey weights and design variables. We renumbered strata to appropriately represent their respective surveys, and we calculated degrees of freedom as the number of primary sampling units minus the number of strata. Because we used original survey weights (as opposed to constructing new weights for pooled analyses), these analyses make the assumption that each survey sample is drawn from a different population, as opposed to 3 surveys from a single underlying population (25). We conducted all statistical analyses by using SUDAAN, version 9.1 (RTI International, Research Triangle Park, North Carolina), which uses Taylor series linearization to estimate variances. Role of the Funding Source The U.S. Department of Health and Human Services is the funding source for NHANES and oversees the conduct and reporting of the NHANES surveys. Results Among both men and women with diabetes, the proportion of nonwhite persons roughly doubled across the survey years, the level of education increased substantially, and mean BMI increased (Table 1). In diabetic womenbut not diabetic menthe average age at diagnosis decreased statistically significantly (mean decrease, 2.9 years) across the 3 surveys, and the average age of the diabetic population decreased by 2.5 years, from 59.1 to 56.6 years. Almost all of the secular trends in race or ethnicity, education, and BMI observed in persons with diabetes also occurred in those without diabetes. Table 1. Characteristics of the U.S. Population Age 35 to 74 Years with and without Diagnosed Diabetes Between 1971 to 1986 and 1988 to 2000 in the overall nondiabetic population (both men and women), all-cause mortality rates decreased from 14.4 to 9.5 annual deaths per 1000 persons (P< 0.001) and CVD deaths decreased from 7.0 to 3.4 annual deaths per 1000 persons (P< 0.001) (Table 2). Among the overall diabetic population, the all-cause mortality rate did not statistically significantly change (30 annual deaths per 1000 persons in 1971 to 1986 vs. 25.2 annual deaths per 1000 persons in 1988 to 2000). For CVD mortality, the absolute difference in mortality among the diabetic population between 1971 to 1986 and 1988 to 2000 (18.2 vs. 11.1 annual deaths per 1000 persons) was greater than that of the nondiabetic population, but this decrease was not significant (P= 0.09). Table 2. Trends in Mortality Rates in the U.S. Population Age 35 to 74 Years, by Diabetes Status and Sex, 19712000 Findings in the overall population, however, obscured important sex-related differences, wherein mortality rates decreased among diabetic men but not among diabetic women (interaction between survey year and sex, P= 0.005 for all-cause mortality and P= 0.59 for CVD mortality) (Figure 1). All-cause mortality rates among diabetic men decreased by 43% (from 42.6 to 24.4 annual deaths per 1000 persons) between 1971 to 1986 and 1988 to 2000 (P= 0.03). In an analysis that controlled for age and race or ethnicity, the all-cause mortality rate ratio for diabetic men in 1988 to 2000 compared with 1971 to 1986 was 0.61 (95% CI, 0.43 to 0.86). Trends for the CVD mortality rate paralleled those of all-cause mortality (26.4 vs. 12.8 annual deaths per 1000 persons; P= 0.06 for difference) (Table 2 and Figure 2). In an analysis that controlled for age, sex, and race or ethnicity, the CVD mortality rate ratio for diabetic men in 1988 to 2000 compared with 1971 to 1986 was 0.62 (CI, 0.39 to 1.01) (Table 2 and Figure 2). Additional adjustment for diabetes duration, BMI, and prevalent CVD had no appreciable effect on the mortality rate ratios (data not shown). Figure 1. Age-adjusted all-cause mortality rates among the U.S. population age 35 to 74 years with and without diabetes, by cohort and sex. Figure 2. Age-adjusted cardiovascular disease mortality rates among the U.S. population age 35 to 74 years with and without diabetes, by cohort and sex. The absolute difference in all-cause mortality rates between men with and without diabetes was 23.6 annual deaths per 1000 persons (42.6 vs. 19.0 deaths) in 1971 to 1986 compared with 12.

Comparison of Diabetes Diagnostic Categories in the U.S. Population According to 1997 American Diabetes Association and 1980–1985 World Health Organization Diagnostic Criteria

OBJECTIVE To compare the 1997 American Diabetes Association (ADA) and the 1980–1985 World Health Organization (WHO) diagnostic criteria in categorization of the diabetes diagnostic status of adults in the U.S. RESEARCH DESIGN AND METHODS Analyses are based on a probability sample of the U.S. population age 40–74 years in the 1988–1994 Third National Health and Nutrition Examination Survey (NHANES III). People with diabetes diagnosed before the survey were identified by questionnaire. For 2,844 people without diagnosed diabetes, fasting plasma glucose was obtained after an overnight 9 to < 24-h fast, HbA1c was measured, and a 2-h oral glucose tolerance test was administered. RESULTS Prevalence of diagnosed diabetes in this age-group is 7.9%. Prevalence of undiagnosed diabetes is 4.4% by ADA criteria and 6.4% by WHO criteria. The net change of −2.0% occurs because 1.0% are classified as having undiagnosed diabetes by ADA criteria but have impaired or normal glucose tolerance by WHO criteria, and 3.0% are classified as having impaired fasting glucose or normal fasting glucose by ADA criteria but have undiagnosed diabetes by WHO criteria. Prevalence of impaired fasting glucose is 10.1% (ADA), compared with 15.6% for impaired glucose tolerance (WHO). For those with undiagnosed diabetes by ADA criteria, 62.1% are above the normal range for HbA1c compared with 47.1% by WHO criteria. Mean HbA1c is 7.07% for undiagnosed diabetes by ADA criteria and 6.58% by WHO criteria. CONCLUSIONS The number of people with undiagnosed diabetes by ADA criteria is lower than that by WHO criteria. However, those individuals classified by ADA criteria are more hyperglycemic, with higher HbA1c values and a greater proportion of values above the normal range. This fact, together with the simplicity of obtaining a fasting plasma glucose value, may result in the detection of a greater proportion of people with undiagnosed diabetes in clinical practice using the new ADA diagnostic criteria.