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 > or =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 > or =20 years was 9.6% (20.4 million), of which 19.0% was undiagnosed (7.8% diagnosed, 1.8% undiagnosed using A1C > or =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.

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 > or =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 > or =20 years was 12.9%, of which approximately 40% was undiagnosed. In people aged > or =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 > or =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 > or =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 neutropenia in the U.S. population: age, sex, smoking status, and ethnic differences.

BACKGROUND: Benign reductions in neutrophil counts may be more common at certain ages and in certain ethnic groups and may be affected by sex and smoking status. OBJECTIVE: To determine differences in neutrophil counts in the U.S. population according to ethnicity, age, sex, and smoking status. DESIGN: Population-based, cross-sectional study. SETTING: Various locations in the United States. PARTICIPANTS: 25,222 participants in the 1999 to 2004 National Health and Nutrition Examination Survey who were 1 year of age or older. MEASUREMENTS: Complete blood counts and comparison of means and the proportion of participants with neutropenia. RESULTS: Relative to white participants, black participants had lower leukocyte counts (mean difference, 0.89 x 10(9) cells/L; P < 0.001), lower neutrophil counts (0.83 x 10(9) cells/L; P < 0.001), and similar lymphocyte counts (0.022 x 10(9) cells/L; P = 0.36), whereas Mexican-American participants had slightly higher mean leukocyte counts (0.16 x 10(9) cells/L; P = 0.014), higher neutrophil counts (0.11 x 10(9) cells/L; P = 0.026), and higher lymphocyte counts (0.095 x 10(9) cells/L; P < 0.001). The prevalence of neutropenia (neutrophil count <1.5 x 10(9) cells/L) was 4.5% among black participants, 0.79% among white participants, and 0.38% among Mexican-American participants. The prevalence of neutropenia was higher among males and children younger than 5 years of age. Neutrophil counts less than 1.0 x 10(9) cells/L were observed in fewer than 1% of the overall sample (0.57% in black participants, 0.11% in white participants, and 0.08% in Mexican-American participants). Smoking was associated with higher leukocyte and neutrophil counts but had a smaller effect among black and Mexican-American participants than among white participants. LIMITATION: Because estimates are based on single measures, fluctuations over time could not be determined. CONCLUSIONS: In the United States, neutrophil counts are lower in black persons than in white persons and neutropenia is more prevalent in black persons. Neutrophil counts are slightly higher in Mexican-American persons than in white persons, and neutropenia is uncommon in both groups. The clinical implications of these findings are unclear, but they suggest that when determining the need for a diagnostic evaluation for neutropenia, clinicians should consider the patient's age, sex, ethnicity, and smoking status.

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 > or =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 > or =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.

Chronic kidney disease awareness, prevalence, and trends among U.S. adults, 1999 to 2000.

The incidence of kidney failure treatment in the United States increased 57% from 1991 to 2000. Chronic kidney disease (CKD) prevalence was 11% among U.S. adults surveyed in 1988 to 1994. The objective of this study was to estimate awareness of CKD in the U.S. population during 1999 to 2000 and to determine whether the prevalence of CKD in the United States increased compared with 1988 to 1994. Analysis was conducted of nationally representative samples of noninstitutionalized adults, aged 20 yr and older, in two National Health and Nutrition Examination Surveys conducted in 1988 to 1994 (n = 15,488) and 1999 to 2000 (n = 4101) for prevalence +/- SE. Awareness of CKD is self-reported. Kidney function (GFR), kidney damage (microalbuminuria or greater), and stages of CKD (GFR and albuminuria) were estimated from calibrated serum creatinine, spot urine albumin to creatinine ratio (ACR), age, gender, and race. GFR was estimated using the simplified Modification of Diet in Renal Disease Study equation. Self-reported awareness of weak or failing kidneys in 1999 to 2000 was strongly associated with decreased kidney function and albuminuria but was low even in the presence of both conditions. Only 24.3 +/- 6.4% of patients at GFR 15 to 59 ml/min per 1.73 m(2) and albuminuria were aware of CKD compared with 1.1 +/- 0.3% at GFR of 90 ml/min per 1.73 m(2) or greater and no microalbuminuria. At moderately decreased kidney function (GFR 30 to 59 ml/min per 1.73 m(2)), awareness was much lower among women than men (2.9 +/- 1.6 versus 17.9 +/- 5.9%; P = 0.008). The prevalence of moderately or severely decreased kidney function (GFR 15 to 59 ml/min per 1.73 m(2)) remained stable over the past decade (4.4 +/- 0.3% in 1988 to 1994 and 3.8 +/- 0.4% in 1999 to 2000; P = 0.23). At the same time, the prevalence of albuminuria (ACR >/= 30 mg/g) in single spot urine increased from 8.2 +/- 0.4% to 10.1 +/- 0.7% (P = 0.01). Overall CKD prevalence was similar in both surveys (9% using ACR > 30 mg/g for persistent microalbuminuria; 11% in 1988 to 1994 and 12% in 1999 to 2000 using gender-specific ACR cutoffs). Despite a high prevalence, CKD awareness in the U.S. population is low. In contrast to the dramatic increase in treated kidney failure, overall CKD prevalence in the U.S. population has been relatively stable.

Projected impact of implementing the results of the diabetes prevention program in the U.S. population.

OBJECTIVE: To determine the feasibility of using either fasting plasma glucose or HbA(1c) to identify individuals in the U.S. population who meet the Diabetes Prevention Program (DPP) criteria for intervention, defined as BMI >/=24 kg/m(2), fasting plasma glucose level 96-125 mg/dl, and 2-h glucose level 140-199 mg/dl in an oral glucose tolerance test (OGTT). RESEARCH DESIGN AND METHODS: Analysis of a representative sample of U.S. adults aged 40-74 years with no medical history of diabetes for whom data on height, weight, fasting plasma glucose, HbA(1c), and 2-h plasma glucose during an OGTT were obtained. Sensitivity, specificity, positive predictive value (PPV), and receiver operator characteristic (ROC) curves for fasting glucose and HbA(1c) were determined. RESULTS: Using BMI <24 kg/m(2) as an initial criterion eliminated 27.2% of U.S. adults from further testing. Of the remaining group, 41.1% did not have to be considered for an OGTT because their fasting glucose level was below or above 96-125 mg/dl. Overall, 10.6% of adults aged 40-74 years without medical history of diabetes met the DPP eligibility criteria for intervention. Among individuals with BMI >/=24 kg/m(2) and fasting glucose level 96-125 mg/dl, applying a fasting plasma glucose cutoff of >/=105 mg/dl excluded 62.5% of this group and resulted in 56.0% of those with 2-h glucose level 140-199 mg/dl in this group being identified, with a specificity of 72.0% and a PPV of 17.1%. Similar values were obtained for an HbA(1c) cutoff value of >/=5.5%. CONCLUSIONS: Using data on BMI and setting cutoff values for fasting glucose and HbA(1c) would greatly reduce the number of individuals who would need to undergo an OGTT while achieving adequate sensitivity, specificity, and PPV.

Microalbuminuria in the US population: third National Health and Nutrition Examination Survey.

Microalbuminuria (MA) is associated with adverse health outcomes in diabetic and hypertensive adults. The prevalence and clinical significance of MA in nondiabetic populations is less clear. The purpose of this study was to generate national estimates of the prevalence of MA in the US population. Untimed urinary albumin concentrations (UACs) and creatinine concentrations were evaluated in a nationally representative sample of 22,244 participants aged 6 years and older. Persons with hematuria and menstruating or pregnant women were excluded from analysis. The percent prevalence of clinical proteinuria (UAC > or = 300 mg/L) was similar for males and females. However, the prevalence of MA (urinary albumin-creatinine ratio [ACR], 30 to 299 mg/g) was significantly lower in males (6.1%) compared with females (9.7%). MA prevalence was greater in children than young adults and increased continuously starting at 40 years of age. MA prevalence was greater in non-Hispanic blacks and Mexican Americans aged 40 to 79 years compared with similar-aged non-Hispanic whites. MA prevalence was 28.8% in persons with previously diagnosed diabetes, 16.0% in those with hypertension, and 5.1% in those without diabetes, hypertension, cardiovascular disease, or elevated serum creatinine levels. In adults aged 40+ years, after excluding persons with clinical proteinuria, albuminuria (defined as ACR > or = 30 mg/g) was independently associated with older age, non-Hispanic black and Mexican American ethnicity, diabetes, hypertension, and elevated serum creatinine concentration. MA is common, even among persons without diabetes or hypertension. Age, sex, race/ethnicity, and concomitant disease contribute to the variability of MA prevalence estimates.