Serum 25-hydroxyvitamin D, diabetes, and ethnicity in the Third National Health and Nutrition Examination Survey

OBJECTIVE: To determine the association between serum 25-hydroxyvitamin D (25OHD) and diabetes risk and whether it varies by ethnicity. RESEARCH DESIGN AND METHODS: We performed an analysis of data from participants who attended the morning examination of the Third National Health and Nutrition Examination Survey (1988-1994), a cross-sectional survey of a nationally representative sample of the U.S. population. Serum levels of 25OHD, which reflect vitamin D status, were available from 6,228 people (2,766 non-Hispanic whites, 1,736 non-Hispanic blacks, and 1,726 Mexican Americans) aged > or =20 years with fasting and/or 2-h plasma glucose and serum insulin measurements. RESULTS: Adjusting for sex, age, BMI, leisure activity, and quarter of year, ethnicity-specific odds ratios (ORs) for diabetes (fasting glucose > or =7.0 mmol/l) varied inversely across quartiles of 25OHD in a dose-dependent pattern (OR 0.25 [95% CI 0.11-0.60] for non-Hispanic whites and 0.17 [0.08-0.37] for Mexican Americans) in the highest vitamin D quartile (25OHD > or =81.0 nmol/l) compared with the lowest 25OHD (< or =43.9 nmol/l). This inverse association was not observed in non-Hispanic blacks. Homeostasis model assessment of insulin resistance (log e) was inversely associated with serum 25OHD in Mexican Americans (P=0.0024) and non-Hispanic whites (P=0.058) but not non-Hispanic blacks (P=0.93), adjusting for confounders. CONCLUSIONS: These results show an inverse association between vitamin D status and diabetes, possibly involving insulin resistance, in non-Hispanic whites and Mexican Americans. The lack of an inverse association in non-Hispanic blacks may reflect decreased sensitivity to vitamin D and/or related hormones such as the parathyroid hormone.     

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.     

Aspirin use among adults with diabetes: estimates from the Third National Health and Nutrition Examination Survey

OBJECTIVE: Since 1997, the American Diabetes Association has recommended that aspirin therapy be considered for adults with diabetes who have cardiovascular disease (CVD) or CVD risk factors. We examined the prevalence of regular aspirin use among adults in the U.S. with diagnosed diabetes. RESEARCH DESIGN AND METHODS: The Third National Health and Nutrition Examination Survey (1988-1994) used a probability sample of the U.S. population and included an interview, physical examination, and laboratory studies. Among the survey participants were 1,503 adults (age > or =21 years) with self-reported diabetes. We defined regular aspirin use as reported having taken aspirin > or = 15 times in the previous month. CVD conditions were self-reported heart attack and stroke and symptoms of angina and claudication. CVD risk factors included smoking, hypertension, obesity, albuminuria, lipid abnormalities, and family history of heart attack. RESULTS: An estimated 27% of adults with diabetes had CVD, and an additional 71% had one or more CVD risk factors. Aspirin was used regularly by 37% of those with CVD and by 13% of those with risk factors only Adjusted odds of regular aspirin use were significantly greater for individuals with CVD than for those with one CVD risk factor (odds ratio [OR] = 4.3); for non-Hispanic whites than for blacks, Mexican-Americans, and others (OR = 2.5); and for individuals age 40-59 years than for those <40 years (OR = 33.3). CONCLUSIONS: Nearly every adult in the U.S. with diabetes has at least one risk factor for CVD and thus may be considered a potential candidate for aspirin therapy. During 1988-1994, only 20% (95% CI 16-23) took aspirin regularly Major efforts are needed to increase aspirin use.     

Chronic abdominal pain and depression. Epidemiologic findings in the United States. Hispanic Health and Nutrition Examination Survey.

We report data on abdominal pain and depression from a survey of Hispanic Americans by the United States National Center for Health Statistics. The point prevalence rates of chronic abdominal pain were 4.6% in Mexican Americans and 5.8% in Cuban Americans in a total of 4175 subjects. The rate was 8.3% among 1323 Puerto Ricans. In 53% the abdominal pain came in waves. Using the Depression scale of the Center for Epidemiologic Studies (CES-D), 18.7% of Mexican and Cuban Americans with pain were found to be depressed to an extent likely to require intervention, and 40.8% of Puerto Ricans were so affected. The Diagnostic Interview Schedule (DIS) gave more conservative figures for major depression in terms of DSM-III, viz., 6.8% for Mexican and Cuban Americans with chronic pain, and 12.6% for Puerto Ricans with chronic pain. Logistic regression analyses demonstrated links between depression and female sex, the single state, low education and income, and chronic abdominal pain. The most consistent relationships for depression were with chronic pain, female sex and the single state. The results confirm the strong relationships between chronic pain, mood and female gender, and other socio-demographic variables.     

The effect of diabetes combined with stroke on disability,self-rated health,and mortality in older Mexican Americans: results from the Hispanic EPESE

OBJECTIVE: To examine how diabetes in combination with stroke affects functional activities of daily living (ADLs) and instrumental activities of daily living (IADLs), self-rated health, and 5-year mortality in elderly Mexican Americans with or without other comorbid conditions. DESIGN: Longitudinal study. SETTING: Five southwestern states. PARTICIPANTS: A total of 3050 subjects of age 65 years or older, of whom 23% had diabetes and 6% had a stroke. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: ADL and IADL disabilities, self-rated health, and 5-year mortality. RESULTS: Subjects with both diabetes and stroke but without other comorbid conditions had almost 18 times higher risk of having any ADL disability (odds ratio [OR]=18.8; 95% confidence interval [CI], 3.3-105.2) and 10 times higher risk of having any IADL disability (OR=10.6; 95% CI, 1.1-101.5), compared with subjects without either of the 2 conditions. The risk of disability was further increased if the subject had a comorbid condition (hypertension, heart attack, cancer, hip fracture, arthritis). The risk of fair or poor self-rated health was 3.5 (95% CI, 1.4-8.6) and the hazard ratio for 5-year mortality was 2.4 (95% CI, 1.7-3.4) in people with both diseases. CONCLUSIONS: Diabetes and stroke in combination is strongly associated with a higher risk of disabilities, poor self-rated health, and 5-year mortality in elderly Mexican Americans. The effect on outcomes appears to follow an additive model. Information on disability risk and morbidity and mortality should be useful to rehabilitation professionals in discharge planning and allocation of therapy resources.     

Cardiovascular Health Metrics and Accelerometer-Measured Physical Activity Levels: National Health and Nutrition Examination Survey, 2003-2006

ObjectiveTo determine whether relationships exist between accelerometer-measured moderate-to-vigorous physical activity (MVPA) and other cardiovascular (CV) health metrics in a large sample.Patients and MethodsData from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) collected from January 1, 2003, through December 31, 2006, were used. Overall, 3454 nonpregnant adults 20 years or older who fasted for 6 hours or longer, with valid accelerometer data and with CV health metrics, were included in the study. Blood pressure (BP), body mass index (BMI), smoking status, diet, fasting plasma glucose level, and total cholesterol level were defined as ideal, intermediate, and poor on the basis of American Heart Association criteria. Results were weighted to account for sampling design, oversampling, and nonresponse.ResultsSignificant increasing linear trends in mean daily MVPA were observed across CV health levels for BMI, BP, and fasting plasma glucose (P<.001). Those with a poor BMI and BP had significantly lower mean daily MVPA than those with intermediate and ideal BMIs and BPs (all P<.001). In addition, individuals with an intermediate fasting plasma glucose level had significantly lower mean daily MVPA than individuals at the ideal levels (P<.001). No significant linear trends were observed for cholesterol, smoking, and diet. A significant linear trend was observed for mean daily MVPA and the overall number of other CV health metrics (P<.001).ConclusionObjectively measured MVPA was related to other CV health metrics in this large sample. These results support the inclusion of physical activity in the overall definition of ideal CV health.     

Prevalence and risk factors for urinary incontinence in women with type 2 diabetes and impaired fasting glucose: findings from the National Health and Nutrition Examination Survey (NHANES) 2001-2002

OBJECTIVE: Diabetes is associated with increased risk of urinary incontinence. It is unknown whether women with pre-diabetes, or impaired fasting glucose (IFG), have increased prevalence of incontinence. We determined the prevalence of, and risk factors for, incontinence among U.S. women with diabetes and IFG. RESEARCH DESIGN AND METHODS: The 2001-2002 National Health and Nutrition Examination Survey measured fasting plasma glucose and obtained information about diabetes and urinary incontinence among 1,461 nonpregnant adult women. Self-reported weekly or more frequent incontinence, both overall and by type (urge and stress), was our outcome. RESULTS: Of the 1,461 women, 17% had diabetes and 11% met criteria for IFG. Prevalence of weekly incontinence was similar among women in these two groups (35.4 and 33.4%, respectively) and significantly higher than among women with normal fasting glucose (16.8%); both urge and stress incontinence were increased. In addition to well-recognized risk factors including age, weight, and oral estrogen use, two microvascular complications caused by diabetes, specifically macroalbuminuria and peripheral neuropathic pain, were associated with incontinence. CONCLUSIONS: Physicians should be alert for incontinence, an often unrecognized and therefore undertreated disorder, among women with diabetes and IFG, in particular those with microvascular complications. The additional prospect of improvements in their incontinence may help motivate some high-risk women to undertake difficult lifestyle changes to reduce their more serious risk of diabetes and its sequelae.     

Prevalence of diabetes and impaired fasting glucose in Korea: Korean National Health and Nutrition Survey 2001

OBJECTIVE: The purpose of this study was to estimate the prevalence of diabetes and impaired fasting glucose (IFG) and their association with risk factors in the Korean population. RESEARCH DESIGN AND METHODS: The Korean National Health and Nutrition Survey 2001 was a nationally representative survey with a stratified multistage sampling design. Data from a comprehensive questionnaire, a physical examination, and blood tests were obtained from 5,844 Korean adults (2,513 men and 3,331 women) aged >20 years. RESULTS: The age-adjusted prevalence of diabetes in this Korean population was 7.6%, and the age-adjusted prevalences of previously diagnosed diabetes and newly diagnosed diabetes were 4.4 and 3.3%, respectively (fasting plasma glucose > or = 7.0 mmol/l). Overall, these results indicate that 8.1% or 1.4 million Korean men and 7.5% or 1.3 million Korean women have diabetes. The age-adjusted prevalence of IFG was 23.9%, using the new American Diabetes Association criteria (fasting plasma glucose 5.6-6.9 mmol/l). Diabetes prevalence increased with age and peaked in the oldest age-group; however, IFG prevalence did not show the same trend. Diabetes was found to be associated with age, BMI, blood pressure, triglyceride, HDL cholesterol, education levels, alcohol consumption, exercise, and a family history of diabetes. CONCLUSIONS: This study shows that diabetes and IFG are common in Korea, and about one-half of diabetes cases remain undiagnosed. These results emphasize the need to develop an urgent public program to improve the detection, prevention, and treatment of diabetes.     

Inflammation among women with a history of gestational diabetes mellitus and diagnosed diabetes in the Third National Health and Nutrition Examination Survey

OBJECTIVE—We compared inflammatory markers among women with a history of gestational diabetes mellitus (hGDM), women with diagnosed diabetes, and unaffected women in a population-based sample.RESEARCH DESIGN AND METHODS—We conducted cross-sectional analyses of 6,346 nonpregnant women in the Third National Health and Nutrition Examination Survey (1988–1994). Women were classified as having hGDM (n = 87), diagnosed diabetes (n = 244), or neither condition (n = 6,015). Inflammatory markers included ferritin, leukocyte count, and C-reactive protein levels.RESULTS—After adjustment, women with diagnosed diabetes had the most marked differences in inflammatory markers compared with unaffected women. Differences between unaffected women and women with hGDM were minimal.CONCLUSIONS—Women with diagnosed diabetes have less favorable inflammation profiles than unaffected women and greater ferritin levels than women with hGDM. After adjustment, women with hGDM who have not developed diagnosed diabetes have inflammation profiles similar to those of unaffected women.Women with a history of gestational diabetes mellitus (hGDM) are at increased risk for future glucose intolerance, and this risk may be associated with inflammation (1–4). The association has not been examined in population-based studies and may not be robust after adjustment for BMI (1–4). Using data from the third National Health and Nutrition Examination Survey (NHANES III), a population-based cross-sectional study, we compared inflammatory markers among unaffected women versus women with hGDM and women with diagnosed diabetes.     

Prevalence and management of diabetes and metabolic risk factors in Thai adults: the Thai National Health Examination Survey IV, 2009

OBJECTIVE

To determine the prevalence of impaired fasting glucose (IFG) and undiagnosed and diagnosed diabetes in Thai adults in 2009 and examine the extent of changes in proportions of diagnosis, treatment, and control for blood glucose, high blood pressure, and high total cholesterol between 2004 and 2009.

RESEARCH DESIGN AND METHODS

Data from the multistage cross-sectional National Health Examination Survey (NHES) IV of 18,629 Thai adults aged ≥20 years conducted in 2009 were used to analyze and compare with the data from NHES III in 2004.

RESULTS

The prevalence of IFG and diabetes was 10.6 and 7.5%, respectively. Of all diabetes diagnoses, 35.4% were not previously diagnosed, and the proportion was higher in men than in women (47.3 vs. 23.4%, P < 0.05). Compared with those in year 2004, the proportions of individuals with diabetes and concomitant hypertension did not significantly decrease in 2009 in both sexes, but the proportions of women with diabetes who were abdominally obese or had high total cholesterol (≥5.2 mmol/L) significantly increased in 2009 by 18.0 and 23.5%, respectively (all P < 0.01). The rates of treatment and control of blood glucose, high blood pressure, and high total cholesterol were favorably improved in 2009. However, in substantial proportions of individuals with diabetes these concomitants were still controlled suboptimally.

CONCLUSIONS

The prevalence of diabetes and IFG remained high in Thai adults. Improvement in detection and control of diabetes and associated metabolic risk factors, particularly obesity and high serum cholesterol, are necessary.Diabetes has become a major global public health burden. It has been estimated that the number of people with diabetes worldwide was 285 million in 2010 and will increase to 439 million in 2030, with the majority of increase (69%) occurring in developing countries (1). The estimated number of individuals with diabetes in Asia was 113 million in 2010 and will increase to 180 million in 2030 (2). The increase has been the result of the rise in obesity as a consequence of changes in lifestyle toward urbanization, with high energy intake and low physical activity following the rapid economic growth and urbanization in this region (2).In Thailand, a low-middle income country, diabetes has been a major cause of morbidity and mortality in the past decade (3). Diabetes alone is responsible for 3.3 and 8.3% of total deaths in Thai men and women, respectively (3). A high prevalence rate of diabetes in Thailand makes it among the top ten in Asia (2). In 2004, the National Health Examination Survey (NHES) III reported a prevalence of 6.7% in adults aged ≥15 years, of whom 53.3% went undiagnosed. The prevalence of impaired fasting glucose (IFG) is 12.5% (4). Undiagnosed diabetes increases the risk of complications as a result of being untreated, and about 40% of those treated have their fasting plasma glucose (FPG) under control (<7.8 mmol/L) (4).To monitor the diabetes situation, the fourth NHES was conducted in 2009. This study aimed to determine the prevalence of IFG, diabetes, and associated metabolic risk factors in Thai adults aged ≥20 years and older in 2009. Among individuals with diabetes, we also examined the extent of changes in proportions of metabolic risk factors and lack of diagnosis, treatment, and control for high blood glucose, high blood pressure, and high total cholesterol between the years 2004 and 2009.     

Prospective association between lung function and the incidence of diabetes: findings from the National Health and Nutrition Examination Survey Epidemiologic Follow-up Study

OBJECTIVE: To determine whether impaired pulmonary function is a significant predictor of the incidence of diabetes. RESEARCH DESIGN AND METHODS: Using data from the National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study, a cohort study of a representative sample of U.S. adults, we examined the prospective associations between pulmonary function and incidence of diabetes. Our analyses included 4,830 U.S. men and women aged 25-74 years who had a baseline interview and examination (including spirometry) from 1971 through 1975 and were followed through 1992-1993. Incident diabetes (n=443) was based on self- or proxy reports, hospitalization, or death certificates. RESULTS: After multiple adjustment, forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), percentage of predicted FEV1, and percentage of predicted FVC were significantly and inversely associated with the incidence of diabetes, but the ratio of FEV1 to FVC was not. Obstructive lung disease (defined by the Global Initiative for Chronic Obstructive Lung Disease classification) was not significantly associated with the incidence of diabetes, but restrictive lung disease was (hazard ratio=1.45, 95% CI 1.04-2.03). The association did not differ significantly by smoking status. CONCLUSIONS: Although several prospective studies have found that impaired pulmonary function may increase the risk for developing diabetes, additional research is needed to better understand these relationships and their possible implications.     

American Diabetes Association diabetes diagnostic criteria, advancing age, and cardiovascular disease risk profiles: results from the Third National Health and Nutrition Examination Survey

OBJECTIVE: To evaluate age-specific effects on diabetes prevalence estimates resulting from the American Diabetes Association (ADA) recommendation against use of the oral glucose tolerance test (OGTT), we contrasted the prevalence of two mutually exclusive groups: undiagnosed diabetes according to ADA criteria (no report of diabetes and fasting glucose [FG] > or =126 mg/dl) and isolated postchallenge hyperglycemia (IPH) (FG <126 mg/dl and OGTT > or =200 mg/dl), a group designated to have diabetes by World Health Organization (WHO) criteria but not ADA criteria. RESEARCH DESIGN AND METHODS: The weighted age-specific ratios of undiagnosed diabetes:IPH were calculated for 2,844 subjects aged 40-74 years without reported diabetes who had both FG and OGTT. A ratio > 1.0 indicated that the proportion of undiagnosed diabetes was greater than that of IPH. Mean levels of HbA1c and cardiovascular disease (CVD) risk factors were contrasted among people with undiagnosed diabetes and IPH and those without either abnormality ("nondiabetic"). RESULTS: Both undiagnosed diabetes and IPH increased with age, but age-specific undiagnosed diabetes:IPH ratios decreased from 5.49 in the 40-44 age-group to 0.77 in the 70-74 age-group. Regression analysis showed a significant (P = 0.006) negative association between age and these ratios. Mean HbA1c was 7.1% in the undiagnosed diabetes group and differed significantly from that of the IPH and nondiabetic groups (5.6 and 5.3%, respectively). Individuals with undiagnosed diabetes had less favorable triglycerides, BMI, and HDL cholesterol compared with people with IPH. CONCLUSIONS: Compared with WHO criteria, the ADA criteria underestimate glucose abnormalities more with increasing age. However, compared to those with undiagnosed diabetes, individuals with IPH had a mean HbA1c level that is considered in the nondiabetic range, and this group had significantly more favorable levels of several key CVD risk factors. These findings suggest that the ADA criteria, although underestimating the abnormalities of postchallenge hyperglycemia that occur frequently with increasing age, appear to be effective at identifying a group of individuals with both unfavorable CVD risk factor profiles and evidence of long-term exposure to hyperglycemia.     

Periodontal disease and incident type 2 diabetes: results from the First National Health and Nutrition Examination Survey and its epidemiologic follow-up study

OBJECTIVE—Type 2 diabetes and periodontal disease are known to be associated, but the temporality of this relationship has not been firmly established. We investigated whether baseline periodontal disease independently predicts incident diabetes over two decades of follow-up.RESEARCH DESIGN AND METHODS—A total of 9,296 nondiabetic male and female National Health and Nutrition Examination Survey (NHANES I) participants aged 25–74 years who completed a baseline dental examination (1971–1976) and had at least one follow-up evaluation (1982–1992) were studied. We defined six categories of baseline periodontal disease using the periodontal index. Of 7,168 dentate participants, 47% had periodontal index = 0 (periodontally healthy); the remaining were classified into periodontal index quintiles. Incident diabetes was defined by 1) death certificate (ICD-9 code 250), 2) self-report of diabetes requiring pharmacological treatment, or 3) health care facility stay with diabetes discharge code. Multivariable logistic regression models assessed incident diabetes odds across increasing levels of periodontal index in comparison with periodontally healthy participants.RESULTS—The adjusted odds ratios (ORs) for incident diabetes in periodontal index categories 1 and 2 were not elevated, whereas the ORs in periodontal index categories 3 through 5 were 2.26 (95% CI 1.56–3.27), 1.71 (1.0–2.69), and 1.50 (0.99–2.27), respectively. The OR in edentulous participants was 1.30 (1.00–1.70). Dentate participants with advanced tooth loss had an OR of 1.70 (P < 0.05) relative to those with minimal tooth loss.CONCLUSIONS—Baseline periodontal disease is an independent predictor of incident diabetes in the nationally representative sample of NHANES I.Type 2 diabetes is a significant public health concern. The association between type 2 diabetes and periodontal disease is well documented (1,2), and periodontal disease has been traditionally viewed solely as a pathological consequence of diabetes (3). However, prospective data supporting this unidirectional hypothesis are limited, and prevailing views regarding associations between periodontal disease and type 2 diabetes should be informed by the growing body of evidence suggesting periodontal disease as a risk factor for atherosclerotic cardiovascular disease (CVD) (4–7).Type 2 diabetes and CVD have common antecedents, and in view of the American Heart Association''s Scientific Statement on Diabetes stating that “diabetes is a cardiovascular disease” (8), it seems reasonable to hypothesize periodontal disease as a potential contributor to development of type 2 diabetes. As with CVD infection hypotheses, chronic inflammation in response to periodontal bacteria might link periodontal disease and type 2 diabetes. Indeed, systemic inflammation has emerged as a novel predictor of type 2 diabetes (9,10), and individuals with periodontal disease have been consistently shown to exhibit elevated levels of systemic inflammation (2). Moreover, periodontal therapy has resulted in changes in systemic monocytic gene expression (11) and decreases in systemic inflammation (12).We are unaware of any studies that have assessed the association between baseline clinical periodontal disease and risk of subsequent diabetes in an initially diabetes-free cohort. Studies of this nature are important as they can clarify the temporality of periodontal disease/type 2 diabetes associations We hypothesized that baseline periodontal disease predicted incident type 2 diabetes in the First National Health and Nutrition Examination Survey (NHANES I) and its Epidemiologic Follow-up Study (NHEFS).     

C-reactive protein concentration distribution among US children and young adults: findings from the National Health and Nutrition Examination Survey, 1999-2000

BACKGROUND: The distribution of C-reactive protein (CRP) concentrations among children and young adults in the US is not known at present. METHODS: We used data from 3348 US children and young adults 3-19 years of age who participated in the National Health and Nutrition Examination Survey, 1999-2000, to describe the distribution of CRP concentrations, based on results obtained with a high-sensitivity latex-enhanced turbidimetric assay. RESULTS: The range of CRP concentrations was 0.1-90.8 mg/L (mean, 1.6 mg/L; geometric mean, 0.5 mg/L; median, 0.4 mg/L). CRP concentrations increased with age. Females 16-19 years of age had higher concentrations than males in this age range (P = 0.003). Mexican Americans had the highest CRP concentrations among the three major race or ethnic groups (P <0.001). CONCLUSIONS: For the first time, these data describe the CRP concentration distribution among US children and young adults, based on results obtained with a high-sensitivity assay.     

Effect of aging on A1C levels in individuals without diabetes: evidence from the Framingham Offspring Study and the National Health and Nutrition Examination Survey 2001-2004

OBJECTIVE—Although glycemic levels are known to rise with normal aging, the nondiabetic A1C range is not age specific. We examined whether A1C was associated with age in nondiabetic subjects and in subjects with normal glucose tolerance (NGT) in two population-based cohorts.RESEARCH DESIGN AND METHODS—We performed cross-sectional analyses of A1C across age categories in 2,473 nondiabetic participants of the Framingham Offspring Study (FOS) and in 3,270 nondiabetic participants from the National Health and Nutrition Examination Survey (NHANES) 2001–2004. In FOS, we examined A1C by age in a subset with NGT, i.e., after excluding those with impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Multivariate analyses were performed, adjusting for sex, BMI, fasting glucose, and 2-h postload glucose values.RESULTS—In the FOS and NHANES cohorts, A1C levels were positively associated with age in nondiabetic subjects. Linear regression revealed 0.014- and 0.010-unit increases in A1C per year in the nondiabetic FOS and NHANES populations, respectively. The 97.5th percentiles for A1C were 6.0% and 5.6% for nondiabetic individuals aged <40 years in FOS and NHANES, respectively, compared with 6.6% and 6.2% for individuals aged ≥70 years (P_trend < 0.001). The association of A1C with age was similar when restricted to the subset of FOS subjects with NGT and after adjustments for sex, BMI, fasting glucose, and 2-h postload glucose values.CONCLUSIONS—A1C levels are positively associated with age in nondiabetic populations even after exclusion of subjects with IFG and/or IGT. Further studies are needed to determine whether age-specific diagnostic and treatment criteria would be appropriate.Glycemia is recognized to change with age. The prevalence of diabetes and impaired glucose homeostasis (impaired fasting glucose [IFG] and impaired glucose tolerance [IGT]) is increased among older individuals (1). Given the large size of the elderly type 2 diabetic population (approximately 15.3% diagnosed and 6.9% undiagnosed) (2), it is important to consider the effects of aging on glycemic measures, particularly as targets are set for diabetes management.A1C levels are used globally as an index of average glycemia over the preceding 8–12 weeks (3), as a marker for risk of development of diabetes complications, and to guide therapy (4). Some reports have demonstrated an association of A1C with age (5–13), whereas others have not (14–17). Higher A1C levels with advanced age may be a function of a higher prevalence of undiagnosed diabetes in older individuals. The nondiabetic range for A1C, used worldwide and for all age-groups, was established by the Diabetes Control and Complications Trial (DCCT) >20 years ago (18). A group of 124 nondiabetic healthy volunteers aged 13–39 years was drawn from local DCCT clinics to generate the A1C distribution. The volunteers did not have an oral glucose tolerance test (OGTT) to exclude undiagnosed diabetes and were not representative of individuals aged ≥40 years.Current A1C targets for diabetes treatment set by the American Diabetes Association (A1C <7%) (19) or the American College of Endocrinology (A1C ≤6.5%) (20) are not age specific. The central role played by A1C in the management of diabetes (4) and possibly in its diagnosis (21) raises the question of whether there are age-related differences in A1C. If so, current A1C targets may be too stringent for older type 2 diabetic patients, who have an increased risk of hypoglycemia and medication side effects (22,23).Our aim was to examine the relationship between A1C and age using current diagnosis criteria for diabetes in nondiabetic subjects and in subjects with no abnormality in glucose homeostasis using two large, diverse population-based cohorts, the community-based Framingham Offspring Study (FOS) and the nationally representative National Health and Nutrition Examination Survey (NHANES) 2001–2004 population. In subsidiary analyses, we assessed this relationship in FOS subjects with normal glucose tolerance (NGT), after exclusion of those with IFG and/or IGT determined by an OGTT. Finally, in a subset of FOS participants with longitudinal A1C data, we determined the annual rate of change in A1C as an alternate approach to test the hypothesis that A1C increases with age.     

Trends in the risk for coronary heart disease among adults with diagnosed diabetes in the U.S.: findings from the National Health and Nutrition Examination Survey, 1999-2008

OBJECTIVE

Coronary heart disease (CHD) is a major cause of mortality among people with diabetes. The objective of this study was to examine the trend in an estimated 10-year risk for developing CHD among adults with diagnosed diabetes in the U.S.

RESEARCH DESIGN AND METHODS

Data from 1,977 adults, aged 30–79 years, with diagnosed diabetes who participated in the National Health and Nutrition Examination Survey from 1999–2000 to 2007–2008 were used. Estimated risk was calculated using risk prediction algorithms from the UK Prospective Diabetes Study (UKPDS), the Atherosclerosis Risk in Communities study, and the Framingham Heart Study.

RESULTS

Significant improvements in mean HbA_1c concentrations, systolic blood pressure, and the ratio of total cholesterol to HDL cholesterol occurred. No significant linear trend for current smoking status was observed. The estimated UKPDS 10-year risk for CHD was 21.1% in 1999–2000 and 16.4% in 2007–2008 (P_{linear trend} < 0.001). The risk decreased significantly among men, women, whites, African Americans, and Mexican Americans.

CONCLUSIONS

The estimated 10-year risk for CHD among adults with diabetes has improved significantly from 1999–2000 to 2007–2008. Sustained efforts in improving risk factors should further benefit the cardiovascular health of people with diabetes.Many people with diabetes will die from cardiovascular disease. Therefore, controlling the risk factors for cardiovascular disease is of the utmost importance in reducing the risk for developing cardiovascular disease in the diabetic population. In the U.S., important strides have been made in reducing the impact of several key risk factors for cardiovascular disease. Thus, the prevalence of smoking has fallen substantially, and concentrations of total cholesterol (TC) have decreased, but blood pressure levels have moved less consistently (1–3). Some data suggest that these trends in the general population also have played out in the diabetic population (4). If so, the risk for developing coronary heart disease (CHD) should have decreased among people with diabetes. Therefore, the objective of this study was to examine the trends in the 10-year risk for CHD among adults with diagnosed diabetes in the U.S. from 1999 to 2008.