National Health And Nutrition Examination Survey Cohort Research Articles

Combined exposure to lead, cadmium, mercury, and arsenic and kidney health in adolescents age 12–19 in NHANES 2009–2014

BackgroundOccupational and environmental exposures to toxic metals are established risk factors for the development of hypertension and kidney disease in adults. There is some evidence of developmental metal nephrotoxicity in children and from animal studies; however, to our knowledge no previous studies have examined associations between co-exposure to nephrotoxic environmental metals and children's kidney health. ObjectiveThe objective of this study was to assess the association between co-exposure to lead (Pb), cadmium (Cd), mercury (Hg), and arsenic (As), measured in urine and blood, and kidney parameters in US adolescents. MethodsWe performed a cross-sectional analysis of a subsample of 2709 children aged 12–19 participating in the National Health and Nutrition Examination Survey (NHANES) between 2009 and 2014. We analyzed urine levels of 4 nephrotoxic metals selected a priori (As, Cd, Pb and Hg), Umix, and 3 nephrotoxic metals in blood (Cd, Pb, and Hg), Bmix, using a weighted quantile sum (WQS) approach. We applied WQS regression to analyze the association of Bmix and Umix with estimated glomerular filtration rate (eGFR), serum uric acid (SUA), urine albumin, blood urea nitrogen (BUN), and systolic blood pressure (SBP), adjusting for sex, race/ethnicity, age, head of household's education level, height, BMI, serum cotinine, and NHANES cohort year. Umix and urine albumin models were also adjusted for urine creatinine, and Bmix models were also adjusted for fish consumption. Subanalyses included stratification by sex and an arsenic-only model including six speciated forms of As measured in urine. ResultsIn WQS regression models, each decile increase of Umix was associated with 1.6% (95% CI: 0.5, 2.8) higher BUN, 1.4% (95% CI: 0.7, 2.0) higher eGFR, and 7.6% (95% CI: 2.4, 13.1) higher urine albumin. The association between Umix and BUN was primarily driven by As (72%), while the association with eGFR was driven by Hg (61%), and Cd (17%), and the association with urine albumin was driven by Cd (37%), Hg (33%), and Pb (25%). There was no significant relationship between Umix and SUA or SBP. In WQS models using the combined blood metals, Bmix, each decile increase of Bmix was associated with 0.6% (95% CI: 0.0, 1.3) higher SUA; this association was driven by Pb (43%), Hg (33%), and Cd (24%) and was marginally significant (p = 0.05). No associations were observed between Bmix and urine albumin, eGFR, BUN, or SBP. ConclusionsThe findings suggest metals including As, Pb, Hg, Cd and their combinations may affect renal parameters, although potential reverse causation cannot be ruled out due to the cross-sectional study design. Implications of early life low-level exposure to multiple metals on kidney function may have far-reaching consequences later in life in the development of hypertension, kidney disease, and renal dysfunction. Longitudinal studies should further evaluate these relationships.

Rates of Chronic Medical Conditions in 1991 Gulf War Veterans Compared to the General Population.

Prevalence of nine chronic medical conditions in the population-based Ft. Devens Cohort (FDC) of GW veterans were compared with the population-based 2013–2014 National Health and Nutrition Examination Survey (NHANES) cohort. Excess prevalence was calculated as the difference in prevalence estimates from the Ft. Devens and NHANES cohorts; and confidence intervals and p-values are based on the standard errors for the two prevalence estimates. FDC males were at increased risk for reporting seven chronic medical conditions compared with NHANES males. FDC females were at decreased risk for high blood pressure and increased risk for diabetes when compared with NHANES females. FDC veterans reporting war-related chemical weapons exposure showed higher risk of high blood pressure; diabetes; arthritis and chronic bronchitis while those reporting taking anti-nerve gas pills had increased risk of heart attack and diabetes. GW veterans are at higher risk of chronic conditions than the general population and these risks are associated with self-reported toxicant exposures.

Elevated glycohemoglobin HbA1c is associated with low back pain in nonoverweight diabetics

Background ContextLow back pain (LBP) is a common complaint in clinical practice of multifactorial origin. Although obesity has been thought to contribute to LBP primarily by altering the distribution of mechanical loads on the spine, the additional contribution of obesity-related conditions such as diabetes mellitus (DM) to LBP has not been thoroughly examined. PurposeTo determine if there is a relationship between DM and LBP that is independent of body mass index (BMI) in a large cohort of adult survey participants. Study DesignRetrospective analysis of prospectively collected National Health and Nutrition Examination Survey (NHANES) data to characterize associations between LBP, DM, and BMI in adults subdivided into 6 subpopulations: normal weight (BMI 18.5–25), overweight (BMI 25–30), and obese (BMI >30) diabetics and nondiabetics. Diabetes was defined with glycohemoglobin A1c (HbA1c) ≥6.5%. Patient Sample11,756 participants from NHANES cohort. Outcome MeasuresPercentage of LBP reported. MethodsLBP reported in the 1999-2004 miscellaneous pain NHANES questionnaire was the dependent variable examined. Covariates included HbA1c, BMI, age, and family income ratio to poverty as continuous variables as well as race, gender, and smoking as binary variables. Individuals were further subdivided by weight class and diabetes status. Regression and graphical analyses were performed on the study population as a whole and also on subpopulations. ResultsIncreasing HbA1c did not increase the odds of reporting LBP in the full cohort. However, multivariate logistic regression of the 6 subpopulations revealed that the odds of LBP significantly increased with increasing HbA1c levels in normal weight diabetics. No other subpopulations reported significant relationships between LBP and HbA1c. LBP was also significantly associated with BMI for normal weight diabetics and also for obese subjects regardless of their DM status. ConclusionsLBP is significantly related to DM status, but this relationship is complex and may interact with BMI. These results support the concept that LBP may be improved in normal weight diabetic subjects with improved glycemic control and weight loss, and that all obese LBP subjects may benefit from improved weight loss alone.

Evidence on the Validity of a Comprehensive Health Risk Index and Implications for Ambulatory Care and Population Health Management.

A novel, comprehensive health risk index for adults has been validated and is now ready for use to improve the health of individuals and populations. This health risk index provides an estimate of the avoidable risk of death for adults 30 years or older. It includes 12 evidence-based clinical and behavioral risk factors and was validated on discrimination and calibration using the NHANES (National Health and Nutrition Examination Survey) and Framingham Heart Study cohorts. The results from both cohorts were consistent and similar. Discrimination was good, and calibration was acceptable but tended to overpredict mortality risk for females in the higher-risk deciles.

Elevated High-Density Lipoprotein Cholesterol Is Associated with Hyponatremia in Hypertensive Patients

BackgroundRecently, the Systolic Blood Pressure Intervention Trial (SPRINT) showed that intensive lowering of systolic blood pressure is beneficial, but is associated with more adverse events. Hyponatremia was notably more frequent in the intensive treatment group. Investigating its risk factors is crucial for preventing this complication. Our objective in this study was to identify risk factors for hyponatremia in the adult population. MethodsWe investigated the baseline demographic, clinical, and laboratory data from the 9361 participants of SPRINT to identify the best predictors of hyponatremia (serum sodium ≤130 mEq/L), and adverse events, which could be attributed to hyponatremia, using machine learning and multivariable Cox proportional hazards models. We confirmed our results in the independent National Health and Nutrition Examination Survey (NHANES) cohort between the years 2005 and 2010 (16,501 participants). ResultsElevated baseline high-density lipoprotein cholesterol (HDL-C) was a strong predictor of future hyponatremia. Multivariable Cox regression showed hyponatremia events to be significantly increased for SPRINT participants with baseline HDL-C levels in the highest quintile (hazard ratio [HR] 2.8; 95% confidence interval [CI], 2.2-3.7; P <.001), and were also associated with treatment-related serious adverse events (HR 1.6; 95% CI, 1.3-2.1; P <.001). We confirmed the association between HDL-C and hyponatremia in the NHANES cohort (HR 2.5; 95% CI, 1.7-3.7; P <.001). ConclusionsElevated HDL-C (≥62 mg/dL) is a risk factor for hyponatremia. Thus, hypertensive patients with elevated HDL-C should be closely monitored for hyponatremia when treated for hypertension.

Endotoxin exposure, serum vitamin D, asthma and wheeze outcomes

BackgroundEndotoxin has been shown to induce neutrophilic asthma and wheeze after binding toll-like receptor 4 to produce pro-inflammatory cytokines. Animal models have demonstrated that vitamin D might inhibit lipopolysaccharide-induced cytokines. However, whether endotoxin exposure and serum vitamin D deficiency interact to affect asthma and wheeze in humans has never been investigated in an epidemiological study. MethodsJoint associations of house dust endotoxin and vitamin D with asthma and wheeze were examined using logistic regression adjusted for covariates in 5924 US participants of the National Health and Nutrition Examination Survey (NHANES). Interactions were assessed on the multiplicative as well as additive scale using the relative excess risk, the attributable portion due to additive interaction, and the synergy index. ResultsThe median endotoxin concentration was 19.1 EU/mg. Prevalence of vitamin D inadequacy (20–30 ng/ml) and deficiency (<20 ng/ml) were respectively 42.9 and 33.4%. The combination of high endotoxin and low vitamin D was associated with current asthma (OR: 1.56, 95% CI: 1.09, 2.23), wheeze in the past 12 months (OR: 1.72, 95% CI: 1.10, 3.71), recurrent wheeze (OR: 1.97, 95% CI: 1.00, 4.00), asthma diagnosis or recurrent wheeze (OR: 1.88, 95% CI: 1.33, 2.66), and current asthma or recurrent wheeze (OR:1.81, 95% CI: 1.23, 2.68) when compared to low endotoxin and normal vitamin D. The interactions between the exposures were not significant on the multiplicative or additive scale for any of the outcomes. ConclusionsCombination of high endotoxin exposure and low vitamin D increases the odds of asthma and wheeze, but the exposures do not interact or modify each other's effect in the NHANES cohort.

Incidence rate of type 2 diabetes is >50% lower in GrassrootsHealth cohort with median serum 25–hydroxyvitamin D of 41 ng/ml than in NHANES cohort with median of 22 ng/ml

Higher serum 25–hydroxyvitamin D [25(OH)D] concentrations have been associated with lower risk of type 2 diabetes. This study compared incidence rates of type 2 diabetes among participants aged ≥20 years in two U.S. cohorts with markedly different median 25(OH)D concentrations. The median 25(OH)D concentration in the GrassrootsHealth (GRH) cohort was 41ng/ml (N=4933) while in the 2005–6 National Health and Nutrition Examination Survey (NHANES) it was 22ng/ml (N=4078) (P<0.0001). The adjusted annual incidence rate of type 2 diabetes was 3.7 per 1000 population (95% confidence interval=1.9, 6.6) in the GRH cohort, compared to 9.3 per 1000 population (95% confidence interval=6.7, 12.6) in NHANES. In the NHANES cohort, the lowest 25(OH)D tertiles (<17, 17–24ng/ml) had higher odds of developing diabetes than the highest tertile (OR: 4.9, P=0.02 and 4.8, P=0.01 respectively), adjusting for covariates. Differences in demographics and methods may have limited comparability. Raising serum 25(OH)D may be a useful tool for reducing risk of diabetes in the population.

Habitual Physical Activity and Exercise Patterns in Children and Adolescents with Sickle Cell Disease

Background Sickle cell disease (SCD) and its complications have a major impact on physical functioning in affected children and adolescents. However, little is known about habitual physical activity patterns and exercise routines in this population. The aims of this study were to evaluate the amount of time spent in moderate (MPA) or vigorous (VPA) physical activity, examine participation in school-based physical education or organized sports, and explore factors that influence physical activity or exercise habits in children and adolescents with SCD.Methods A58-question, self-administered survey was given to a cross-sectional group of children with SCD (all genotypes) in grades 6 through 12 followed in the Comprehensive Sickle Cell Programs at Ann & Robert H. Lurie Children’s Hospital of Chicago and the University of Illinois at Chicago. Children on hydroxyurea therapy and chronic transfusions were included. The survey included 2 sections: 1) questions adapted from the National Health and Nutrition Examination Survey (NHANES) Physical Activity Questionnaire and 2) supplemental questions addressing participation in school-based physical education and organized sports; disease severity and impact on physical activity; and attitudes about physical activity and exercise. We performed standard descriptive analyses and bivariate analysis using Pearson’s chi-square or Student’s t-test for independent samples for comparison of categorical and continuous data, respectively. Responses from NHANES questions were compared to age, sex and race matched data collected from the 2009-2010 NHANES survey.Results A total of 88 surveys have been collected to date. Among respondents with SCD, 59% were between 11 and 15 years old, 51% were male, 66% had hemoglobin SS disease, 44% were on hydroxyurea and 19% were on chronic transfusions. Data were compared to extracted data from 1362 NHANES participants weighted to adjust for differences in distributions in age, sex and race between groups. The proportion of children with SCD who reported at least 10 minutes of VPA in a typical week (66 vs. 65%, p = 0.91) and their frequency of VPA (2.8 vs. 2.5 days per week, p = 0.44) did not differ from that of children from the NHANES cohort. However, a higher proportion of children with SCD reported MPA (67 vs. 42%, p < 0.001) with a frequency (2.3 vs. 1.4 days per week, p < 0.001) that was significantly higher than that reported in NHANES. The duration of VPA or MPA on a typical day also differed significantly between groups. Compared to children from NHANES, fewer children with SCD reported spending more than 60 minutes in VPA or MPA on a typical day. Overall, only 13% of children with SCD met US physical activity guidelines recommending at least 60 minutes of physical activity every day. Of those children with SCD surveyed, 47% reported participating in school-based sports teams or physical activity clubs and 74% reported participating in physical education when offered at their school. Finally, we examined those variables that were associated with physical activity and participation in organized sports or physical education in children with SCD. Children 11 to 15 years old, when compared to children greater than 15 years old, were more likely to report 60 min of physical activity on more than 2 days per week (73 vs. 27%, p < 0.05). However, neither age nor sex affected participation in organized sports or physical education. We found that physical activity and participation in organized sports or physical education were not significantly affected by respondent beliefs regarding the impact of SCD on enjoyment of those activities. Sickle cell genotype, hydroxyurea use, chronic transfusions, and parental and personal attitudes toward physical activity also had no influence on participation in physical activity, organized sports or physical education in children with SCD.Conclusions When compared to matched peers in the NHANES study, children with SCD participate in comparable levels of VPA and even exceed their peers in levels of MPA. Participation in school-based organized sports and physical education was also common in children with SCD despite the previously reported impact of SCD on physical functioning in this population. Further studies are needed to determine the safety and potential health benefits of regular exercise and athletic participation in this population. DisclosuresNo relevant conflicts of interest to declare.

Physical Activity and Other Health Behaviors in Adults With Hypertrophic Cardiomyopathy

The clinical expression of hypertrophic cardiomyopathy (HC) is undoubtedly influenced by modifying genetic and environmental factors. Lifestyle practices such as tobacco and alcohol use, poor nutritional intake, and physical inactivity are strongly associated with adverse cardiovascular outcomes and increased mortality in the general population. Before addressing the direct effect of such modifiable factors on the natural history of HC, it is critical to define their prevalence in this population. A voluntary survey, drawing questions in part from the 2007 to 2008 National Health and Nutrition Examination Survey (NHANES), was posted on the HC Association website and administered to patients with HC at the University of Michigan. Propensity score matching to NHANES participants was used. Dichotomous and continuous health behaviors were analyzed using logistic and linear regression, respectively, and adjusted for body mass index and propensity score quintile. Compared to the matched NHANES participants, the patients with HC reported significantly less alcohol and tobacco use but also less time engaged in physical activity at work and for leisure. Time spent participating in vigorous or moderate activity was a strong predictor of self-reported exercise capacity. The body mass index was greater in the HC cohort than in the NHANES cohort. Exercise restrictions negatively affected emotional well-being in most surveyed subjects. In conclusion, patients with HC are less active than the general United States population. The well-established relation of inactivity, obesity, and cardiovascular mortality might be exaggerated in patients with HC. More data are needed on exercise in those with HC to strike a balance between acute risks and the long-term health benefits of exercise.

A Nutrient-Wide Association Study on Blood Pressure

A nutrient-wide approach may be useful to comprehensively test and validate associations between nutrients (derived from foods and supplements) and blood pressure (BP) in an unbiased manner. Data from 4680 participants aged 40 to 59 years in the cross-sectional International Study of Macro/Micronutrients and Blood Pressure (INTERMAP) were stratified randomly into training and testing sets. US National Health and Nutrition Examination Survey (NHANES) four cross-sectional cohorts (1999-2000, 2001-2002, 2003-2004, 2005-2006) were used for external validation. We performed multiple linear regression analyses associating each of 82 nutrients and 3 urine electrolytes with systolic and diastolic BP in the INTERMAP training set. Significant findings were validated in the INTERMAP testing set and further in the NHANES cohorts (false discovery rate <5% in training, P<0.05 for internal and external validation). Among the validated nutrients, alcohol and urinary sodium-to-potassium ratio were directly associated with systolic BP, and dietary phosphorus, magnesium, iron, thiamin, folacin, and riboflavin were inversely associated with systolic BP. In addition, dietary folacin and riboflavin were inversely associated with diastolic BP. The absolute effect sizes in the validation data (NHANES) ranged from 0.97 mm Hg lower systolic BP (phosphorus) to 0.39 mm Hg lower systolic BP (thiamin) per 1-SD difference in nutrient variable. Inclusion of nutrient intake from supplements in addition to foods gave similar results for some nutrients, though it attenuated the associations of folacin, thiamin, and riboflavin intake with BP. We identified significant inverse associations between B vitamins and BP, relationships hitherto poorly investigated. Our analyses represent a systematic unbiased approach to the evaluation and validation of nutrient-BP associations.

Abstract P355: Hemoglobin A1c Vs. Oral Glucose Tolerance Test for Diabetes Diagnosis in NHANES 1988-1994 and 2005-2006

Background Approximately 6.2 million people with diabetes mellitus (DM) are undiagnosed. At diagnosis, 25% already have established microvascular disease. Earlier diagnosis may reduce the risk of DM complications. Oral glucose tolerance testing (OGTT), the gold standard for DM diagnosis, is difficult to administer, inconvenient for patients and expensive. Fasting plasma glucose is flawed by its laboratory instability and day to day variation. The use of HBA1c as a screening tool has been previously evaluated and shown to be poor (HbA1c ≥ 5.5% sensitivity 60.0%, specificity 55.0%, positive predictive value [PPV] 21.4%) but its utility as a diagnostic test is unclear since widespread assay standardization has only occurred since 1997. The objective of this study was to determine the feasibility of using HbA1c for DM diagnosis based on OGTT results. Methods Cross-sectional analysis of non-pregnant adults aged 40-74 years data from the 1988-1994 National Health and Nutrition Examination Survey (NHANES), who had complete data for a morning 2-h plasma during an OGTT, HbA1c and BMI, who were not taking insulin or oral hypoglycemic agents to determine an HBA1c cutoff value that have an adequate sensitivity and specificity for the diagnosis of diabetes. We then applied the obtained HbA1c cutoff value to the 2005-2006 NHANES to determine the reliability of our results. Results In the NHANES 1988-1994 and 2005-2006 data sets 6293 and 798 patients had complete data, respectively. The area under the curve for HbA1c was 0.752 for both the NHANES cohorts. Table: NHANES Cohort HbA1c % Cutpoint Stratified For Sensitivity (%) Specificity (%) Correctly Classified (%) Likelihood Ratio (+) 1988-1994 - - - - - ≥ 6.5 - 34.6 98.3 89.2 20.7 ≥ 6.6 - 31.8 98.8 89.2 26.0 ≥ 6.7 - 30.0 99.3 89.4 41.5 ≥ 6.8 - 28.2 99.6 89.4 63.4 ≥ 6.9 - 25.4 99.8 89.2 105.5 ≥ 6.7 BMI &lt; 30 kg/M 2 23.7 99.6 88.7 57.9 ≥ 6.7 BMI ≥ 30 kg/M 2 39.1 98.5 86.1 25.3 ≥ 6.7 Age 40-59 years 38.1 99.5 88.7 74.7 ≥ 6.7 Age 60-74 years 24.8 98.9 86.0 23.2 ≥ 6.7 Men 33.7 99.2 86.4 40.4 ≥ 6.7 Women 26.8 99.4 88.4 43.4 2005-2006 HbA1c% ≥ 6.5 - 31.1 99.5 93.1 56.3 ≥ 6.6 - 25.7 99.9 93.0 185.9 ≥ 6.7 - 25.7 100.0 93.1 - ≥ 6.8 - 23.0 100.0 92.9 - ≥ 6.9 - 23.0 100.0 92.9 - ≥ 6.7 BMI &lt; 30 kg/M 2 21.2 100.0 - ≥ 6.7 BMI ≥ 30 kg/M 2 29.3 100.0 - ≥ 6.7 Age 40-59 years 33.3 100.0 - ≥ 6.7 Age 60-74 years 21.3 100.0 - ≥ 6.7 Men 31.6 100.0 - ≥ 6.7 Women 19.4 100.0 - Repeating our analysis in the 2005-2006 NHANES cohort we found a similar level of sensitivity and specificity for a HbA1c cutoff of ≥6.7%. In both the NHANES cohorts stratification for BMI, age and gender did not impact sensitivity and specificity significantly. Conclusion Using an HbA1c cutoff of ≥6.7% would achieve adequate sensitivity, specificity and reliability for DM diagnosis across different subgroups and time periods.

Trends of VOC exposures among a nationally representative sample: Analysis of the NHANES 1988 through 2004 data sets.

Exposures to volatile organic compounds (VOCs) are ubiquitous due to emissions from personal, commercial and industrial products, but quantitative and representative information regarding long term exposure trends is lacking. This study characterizes trends from1988 to 2004 for the 15 VOCs measured in blood in five cohorts of the National Health and Nutrition Examination Survey (NHANES), a large and representative sample of U.S. adults. Trends were evaluated at various percentiles using linear quantile regression (QR) models, which were adjusted for solvent-related occupations and cotinine levels. Most VOCs showed decreasing trends at all quantiles, e.g., median exposures declined by 2.5 (m, p-xylene) to 6.4 (tetrachloroethene) percent per year over the 15 year period. Trends varied by VOC and quantile, and were grouped into three patterns: similar decreases at all quantiles (including benzene, toluene); most rapid decreases at upper quantiles (ethylbenzene, m, p-xylene, o-xylene, styrene, chloroform, tetrachloroethene); and fastest declines at central quantiles (1,4-dichlorobenzene). These patterns reflect changes in exposure sources, e.g., upper-percentile exposures may result mostly from occupational exposure, while lower percentile exposures arise from general environmental sources. Both VOC emissions aggregated at the national level and VOC concentrations measured in ambient air also have declined substantially over the study period and are supportive of the exposure trends, although the NHANES data suggest the importance of indoor sources and personal activities on VOC exposures. While piecewise QR models suggest that exposures of several VOCs decreased little or any during the 1990's, followed by more rapid decreases from 1999 to 2004, questions are raised concerning the reliability of VOC data in several of the NHANES cohorts and its applicability as an exposure indicator, as demonstrated by the modest correlation between VOC levels in blood and personal air collected in the 1999/2000 cohort. Despite some limitations, the NHANES data provides a unique, long term and direct measurement of VOC exposures and trends.

Limitations of metformin use in patients with kidney disease: are they warranted?

Aim: To show that metformin, one of the most widely used agents, is contraindicated in patients with diabetes having chronic kidney disease (CKD) (i.e. serum creatinine >1.5 mg/dl) secondary to fear of lactic acidosis. The overall incidence of lactic acidosis is estimated at an upper limit of eight cases per 100 000 patient-years. We evaluated metformin use in two cohorts, one from the University of Chicago Diabetes Center and the other from National Health and Nutrition Examination Survey (NHANES) 1999–2006. Methods: Estimated glomerular filtration rate (eGFR) was calculated using the re-expressed Modification of Diet in Renal Disease (MDRD) Study equation and compared to serum creatinine. We hypothesized that metformin is used in patients with undetected advanced CKD (i.e. serum creatinine is ≥1.5 mg/dl). A chi-squared test was used to compare per cent differences of metformin use across demographic variables and eGFR in the NHANES cohort. Results: At the University of Chicago Diabetes Center, 36 of 234 (15.3%) patients with an eGFR of 18 years and eGFR <60 ml/min/1.73 m2 showed that Blacks with advanced nephropathy were three times more likely to receive metformin. Conclusions: We conclude that metformin utilization occurs with a higher frequency than predicted by serum creatinine in people with eGFR <60 ml/min/1.73 m2. Given the very low incidence of lactic acidosis, the recommendation should be changed to reflect eGFR cut-off values rather than serum creatinine.

Urinary Incontinence Among Women With Type 1 Diabetes—How Common is it?

We compared the prevalence, level of bother and effect on daily activities of urinary incontinence among women with type 1 diabetes enrolled in the Epidemiology of Diabetes Interventions and Complications study to a population based sample of women with normal glucose. We performed a cross-sectional analysis of women with type 1 diabetes and normal glucose tolerance using 2 study populations. The Diabetes Control and Complications Trial cohort followup, Epidemiology of Diabetes Interventions and Complications, began in 1994. In 2004 women participants (550) completed a self-administered questionnaire on urinary incontinence. Our primary outcome was weekly or greater incontinence, overall and by type. Prevalence of urinary incontinence was compared to a subgroup of women with normal glucose in the 2001 to 2002 National Health and Nutrition Examination Survey (NHANES). Overall 65% of women with type 1 diabetes reported any urinary incontinence (17% reported weekly incontinence). Nearly 40% of these women were greatly bothered by their incontinence and 9% believed it affected their day-to-day activities. Women with type 1 diabetes had a nearly 2-fold greater prevalence of weekly urge incontinence compared to those without diabetes in the NHANES cohort (8.8% vs 4.5%, p = 0.01). Urinary incontinence is common in women with type 1 diabetes and the prevalence of weekly urge incontinence is far greater compared to that in women with normal glucose levels. Moreover, the prevalence of urinary incontinence in women with type 1 diabetes was greater than that of neuropathy, retinopathy and nephropathy. These findings highlight the importance of screening for urinary incontinence among women with type 1 diabetes. Studies examining factors associated with urinary incontinence in women with type 1 diabetes are warranted.

Effect of Aging on A1C Levels in Individuals Without Diabetes

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 (Ptrend < 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.

Prevalence and Associations of Anemia of CKD: Kidney Early Evaluation Program (KEEP) and National Health and Nutrition Examination Survey (NHANES) 1999-2004

Early identification of anemia of chronic kidney disease may be important for the development of preventive strategies. We compared anemia prevalence and characteristics in the National Kidney Foundation Kidney Early Evaluation Program (KEEP) and National Health and Nutrition Examination Survey (NHANES) 1999-2004 populations. Clinical, demographic, and laboratory data were collected from August 2000 to December 31, 2006, from participants in KEEP, a community-based health-screening program targeting individuals 18 years and older with diabetes, hypertension, or family history of kidney disease, diabetes, or hypertension. Anemia was defined as hemoglobin level less than 13.5 g/dL for men and less than 12.0 g/dL for women (Kidney Disease Outcomes Quality Initiative [KDOQI] 2006) or less than 13.0 g/dL for men and less than 12.0 g/dL for women (World Health Organization [WHO]). In KEEP (n = 70,069), 68.3% of participants, and in NHANES (n = 17,061), 52% of participants, were women. African Americans represented 33.9% of the KEEP and 11.2% of the NHANES cohorts, and Hispanics comprised 12.4% of KEEP and 13.2% of NHANES. Using the KDOQI classification, anemia was present in 13.9% and 6.3% of KEEP and NHANES participants, whereas using the WHO classification, anemia was present in 11.8% and 5.3%, respectively. In adjusted analysis of KEEP data, KDOQI-defined anemia was significantly more likely in men (odds ratio [OR], 1.30; 95% confidence interval [CI], 1.23 to 1.37); this pattern was reversed when using WHO-defined anemia (OR, 0.68; 95% CI, 0.64 to 0.72). Adjusted odds of anemia were greater for African American than white KEEP participants (OR, 2.98; 95% CI, 2.80 to 3.16; OR, 3.00; 95% CI, 2.81 to 3.20 for KDOQI- and WHO-defined anemia, respectively). Anemia was twice as common in the targeted KEEP chronic kidney disease screening program cohort than in the NHANES sample population. African Americans had a 3-fold increased likelihood of anemia compared with whites. Targeted screening can identify anemia in a high-risk population.

Black-white differences in age trajectories of hypertension prevalence among adult women and men, 1999-2002.

To describe age patterns of hypertension prevalence in young through middle-aged adults and to test the hypothesis that hypertension prevalence rises more rapidly with age among Blacks than Whites in the United States. Using multiple logistics regression, we predicted probability of being hypertensive for participants ages 15-65 years in the National Health and Nutrition Examination Survey (NHANES) IV, 1999-2002. We estimated age-specific Black-to-White odds ratios of hypertension overall, by sex, and adjusted for body mass index (BMI) and poverty income ratio. We also followed NHANES cohorts to test whether differential age patterns of hypertension prevalence by race or gender represented cohort effects. Hypertension: systolic blood pressure > or = 140 mm Hg, diastolic blood pressure > or = 90 mm Hg, or current antihypertensive medication use. Black/White odds of hypertension increased from 1.71 to 3.12 between ages 15 and 65. Odds for women increased faster, from 2.11 to 4.04. By age 40, Black women had the highest hypertension rates and steepest age-gradient of race/sex groups. Adjustment for poverty income ratio did not affect results. Adjustment for BMI reduced Black women's hypertension risk somewhat but not men's. Cohort analysis confirmed a more rapid increase in hypertension prevalence among Blacks and women. Hypertension screening of Blacks should begin at young ages. Early diagnosis and vigilant management are critical to addressing racial and sex differences and their effect on cardiovascular disease, life expectancy, and maternal and infant health. Psychosocial stressors merit consideration as candidates for primary prevention. Addressing fundamental causes is needed. Understanding the growing age-gradient increase among US Black women is pressing.

Comparison of the Heart and Estrogen/Progestin Replacement Study (HERS) cohort with women with coronary disease from the National Health and Nutrition Examination Survey III (NHANES III)

Background The Heart and Estrogen/Progestin Replacement Study (HERS) is the first large clinical trial designed to test the efficacy of postmenopausal estrogen/progestin therapy for secondary prevention of coronary heart disease (CHD). To examine the representativeness of the HERS cohort to the general population of postmenopausal women with CHD, we compared the baseline cardiovascular risk factor data from HERS with similar data from women presumed to have CHD from the National Health and Nutrition Examination Survey (NHANES) III. Methods Age, race, and cardiovascular disease risk factors were compared in the 2763 postmenopausal women younger than 80 years old, with a uterus, and with documented CHD in HERS versus 145 similarly aged women with clinical or electrocardiographic evidence of CHD from phase I of NHANES III. Results There were fewer current smokers in HERS (13%) than in the NHANES cohort (21.7%, p = 0.05). Similarly, a history of hypertension was less prevalent in HERS (58.6%) than in the NHANES cohort (69.3%, p = 0.03). Women with fasting triglyceride levels >3.39 mmol/L or fasting glucose levels >16.6 mmol/L were excluded from HERS, resulting in fewer diabetics (22.9% vs 29.5%, p = 0.26) and lower serum triglyceride levels (1.88 mmol/L vs 2.25 mmol/L, p = 0.19) in HERS versus the NHANES cohort. Systolic and diastolic blood pressure, body mass index, physical activity, and total LDL and HDL cholesterol were not significantly different between the two groups. Conclusions The HERS cohort had fewer CHD risk factors than women with myocardial infarction or angina in NHANES III, although comparison is hindered by differences in selection criteria. The many women with diabetes and hypertriglyceridemia in the NHANES cohort emphasizes the importance of testing strategies for secondary prevention of CHD in this high-risk subgroup. (Am Heart J 1998;136;115-24.)