Trends in Levels of Lipids and Apolipoprotein B in US Youths Aged 6 to 19 Years, 1999-2016.

Importance: Favorable trends occurred in the lipid levels of US youths through 2010, but these trends may be altered by ongoing changes in the food supply, obesity prevalence, and other factors. Objective: To analyze trends in levels of lipids and apolipoprotein B in US youths during 18 years from 1999 through 2016. Design, Setting, and Participants: Serial cross-sectional analysis of US population-weighted data for youths aged 6 to 19 years from the National Health and Nutrition Examination Surveys for 1999 through 2016. Linear temporal trends were analyzed using multivariable regression models with regression coefficients (ß) reported as change per 1 year. Exposures: Survey year; examined periods spanned 10 to 18 years based on data availability. Main Outcomes and Measures: Age- and race/ethnicity-adjusted mean levels of high-density lipoprotein (HDL), non-HDL, and total cholesterol. Among fasting adolescents (aged 12-19 years), mean levels of low-density lipoprotein cholesterol, geometric mean levels of triglycerides, and mean levels of apolipoprotein B. Prevalence of ideal and adverse (vs borderline) levels of lipids and apolipoprotein B per pediatric lipid guidelines. Results: In total, 26 047 youths were included (weighted mean age, 12.4 years; female, 51%). Among all youths, the adjusted mean total cholesterol level declined from 164 mg/dL (95% CI, 161 to 167 mg/dL) in 1999-2000 to 155 mg/dL (95% CI, 154 to 157 mg/dL) in 2015-2016 (ß for linear trend, -0.6 mg/dL [95% CI, -0.7 to -0.4 mg/dL] per year). Adjusted mean HDL cholesterol level increased from 52.5 mg/dL (95% CI, 51.7 to 53.3 mg/dL) in 2007-2008 to 55.0 mg/dL (95% CI, 53.8 to 56.3 mg/dL) in 2015-2016 (ß, 0.2 mg/dL [95% CI, 0.1 to 0.4 mg/dL] per year) and non-HDL cholesterol decreased from 108 mg/dL (95% CI, 106 to 110 mg/dL) to 100 mg/dL (95% CI, 99 to 102 mg/dL) during the same years (ß, -0.9 mg/dL [95% CI, -1.2 to -0.6 mg/dL] per year). Among fasting adolescents, geometric mean levels of triglycerides declined from 78 mg/dL (95% CI, 74 to 82 mg/dL) in 1999-2000 to 63 mg/dL (95% CI, 58 to 68 mg/dL) in 2013-2014 (log-transformed ß, -0.015 [95% CI, -0.020 to -0.010] per year), mean levels of low-density lipoprotein cholesterol declined from 92 mg/dL (95% CI, 89 to 95 mg/dL) to 86 mg/dL (95% CI, 83 to 90 mg/dL) during the same years (ß, -0.4 mg/dL [95% CI, -0.7 to -0.2 mg/dL] per year), and mean levels of apolipoprotein B declined from 70 mg/dL (95% CI, 68 to 72 mg/dL) in 2005-2006 to 67 mg/dL (95% CI, 65 to 70 mg/dL) in 2013-2014 (ß, -0.4 mg/dL [95% CI, -0.7 to -0.04 mg/dL] per year). Favorable trends were generally also observed in the prevalence of ideal and adverse levels. By the end of the study period, 51.4% (95% CI, 48.5% to 54.2%) of all youths had ideal levels for HDL, non-HDL, and total cholesterol; among adolescents, 46.8% (95% CI, 40.9% to 52.6%) had ideal levels for all lipids and apolipoprotein B, whereas 15.2% (95% CI, 13.1% to 17.3%) of children aged 6 to 11 years and 25.2% (95% CI, 22.2% to 28.2%) of adolescents aged 12 to 19 years had at least 1 adverse level. Conclusions and Relevance: Between 1999 and 2016, favorable trends were observed in levels of lipids and apolipoprotein B in US youths aged 6 to 19 years.

Prevalence and Correlates of Receiving Medical Advice to Increase Physical Activity in U.S. Adults: National Health and Nutrition Examination Survey 2013-2016.

INTRODUCTION: National objectives recommend healthcare professionals provide physical activity advice. This study examined health and demographic characteristics associated with receipt of medical advice to increase physical activity among U.S. health care-utilizing adults and differences in associations by age group. METHODS: Analyses included 8,410 health care-utilizing adults aged ≥20 years from the 2013-2016 National Health and Nutrition Examination Surveys (analyzed in 2018). Logistic regression was used to examine associations between receipt of medical advice to increase physical activity in the past year and measured health conditions, reported health behaviors, and demographic characteristics. Models were stratified by age group (20-39, 40-59, and ≥60 years). RESULTS: Physical activity medical advice was received by 42.9% (95% CI=40.8, 44.9) of adults overall. By age group, 32.7% of younger adults, 46.7% of middle-aged adults, and 48.9% of older adults received advice. Among all adults and across all age groups, receipt of advice was higher among adults with chronic health conditions: obesity (63.0%, 95% CI=60.3, 65.7), hypertension (56.5%, 95%=CI 53.8, 59.2), diabetes (69.8%, 95% CI=66.5, 72.8), hypercholesterolemia (55.6%, 95% CI=52.3, 59.0), and low high-density lipoprotein cholesterol (53.8%, 95% CI=50.1, 57.4). Among all adults, those with obesity, hypertension, and diabetes had significantly greater odds of receipt of advice after adjustment. Stronger associations between diabetes and hypercholesterolemia and receiving physical activity advice were observed among younger adults. CONCLUSIONS: Receipt of physical activity medical advice was highest among adults with specific chronic health conditions, and this pattern was stronger among younger adults with diabetes and hypercholesterolemia. However, most health care-utilizing adults did not receive physical activity medical advice.

Implementing the National Heart, Lung, and Blood Institute's Strategic Vision in the Division of Cardiovascular Sciences.

As we commemorate the 70th Anniversary of the National Heart, Lung, and Blood Institute (NHLBI) and celebrate important milestones that have been achieved by the Division of Cardiovascular Sciences (DCVS), it is imperative that DCVS and the Extramural Research community at-large continue to address critical public health challenges that persist within the area of Cardiovascular Diseases (CVD). The NHLBI's Strategic Vision, developed with extensive input from the extramural research community and published in 2016, included overarching goals and strategic objectives that serve to provide a general blueprint for sustaining the legacy of the Institute by leveraging opportunities in emerging scientific areas (e.g., regenerative medicine, omics technology, data science, precision medicine, and mobile health), finding new ways to address enduring challenges (e.g., social determinants of health, health inequities, prevention, and health promotion), and training the next generation of heart, lung, blood, and sleep researchers. DCVS has developed a strategic vision implementation plan to provide a cardiovascular framing for the pursuit of the Institute's overarching goals and strategic objectives garnered from the input of the broader NHLBI community. This plan highlights six scientific focus areas that demonstrate a cross-cutting and multifaceted approach to addressing cardiovascular sciences, including 1) addressing social determinants of cardiovascular health (CVH) and health inequities, 2) enhancing resilience, 3) promoting CVH and preventing CVD Across the lifespan, 4) eliminating hypertension-related CVD, 5) reducing the burden of heart failure, and 6) preventing vascular dementia. These priorities will guide our efforts in Institute-driven activities in the coming years but will not exclude development of other novel ideas or the support of investigator-initiated grant awards. The DCVS Strategic Vision implementation plan is a living document that will evolve with iterative dialogue with the NHLBI community and adapt as the dynamic scientific landscape changes to seize emerging opportunities.

Trends in Prescription Medication Use Among Children and Adolescents-United States, 1999-2014.

Importance: Access to appropriate prescription medications, use of inappropriate or ineffective treatments, and adverse drug events are public health concerns among US children and adolescents. Objective: To evaluate trends in use of prescription medications among US children and adolescents. Design, Setting, and Participants: US children and adolescents aged 0 to 19 years in the 1999-2014 National Health and Nutrition Examination Survey (NHANES)-serial cross-sectional, nationally representative surveys of the civilian noninstitutionalized population. Exposures: Sex, age, race and Hispanic origin, household income and education, insurance status, current health status. Main Outcomes and Measures: Use of any prescription medications or 2 or more prescription medications taken in the past 30 days; use of medications by therapeutic class; trends in medication use across 4-year periods from 1999-2002 to 2011-2014. Data were collected though in-home interview and direct observation of the prescription container. Results: Data on prescription medication use were available for 38 277 children and adolescents (mean age, 10 years; 49% girls). Overall, use of any prescription medication in the past 30 days decreased from 24.6% (95% CI, 22.6% to 26.6%) in 1999-2002 to 21.9% (95% CI, 20.3% to 23.6%) in 2011-2014 (ß = -0.41 percentage points every 2 years [95% CI, -0.79 to -0.03]; P = .04), but there was no linear trend in the use of 2 or more prescription medications (8.5% [95% CI, 7.6% to 9.4%] in 2011-2014). In 2011-2014, the most commonly used medication classes were asthma medications (6.1% [95% CI, 5.4% to 6.8%]), antibiotics (4.5% [95% CI, 3.7% to 5.5%]), attention-deficit/hyperactivity disorder (ADHD) medications (3.5% [95% CI, 2.9% to 4.2%]), topical agents (eg, dermatologic agents, nasal steroids) (3.5% [95% CI, 3.0% to 4.1%]), and antihistamines (2.0% [95% CI, 1.7% to 2.5%]). There were significant linear trends in 14 of 39 therapeutic classes or subclasses, or in individual medications, with 8 showing increases, including asthma and ADHD medications and contraceptives, and 6 showing decreases, including antibiotics, antihistamines, and upper respiratory combination medications. Conclusions and Relevance: In this study of US children and adolescents based on a nationally representative survey, estimates of prescription medication use showed an overall decrease in use of any medication from 1999-2014. The prevalence of asthma medication, ADHD medication, and contraceptive use increased among certain age groups, whereas use of antibiotics, antihistamines, and upper respiratory combination medications decreased.

Bias in Hazard Ratios Arising From Misclassification According to Self-Reported Weight and Height in Observational Studies of Body Mass Index and Mortality.

Misclassification of body mass index (BMI) categories arising from self-reported weight and height can bias hazard ratios in studies of BMI and mortality. We examined the effects on hazard ratios of such misclassification using national US survey data for 1976 through 2010 that had both measured and self-reported weight and height along with mortality follow-up for 48,763 adults and a subset of 17,405 healthy never-smokers. BMI was categorized as <22.5 (low), 22.5-24.9 (referent), 25.0-29.9 (overweight), 30.0-34.9 (class I obesity), and ≥35.0 (class II-III obesity). Misreporting at higher BMI categories tended to bias hazard ratios upwards for those categories, but that effect was augmented, counterbalanced, or even reversed by misreporting in other BMI categories, in particular those that affected the reference category. For example, among healthy male never-smokers, misclassifications affecting the overweight and the reference categories changed the hazard ratio for overweight from 0.85 with measured data to 1.24 with self-reported data. Both the magnitude and direction of bias varied according to the underlying hazard ratios in measured data, showing that findings on bias from one study should not be extrapolated to a study with different underlying hazard ratios. Because of misclassification effects, self-reported weight and height cannot reliably indicate the lowest-risk BMI category.

Contribution of weight status to asthma prevalence racial disparities, 2-19 year olds, 1988-2014.

PURPOSE: Racial disparities in childhood asthma prevalence increased after the 1990s. Obesity, which also varies by race/ethnicity, is an asthma risk factor but its contribution to asthma prevalence disparities is unknown. METHODS: We analyzed nationally representative National Health Examination and Nutrition Survey data for 2-19 year olds with logistic regression and decomposition analyses to assess the contributions of weight status to racial disparities in asthma prevalence, controlling for sex, age, and income status. RESULTS: From 1988-1994 to 2011-2014, asthma prevalence increased more among non-Hispanic black (NHB) (8.4% to 18.0%) than non-Hispanic white (NHW) youth (7.2% to 10.3%). Logistic regression showed that obesity was an asthma risk factor for all groups but that a three-way "weight status-race/ethnicity-time" interaction was not significant. That is, weight status did not modify the race/ethnicity association with asthma over time. In decomposition analyses, weight status had a small contribution to NHB/NHW asthma prevalence disparities but most of the disparity remained unexplained by weight status or other asthma risk factors (sex, age and income status). CONCLUSIONS: NHB youth had a greater asthma prevalence increase from 1988-1994 to 2011-2014 than NHW youth. Most of the racial disparity in asthma prevalence remained unexplained after considering weight status and other characteristics.

Factors Associated With Home Blood Pressure Monitoring Among US Adults: National Health and Nutrition Examination Survey, 2011-2014.

BACKGROUND: Home blood pressure monitoring (HBPM) has a substantial role in hypertension management and control. METHODS: Cross-sectional data for noninstitutionalized US adults 18 years and older (10,958) from the National Health and Nutrition Examination Survey (NHANES), years 2011-2014, were used to examine factors related to HBPM. RESULTS: In 2011-2014, estimated 9.5% of US adults engaged in weekly HBPM, 7.2% engaged in monthly HBPM, 8.0% engaged in HBPM less than once a month, and 75.3% didn't engage any HBPM. The frequency of HBPM increased with age, body mass index, and the number of health care visits (all, P < 0.05). Also, race/ethnicity (Non-Hispanic Blacks and non-Hispanic Asians), health insurance, diagnosed with diabetes, told by a health care provider to engage in HBPM, and diagnosed as hypertensive, were all associated with more frequent HBPM (P < 0.05). Adjusting for covariates, hypertensives who were aware of, treated for, and controlled engaged in more frequent HBPM compared to their respective references: unaware (odds ratio [OR] = 2.00, 95% confidence interval [CI] = 1.53-2.63), untreated (OR = 1.99, 95% CI = 1.52-2.60), and uncontrolled (OR = 1.42, 95% CI = 1.13-1.82). Hypertensive adults (aware/unaware, treated/untreated, or controlled/uncontrolled), who received providers' recommendations to perform HBPM, were more likely to do so compared to those who did not receive recommendations (OR = 8.04, 95% CI = 6.56-9.86; OR = 7.98, 95% CI = 6.54-9.72; OR = 8.75, 95% CI = 7.18-10.67, respectively). CONCLUSIONS: Seventeen percent of US adults engaged in monthly or more frequent HBPM and health care providers' recommendations to engage in HBPM have a significant impact on the frequency of HBPM.

Prevalence of high fractional exhaled nitric oxide among US youth with asthma.

BACKGROUND: High fractional exhaled nitric oxide (FeNO) is an indicator of poor asthma control and has been proposed as a non-invasive assessment tool to guide asthma management. OBJECTIVE: We aimed to describe the prevalence of and factors associated with high FeNO among US youth with asthma. METHODS: Data from 716 children and adolescents with asthma ages 6-19 years who participated in the 2007-2012 National Health and Nutrition Examination Survey were analyzed. Using American Thoracic Society guidelines, high FeNO was defined as >50 ppb for ages 12-19 years and >35 ppb for ages 6-11 years. Multivariate logistic regression examined associations between high FeNO and age, sex, race/Hispanic origin, income status, weight status, tobacco smoke exposure, and other factors associated with asthma control (recent use of inhaled corticosteroids, recent respiratory illness, asthma-related respiratory signs/symptoms, and spirometry). RESULTS: About 16.5% of youth with asthma had high FeNO. The prevalence of high FeNO was higher among non-Hispanic black (27%, P < 0.001) and Hispanic (20.2%, P = 0.002) youth than non-Hispanic white (9.7%) youth. Differences in high FeNO prevalence by sex (girls < boys), weight status (obese < normal weight), tobacco smoke exposure (smokers < home exposure < no exposure), and FEV1/FVC (normal < abnormal) were also observed. No differences were noted between categories for the remaining covariates. CONCLUSION: High FeNO was observed to be associated with sex, race/Hispanic origin, weight status, tobacco smoke exposure, and abnormal FEV1/FVC, but was not associated with asthma-related respiratory symptoms. These findings may help inform future research and clinical practice guidelines on the use of high FeNO in the assessment of asthma control.

Trends in Anthropometric Measures Among US Children 6 to 23 Months, 1976-2014.

BACKGROUND AND OBJECTIVES: The surveillance of children's growth reflects a population's nutritional status and risk for adverse outcomes. This study aimed to describe trends in length-for-age, weight-for-age, weight-for-length, and early childhood weight gain among US children aged 6 to 23 months. METHODS: We analyzed NHANES data from 1976-1980, 1988-1994, 1999-2002, 2003-2006, 2007-2010, and 2011-2014. We estimated z scores < -2 (low) and ≥+2 (high) in comparison with World Health Organization growth standards for each indicator. Weight gain (relative to sex-age-specific medians) from birth until survey participation was estimated. Trends were assessed by low birth weight status and race/Hispanic origin. Race/Hispanic origin trends were assessed from 1988-1994 to 2011-2014. RESULTS: In 2011-2014, the prevalence of low and high length-for-age was 3.3% (SE, 0.8) and 3.7% (SE, 0.8); weight-for-age was 0.6% (SE, 0.3) and 7.0% (SE, 1.1); and weight-for-length was 1.0% (SE, 0.4) and 7.7% (SE, 1.2). The only significant trend was a decrease in high length-for-age (5.5% in 1976-1980 vs 3.7% in 2011-2014; P = .04). Relative weight gain between birth and survey participation did not differ over time, although trends differed by race/Hispanic origin. Non-Hispanic black children gained more weight between birth and survey participation in 2011-2014 versus 1988-1994, versus no change among other groups. CONCLUSIONS: Between 1976-1980 and 2011-2014, there were no significant trends in low or high weight-for-age and weight-for-length among 6- to 23-month-old children whereas the percent with high length-for-age decreased. A significant trend in relative weight gain between birth and survey participation was observed among non-Hispanic black children.

Gross Motor Development in Children Aged 3-5 Years, United States 2012.

Objective Gross motor development in early childhood is important in fostering greater interaction with the environment. The purpose of this study is to describe gross motor skills among US children aged 3-5 years using the Test of Gross Motor Development (TGMD-2). Methods We used 2012 NHANES National Youth Fitness Survey (NNYFS) data, which included TGMD-2 scores obtained according to an established protocol. Outcome measures included locomotor and object control raw and age-standardized scores. Means and standard errors were calculated for demographic and weight status with SUDAAN using sample weights to calculate nationally representative estimates, and survey design variables to account for the complex sampling methods. Results The sample included 339 children aged 3-5 years. As expected, locomotor and object control raw scores increased with age. Overall mean standardized scores for locomotor and object control were similar to the mean value previously determined using a normative sample. Girls had a higher mean locomotor, but not mean object control, standardized score than boys (p < 0.05). However, the mean locomotor standardized scores for both boys and girls fell into the range categorized as "average." There were no other differences by age, race/Hispanic origin, weight status, or income in either of the subtest standardized scores (p > 0.05). Conclusions In a nationally representative sample of US children aged 3-5 years, TGMD-2 mean locomotor and object control standardized scores were similar to the established mean. These results suggest that standardized gross motor development among young children generally did not differ by demographic or weight status.

Normative Values for Cardiorespiratory Fitness Testing Among US Children Aged 6-11 years.

BACKGROUND: Nationally representative normative values for cardiorespiratory fitness (CRF) have not been described for US children since the mid 1980s. OBJECTIVE: To provide sex- and age-specific normative values for CRF of US children aged 6-11 years. METHODS: Data from 624 children aged 6-11 years who participated in the CRF testing as part of the 2012 National Health and Nutrition Examination Survey National Youth Fitness Survey, a cross-sectional survey, were analyzed. Participants were assigned to one of three age-specific protocols and asked to exercise to volitional fatigue. The difficulty of the protocols increased with successive age groups. CRF was assessed as maximal endurance time (min:sec). Data analysis was conducted in 2016. RESULTS: For 6-7, 8-9, 10-11 year olds, corresponding with the age-specific protocols, mean endurance time was 12:10 min:sec (95% CI: 11:49-12:31), 11:16 min:sec (95% CI: 11:00-11:31), and 10:01 min:sec (95% CI: 9:37-10:25), respectively. Youth in the lowest 20th percentile for endurance time were more likely to be obese, to report less favorable health, and to report greater than two hours of screen time per day. CONCLUSIONS: These data may serve as baseline estimates to monitor trends over time in CRF among US children aged 6-11 years.

Trends in Obesity Prevalence Among Children and Adolescents in the United States, 1988-1994 Through 2013-2014.

IMPORTANCE: Previous analyses of obesity trends among children and adolescents showed an increase between 1988-1994 and 1999-2000, but no change between 2003-2004 and 2011-2012, except for a significant decline among children aged 2 to 5 years. OBJECTIVES: To provide estimates of obesity and extreme obesity prevalence for children and adolescents for 2011-2014 and investigate trends by age between 1988-1994 and 2013-2014. DESIGN, SETTING, AND PARTICIPANTS: Children and adolescents aged 2 to 19 years with measured weight and height in the 1988-1994 through 2013-2014 National Health and Nutrition Examination Surveys. EXPOSURES: Survey period. MAIN OUTCOMES AND MEASURES: Obesity was defined as a body mass index (BMI) at or above the sex-specific 95th percentile on the US Centers for Disease Control and Prevention (CDC) BMI-for-age growth charts. Extreme obesity was defined as a BMI at or above 120% of the sex-specific 95th percentile on the CDC BMI-for-age growth charts. Detailed estimates are presented for 2011-2014. The analyses of linear and quadratic trends in prevalence were conducted using 9 survey periods. Trend analyses between 2005-2006 and 2013-2014 also were conducted. RESULTS: Measurements from 40,780 children and adolescents (mean age, 11.0 years; 48.8% female) between 1988-1994 and 2013-2014 were analyzed. Among children and adolescents aged 2 to 19 years, the prevalence of obesity in 2011-2014 was 17.0% (95% CI, 15.5%-18.6%) and extreme obesity was 5.8% (95% CI, 4.9%-6.8%). Among children aged 2 to 5 years, obesity increased from 7.2% (95% CI, 5.8%-8.8%) in 1988-1994 to 13.9% (95% CI, 10.7%-17.7%) (P < .001) in 2003-2004 and then decreased to 9.4% (95% CI, 6.8%-12.6%) (P = .03) in 2013-2014. Among children aged 6 to 11 years, obesity increased from 11.3% (95% CI, 9.4%-13.4%) in 1988-1994 to 19.6% (95% CI, 17.1%-22.4%) (P < .001) in 2007-2008, and then did not change (2013-2014: 17.4% [95% CI, 13.8%-21.4%]; P = .44). Obesity increased among adolescents aged 12 to 19 years between 1988-1994 (10.5% [95% CI, 8.8%-12.5%]) and 2013-2014 (20.6% [95% CI, 16.2%-25.6%]; P < .001) as did extreme obesity among children aged 6 to 11 years (3.6% [95% CI, 2.5%-5.0%] in 1988-1994 to 4.3% [95% CI, 3.0%-6.1%] in 2013-2014; P = .02) and adolescents aged 12 to 19 years (2.6% [95% CI, 1.7%-3.9%] in 1988-1994 to 9.1% [95% CI, 7.0%-11.5%] in 2013-2014; P < .001). No significant trends were observed between 2005-2006 and 2013-2014 (P value range, .09-.87). CONCLUSIONS AND RELEVANCE: In this nationally representative study of US children and adolescents aged 2 to 19 years, the prevalence of obesity in 2011-2014 was 17.0% and extreme obesity was 5.8%. Between 1988-1994 and 2013-2014, the prevalence of obesity increased until 2003-2004 and then decreased in children aged 2 to 5 years, increased until 2007-2008 and then leveled off in children aged 6 to 11 years, and increased among adolescents aged 12 to 19 years.

Differences in spirometry values between U.S. children 6-11 years and adolescents 12-19 years with current asthma, 2007-2010.

BACKGROUND: National Asthma Education and Prevention Program (NAEPP) guidelines recommend that periodic spirometry be performed in youth with asthma. NAEPP uses different spirometry criteria to define uncontrolled asthma for children (6-11 years) and adolescents (12+ years). OBJECTIVE: To describe differences in spirometry between U.S. children and adolescents with current asthma. METHODS: We examined cross-sectional spirometry data from 453 U.S. youth with current asthma age 6-19 years from the 2007-2010 National Health and Nutrition Examination Surveys. The main outcomes were percentage predicted forced expiratory volume at 1 sec (FEV1%) ≤80 and the ratio of FEV1 to forced vital capacity (FEV1/FVC) ≤0.80. We also examined the prevalence of youth with spirometry values consistent with uncontrolled asthma, using NAEPP age-specific criteria, defined for children aged 6-11 years as FEV1% ≤80 or FEV1/FVC ≤0.80, and for adolescents aged 12-19 years as FEV1% ≤80. RESULTS: Children 6-11 years and adolescents 12-19 years did not differ in prevalence of FEV1% ≤80 (10.1% vs. 9.0%) or FEV1/FVC ≤0.80 (30.6% vs. 29.8%). However, based on the NAEPP age-specific criteria, 33.0% of children 6-11 years and 9.0% of adolescents 12-19 years had spirometry values consistent with uncontrolled asthma (P < 0.001). CONCLUSION: Children 6-11 years and adolescents 12-19 years with current asthma did not differ in the percentage with FEV1% ≤80 or FEV1/FVC ≤0.80. However, the percent of children and adolescents with spirometry values consistent with uncontrolled asthma did differ. The difference appears to stem mainly from the different spirometry criteria for the two age groups.

Trends in the use of prescription antibiotics: NHANES 1999-2012.

OBJECTIVES: The objectives of this study were: to examine trends in the use of prescription antibiotics overall and by population subgroups between 1999 and 2012; and to examine trends in the use of categories of antibiotics and individual antibiotics. METHODS: Use of antibiotics was examined among 71 444 participants in the nationally representative National Health and Nutrition Examination Survey (NHANES; 1999-2012). Use of an antibiotic in the past 30 days was the main outcome variable. Analyses of trends were conducted overall and separately by population subgroups (i.e. age, sex, race/Hispanic origin, health insurance status and respiratory conditions) across four time periods (1999-2002, 2003-06, 2007-10 and 2011-12). RESULTS: The percentage of the US population that used a prescription antibiotic in the past 30 days significantly declined from 6.1% in 1999-2002 to 4.1% in 2011-12 (P < 0.001). Declines were also identified for five age groups (0-1 year, 6-11 years, 12-17 years, 18-39 years and 40-59 years), both sexes, non-Hispanic white and non-Hispanic black persons, persons with and without insurance and among those who currently had asthma. Significant declines were also observed for three categories of antibiotics (penicillins, cephalosporins and macrolide derivatives). Of the most common antibiotics prescribed, only amoxicillin use decreased significantly. CONCLUSIONS: Overall, there was a significant decline in the use of antibiotics between 1999-2002 and 2011-12. Due to concerns about antimicrobial resistance, it is important to continue monitoring the use of antibiotics.

Total and High-density Lipoprotein Cholesterol in Adults: United States, 2011-2014.

KEY FINDINGS: High levels of total cholesterol and low levels of high-density lipoprotein (HDL) cholesterol (the "good cholesterol") are risk factors for coronary heart disease (1-3). During 2009-2010, 13.4% of adults had high total cholesterol and 21.3% had low HDL cholesterol (4). This report presents estimates of the percentage of adults with high total and low HDL cholesterol during 2011-2014, and trends in prevalence of high total and low HDL cholesterol from 2007-2008 to 2013-2014. Analysis is based on measured cholesterol only and does not account for cholesterol-lowering medication use.

Interrelationships between BMI, skinfold thicknesses, percent body fat, and cardiovascular disease risk factors among U.S. children and adolescents.

BACKGROUND: Although the estimation of body fatness by Slaughter skinfold thickness equations (PBF(Slaughter)) has been widely used, the accuracy of this method is uncertain. We have previously examined the interrelationships among the body mass index (BMI), PBF(Slaughter), percent body fat from dual energy X-ray absorptiometry (PBF(DXA)) and CVD risk factor levels among children who were examined in the Bogalusa Heart Study and in the Pediatric Rosetta Body Composition Project. The current analyses examine these associations among 7599 8- to 19-year-olds who participated in the (U.S.) National Health and Nutrition Examination Survey from 1999 to 2004. METHODS: We analyzed (1) the agreement between (1) estimates of percent body fat calculated from the Slaughter skinfold thickness equations and from DXA, and (2) the relation of lipid, lipoprotein, and blood pressure levels to BMI, PBF(Slaughter) and PBF(DXA). RESULTS: PBF(Slaughter) was highly correlated (r ~ 0.85) with PBF(DXA). However, among children with a relatively low skinfold thicknesses sum (triceps + subscapular), PBF(Slaughter) underestimated PBF(DXA) by 8 to 9 percentage points. In contrast, PBF(Slaughter) overestimated PBF(DXA) by 10 points among boys with a skinfold thickness sum ≥ 50 mm. After adjustment for sex and age, lipid levels were related similarly to the body mass index, PBF(DXA) and PBF(Slaughter). There were, however, small differences in associations with blood pressure levels: systolic blood pressure was more strongly associated with body mass index, but diastolic blood pressure was more strongly associated with percent body fat. CONCLUSIONS: The Slaughter equations yield biased estimates of body fatness. In general, lipid and blood pressure levels are related similarly to levels of BMI (following adjustment for sex and age), PBF(Slaughter,) and PBF(DXA).

Are the Recent Secular Increases in Waist Circumference among Children and Adolescents Independent of Changes in BMI?

BACKGROUND: Several studies have shown that the waist circumference of children and adolescents has increased over the last 25 years. However, given the strong correlation between waist circumference and BMI, it is uncertain if the secular trends in waist circumference are independent of those in BMI. METHODS: We analyzed data from 6- to 19-year-olds who participated in the 1988-1994 through 2011-2012 cycles of the National Health and Nutrition Examination Survey to assess whether the trends in waist circumference were independent of changes in BMI, race-ethnicity and age. RESULTS: Mean, unadjusted levels of waist circumference increased by 3.7 cm (boys) and 6.0 cm (girls) from 1988-94 through 2011-12, while mean BMI levels increased by 1.1 kg/m2 (boys) and 1.6 kg/m2 (girls). Overall, the proportional changes in mean levels of both waist circumference and BMI were fairly similar among boys (5.3%, waist vs. 5.6%, BMI) and girls (8.7%, waist vs. 7.7%, BMI). As assessed by the area under the curve, adjustment for BMI reduced the secular increases in waist circumference by about 75% (boys) and 50% (girls) beyond that attributable to age and race-ethnicity. There was also a race-ethnicity interaction (p < 0.001). Adjustment for BMI reduced the secular trend in waist circumference among non-Hispanic (NH) black children (boys and girls) to a greater extent (about 90%) than among other children. CONCLUSIONS: Our results indicate that among children in the U.S., about 75% (boys) and 50% (girls) of the secular increases in waist circumference since 1988-94 can be accounted for by changes in BMI. The reasons for the larger independent effects among girls and among NH blacks are uncertain.

More than half of US youth consume seafood and most have blood mercury concentrations below the EPA reference level, 2009-2012.

BACKGROUND: Consuming seafood has health benefits, but seafood can also contain methylmercury, a neurotoxicant. Exposure to methylmercury affects children at different stages of brain development, including during adolescence. OBJECTIVE: The objective was to examine seafood consumption and blood mercury concentrations in US youth. METHODS: In the 2009-2012 NHANES, a cross-sectional nationally representative sample of the US population, seafood consumption in the past 30 d and blood mercury concentrations on the day of examination were collected from 5656 youth aged 1-19 y. Log-linear regression was used to examine the association between frequency of specific seafood consumption and blood mercury concentration, adjusting for race/Hispanic origin, sex, and age. RESULTS: In 2009-2012, 62.4% ± 1.4% (percent ± SE) of youth consumed any seafood in the preceding month; 38.4% ± 1.4% and 48.5% ± 1.5% reported consuming shellfish and fish, respectively. In 2009-2012, the geometric mean blood mercury concentration was 0.50 ± 0.02 µg/L among seafood consumers and 0.27 ± 0.01 µg/L among those who did not consume seafood. Less than 0.5% of youth had blood mercury concentrations ≥5.8 µg/L. In adjusted log-linear regression analysis, no significant associations were observed between frequency of breaded fish or catfish consumption and blood mercury concentrations, but frequency of consuming certain seafood types had significant positive association with blood mercury concentrations: high-mercury fish (swordfish and shark) [exponentiated ß coefficient (expß): 2.40; 95% CI: 1.23, 4.68]; salmon (expß: 1.41; 95% CI: 1.26, 1.55); tuna (expß: 1.38; 95% CI: 1.29, 1.45); crabs (expß: 1.35; 95% CI: 1.17, 1.55); shrimp (expß: 1.12; 95% CI: 1.05, 1.20), and all other seafood (expß: 1.23; 95% CI: 1.17, 1.32). Age-stratified log-linear regression analyses produced similar results. CONCLUSION: Few US youth have blood mercury concentrations ≥5.8 µg/L, although more than half of US youth consumed seafood in the past month.

Prevalence of and trends in dyslipidemia and blood pressure among US children and adolescents, 1999-2012.

IMPORTANCE: Recent national data suggest there were improvements in serum lipid concentrations among US children and adolescents between 1988 and 2010 but an increase in or stable blood pressure (BP) during a similar period. OBJECTIVE: To describe the prevalence of and trends in dyslipidemia and adverse BP among US children and adolescents. DESIGN: The National Health and Nutrition Examination Survey, a cross-sectional survey. SETTING: Noninstitutionalized US population. PARTICIPANTS: Children and adolescents aged 8 to 17 years with measured lipid concentrations (n = 1482) and BP (n = 1665). MAIN OUTCOMES AND MEASURES: Adverse concentrations of total cholesterol (TC) (≥ 200 mg/dL), high-density lipoprotein cholesterol (HDL-C) (<40 mg/dL), and non-HDL-C (≥ 145 mg/dL) (to convert TC, HDL-C, and non-HDL-C to millimoles per liter, multiply by 0.0259) and high or borderline BP were examined. Definitions of BP were informed by the Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents by the National High Blood Pressure Education Program Working Group on High Blood Pressure in Children and Adolescents. Analyses of linear trends in dyslipidemias and BP were conducted overall and separately by sex across 7 periods (1999-2000, 2001-2002, 2003-2004, 2005-2006, 2007-2008, 2009-2010, and 2011-2012). RESULTS: In 2011-2012, 20.2% (95% CI, 16.3-24.6) of youths had an adverse concentration of TC, HDL-C, or non-HDL-C and 11.0% (95% CI, 8.8-13.4) had either high or borderline BP. The prevalences of adverse concentrations decreased between 1999-2000 and 2011-2012 for TC (10.6% [95% CI, 8.3-13.2] vs 7.8% [95% CI, 5.7-10.4]; P = .006), HDL-C (17.9% [95% CI, 15.0-21.0] vs 12.8% [95% CI, 9.8-16.2]; P = .003), and non-HDL-C (13.6% [95% CI, 11.3-16.2] vs 8.4% [95% CI, 5.9-11.5]; P < .001). There was a decrease in high BP between 1999-2000 (3.0% [95% CI, 2.0-4.3]) and 2011-2012 (1.6% [95% CI, 1.0-2.4]) (P = .003). There was no change from 1999-2000 to 2011-2012 in borderline high BP (7.6% [95% CI, 5.8-9.8] vs 9.4% [95% CI, 7.2-11.9]; P = .90) or either high or borderline high BP (10.6% [8.4-13.1] vs 11.0% [95% CI, 8.8-13.4]; P = .26). CONCLUSIONS AND RELEVANCE: In 2011-2012, approximately 1 in 5 children and adolescents aged 8 to 17 years had an adverse lipid concentration of TC, HDL-C, or non-HDL-C and slightly more than 1 in 10 had either borderline high or high BP. The prevalence of dyslipidemia modestly decreased between 1999-2000 and 2011-2012, but either high or borderline high BP remained stable. The reasons for these trends require further study.