Annual Change In Body Mass Index Research Articles

Changes in Body Mass Index Over Time in People With and Without HIV Infection.

Excess weight gain is an important health concern among people with HIV (PWH) on antiretroviral therapy (ART). The extent to which ART contributes to body mass index (BMI) changes is incompletely understood. We conducted a retrospective study of PWH initiating ART and demographically matched people without HIV (PWoH). Data on baseline BMI (kg/m2; categorized as underweight/normal, overweight, or obese) and ART class (integrase strand transfer inhibitor [INSTI], non-nucleoside reverse transcriptase inhibitor [NNRTI], protease inhibitor [PI]) were obtained from electronic health records. BMI was evaluated longitudinally using piecewise linear splines in mixed effects models by HIV status, baseline BMI, and ART class. Models were adjusted for sociodemographics, comorbidities, and substance use. The study included 8256 PWH and 129 966 PWoH (mean baseline age, 40.9 and 42.2 years, respectively; 88% men). In adjusted models, the average annual change in BMI in the first 2 years after ART initiation was 0.53 for PWH and 0.12 for PWoH (P < .001). BMI increases among PWH were observed for all ART classes: 0.69 for INSTIs, 0.69 for PIs, and 0.40 for NNRTIs vs 0.12 among PWoH. For PWH initiating INSTIs, BMI increases were observed regardless of baseline BMI. Overall BMI changes >2 years after ART initiation were similar by HIV status (0.02 average annual increase for PWH and PWoH). PWH initiating ART gained excess weight in the first 2 years, emphasizing the importance of monitoring weight and cardiometabolic health among ART-treated PWH.

Trends in body mass index, overweight and obesity among adults in the USA, the NHANES from 2003 to 2018: a repeat cross-sectional survey

ObjectivesTo analyse detailed trends in adult obesity from 2003 to 2018 in the USA, and provide the latest national estimates of adult obesity in 2017–2018.Design, setting and participantsAnalysis of data,...

Assessing the Added Value of Vital Signs Extracted from Electronic Health Records in Healthcare Risk Adjustment Models.

PurposePatient vital signs are related to specific health risks and outcomes but are underutilized in the prediction of health-care utilization and cost. To measure the added value of electronic health record (EHR) extracted Body Mass Index (BMI) and blood pressure (BP) values in improving healthcare risk and utilization predictions.Patients and MethodsA sample of 12,820 adult outpatients from the Johns Hopkins Health System (JHHS) were identified between 2016 and 2017, having high data quality and recorded values for BMI and BP. We evaluated the added value of BMI and BP in predicting health-care utilization and cost through a retrospective cohort design. BMI, mean arterial pressure (MAP), systolic and diastolic BPs were summarized as annual aggregated values. Concurrent annual BMI and MAP changes were quantified as the difference between maximum and minimum recorded values. Model performance estimates consisted of repeated 10-fold cross validation, compared to base model point estimates for demographic and diagnostic, coded events: (1) patient age and sex, (2) age, sex, and the Charlson weighted index, (3) age, sex and the Johns Hopkins ACG system’s DxPM risk score.ResultsBoth categorical BMI and BP were progressively indicative of disease comorbidity, but not uniformly related to health-care utilization or cost. Annual change in BMI and MAP improved predictions for most concurrent year outcomes when compared to base models.ConclusionWhen a healthcare system lacks relevant diagnostic or risk assessment information for a patient, vital signs may be useful for a simple estimation of disease risk, cost and utilization.

Modeling the natural history of fatty liver using lifestyle-related risk factors: Effects of body mass index (BMI) on the life-course of fatty liver.

BackgroundIncident fatty liver increases the risk of non–alcoholic fatty liver disease (NAFLD), which may lead to end-stage liver diseases, and increase the risk of cardiovascular disease and diabetes. For its prevention, modeling the natural history of fatty liver is useful to demonstrate which lifestyle-related risk factors (e.g. body mass index and cholesterol) play the greatest role in the life-course of fatty liver.MethodsModel predictors and their predictive algorithms were determined by prospective regression analyses using 5–year data from approximately 2000 Japanese men aged 20–69 years. The participants underwent health examinations and completed questionnaires on their lifestyle behaviors annually from 2012 to 2016. The life–course of fatty liver was simulated based on this participant data using Monte Carlo simulation methods. Sensitivity analyses were performed. The validity of the model was discussed.ResultsThe body mass index (BMI) and low–density/high–density lipoprotein cholesterol (LDL–C/HDL–C) ratio significantly aided in predicting incident fatty liver. When the natural history of fatty liver was simulated using the data of participants aged 30–39 years, the prevalence increased from 20% to 32% at 40–59 years before decreasing to 24% at 70–79 years. When annual updates of BMI and LDL–C/HDL–C ratio decreased/increased by 1%, the peak prevalence of fatty liver (32%) changed by −8.0/10.7% and −1.6/1.4%, respectively.ConclusionsWe modeled the natural history of fatty liver for adult Japanese men. The model includes BMI and LDL‒C/HDL‒C ratio, which played a significant role in predicting the presence of fatty liver. Specifically, annual changes in BMI of individuals more strongly affected the life‒course of fatty liver than those in the LDL–C/HDL–C ratio. Sustainable BMI control for individuals may be the most effective option for preventing fatty liver in a population.

Effects of body weight variation in obese kidney recipients: a retrospective cohort study.

BackgroundObese kidney allograft recipients have worse results in kidney transplantation (KT). However, there is lack of information regarding the effect of body mass index (BMI) variation after KT. The objective of the study was to evaluate the effects of body weight changes in obese kidney transplant recipients.MethodsIn this study we used data from the Catalan Renal Registry that included KT recipients from 1990 to 2011 (n = 5607). The annual change in post-transplantation BMI was calculated. The main outcome variables were delayed graft function (DGF), estimated glomerular filtration rate (eGFR) and patient and graft survival.ResultsObesity was observed in 609 patients (10.9%) at the time of transplantation. The incidence of DGF was significantly higher in obese patients (40.4% versus 28.3%; P < 0.001). Baseline obesity was significantly associated with worse short- and long-term graft survival (P < 0.05) and worse graft function during the follow-up (P < 0.005). BMI variations in obese patients did not improve eGFR or graft or patient survival.ConclusionsOur conclusion is that in obese patients, decreasing body weight after KT does not improve either short-term graft outcomes or long-term renal function.

Monitoring children and adolescents with severe obesity: body mass index (BMI), BMI z-score or percentage above the International Obesity Task Force overweight cut-off?

Body mass index (BMI) metrics are widely used as a proxy for adiposity in children with severe obesity. The BMI expressed as the percentage of a cut-off percentile for overweight or obesity has been proposed as a better alternative than BMI z-scores when monitoring children and adolescents with severe obesity. Annual changes in BMI, BMI z-score and the percentage above the International Obesity Task Force overweight cut-off (%IOTF-25) were compared with dual-energy X-ray absorptiometry (DXA) derived body fat (%BF-DXA) in 59 children and adolescents with severe obesity. The change in %BF-DXA was correlated with the change in %IOTF-25 (r=0.68) and BMI (r=0.70), and somewhat less with the BMI z-score (r=0.57). Cohen's Kappa statistic to detect an increase or decrease in %BF-DXA was fair for %IOTF-25 (κ=0.25; p=0.04) and BMI (κ=0.33; p=0.01), but not for the BMI z-score (κ=0.08; p=0.5). The change in BMI was positively biased due to a natural increase with age. Changes in the BMI metrics included in the study are associated differently with changes in %BF-DXA. The BMI z-score is widely used to monitor changes in adiposity in children and adolescents with severe obesity, but the %IOTF-25 might be a better alternative.

Skipping breakfast and 5-year changes in body mass index and waist circumference in Japanese men and women.

SummaryObjectiveThis study investigated the relationship between frequency of skipping breakfast and annual changes in body mass index (BMI) and waist circumference (WC).MethodsThe participants were 4,430 factory employees. BMI and WC were measured repeatedly at annual medical examinations over a 5‐year period. The association between frequency of skipping breakfast at the baseline examination and annual changes in anthropometric indices was evaluated using the generalized estimating equation method.ResultsThe mean (standard deviation) BMI was 23.3 (3.0) kg m−2 for men and 21.9 (3.6) kg m−2 for women; and the mean WC was 82.6 (8.7) cm for men and 77.8 (9.8) cm for women. During the follow‐up period, mean BMI increased by 0.2 kg m−2 for men and women, and mean WC increased by 1.1 cm for men and 1.0 cm for women. The annual change in the BMI of men who skipped breakfast four to six times per week was 0.061 kg m−2 higher, and that of those who skipped breakfast seven times per week was 0.046 kg m−2 higher, compared with those who did not skip breakfast. Annual changes in the WC of male participants who skipped breakfast seven times per week was 0.248 cm higher than that of those who did not skip breakfast. Skipping breakfast was not associated with changes in BMI or WC in women.ConclusionsSkipping breakfast was closely associated with annual changes in BMI and WC among men, and eating breakfast more than four times per week may prevent the excessive body weight gain associated with skipping breakfast.

Late-Life Vascular Risk Factors and Alzheimer Disease Neuropathology in Individuals with Normal Cognition.

Vascular risk factors (VRFs) have been associated with clinically diagnosed Alzheimer disease (AD), but few studies have examined the association between VRF and AD neuropathology (ADNP) in cognitively normal individuals. We used longitudinal data from the National Alzheimer's Disease Center's Uniform Data Set and Neuropathology Data Set to examine the association between VRF and ADNP (moderate to frequent neuritic plaques; Braak stage III-VI) in those with normal cognition. Our sample included 53 participants with ADNP and 140 without ADNP. Body mass index (BMI), resting heart rate (HR), and pulse pressure (PP) were measured at each visit; values were averaged across participant visits and examined annual change in BMI, PP, and HR. Hypertension, diabetes, and hypercholesterolemia were self-reported. In the multivariable logistic regression analyses, average BMI and HR were associated with lower odds of ADNP, and annual increases in HR and BMI were associated with higher odds of ADNP. A previously experienced decline in BMI or HR in late-life (therefore, currently low BMI and low HR) as well as a late-life increase in BMI and HR may indicate underlying AD pathology. Additional clinicopathological research is needed to elucidate the role of changes in late-life VRF and AD pathogenesis.

BMI and BMI SDS in childhood: annual increments and conditional change

Background Early detection of abnormal weight gain in childhood may be important for preventive purposes. It is still debated which annual changes in BMI should warrant attention.Aim To analyse 1-year increments of Body Mass Index (BMI) and standardised BMI (BMI SDS) in childhood and explore conditional change in BMI SDS as an alternative method to evaluate 1-year changes in BMI.Subjects and methods The distributions of 1-year increments of BMI (kg/m2) and BMI SDS are summarised by percentiles. Differences according to sex, age, height, weight, initial BMI and weight status on the BMI and BMI SDS increments were assessed with multiple linear regression. Conditional change in BMI SDS was based on the correlation between annual BMI measurements converted to SDS.Results BMI increments depended significantly on sex, height, weight and initial BMI. Changes in BMI SDS depended significantly only on the initial BMI SDS. The distribution of conditional change in BMI SDS using a two-correlation model was close to normal (mean = 0.11, SD = 1.02, n = 1167), with 3.2% (2.3–4.4%) of the observations below −2 SD and 2.8% (2.0–4.0%) above +2 SD.Conclusion Conditional change in BMI SDS can be used to detect unexpected large changes in BMI SDS. Although this method requires the use of a computer, it may be clinically useful to detect aberrant weight development.

Gene-environment interactions in obesity: implication for future applications in preventive medicine.

Obesity is associated with environmental factors; however, information about gene-environment interactions is lacking. We aimed to elucidate the effects of gene-environment interactions on obesity, specifically between genetic predisposition and various obesity-related lifestyle factors, using data from a population-based prospective cohort study. The genetic risk score (GRS) calculated from East Asian ancestry single-nucleotide polymorphisms was significantly associated with the body mass index (BMI) at baseline (P<0.001). Significant gene-environment interactions were observed for six nutritional factors, alcohol intake, metabolic equivalents-hour per day and the homeostasis model assessment ratio. The GRS altered the effects of lifestyle factors on BMI. Increases in the BMI at baseline per unit intake for each nutritional factor differed depending on the GRS. However, we did not observe significant correlations between the GRS and annual changes in BMI during the follow-up period. This study suggests that the effects of lifestyle factors on obesity differ depending on the genetic risk factors. The approach used to evaluate gene-environment interaction in this study may be applicable to the practice of preventive medicine.

BMI and lifetime changes in BMI and cancer mortality risk.

Body Mass Index (BMI) is known to be associated with cancer mortality, but little is known about the link between lifetime changes in BMI and cancer mortality in both males and females. We studied the association of BMI measurements (at baseline, highest and lowest BMI during the study-period) and lifetime changes in BMI (calculated over different time periods (i.e. short time period: annual change in BMI between successive surveys, long time period: annual change in BMI over the entire study period) with mortality from any cancer, and lung, colorectal, prostate and breast cancer in a large cohort study (n=8,645. Vlagtwedde-Vlaardingen, 1965-1990) with a follow-up on mortality status on December 31st 2008. We used multivariate Cox regression models with adjustments for age, smoking, sex, and place of residence. Being overweight at baseline was associated with a higher risk of prostate cancer mortality (hazard ratio (HR) =2.22; 95% CI 1.19-4.17). Obesity at baseline was associated with a higher risk of any cancer mortality [all subjects (1.23 (1.01-1.50)), and females (1.40 (1.07-1.84))]. Chronically obese females (females who were obese during the entire study-period) had a higher risk of mortality from any cancer (2.16 (1.47-3.18), lung (3.22 (1.06-9.76)), colorectal (4.32 (1.53-12.20)), and breast cancer (2.52 (1.15-5.54)). We found no significant association between long-term annual change in BMI and cancer mortality risk. Both short-term annual increase and decrease in BMI were associated with a lower mortality risk from any cancer [all subjects: (0.67 (0.47-0.94)) and (0.73 (0.55-0.97)), respectively]. In conclusion, a higher BMI is associated with a higher cancer mortality risk. This study is the first to show that short-term annual changes in BMI were associated with lower mortality from any type of cancer.

National economic development and disparities in body mass index: a cross-sectional study of data from 38 countries.

BackgroundIncreases in body mass index (BMI) and the prevalence of overweight in low- and middle income countries (LMICs) are often ascribed to changes in global trade patterns or increases in national income. These changes are likely to affect populations within LMICs differently based on their place of residence or socioeconomic status (SES).ObjectiveUsing nationally representative survey data from 38 countries and national economic indicators from the World Bank and other international organizations, we estimated ecological and multilevel models to assess the association between national levels of gross domestic product (GDP), foreign direct investment (FDI), and mean tariffs and BMI.DesignWe used linear regression to estimate the ecological association between average annual change in economic indicators and BMI, and multilevel linear or ordered multinomial models to estimate associations between national economic indicators and individual BMI or over- and underweight. We also included cross-level interaction terms to highlight differences in the association of BMI with national economic indicators by type of residence or socioeconomic status (SES).ResultsThere was a positive but non-significant association of GDP and mean BMI. This positive association of GDP and BMI was greater among rural residents and the poor. There were no significant ecological associations between measures of trade openness and mean BMI, but FDI was positively associated with BMI among the poorest respondents and in rural areas and tariff levels were negatively associated with BMI among poor and rural respondents.ConclusionMeasures of national income and trade openness have different associations with the BMI across populations within developing countries. These divergent findings underscore the complexity of the effects of development on health and the importance of considering how the health effects of “globalizing” economic and cultural trends are modified by individual-level wealth and residence.

Longitudinal age-and cohort trends in body mass index in Sweden – a 24-year follow-up study

BackgroundThe aim of this longitudinal study was to analyze whether mean Body Mass Index (BMI), assessed at four occasions, changed within different age groups and birth cohorts over time, i.e., between 1980/81 and 2004/05, after adjustment for possible confounders.MethodsA sample of 2728 men and 2770 women aged 16–71 years at study start were randomly drawn from the Swedish Total Population Register and followed from 1980/81 to 2004/05. The same sample was assessed on four occasions during the 24-year study period (i.e., every eighth year). The outcome variable, BMI, was based on self-reported height and weight. A mixed model, with random intercept and random slope, was used to estimate annual changes in BMI within the different age groups and birth cohorts.ResultsMean BMI increased from 24.1 to 25.5 for men and from 23.1 to 24.3 for women during the 24-year study period. The annual change by age group was highest in the ages of 32–39, 40–47 and 48–55 years among men, and in the ages of 24–31, 32–39, and 40–47 years among women. The highest annual changes were found in the youngest birth cohorts for both men and women, i.e., those born 1958–65, 1966–73, and 1974–81. For each birth cohort, the annual change in BMI increased compared to the previous, i.e., older, birth cohort. In addition, age-by-cohort interaction tests revealed that the increase in BMI by increasing age was higher in the younger birth cohorts (1966–1989) than in the older ones.ConclusionsPublic health policies should target those age groups and birth cohorts with the highest increases in BMI. For example, younger birth cohorts had higher annual increases in BMI than older birth cohorts, which means that younger cohorts increased their BMI more than older ones during the study period.

Body satisfaction, weight gain and binge eating among overweight adolescent girls

ObjectiveTo examine if body satisfaction is associated with body mass index (BMI) change and whether it protects against the development of frequent binge eating among overweight and obese adolescent girls.MethodsWe used prospective data from 9 waves of an ongoing cohort study of adolescents, the Growing Up Today Study. At enrollment in 1996, participants were 9 to 14 years old. Questionnaires were mailed to participants annually until 2001, then biennially through 2007. Girls who were overweight or obese in 1996 were included in the analysis (n=1 559). Our outcomes were annual change in BMI and incident frequent binge eating, defined as binge eating at least weekly and no use of compensatory behaviors.ResultsAt baseline, 57.2% of the overweight and obese girls were at least somewhat satisfied with their bodies. During 11 years of follow-up, 9.5% (95% confidence interval (CI) [7.8, 10.8]) of the girls started to binge eat frequently. Controlling for BMI and other confounders, overweight and obese girls who reported being at least somewhat satisfied with their bodies made smaller BMI gains (β=−0.10 kg/m2, 95% CI [−0.19, −0.02]) and had 61% lower odds of starting to binge eat frequently (odds ratio (OR)=0.39, 95% CI [0.24, 0.64]) than their less satisfied peers. Compared to girls who were the least satisfied with their bodies, girls who were the most satisfied had 85% lower odds of starting to binge eat frequently (OR=0.15, 95% CI [0.06, 0.37]). The association between body satisfaction and starting to binge eat frequently was stronger for younger adolescents than older adolescents.ConclusionsWhile body dissatisfaction is common among overweight and obese girls, body satisfaction may protect against excessive weight gain and binge eating. Prevention of body dissatisfaction must begin early and should be considered as a component of both obesity and eating disorder prevention programs.

Maintaining a High Physical Activity Level Over 20 Years and Weight Gain

Data supporting physical activity guidelines to prevent long-term weight gain are sparse, particularly during the period when the highest risk of weight gain occurs. To evaluate the relationship between habitual activity levels and changes in body mass index (BMI) and waist circumference over 20 years. The Coronary Artery Risk Development in Young Adults (CARDIA) study is a prospective longitudinal study with 20 years of follow-up, 1985-1986 to 2005-2006. Habitual activity was defined as maintaining high, moderate, and low activity levels based on sex-specific tertiles of activity scores at baseline. Participants comprised a population-based multicenter cohort (Chicago, Illinois; Birmingham, Alabama; Minneapolis, Minnesota; and Oakland, California) of 3554 men and women aged 18 to 30 years at baseline. Average annual changes in BMI and waist circumference. Over 20 years, maintaining high levels of activity was associated with smaller gains in BMI and waist circumference compared with low activity levels after adjustment for race, baseline BMI, age, education, cigarette smoking status, alcohol use, and energy intake. Men maintaining high activity gained 2.6 fewer kilograms (0.15 BMI units per year; 95% confidence interval [CI], 0.11-0.18 vs 0.20 in the lower activity group; 95% CI, 0.17-0.23), and women maintaining higher activity gained 6.1 fewer kilograms (0.17 BMI units per year; 95% CI, 0.12-0.21 vs 0.30 in the lower activity group; 95% CI, 0.25-0.34). Men maintaining high activity gained 3.1 fewer centimeters in waist circumference (0.52 cm per year; 95% CI, 0.43-0.61 cm vs 0.67 cm in the lower activity group; 95% CI,0.60-0.75 cm) and women maintaining higher activity gained 3.8 fewer centimeters(0.49 cm per year; 95% CI, 0.39-0.58 cm vs 0.67 cm in the lower activity group; 95% CI, 0.60-0.75 cm) [corrected]. Maintaining high activity levels through young adulthood may lessen weight gain as young adults transition to middle age, particularly in women.

Longitudinal association of anthropometry with mammographic breast density in the Study of Women's Health Across the Nation

High percent mammographic breast density is strongly associated with increased breast cancer risk. Though body mass index (BMI) is positively associated with risk of postmenopausal breast cancer, BMI is negatively associated with percent breast density in cross-sectional studies. Few longitudinal studies have evaluated associations between BMI and weight and mammographic breast density. We studied the longitudinal relationships between anthropometry and breast density in a prospective cohort of 834 pre- and perimenopausal women enrolled in an ancillary study to the Study of Women's Health Across the Nation (SWAN). Routine screening mammograms were collected and read for breast density. Random intercept regression models were used to evaluate whether annual BMI change was associated with changes over time in dense breast area and percent density. The study population was 7.4% African-American, 48.8% Caucasian, 21.8% Chinese, and 21.9% Japanese. Mean follow-up was 4.8 years. Mean annual weight change was +0.32 kg/year, mean change in dense area was -0.77 cm(2)/year, and mean change in percent density was -1.14%/year. In fully adjusted models, annual change in BMI was not significantly associated with changes in dense breast area (-0.17 cm(2), 95% CI -0.64, 0.29). Borderline significant negative associations were observed between annual BMI change and annual percent density change, with percent density decreasing 0.36% (95% CI -0.74, 0.02) for a one unit increase in BMI over a year. This longitudinal study provides modest evidence that changes in BMI are not associated with changes in dense area, yet may be negatively associated with percent density.

Abstract 1266: Do Gender Differences Exist in the Relation of Physical Activity with Changes in Body Mass Index and Waist Circumference over 20 years: the CARDIA Study

Public health guidelines recommend physical activity to minimize weight gain. Yet, the data are ambiguous; some studies show weaker associations between activity and adiposity/weight changes in women perhaps due to inability to control for gender differences in energy intake and fat distribution. We hypothesized that after accounting for energy intake and fat distribution, associations between high activity levels and changes in weight, body mass index (BMI) or waist circumference over 20 years would not differ by gender. Black and white adults ages 18 –30 from the CARDIA Study, an NHLBI sponsored multi-center longitudinal study, had anthropometric measures taken and activity habits assessed using an interviewer-based questionnaire at 7 exams over 20 years (n=3555). Generalized estimating equations were used to calculate average annual changes in weight (pounds), BMI (kg/m 2 ), and waist circumference (cm) by long-term activity level over 20 years, stratified by sex and baseline overweight status. High activity was associated with smaller gains in weight, BMI and waist circumference in men and women over 20 years (Table , weight data not shown). Formal interaction tests by sex and baseline overweight status were significant (p&lt;0.05). When comparing high versus low activity, women showed larger differences in weight change than men. Compared with low activity, normal weight women with high activity gained 16.8 fewer pounds over 20 years while normal weight men gained 5.6 fewer pounds. Consistently high activity during young adulthood is associated with smaller gains in weight, BMI and waist circumference. The difference in weight gain between high and low activity is greater in women and persists after adjustment for energy intake. These results suggest that weight gain in young adults, particularly women, may be slowed by incorporating high activity into daily life in a manner that can be maintained over many years. Table: Average annual changes in BMI and waist circumference by long-term activity categories, stratified by gender and baseline overweight status

Weight change and cognitive performance.

To investigate whether under- or overweight and weight change is associated with cognitive performance of elderly citizens. Explorative analysis out of the Basel Study cohort. In all, 531 healthy subjects (445 men/86 women) were assessed with the Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery (CERAD-NAB) in 2000 (age: 69.4+/-7.8 y) and weight measurements obtained in 1990 (body mass index (BMI): 25.2+/-3.1 kg/m(2)) and in 2000 (BMI: 25.6+/-3.4 kg/m(2)). The predictive power of the annual change in BMI with cognitive performance was investigated by a binary logistic regression analysis (backward) using sex, age, BMI 1990, BMI 2000, diastolic blood pressure, diabetes status, and optimal health status as additional predictors. In the last step, the following variables remained in the model: annual change in BMI (quadratic term; P<0.01); ApoE genotype (P<0.05); and optimal health status (P<0.01). The association between the extent of weight change and poorer cognitive performance could be either a consequence of cognitive impairment or an early symptom of neurodegenerative decline.

Body‐mass index as a predictor of incident asthma in a prospective cohort of children

An epidemic rise in asthma has occurred concurrently with a rise in overweight among United States children, but it is unclear whether body weight affects the risk of incident childhood asthma. We studied the prospective relation of body-mass index (BMI) to incident asthma in a longitudinal study of 9,828 children aged 6-14 years, examined annually over a median follow-up time of 5 years in six US cities. An increased risk of a new asthma diagnosis in girls was associated with higher BMI at entry into the study (P=0.009) and greater increase in BMI during follow-up (P=0.0003). Compared with girls in the leanest quintile of BMI at entry (age taken into account), girls in the top quintile of adiposity had 2.2 times greater risk of incident asthma with any wheeze in subsequent years. Girls with the largest annual rate of increase in BMI (top compared to bottom quintile, age taken into account) had 1.5 times the risk of asthma with any wheeze, and 2.2 times the risk of asthma with persistent wheeze. Boys with the largest and smallest annual changes in BMI also had an increased risk of asthma. For girls, overweight contributes to development of asthma. For boys and girls, extremes of annual BMI growth rates increase the risk of asthma.

Association between fruit and vegetable intake and change in body mass index among a large sample of children and adolescents in the United States.

To assess whether intake of fruits and vegetables was associated with change in body mass index (BMI) among a large sample of children and adolescents in the United States. Prospective cohort study of children and adolescent who were 9-14 y of age in 1996, when the study began. The subjects included 8203 girls and 6715 boys in an ongoing cohort study who completed at least two questionnaires between 1996 and 1999. Fruit and vegetable intake was assessed in 1996-1998 with a validated food frequency questionnaire designed specifically for children and adolescents. The outcome measure was change in age- and gender-specific z-score of BMI (kg/m(2)). Self-reported weight and height, which were used to calculate BMI, were collected annually from 1996 to 1999. During 3 years of follow-up, annual changes in BMI were slightly greater among the boys than the girls. After controlling for Tanner stage of development, age, height change, activity and inactivity, which are known or suspected predictors of change in BMI, among the girls there was no relation between intake of fruits, fruit juice, or vegetables (alone or combined) and subsequent changes in BMI z-score. Among the boys, intake of fruit and fruit juice was not predictive of changes in BMI, however, vegetables intake was inversely related to changes in BMI z-score (beta per serving=-0.003). However, after adjusting for caloric intake, the magnitude of the effect was diminished and no longer significant. Our results suggest that the recommendation for consumption of fruits and vegetables may be well founded, but should not be based on a beneficial effect on weight regulation.