Seven-year trends in body weight and associations with lifestyle and behavioral characteristics in black and white young adults: the CARDIA study

Contribution of social, behavioral, and contextual exposures to Black-White disparities in incident obesity: The CARDIA study

OBJECTIVE

The aim of this study was to quantify the contributions of socioeconomic, psychosocial, behavioral, reproductive, and neighborhood exposures in young adulthood to Black-White differences in incident obesity.

METHODS

In the Coronary Artery Risk Development in Young Adults (CARDIA) study, 4488 Black or White adults aged 18 to 30 years without obesity at baseline (1985-1986) were followed over 30 years. Sex-specific Cox proportional hazard models were used to estimate Black-White differences in incident obesity. Models were adjusted for baseline and time-updated indicators.

RESULTS

During follow-up, 1777 participants developed obesity. Black women were 1.87 (95% CI: 1.63-2.13) times more likely and Black men were 1.53 (95% CI: 1.32-1.77) times more likely to develop obesity than their White counterparts after adjusting for age, field center, and baseline BMI. Baseline exposures explained 43% of this difference in women and 52% in men. Time-updated exposures explained more of the racial difference in women but less for men, compared with baseline exposures.

CONCLUSIONS

Adjusting for these exposures accounted for a substantial but incomplete proportion of racial disparities in incident obesity. Remaining differences may be explained by incomplete capture of the most salient aspects of these exposures or potential variation in the impact of these exposures on obesity by race.

Factors Associated with Age-Related Declines in Cardiorespiratory Fitness from Early Adulthood Through Midlife: CARDIA

PURPOSE

This study aimed to describe maximal and submaximal cardiorespiratory fitness from early adulthood to midlife and examine differences in maximal fitness at age 20 yr and changes in fitness overtime by subcategories of sociodemographic, behavioral, and health-related factors.

METHODS

Data include 5018 Coronary Artery Risk Development in Young Adults participants (mean (SD) age, 24.8 (3.7) yr; 53.3% female; and 51.4% Black participants) who completed at least one maximal graded exercise test at baseline and/or the year 7 and 20 exams. Maximal and submaximal fitness were estimated by exercise duration and heart rate at the end of stage 2. Multivariable adjusted linear-mixed models were used to estimate fitness trajectories using age as the mechanism for time after adjustment for covariates. Fitness trajectories from ages 20 to 50 yr in 5-yr increments were estimated overall and by subgroups determined by each factor after adjustment for duration within the less favorable category.

RESULTS

Mean (95% confidence interval) maximal fitness at age 20 and 50 yr was 613 (607-616) and 357 (350-362) s; submaximal heart rate during this period also reflected age-related fitness declines (126 (125-127) and 138 (137-138) bpm). Compared with men, women had lower maximal fitness at age 20 yr (P < 0.001), which persisted over follow-up (P < 0.001); differences were also found by race within sex strata (all P < 0.001). Differences in maximal fitness at age 20 yr were noted by socioeconomic, behavioral, and health-related status in young adulthood (all P < 0.05), which persisted over follow-up (all P < 0.001) and were generally consistent in sex-stratified analyses.

CONCLUSIONS

Targeting individuals experiencing accelerated fitness declines with tailored intervention strategies may provide an opportunity to preserve fitness throughout midlife to reduce lifetime cardiovascular disease risk.

Influential Periods in Longitudinal Clinical Cardiovascular Health Scores

The prevalence of ideal cardiovascular health (CVH) among adults in the United States is low and decreases with age. Our objective was to identify specific age windows when the loss of CVH accelerates, to ascertain preventive opportunities for intervention. Data were pooled from 5 longitudinal cohorts (Project Heartbeat!, Cardiovascular Risk in Young Finns Study, The Bogalusa Heart Study, Coronary Artery Risk Development in Young Adults, Special Turku Coronary Risk Factor Intervention Project) from the United States and Finland from 1973 to 2012. Individuals with clinical CVH factors (i.e., body mass index, blood pressure, cholesterol, blood glucose) measured from ages 8 to 55 years were included. These factors were categorized and summed into a clinical CVH score ranging from 0 (worst) to 8 (best). Adjusted, segmented, linear mixed models were used to estimate the change in CVH over time. Among the 18,343 participants, 9,461 (52%) were female and 12,346 (67%) were White. The baseline mean (standard deviation) clinical CVH score was 6.9 (1.2) at an average age of 17.6 (8.1) years. Two inflection points were estimated: at 16.9 years (95% confidence interval: 16.4, 17.4) and at 37.2 years (95% confidence interval: 32.4, 41.9). Late adolescence and early middle age appear to be influential periods during which the loss of CVH accelerates.

Racial inequality, racial discrimination and obesity incidence in adults from the ELSA-Brasil cohort

BACKGROUND

This study investigated whether self-reported race/skin colour and perceived racial discrimination predict higher obesity incidence after approximately 4-year follow-up of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). We also investigated whether these associations are modified by educational level.

METHODS

Following exclusion of individuals defined as obese (body mass index ≥30 kg/m2) at baseline, associations between race/skin colour and obesity incidence between the first (2008-2010) and second (2012-2014) visits were investigated in 10 130 participants. Next, associations between perceived racial discrimination and obesity incidence among black (n=1532) and brown (n=2958) individuals were investigated separately. Racial discrimination (yes/no) was assessed using the Lifetime Major Event Scale. Logistic regression models adjusted for age, sex and research site were used. All analyses were stratified for educational level.

RESULTS

Obesity risk was higher in Blacks with high education compared with white individuals to the same education level (OR: 2.22; 95% CI 1.62 to 3.04) following adjustments. After adjustments, obesity incidence was higher among black individuals reporting racial discrimination compared with peers who did not report this experience, but only among the low education group (OR: 1.64; 95% CI 1.08 to 2.51). No statistical association with perceived discrimination was observed among brown individuals.

CONCLUSION

Results are congruent with findings from other studies reporting associations between racial inequality and obesity incidence and also suggest racial discrimination may be one of the mechanisms leading to such inequalities. Also, it supports the paradox theory by which education modify the association in distinct directions.

O-GlcNAc cycling mediates energy balance by regulating caloric memory

Caloric need has long been thought a major driver of appetite. However, it is unclear whether caloric need regulates appetite in environments offered by many societies today where there is no shortage of food. Here we observed that wildtype mice with free access to food did not match calorie intake to calorie expenditure. While the size of a meal affected subsequent intake, there was no compensation for earlier under- or over-consumption. To test how spontaneous eating is subject to caloric control, we manipulated O-linked β-N-acetylglucosamine (O-GlcNAc), an energy signal inside cells dependent on nutrient access and metabolic hormones. Genetic and pharmacological manipulation in mice increasing or decreasing O-GlcNAcylation regulated daily intake by controlling meal size. Meal size was affected at least in part due to faster eating speed. Without affecting meal frequency, O-GlcNAc disrupted the effect of caloric consumption on future intake. Across days, energy balance was improved upon increased O-GlcNAc levels and impaired upon removal of O-GlcNAcylation. Rather than affecting a perceived need for calories, O-GlcNAc regulates how a meal affects future intake, suggesting that O-GlcNAc mediates a caloric memory and subsequently energy balance.

On the joint role of non-Hispanic Black race/ethnicity and weight status in predicting postmenopausal weight gain

Objectives

To determine how baseline weight status contributes to differences in postmenopausal weight gain among non-Hispanic Blacks (NHBs) and non-Hispanic Whites (NHWs).

Methods

Data were included from 70,750 NHW and NHB postmenopausal women from the Women’s Health Initiative Observational Study (WHI OS). Body Mass Index (BMI) at baseline was used to classify women as having normal weight, overweight, obese class I, obese class II or obese class III. Cox proportional hazards was used to estimate the hazard of a 10% or more increase in weight from baseline.

Results

In both crude and adjusted models, NHBs were more likely to experience ≥10% weight gain than NHWs within the same category of baseline weight status. Moreover, NHBs who were normal weight at baseline were most likely to experience ≥10% weight gain in both crude and adjusted models. Age-stratified results were consistent with overall findings. In all age categories, NHBs who were normal weight at baseline were most likely to experience ≥10% weight gain. Based on the results of adjusted models, the joint influence of NHB race/ethnicity and weight status on risk of postmenopausal weight gain was both sub-additive and sub-multiplicative.

Conclusion

NHBs are more likely to experience postmenopausal weight gain than NHWs, and the disparity in risk is most pronounced among those who are normal weight at baseline. To address the disparity in postmenopausal obesity, future studies should focus on identifying and modifying factors that promote weight gain among normal weight NHBs.

Childbearing age is correlated with components of metabolic syndrome and parameters of insulin resistance in Chinese menopausal women

OBJECTIVE

To assess the relationship between childbearing age and elements of metabolic syndrome (MS) among menopausal women in China.

MATERIALS AND METHODS

One thousand one hundred and forty-one subjects were divided into four interim average childbearing age (ACA) groups: ≥16 < 24 years old, ≥24 < 29 years old, ≥29 < 34 years old, and ≥34 years old. The group with the lowest prevalence of MS was used as a control. Body mass index, waist circumference (WC) and waist-to-hip ratio were assessed. Plasma glucose, lipids, glycated hemoglobin (HbA1c) and fasting insulin (FINS) were measured. Insulin resistance (IR) was assessed using the homeostasis model assessment (HOMA) method.

RESULTS

The prevalence of MS in the 16-24 and 29-34 age groups was higher than that in the control group (p < .05). Compared with the control group, the odds ratios of MS were 1.431 for the 16-24 group (p < .05) and 1.553 for the 29-34 group (P < 0.01). ACA was correlated with FINS, HOMA-IR, WC, fasting plasma glucose, and triglycerides independent of age (p < .05).

CONCLUSIONS

Average childbearing age was correlated with parameters of IR and components of MS independent of age in Chinese menopausal women.

Promoting physical activity in young adult cancer survivors using mHealth and adaptive tailored feedback strategies: Design of the Improving Physical Activity after Cancer Treatment (IMPACT) randomized controlled trial

INTRODUCTION

Despite the health benefits of physical activity for cancer survivors, nearly 60% of young adult cancer survivors (YACS) are physically inactive. Few physical activity interventions have been designed specifically for YACS.

PURPOSE

To describe the rationale and design of the IMPACT (IMproving Physical Activity after Cancer Treatment) trial, which tests the efficacy of a theory-based, mobile physical activity intervention for YACS.

METHODS

A total of 280 physically inactive YACS (diagnosed at ages 18-39) will be randomized to a self-help control or intervention condition. All participants will receive an activity tracker and companion mobile app, cellular-enabled scale, individual videochat session, and access to a Facebook group. Intervention participants will also receive a 6-month mobile intervention based on social cognitive theory, which targets improvements in behavioral capability, self-regulation, self-efficacy, and social support, and incorporates self-regulation strategies and behavior change techniques. The program includes: behavioral lessons; adaptive goal-setting in response to individuals' changing activity patterns; tailored feedback based on objective data and self-report measures; tailored text messages; and Facebook prompts encouraging peer support. Assessments occur at baseline, 3, 6, and 12 months. The primary outcome is total physical activity min/week at 6 months (assessed via accelerometry); secondary outcomes include total physical activity at 12 months, sedentary behavior, weight, and psychosocial measures.

CONCLUSIONS

IMPACT uniquely focuses on physical activity in YACS using an automated tailored mHealth program. Study findings could result in a high-reach, physical activity intervention for YACS that has potential to be adopted on a larger scale and reduce cancer-related morbidity. ClinicalTrials.gov Identifier: NCT03569605.

Life Course Changes in Cardiometabolic Risk Factors Associated With Preterm Delivery: The 30-Year CARDIA Study

Background

Women who deliver preterm infants (<37 weeks) have excess cardiovascular risk; however, it is unclear whether the unfavorable changes in the cardiometabolic profile associated with preterm delivery initiate before, during, or after childbearing.

Methods and Results

We identified 1306 women (51% Black) with births between baseline (1985–1986) and year 30 in the CARDIA (Coronary Artery Risk Development in Young Adults) study. We compared life course changes in blood pressure, body mass index, waist circumference, and lipids in women with preterm deliveries (n=318) with those with all term deliveries (n=988), using piecewise linear mixed‐effects models. Specifically, we evaluated group differences in rates of change before and after the childbearing period and change in level across the childbearing period. After adjusting for the covariates, women with preterm deliveries had a higher change in diastolic blood pressure across the childbearing period than those with all term deliveries (1.59 versus −0.73 mm Hg, P<0.01); the rates of change did not differ by group, both prechildbearing and postchildbearing. Women with preterm deliveries had a larger body mass index increase across the childbearing period (1.66 versus 1.22 kg/m², P=0.03) compared with those with all term deliveries, followed by a steeper increase after the childbearing period (0.22 versus 0.17 kg/m² per year, P=0.02).

Conclusions

Preterm delivery was associated with unfavorable patterns of change in diastolic blood pressure and adiposity that originate during the childbearing years and persist or exacerbate later in life. These adverse changes may contribute to the elevated cardiovascular risk among women with preterm delivery.

Why young women gain weight: A narrative review of influencing factors and possible solutions

Significant weight gain occurs in women during young adulthood, which increases risk of diseases such as diabetes, cardiovascular disease, and many cancers. This review aims to inform future individually targeted weight gain prevention programmes and summarizes possible targets: key life events, mediators that influence energy intake and physical activity levels, and moderators that could identify groups of women at greatest risk. Life events affecting weight include pregnancy and motherhood, smoking cessation, marriage and cohabiting, attending university, and possibly bereavement. Research has identified successful methods for preventing weight gain associated with pregnancy and motherhood, which could now be used in practice, but evidence is inconclusive for preventing weight gain around other life events. Weight gain is mediated by lack of knowledge and skills around food and nutrition, depression, anxiety, stress, satiety, neural responses, and possibly sleep patterns and premenstrual cravings. A paucity of research exists into altering these to limit weight gain. Moderators include socioeconomic status, genetics, personality traits, and eating styles. More research is required to identify at-risk females and engage them in weight gain prevention. There is a need to address evidence gaps highlighted and implement what is currently known to develop effective strategies to limit weight gain in young women.

Evaluation of free-floating bike-share on a university campus using a multi-method approach

Bike-sharing, especially free-floating bike-share, has tremendous potential for increasing active transport on a college campus. Increased bike use improves public health, reduces pollution, and solves traffic congestion problems. Like other innovations, free-floating bikeshare proceeds through various stages while disseminated and before being widely adopted and accepted. A multi-method study using quantitative bike usage data, a cross-sectional survey, and focus group discussions was used to evaluate the Spring 2018 launch of a free-floating bike-share program at a large public university. Three months after implementation, there were 19,504 registered users, 24,371 different riders, 165,854 rides, and 85,778 miles traveled. The average trip length was 0.52 miles and lasted 8.3 min. Survey data from 2845 students, faculty, and staff revealed that 33.6% had used the bikes. Bike users were more likely to be students, freshmen, living on campus, be a current biker, and have confidence in their biking ability. Focus groups revealed that safety was a concern, knowledge about how the program worked was low among non-users and faculty and staff, cost was a barrier, and that adherence to bike-share rules needed to be improved. A large segment of the university population quickly adopted free-floating bike-share. However, continued work needs to be done to enhance safety, provide clear guidelines on bike-share rules (e.g., bike parking), and increase knowledge of the program with a specific focus on use by faculty and staff to ensure continued success and ultimately improve health.

Social Network Structures in African American Churches: Implications for Health Promotion Programs

The prevalence of obesity among African Americans is higher than among other racial/ethnic groups. African American churches hold a central role in promoting health in the community; yet, church-based interventions have had limited impact on obesity. While recent studies have described the influence of social networks on health behaviors, obesity interventions informed by social network analysis have been limited. We conducted a cross-sectional study with 281 African American men and women from three churches in northeast urban cities in the USA. Data were collected on sociodemographic and clinical factors and anthropometrics. Using a social network survey applying a name generator, we computed network level metrics. Exponential random graph models (ERGM) were performed to examine whether each structural property found in the empirical (observed) networks occurred more frequently than expected by chance by comparing the empirical networks to the randomly simulated networks. Overall, church friendship networks were sparse (low density). We also found that while friendship ties were more reciprocated between dyads in church networks, and there were more tendencies for clustering of friendships (significant positive transitive closure) than in random networks, other characteristics such as expansiveness (number of actors with a great number of friends) did not differ from what would be expected by chance in random networks. These data suggest that interventions with African American churches should not assume a unitary network through which a single intervention should be used.

VO2max is associated with measures of energy expenditure in sedentary condition but does not predict weight change

BACKGROUND/OBJECTIVES

Energy expenditure measured under sedentary conditions predicts weight change but evidence that directly measured VO₂max is associated with weight change is lacking. The aim of this study was to determine the associations of VO₂max with measures of predominantly sedentary 24-h thermogenesis, and subsequent weight change.

SUBJECTS/METHODS

Three hundred fifty-seven individuals (162 females; 27 Blacks, 72 Caucasians, and 258 American Indians) had measures of body composition, resting metabolic rate (RMR), and intermittent treadmill run test for assessment of VO₂max. On a separate day, 24-h energy expenditure (EE), diet-induced thermogenesis (DIT) expressed as "awake and fed" thermogenesis (AFT), sleeping metabolic rate (SMR), and spontaneous physical activity (SPA) were measured in a whole-room indirect calorimeter. Follow-up weight for 217 individuals was available (median follow-up time, 9.5 y; mean weight change, 12.4 ± 14.9 kg).

RESULTS

After adjustment for fat free mass, fat mass, age, sex, and race, a higher VO₂max was associated with a higher RMR (β = 68.2 kcal/day per L/min, P < 0.01) and 24-h EE (β = 62.2 kcal/day per L/min, P < 0.05) and including additional adjustment for energy intake higher AFT (β = 66.1 kcal/day per L/min, P = 0.01). Neither SMR (P > 0.2) nor SPA (P > 0.8) were associated with VO₂max. VO₂max at baseline did not predict follow-up weight after adjustment for baseline weight, follow-up time, sex, and race (P > 0.4).

CONCLUSION

VO₂max is associated with measures of EE including 24-h EE, RMR and DIT implying a common mechanism regulating the energetics of skeletal muscle during exercise and thermogenesis. However, this did not translate to VO₂max as a predictor of weight change.

Transethnic and race-stratified genome-wide association study of fibroid characteristics in African American and European American women

OBJECTIVE

To identify, through genome-wide association studies, genetic loci that associate with differences in fibroid size and number in a population of African American and European American women.

DESIGN

Cross-sectional study.

SETTING

Not applicable.

PATIENT(S)

Using BioVU, a clinical population from the Vanderbilt University Medical Center, and the Coronary Artery Risk Development in Young Adults cohort, a prospective cohort, we identified 1520 women (609 African American and 911 European American) with documented fibroid characteristics.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Outcome measurements include volume of largest fibroid, largest fibroid dimension, and number of fibroids (single vs. multiple).

RESULT(S)

In race-stratified analyses we achieved genome-wide significance at a variant located between MAT2B and TENM2 (rs57542984, β = 0.13; 95% confidence interval 0.09, 0.17) for analyses of largest fibroid dimension in African Americans. The strongest signal for transethnic analyses was at a variant on 1q31.1 located between PLA2G4A and BRINP3 (rs6605005, β = 0.24; 95% confidence interval 0.15, 0.33) for fibroid volume. Results from MetaXcan identified an association between predicted expression of the gene ER degradation enhancing alpha-mannosidase like protein 2 (EDEM2) in the thyroid and number of fibroids (Z score = -4.51).

CONCLUSION(S)

This study identified many novel associations between genetic loci and fibroid size and number in both race-stratified and transethnic analyses. Future studies are necessary to further validate our study findings and to better understand the mechanisms underlying these associations.

Association Between Gestational Diabetes and Incident Maternal CKD: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

BACKGROUND

Gestational diabetes mellitus (GDM) is associated with increased risk for diabetes mellitus, metabolic syndrome, and cardiovascular disease. We evaluated whether GDM is associated with incident chronic kidney disease (CKD), controlling for prepregnancy risk factors for both conditions.

STUDY DESIGN

Prospective cohort.

SETTING & PARTICIPANTS

Of 2,747 women (aged 18-30 years) enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) Study in 1985 to 86, we studied 820 who were nulliparous at enrollment, delivered at least 1 pregnancy longer than 20 weeks' gestation, and had kidney function measurements during 25 years of follow-up.

PREDICTOR

GDM was self-reported by women for each pregnancy.

OUTCOMES

CKD was defined as the development of estimated glomerular filtration rate (eGFR)<60mL/min/1.73m2 or urine albumin-creatinine ratio ≥ 25mg/g at any one CARDIA examination in years 10, 15, 20, or 25.

MEASUREMENTS

HRs for developing CKD were estimated for women who developed GDM versus women without GDM using complementary log-log models, adjusting for prepregnancy age, systolic blood pressure, dyslipidemia, body mass index, smoking, education, eGFR, fasting glucose concentration, physical activity level (all measured at the CARDIA examination before the first pregnancy), race, and family history of diabetes. We explored for an interaction between race and GDM.

RESULTS

During a mean follow-up of 20.8 years, 105 of 820 (12.8%) women developed CKD, predominantly increased urine albumin excretion (98 albuminuria only, 4 decreased eGFR only, and 3 both). There was evidence of a GDM-race interaction on CKD risk (P=0.06). Among black women, the adjusted HR for CKD was 1.96 (95% CI, 1.04-3.67) in GDM compared with those without GDM. Among white women, the HR was 0.65 (95% CI, 0.23-1.83).

LIMITATIONS

Albuminuria was assessed by single untimed measurements of urine albumin and creatinine.

CONCLUSIONS

GDM is associated with the subsequent development of albuminuria among black women in CARDIA.

Admixture mapping of uterine fibroid size and number in African American women

OBJECTIVE

To evaluate the relationship between genetic ancestry and uterine fibroid characteristics.

DESIGN

Cross-sectional study.

SETTING

Not applicable.

PATIENT(S)

A total of 609 African American participants with image- or surgery-confirmed fibroids in a biorepository at Vanderbilt University electronic health record biorepository and the Coronary Artery Risk Development in Young Adults studies were included.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Outcome measures include fibroid number (single vs. multiple), volume of largest fibroid, and largest fibroid dimension of all fibroid measurements.

RESULT(S)

Global ancestry meta-analyses revealed a significant inverse association between percentage of European ancestry and risk of multiple fibroids (odds ratio: 0.78; 95% confidence interval 0.66, 0.93; P=6.05 × 10-3). Local ancestry meta-analyses revealed five suggestive (P<4.80 × 10-3) admixture mapping peaks in 2q14.3-2q21.1, 3p14.2-3p14.1, 7q32.2-7q33, 10q21.1, 14q24.2-14q24.3, for number of fibroids and one suggestive admixture mapping peak (P<1.97 × 10-3) in 10q24.1-10q24.32 for volume of largest fibroid. Single variant association meta-analyses of the strongest associated region from admixture mapping of fibroid number (10q21.1) revealed a strong association at single nucleotide polymorphism variant rs12219990 (odds ratio: 0.41; 95% confidence interval 0.28, 0.60; P=3.82 × 10-6) that was significant after correction for multiple testing.

CONCLUSION(S)

Increasing African ancestry is associated with multiple fibroids but not with fibroid size. Local ancestry analyses identified several novel genomic regions not previously associated with fibroid number and increasing volume. Future studies are needed to explore the genetic impact that ancestry plays into the development of fibroid characteristics.

Special Article: Physical Activity, Physical Fitness, and Cardiovascular Risk Factors in Childhood

In adults, physical activity and exercise training are associated with reduced cardiovascular morbidity and mortality, a reduced likelihood of developing adverse cardiovascular risk factors, and improved insulin sensitivity. In childhood, participation in appropriate physical activity may prevent the development of cardiovascular risk factors in the future and complement treatment of existing cardiovascular risk factors, including hypertension, dyslipidemia, and overweight. Exercise in children can also significantly improve insulin sensitivity independent of weight loss. These e fects are mediated in overweight children by increases in lean body mass relative to fat mass and associated improvements in inflammatory mediators, endothelial function, and the associated adverse hormonal milieu.

Impact of Self-Preference Community Fitness Interventions in High-Risk African Americans

African Americans have a high prevalence of obesity and physical inactivity, but few interventions have been successful in the long term. We describe a 1-year intervention program to increase physical activity and reduce cardiometabolic risk. Interventions incorporated the premise that self-selection into flexible venues and varying exercise modalities would result in improvement in fitness and risk factors. Results of this single-group pretest/posttest observational study show 1-year overall group reductions in body weight and body mass index and cardiometabolic factors including high-sensitivity C-reactive protein, and increases in dual-energy x-ray absorptiometry-derived absolute and percent lean mass and lean-fat ratio, and decreased fat mass.

Instrumental-Variables Simultaneous Equations Model of Physical Activity and Body Mass Index: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

We used full-system-estimation instrumental-variables simultaneous equations modeling (IV-SEM) to examine physical activity relative to body mass index (BMI; weight (kg)/height (m)(2)) using 25 years of data (1985/1986 to 2010/2011) from the Coronary Artery Risk Development in Young Adults (CARDIA) Study (n = 5,115; ages 18-30 years at enrollment). Neighborhood environment and sociodemographic instruments were used to characterize physical activity, fast-food consumption, smoking, alcohol consumption, marriage, and childbearing (women) and to predict BMI using semiparametric full-information maximum likelihood estimation to control for unobserved time-invariant and time-varying residual confounding and differential measurement error through model-derived discrete random effects. Comparing robust-variance ordinary least squares, random-effects regression, fixed-effects regression, single-equation-estimation IV-SEM, and full-system-estimation IV-SEM, estimates from random- and fixed-effects models and the full-system-estimation IV-SEM were unexpectedly similar, despite the lack of control for residual confounding with the random-effects estimator. Ordinary least squares tended to overstate the significance of health behaviors in BMI, while results from single-equation-estimation IV-SEM were notably different, revealing the impact of weak instruments in standard instrumental-variable methods. Our robust findings for fixed effects (which does not require instruments but has a high cost in lost degrees of freedom) and full-system-estimation IV-SEM (vs. standard IV-SEM) demonstrate potential for a full-system-estimation IV-SEM method even with weak instruments.

25-year weight gain in a racially balanced sample of U.S. adults: The CARDIA study

OBJECTIVE

To examine 25-year trends in weight gain, partitioned by time-related and aging-related changes, during early and middle adulthood.

METHODS

Coronary Artery Risk Development in Young Adults (CARDIA), a prospective, non-nationally representative cohort study conducted at four urban field centers that began in 1985 to 1986 with 5,109 Black (B) and White (W) men (M) and women (W) aged 18 to 30 years, has followed participants for 25 years (aged 43-55 years in 2010-2011). Time-related and aging-related components of weight change were estimated to construct longitudinal models of linear and nonlinear trends.

RESULTS

There were nonlinear trends in time-related weight gain in W, with larger weight gains early that attenuated at subsequent exams. Time-related trends were linear in M. There were nonlinear trends in aging-related weight gain in BM, BW, and WM, with the greatest weight gains at younger ages. Aging-related trends were linear in WW. Participants with overweight or obesity in early adulthood had greater attenuation of aging-related weight gain during middle adulthood.

CONCLUSIONS

These findings partially support recent surveys indicating slower increases in obesity prevalence in recent years. Findings further suggest that aging-related weight gain is greatest in the 20s and may begin attenuating as early as the mid-30s among some groups.

Weight Change and Associated Factors in Long-Term Breast Cancer Survivors

PURPOSE

Weight gain often occurs after breast cancer diagnosis and significantly impacts the general health of cancer survivors. While the number of breast cancer survivors is increasing, few studies have reported data on weight change beyond 5 years post-diagnosis. We investigated weight change and associated factors in long-term survivors of breast cancer.

PATIENTS AND METHODS

Medical records were reviewed on 1363 breast cancer patients and a total of 822 women who had survived beyond 5 years since diagnosis were included in the final analysis. The association between demographic, anthropometric, lifestyle, cancer related factors (including time since diagnosis, treatment modality, pathologic stage, and hormone receptor status), and weight-change over 5 years were examined.

RESULTS

During an average 8.2 years of follow-up time, mean weight gain was 0.32kg (p = 0.017). 175 (21.3%) patients had gained more than 5% of their weight at diagnosis and their average gain was 5.55kg. Body mass index (BMI) at diagnosis, age at diagnosis, aromatase inhibitor (AI) use, heavy drinking, and type of surgery were associated with relative weight gain (≥5%) in univariate analysis (all p-values<0.05). Patients who were non-obese at diagnosis showed weight gain, while those who were obese at diagnosis lost weight (0.78kg,-1.11kg, respectively, p<0.001). In multivariate analysis, the non-obese group showed odds ratio of 2.7 (p = 0.001) relative to the obese group. Younger age group (age 18-54 years) showed odds ratio of 1.9 (p = 0.021) relative to the older age group (age 55-75 years), and patients who did not use AI showed odds ratio of 2.2 (p = 0.006) relative to women who did.

CONCLUSION

Long-term breast cancer survivors who were non-obese at diagnosis are more likely to gain weight than obese survivors. Younger survivors and survivors who have never used AI are also likely to gain weight.

Trajectories of Body Mass Index from Young Adulthood to Middle Age among Canadian Men and Women

Knowledge regarding the heterogeneity of BMI trajectories is limited for the Canadian population. Using latent class growth modelling, four distinct BMI trajectories of individuals from young adulthood to middle age were identified for both women and men from the longitudinal data of the National Population Health Survey. The associations between BMI trajectories and the individuals’ sociodemographic characteristics and behavioural factors were also examined. Aboriginal women were found more likely to be in the long-term overweight or obese groups. It reveals that increased years of smoking, drinking, and being physically active were associated with lowering the BMI trajectory in all groups for both women and men, with some exceptions in the long-term normal weight group for men. Increased years of rural living, being employed, and living with low income were associated with raising the BMI trajectory in all groups for women and in some groups for men. Food insecurity was associated with raising the BMI trajectory in each group for both women and men.

Anti-mullerian hormone (AMH) is associated with natural menopause in a population-based sample: The CARDIA Women's Study

OBJECTIVE

AMH is associated with menopausal timing in several studies. In contrast to prior studies that were restricted to women with regular cycles, our objective was to examine this association in women with either regular or irregular menstrual cycles.

METHODS

CARDIA is a longitudinal, population-based study that recruited adults ages 18-30 when it began in 1985-1986. AMH was measured in serum stored in 2002-2003. Natural menopause was assessed by survey in 2005-2006 and 2010-2011.

RESULTS

Among 716 premenopausal women, median [25th, 75th] AMH was 0.77 [0.22-2.02]ng/dL at a median age of 42 [39-45] years. Twenty-nine percent of the women (n=207) reported natural menopause during 9 years of follow up. In fully adjusted discrete-time hazard models, a 0.5 ng/dL AMH decrement was associated with higher risk of menopause (p<0.001). Hazard ratios varied with time since AMH measurement. The HR (95% CI) for menopause was 8.1 (2.5-26.1) within 0-3 years and 2.3 (1.7-3.3) and 1.6 (1.3-2.1) for 3-6 and 6-9 years, respectively. When restricted to women with regular menses, results were similar (e.g., HR=6.1; 95% CI: 1.9-20.0 for 0-3 years).

CONCLUSION

AMH is independently associated with natural menopause. AMH appears most useful in identifying women at risk of menopause in the near future (within 3 years of AMH measurement).

Weight change and its determinants in Portuguese adult women: a longitudinal analysis in the EPIPorto cohort

BACKGROUND

We aimed to characterise between-women and within-women weight change in adult women, and to assess the association of sociodemographic, reproductive and lifestyle characteristics with the variations.

METHODS

This study comprised 1040 adult women from a population-based cohort of adults from Porto, Portugal, assembled in 1999-2003 and re-evaluated in 2005-2008 (median follow-up 5 years). A mixed-effects model for longitudinal analysis of body weight was fitted, with random intercepts and random slopes. Multivariate-adjusted coefficients with 95% CIs were computed for the determinants of weight at baseline and weight change between visits.

RESULTS

There was an average crude increase of 0.11 kg of measured weight per calendar year (95% CI 0.05 to 0.17). In a multivariate model, despite not explaining differences in weight between women at baseline, years of fertile life were associated with individual weight change: -0.34 kg/year for women with up to 21 years of fertile life, whereas after that, weight increased progressively more with increasing fertile time (21.1-34 years: -0.34 kg+0.42 kg=0.08 kg; 34.1-41 years: -0.34 kg+0.46 kg=0.12 kg) up to 0.44 kg/year above 41 years. Height, age, education, marital status, residential neighbourhood deprivation, number of children delivered and use of oral contraceptives, influenced interindividual weight variation at baseline, but did not influence weight change from baseline to follow-up.

CONCLUSIONS

Cross-sectional determinants of weight and those of weight change over time are vary. Reproductive factors play important roles in explaining both differences among women as well as in individual weight change over time.

Images of a Healthy Worksite: A Group-Randomized Trial for Worksite Weight Gain Prevention With Employee Participation in Intervention Design

OBJECTIVES

We assessed the effects of a worksite multiple-component intervention addressing diet and physical activity on employees' mean body mass index (BMI) and the percentage of employees who were overweight or obese.

METHODS

This group-randomized trial (n = 3799) was conducted at 10 worksites in the northeastern United States. Worksites were paired and allocated into intervention and control conditions. Within- and between-groups changes in mean BMIs and in the percentage of overweight or obese employees were examined in a volunteer sample.

RESULTS

Within-group mean BMIs decreased by 0.54 kilograms per meter squared (P = .02) and 0.12 kilograms per meter squared (P = .73) at the intervention and control worksites, respectively, resulting in a difference in differences (DID) decrease of 0.42 kilograms per meter squared (P = .33). The within-group percentage of overweight or obese employees decreased by 3.7% (P = .07) at the intervention worksites and increased by 4.9% (P = .1) at the control worksites, resulting in a DID decline of 8.6% (P = .02).

CONCLUSIONS

Our findings support a worksite population strategy that might eventually reduce the prevalence of overweight and obesity by minimizing environmental exposures to calorically dense foods and increasing exposures to opportunities for energy expenditure within worksite settings.

Patterns of shoulder pain during a 14-year follow-up: results from a longitudinal population study in Norway

BACKGROUND

Population studies have reported that shoulder pain is the third most frequently reported musculoskeletal pain. Long duration, pain intensity and high level of disability predict persistent complaints. The present study aimed to describe the prevalence of shoulder pain in a general population and follow this over a long period (1990 to 2004). The objective was also to describe the stability of shoulder pain and patterns of co-occurrence with neck and upper back pain.

METHODS

Data were obtained from a self-reported questionnaire in a population in Ullensaker muncipality, north-east of Oslo. The Standard Nordic Questionnaire was sent in 1990, 1994 and 2004 to inhabitants belonging to six birth cohorts from 1918-20 to 1968-70.

RESULTS

The 1-year prevalence of shoulder pain was 46.7% (95% CI, 44.9% to 48.6%) in 1990, 48.7% (95% CI, 46.8% to 50.5%) in 1994, and 55.2% (95% CI, 53.5% to 56.9%) in 2004. Approximately three-quarters of the persons with shoulder pain at one given time also reported shoulder pain at the next follow-up.

CONCLUSIONS

Prevalence of shoulder pain during a 14-year period was high and slightly increasing. Shoulder pain was reported most frequently in co-occurrence with neck pain. Classification models should include neck pain as well as other co-occurring pain sites.

Weight-related self-efficacy in relation to maternal body weight from early pregnancy to 2 years post-partum

Excessive gestational weight gain may lead to long-term increases in maternal body weight and associated health risks. The purpose of this study was to examine the relationship between maternal body weight and weight-related self-efficacy from early pregnancy to 2 years post-partum. Women with live, singleton term infants from a population-based cohort study were included (n = 595). Healthy eating self-efficacy and weight control self-efficacy were assessed prenatally and at 1 year and 2 years post-partum. Body weight was measured at early pregnancy, before delivery, and 6 weeks, 1 year and 2 years post-partum. Behavioural (smoking, breastfeeding) and sociodemographic (age, education, marital status, income) covariates were assessed by medical record review and baseline questionnaires. Multi-level linear regression models were used to examine the longitudinal associations of self-efficacy measures with body weight. Approximately half of the sample (57%) returned to early pregnancy weight at some point by 2 years post-partum, and 9% became overweight or obese at 2 years post-partum. Body weight over time was inversely related to healthy eating (β = -0.57, P = 0.02) and weight control (β = -0.99, P < 0.001) self-efficacy in the model controlling for both self-efficacy measures as well as time and behavioural and sociodemographic covariates. Weight-related self-efficacy may be an important target for interventions to reduce excessive gestational weight gain and post-partum weight gain.

How weight change is modelled in population studies can affect research findings: empirical results from a large-scale cohort study

OBJECTIVES

To investigate how results of the association between education and weight change vary when weight change is defined and modelled in different ways.

DESIGN

Longitudinal cohort study.

PARTICIPANTS

60 404 men and women participating in the Social, Environmental and Economic Factors (SEEF) subcomponent of the 45 and Up Study-a population-based cohort study of people aged 45 years or older, residing in New South Wales, Australia.

OUTCOME MEASURES

The main exposure was self-reported education, categorised into four groups. The outcome was annual weight change, based on change in self-reported weight between the 45 and Up Study baseline questionnaire and SEEF questionnaire (completed an average of 3.3 years later). Weight change was modelled in four different ways: absolute change (kg) modelled as (1) a continuous variable and (2) a categorical variable (loss, maintenance and gain), and relative (%) change modelled as (3) a continuous variable and (4) a categorical variable. Different cut-points for defining weight-change categories were also tested.

RESULTS

When weight change was measured categorically, people with higher levels of education (compared with no school certificate) were less likely to lose or to gain weight. When weight change was measured as the average of a continuous measure, a null relationship between education and annual weight change was observed. No material differences in the education and weight-change relationship were found when comparing weight change defined as an absolute (kg) versus a relative (%) measure. Results of the logistic regression were sensitive to different cut-points for defining weight-change categories.

CONCLUSIONS

Using average weight change can obscure important directional relationship information and, where possible, categorical outcome measurements should be included in analyses.

Patterns of obesity development before the diagnosis of type 2 diabetes: the Whitehall II cohort study

BACKGROUND

Patients with type 2 diabetes vary greatly with respect to degree of obesity at time of diagnosis. To address the heterogeneity of type 2 diabetes, we characterised patterns of change in body mass index (BMI) and other cardiometabolic risk factors before type 2 diabetes diagnosis.

METHODS AND FINDINGS

We studied 6,705 participants from the Whitehall II study, an observational prospective cohort study of civil servants based in London. White men and women, initially free of diabetes, were followed with 5-yearly clinical examinations from 1991-2009 for a median of 14.1 years (interquartile range [IQR]: 8.7-16.2 years). Type 2 diabetes developed in 645 (1,209 person-examinations) and 6,060 remained free of diabetes during follow-up (14,060 person-examinations). Latent class trajectory analysis of incident diabetes cases was used to identify patterns of pre-disease BMI. Associated trajectories of cardiometabolic risk factors were studied using adjusted mixed-effects models. Three patterns of BMI changes were identified. Most participants belonged to the "stable overweight" group (n = 604, 94%) with a relatively constant BMI level within the overweight category throughout follow-up. They experienced slightly worsening of beta cell function and insulin sensitivity from 5 years prior to diagnosis. A small group of "progressive weight gainers" (n = 15) exhibited a pattern of consistent weight gain before diagnosis. Linear increases in blood pressure and an exponential increase in insulin resistance a few years before diagnosis accompanied the weight gain. The "persistently obese" (n = 26) were severely obese throughout the whole 18 years before diabetes diagnosis. They experienced an initial beta cell compensation followed by loss of beta cell function, whereas insulin sensitivity was relatively stable. Since the generalizability of these findings is limited, the results need confirmation in other study populations.

CONCLUSIONS

Three patterns of obesity changes prior to diabetes diagnosis were accompanied by distinct trajectories of insulin resistance and other cardiometabolic risk factors in a white, British population. While these results should be verified independently, the great majority of patients had modest weight gain prior to diagnosis. These results suggest that strategies focusing on small weight reductions for the entire population may be more beneficial than predominantly focusing on weight loss for high-risk individuals.

Appetite Response among Those Susceptible or Resistant to Obesity

An alternative approach in determining cause, treatment, and prevention of obesity is to study those who appear resistant to the obesogenic environment. We examined appetite responses in 33 obesity resistant individuals (ORI) versus 28 obesity susceptible individuals (OSI). Fingerprick blood samples to measure ghrelin, total peptide YY (PYY), leptin, glucose, and insulin along with appetite ratings were collected at baseline and 15, 30, 60, 120, and 180 min following consumption of a standardized meal. Fasting, area under the curve (AUC), peak/nadir, and time to peak/nadir were compared. Participants completed the three factor eating questionnaire (TFEQ). No significant differences were observed for ghrelin or PYY. Higher leptin concentrations in the OSI disappeared after controlling for percent body fat (%BF). Significant differences in appetite ratings included a lower hunger nadir among OSI compared with ORI (P = 0.017). Dietary restraint (P < 0.001) and disinhibition (P < 0.001) were lower in ORI compared with OSI, with and without adjustment for %BF. Given the differential body weight of the study groups, similar observed ghrelin concentrations were unexpected, perhaps indicating OSI and ORI respond differently to the same ghrelin concentration. Also ORI response to hunger appears different as they exhibit lower levels of dietary restraint and disinhibition compared with OSI.

Strategies to prevent weight gain in adults: a systematic review

CONTEXT

A Healthy People 2020 objective is to increase the prevalence of healthy-weight adults in the U.S. A systematic review of the effectiveness and safety of strategies to prevent weight gain in adults was performed.

EVIDENCE ACQUISITION

MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, and ClinicalTrials.gov were searched through June 2012. Two reviewers independently reviewed titles, abstracts, and articles. Trials and observational studies with at least 1 year of follow-up that reported on strategies to prevent weight gain or maintain weight were included. Data were abstracted on weight, adherence, safety, and quality-of-life outcomes. The quantity, quality, and consistency of the evidence were graded, with a focus on studies' risks of bias, consistency of results across studies, how directly the question of interest was addressed, and precision of results. A meaningful difference and a significant threshold (p<0.05) were used to identify effective strategies. Evidence was synthesized qualitatively.

EVIDENCE SYNTHESIS

Twenty-two studies (11 trials and 11 observational studies) involving 480,142 participants were included. The strength of evidence is low for all strategies, but effective approaches may include low-fat diets, eating fewer meals prepared away from home, eating more fruits and vegetables, monitoring heart rate during exercise, and participation in group lifestyle sessions with reminder text messages. Safety and quality of life were rarely reported.

CONCLUSIONS

Although the evidence is not strong, there may be effective strategies to prevent weight gain.

PACES: a Physical Activity Campus Environmental Supports Audit on university campuses

PURPOSE

This study evaluated the policy and built and recreation environmental supports for physical activity on 13 university campuses.

DESIGN

Environmental audit survey.

SETTING

Thirteen U.S. universities, 2009. Subjects. University policies, recreation programs and facilities, and at least five additional buildings per campus.

MEASURES

The Physical Activity Campus Environmental Supports Audit was developed for this study.

ANALYSIS

Analysis of variance with post hoc Tukey's B and χ(2) assessed differences by institution and building type.

RESULTS

The mean obesogenic policy score was significantly lower than the desired score, ≥7 (p = .002), with only one campus scoring 10. The mean built environment audit score (5.4 ± 1.7) was low, with significant differences between institutions (p < .001) and only three campuses scoring above the desired score, ≥7. Although generally stairwells were clean and well lighted, there was a lack of signage to encourage stair use (p < .001). Overall, recreation programs (7.1 ± .7) and facilities (7.1 ± 1.2) scored well, but amenities scores were lower for satellite (2.8 ± 1.6) versus main (4.1 ± 1.8) recreation facilities (p = .04).

CONCLUSION

On these 13 university campuses, recreation programs and facilities were supportive of healthful lifestyles for obesity prevention, but policies and the built environment were not. This physical activity environmental audit survey requires testing in a wider sample of postsecondary institutions to corroborate its utility and provide evidence to support initiatives to improve campus environments for physical activity.

Weight gain among men and women who have a child enter their home

Parenthood is associated with decreased physical activity and dietary changes. Previously, mothers have been the focus of studies examining the influence of children on parents' body mass index (BMI), largely ignoring whether parenting affects fathers. This study assessed weight gain in mothers and fathers (by birth or other), using longitudinal repeated-measures models to assess BMI changes over time; parents were compared with nonparents. Data were from the Coronary Artery Risk Development in Young Adults cohort study and included 2,881 black and white adults, ages 18 to 30 years, without children at baseline (1985-1986), and from four urban locations. At each time point (years 2, 5, and 7), changes in BMI from baseline were analyzed, comparing those who had their children in their household at that time point (parents) and those without children (nonparents). The "child effect" is the mean difference in BMI change in parents compared with nonparents. In fathers, overall, the child effect was not significant (black males: 0.30; P=0.09; white males: 0.03; P=0.77). Among black men, however, interactions between age and parental status were significant (P=0.02). Black men who were aged 18 to 24 years at baseline and became fathers during the next 7 years demonstrated a significant child effect, gaining an average of 0.68 more in BMI than nonfathers (P=0.003). Mothers of both races demonstrated the child effect; for blacks it was 0.65 (P=0.003) and for whites it was 1.12 (P≤0.001). These data reveal that becoming a parent can affect the BMI of some adults and suggest that obesity-prevention interventions for children and adult-focused healthy-lifestyle interventions could have additional impact through a family focus targeting both parent and child outcomes.

Health-care access and weight change among young adults: the Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE

Health-care access is associated with improved control of multiple chronic diseases, but the association between health-care access and weight change is unclear. The present study aims to test the association between health-care access and weight change.

DESIGN

The Coronary Artery Risk Development in Young Adults (CARDIA) Study is a multicentre population-based prospective study. Weight change was calculated at 3 and 13 years after CARDIA year 7 (1992-1993). Health-care access was defined as no barriers or one or more barriers to access (health insurance gap, no usual source of care, not seeking care due to expense). Intermediary variables evaluated included history of dieting and use of diet pills, meal replacements or weight-control programmes.

SETTING

Four cities in the USA.

SUBJECTS

Participants were aged 18-30 years at baseline (1985-1986). Analyses include 3922 black and white men and women with relevant data from CARDIA years 7, 10 and 20 (1992-1993, 1995-1996 and 2005-2006, respectively).

RESULTS

Mean weight change was +2.22 kg (+4.9 lb) by 3 years and +8.48 kg (+18.7 lb) by 13 years, with no differences by health-care access. Being on a weight-reducing diet was not consistently associated with health-care access across examinations. Use of diet pills, meal replacements or organized weight-control programmes was low, and did not vary by health-care access.

CONCLUSIONS

Weight gain was high irrespective of health-care access. Public health and clinical approaches are needed to address weight gain.

Prevalence of cardiovascular risk factors and socioeconomic level among public-sector workers in Angola

Background

Cardiovascular diseases are the leading cause of death in the majority of developed and developing countries. African countries are currently facing an increase in both cardiovascular and transmitted diseases. In addition, cardiovascular risk varies among different socioeconomic groups. Thus, we determined the prevalence of modifiable cardiovascular risk factors in apparently healthy public-sector workers and investigated possible relationships with socioeconomic status.

Methods

We employed a cross-sectional study comprising 42.2% (n = 615) of the public-sector workers at Agostinho Neto University, 48% (n = 294) male and 52% (n= 321) female, with ages between 20 and 72 years and from various socioeconomic groups. The study was conducted from February 2009 to December 2010. Personal, anthropometric, biochemical, hemodynamic, socioeconomic, and physical activity data were collected.

Results

The prevalence rates of cardiovascular risk factors were as follows: hypertension, 45.2% (men 46.3%, women 44.2%, P > 0.05); hypercholesterolemia, 11.1% (men 10.5%, women 11.5%, P > 0.05); low high-density lipoprotein (HDL) cholesterol, 50.1% (men 36.9%, women 62.3%; P < 0.05); hypertriglyceridemia, 10.6% (men 12.6%, women 8.7%, P > 0.05); smoking, 7.2% (men 10.2%, women 4.4%; P < 0.05); diabetes, 5.7% (men 5.5%, women 5.9%, P > 0.05); overweight, 29.3% (men 27.3%, women 31.2%, P > 0.05); obesity, 19.6% (men 9.2%, women 29.0%; P < 0.05); sedentary lifestyle, 87.2% (men 83.0%, women 91,0%, P < 0.05); and left ventricular hypertrophy, 20% (men 32.0%, women 9.0%; P < 0.05). At least one risk factor was present in 27.7% of the sample; 15.2% had two risk factors, and 31.4% had three or more risk factors. Among the individuals with low socioeconomic status, 41.0% had three or more risk factors.

Conclusions

The results of this study suggest the existence of a high prevalence of multiple risk factors for cardiovascular disease in apparently healthy public-sector workers in Angola. The workers in lower socioeconomic groups had higher incidences of hypertension, smoking, and left ventricular hypertrophy.

Antral follicle count predicts natural menopause in a population-based sample: the Coronary Artery Risk Development in Young Adults Women's Study

OBJECTIVE

The timing of menopause is associated with multiple chronic diseases. Tools that predict this milestone have relevance for clinical and research purposes. Among infertile women, a positive relationship exists between antral follicle count (AFC) and response to controlled ovarian hyperstimulation, a marker of ovarian reserve. However, an age-independent relationship between AFC and menopause has not been demonstrated. Thus, our objective was to evaluate the relationship between AFC measured in women aged 34 to 49 years and incident natural menopause during 7 years of follow-up.

METHODS

The Coronary Artery Risk Development in Young Adults Study is a longitudinal community-based study (Chicago, IL; Birmingham, AL; Minneapolis, MN; and Oakland, CA) begun in 1985-1986. In 2002-2003, the Coronary Artery Risk Development in Young Adults Women's Study measured follicle-stimulating hormone (FSH) levels and performed a transvaginal ultrasound protocol that included AFC (2-10 mm follicles on both ovaries). Incident natural menopause was assessed by surveys in 2005-2006 and 2009-2010.

RESULTS

In our sample (n = 456), the median (interquartile range) AFC and FSH level were 5 (2-9) and 7.8 (5.6-11.0) mIU/mL, respectively, at a mean (range) age of 42 (34-49) years in 2002-2003. One hundred one women reported natural menopause by 2009-2010. In Cox models, current smoking, stable menses, FSH level higher than 13 mIU/mL, and AFC of 4 or less were independently associated with incident natural menopause. Compared with AFC higher than 4, those with an AFC of 4 or less were nearly twice as likely to have undergone menopause during 7 years of follow-up (hazard ratio, 1.89; 95% CI, 1.19-3.02) after adjustment for covariates.

CONCLUSIONS

AFC has been found to be independently associated with natural menopause during 7 years of follow-up after controlling for other markers of ovarian aging.

Changes in weight and health behaviors after pregnancies complicated by gestational diabetes mellitus: the CARDIA study

OBJECTIVE

Prepregnancy to postpregnancy change in weight, body mass index (BMI), waist circumference, diet, and physical activity in women with and without gestational diabetes mellitus (GDM) were compared.

DESIGN AND METHODS

Using the Coronary Artery Risk Development in Young Adults study, women with at least one pregnancy during 20 years of follow-up (n = 1,488 with 3,125 pregnancies) was identified. Linear regression with generalized estimating equations to compare prepregnancy to postpregnancy changes in health behaviors and anthropometric measurements between 137 GDM pregnancies and 1,637 non-GDM pregnancies, adjusted for parity, age at delivery, outcome measure at the prepregnancy exam, race, education, mode of delivery, and interval between delivery and postpregnancy examination were used.

RESULTS

When compared with women without GDM in pregnancy, women with GDM had higher prepregnancy mean weight (158.3 vs. 149.6 lb, P = 0.011) and BMI (26.7 vs. 25.1 kg/m(2) , P = 0.002), but nonsignificantly lower total daily caloric intake and similar levels of physical activity. Both GDM and non-GDM groups had higher average postpartum weight of 7-8 lbs and decreased physical activity on average 1.4 years after pregnancy.

CONCLUSIONS

Both groups similarly increased total caloric intake but reduced fast food frequency. Prepregnancy to postpregnancy changes in body weight, BMI, waist circumference, physical activity, and diet did not differ between women with and without GDM in pregnancy. Following pregnancy, women with and without GDM increased caloric intake, BMI, and weight and decreased physical activity, but reduced their frequency of eating fast food. Given these trends, postpartum lifestyle interventions, particularly for women with GDM, are needed to reduce obesity and diabetes risk.

Women's higher health risks in the obesogenic environment: a gender nutrition approach to metabolic dimorphism with predictive, preventive, and personalised medicine

Women's evolution for nurturing and fat accumulation, which historically yielded health and longevity advantages against scarcity, may now be counteracted by increasing risks in the obesogenic environment, recently shown by narrowing gender health gap. Women's differential metabolism/disease risks, i.e. in fat accumulation/distribution, exemplified during puberty/adolescence, suggest gender dimorphism with obesity outcomes. Women's higher body fat percentage than men, even with equal body mass index, may be a better risk predictor. Differential metabolic responses to weight-reduction diets, with women's lower abdominal fat loss, better response to high-protein vs. high-carbohydrate diets, higher risks with sedentariness vs. exercise benefits, and tendency toward delayed manifestation of central obesity, metabolic syndrome, diabetes, cardiovascular disease, and certain cancers until menopause-but accelerated thereafter-suggest a need for differing metabolic and chronological perspectives for prevention/intervention. These perspectives, including women's differential responses to lifestyle changes, strongly support further research with a gender nutrition emphasis within predictive, preventive, and personalized medicine.

Impact of an Online Healthful Eating and Physical Activity Program for College Students

Purpose.

To identify impact of an online nutrition and physical activity program for college students.

Design.

Randomized, controlled trial using online questionnaires and on-site physical and fitness assessments with measurement intervals of 0 (baseline), 3 (postintervention), and 15 months (follow-up).

Setting.

Online intervention delivered to college students; a centralized Web site was used for recruitment, data collection, data management, and intervention delivery.

Subjects.

College students (18–24 years old, n = 1689), from eight universities (Michigan State University, South Dakota State University, Syracuse University, The Pennsylvania State University, Tuskegee University, University of Rhode Island, University of Maine, and University of Wisconsin).

Intervention.

A 10-lesson curriculum focusing on healthful eating and physical activity, stressing nondieting principles such as size acceptance and eating competence (software developer: Rainstorm, Inc, Orono, Maine).

Measures.

Measurements included anthropometrics, cardiorespiratory fitness, fruit/vegetable (FV) intake, eating competence, physical activity, and psychosocial stress.

Analysis.

Repeated measures analysis of variance for outcome variables.

Results.

Most subjects were white, undergraduate females (63%), with 25% either overweight or obese. Treatment group completion rate for the curriculum was 84%. Over 15 months, the treatment group had significantly higher FV intake (+.5 cups/d) and physical activity participation (+270 metabolic equivalent minutes per week) than controls. For both groups, anthropometric values and stress increased, and fitness levels decreased. Gender differences were present for most variables. First-year males and females gained more weight than participants in other school years.

Conclusion.

A 10-week online nutrition and physical activity intervention to encourage competence in making healthful food and eating decisions had a positive, lasting effect on FV intake and maintained baseline levels of physical activity in a population that otherwise experiences significant declines in these healthful behaviors.

Obesity and Cardiovascular Disease Risk Factors in Firefighters: A Prospective Cohort Study

OBJECTIVE

Obesity, despite being a significant determinant of fitness for duty, is reaching epidemic levels in the workplace. Firefighters' fitness is important to their health and to public safety.

RESEARCH METHODS AND PROCEDURES

We examined the distribution of BMI and its association with major cardiovascular disease (CVD) risk factors in Massachusetts firefighters who underwent baseline (1996) and annual medical examinations through a statewide medical surveillance program over 5 years of follow-up. We also evaluated firefighters' weight change over time.

RESULTS

The mean BMI among 332 firefighters increased from 29 at baseline to 30 at the follow-up examination (2001), and the prevalence of obesity increased from 35% to 40%, respectively (p < 0.0001). In addition, the proportion of firefighters with extreme obesity increased 4-fold at follow-up (from 0.6% to 2.4%, p < 0.0001). Obese firefighters were more likely to have hypertension (p = 0.03) and low high-density lipoprotein-cholesterol (p = 0.01) at follow-up. Firefighters with extreme obesity had an average of 2.1 CVD risk factors (excluding obesity) in contrast to 1.5 CVD risk factors for normal-weight firefighters (p = 0.02). Finally, on average, normal-weight firefighters gained 1.1 pounds, whereas firefighters with BMI > or = 35 gained 1.9 pounds per year of active duty over 5 years of follow-up.

DISCUSSION

Obesity is a major concern among firefighters and shows worsening trends over time. Periodic medical evaluations coupled with exercise and dietary guidelines are needed to address this problem, which threatens firefighters' health and may jeopardize public safety.

Parity and Body Weight in the United States: Differences by Race and Size of Place of Residence

OBJECTIVE

In women, parity has been studied in relation to body weights. This study examined whether and how relationships between parity and body weight differ by race and size of place of residence, adjusting for sociodemographic factors (age, income, education, working status, and marital status) and health behaviors (alcohol consumption, birth control pills, diet, physical activity, and smoking).

RESEARCH METHODS AND PROCEDURES

A U.S. national sample of 3398 white and black women from the Third National Health and Nutrition Examination Survey was used to study the relationships using multiple linear regression analysis.

RESULTS

The parity-weight relationships varied by race and size of place of residence. After adjusting for the covariates, significant relationships between parity and body weight were found only in black women in metropolitan areas and white women in non-metropolitan areas. Compared with women with no children, white women with two children living in non-metropolitan areas tended to have lower BMIs, whereas black women in metropolitan areas with one or two children showed higher BMIs.

DISCUSSION

Overall, the parity-weight relationships in these groups of women were not strong or linear. The parity-weight relationships of black women in non-metropolitan areas warrant further examination.

Effect of baseline self-efficacy on physical activity and psychological stress after a one-week pedometer intervention

Physical activity and psychological stress were hypothesized to improve more in participants with high self-efficacy than in those with low and medium self-efficacy after a one-week intervention. 39 female university students participated. The intervention had two steps: a lecture on self-monitoring and goal setting (160 min.) and a one-week pedometer intervention. Analyses were conducted on tertile groups according to self-efficacy at baseline. Pedometer step counts were higher in the high self-efficacy group than in the low self-efficacy group after intervention. Helplessness decreased time dependently after intervention only in the high-self-efficacy group. Because physical activity improved more in the high self-efficacy group after a one-week intervention, one hypothesis was supported.

Resistance training volume, energy balance and weight management: rationale and design of a 9 month trial

The increased prevalence of obesity and the lack of treatment success both argue for the design and evaluation of strategies to prevent the development of overweight and obesity. To date, the role of resistance training (RT) in this regard is largely unexplored. RT may be effective for weight management as a result of increased fat-free mass (FFM), which may result in increased resting metabolic rate and increased physical activity energy expenditure. However, the literature relative to the efficacy of RT protocols recommended for healthy adults to alter the aforementioned parameters is inconsistent or inadequately evaluated. We will conduct a 9 month randomized controlled efficacy trial to compare changes in body composition (fat mass, FFM, % body fat) and energy balance in response to 2 volumes of RT (1 vs. 3 sets vs. non-exercise control) both at the completion of training (9 months) and 1 year later (body composition). This investigation will be conducted in a sample of healthy, normal and overweight, sedentary, young adult men and women; a group at high risk for development of overweight and obesity. Our results will provide information relative to the minimum volume of RT that may be associated with body weight/fat gain which may inform the development of guidelines for RT to prevent weight gain or to alter body composition.

Obesity treatment for socioeconomically disadvantaged patients in primary care practice

BACKGROUND

Few evidence-based weight loss treatment options exist for medically vulnerable patients in the primary care setting.

METHODS

We conducted a 2-arm, 24-month randomized effectiveness trial in 3 Boston community health centers (from February 1, 2008, through May 2, 2011). Participants were 365 obese patients receiving hypertension treatment (71.2% black, 13.1% Hispanic, 68.5% female, and 32.9% with less than a high school educational level). We randomized participants to usual care or a behavioral intervention that promoted weight loss and hypertension self-management using eHealth components. The intervention included tailored behavior change goals, self-monitoring, and skills training, available via a website or interactive voice response; 18 telephone counseling calls; primary care provider endorsement; 12 optional group support sessions; and links with community resources.

RESULTS

At 24 months, weight change in the intervention group compared with that in the usual care group was -1.03 kg (95% CI, -2.03 to -0.03 kg). Twenty-four-month change in body mass index (calculated as weight in kilograms divided by height in meters squared) in the intervention group compared with that in the usual care group was -0.38 (95% CI, -0.75 to -0.004). Intervention participants had larger mean weight losses during the 24 months compared with that in the usual care group (area under the receiver operating characteristic curve, -1.07 kg; 95% CI, -1.94 to -0.22). Mean systolic blood pressure was not significantly lower in the intervention arm compared with the usual care arm.

CONCLUSION

The intervention produced modest weight losses, improved blood pressure control, and slowed systolic blood pressure increases in this high-risk, socioeconomically disadvantaged patient population. Trial Registration  clinicaltrials.gov Identifier: NCT00661817.

Physical activity and health during the menopausal transition

The benefits of regular physical activity are well established, but evidence for a protective effect against the adverse health consequences accompanying the menopausal transition is limited. This article reviews that evidence, concluding that more physical activity is generally associated with fewer somatic and mood symptoms. Physical activity seems to minimize weight gain and changes in body composition and fat distribution experienced at midlife and might attenuate the rapid bone density loss that occurs. Given these benefits, clinicians treating perimenopausal women should encourage their patients to follow guidelines for physical activity (≥150 minutes a week of moderate-intensity activity).

Obesity and cannabis use: results from 2 representative national surveys

The role of cannabis and endocannabinoids in appetite regulation has been extensively studied, but the association of cannabis use with weight in the general population is not known. The authors used data from 2 representative epidemiologic studies of US adults aged 18 years or older, the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; 2001-2002) and the National Comorbidity Survey-Replication (NCS-R; 2001-2003), to estimate the prevalence of obesity as a function of cannabis use. The adjusted prevalences of obesity in the NESARC and the NCS-R were 22.0% and 25.3%, respectively, among participants reporting no use of cannabis in the past 12 months and 14.3% and 17.2%, respectively, among participants reporting the use of cannabis at least 3 days per week. These differences were not accounted for by tobacco smoking status. Additionally, after adjustment for sex and age, the use of cannabis was associated with body mass index differences in both samples. The authors conclude that the prevalence of obesity is lower in cannabis users than in nonusers.

Weight gain since menopause and its associations with weight loss maintenance in obese postmenopausal women

Objective

To examine the association between weight gain since menopause and weight regain after a weight loss program.

Methods

Participants were 19 obese women who participated in a 15-week weight loss program and a 12-month follow-up. Main outcomes were: body composition, resting metabolic rate, energy intake, energy expenditure, and weight regain at follow-up.

Results

All body composition measures significantly decreased after intervention (all P ≤ 0.01) while all measures of fatness increased significantly after the 12-month follow-up (P ≤ 0.01). Body weight gain since menopause was associated with body weight regain (r = 0.65; P = 0.003) after follow-up even after adjustment for confounders.

Conclusion

Weight gain since menopause is associated with body weight regain following the weight loss program. Therefore, weight gain since menopause should be considered as a factor influencing weight loss maintenance in older women.

Changes in weight and body composition in women receiving chemotherapy for breast cancer

PURPOSE

This study aimed to identify predictors of changes in weight and body composition among women receiving chemotherapy for breast cancer.

PATIENTS AND METHODS

Data were from 49 women age 40-54 receiving chemotherapy for breast cancer. Weight, height, and body composition measurements from dual-energy x-ray absorptiometry (DEXA) scanning were completed at baseline (within 1 month of beginning chemotherapy) and 12 months. Caloric intake was assessed from food diaries at baseline, 6 and 12 months, and physical activity was measured by questionnaire at baseline, 3, 6, 9, and 12 months.

RESULTS

Baseline body mass index (BMI) was inversely associated with gains in weight (P = .01) and fat mass in torso (P = .006). Women of normal weight gained an average of 4.3 pounds and increased fat mass in torso and arms. Overweight women lost 3.0 pounds, and obese women lost 4.1 pounds, and neither group increased body fat. Decreased physical activity was associated with weight gain (P = .047). Additional predictors of increased fat mass in torso were younger age (P = .023) and treatment with tamoxifen (P = .015). Predictors of loss of bone mineral content included older age (P = .004) and treatment with aromatase inhibitor (P = .024), whereas treatment with bisphosphonate prevented bone loss (P < .0001).

CONCLUSION

Women receiving chemotherapy for breast cancer who are of normal weight at the time of breast cancer diagnosis are more likely to gain weight and body fat during the following year than overweight or obese women.