A Single, Multimodal Exercise Tolerance Test Can Assess Combat Readiness in Army-ROTC Cadets: A Brief Report

The Army Combat Fitness Test (ACFT) is a multi-event assessment battery designed to determine the combat readiness of U.S. Army personnel. However, for Reserve Officers' Training Corps (ROTC) programs the logistical demands of collegiate life make repeated administration of the ACFT challenging. The present study sought to design and evaluate a single, multimodal exercise tolerance test (METT) capable of serving as a time-efficient proxy measure of combat readiness.

METHODS

Using a formal instrument design process, we constructed the METT to mimic the demands of the ACFT and assessed its reliability, validity, and responsiveness.

RESULTS

The METT demonstrates minimal measurement error (i.e., a 2% coefficient of variation), concurrent validity with the ACFT (R2 = 0.327, F = 10.67, p < 0.001), the ability to classify cadets who may be at-risk for failing the ACFT (X2 = 8.16, p = 0.017, sensitivity = 0.878, specificity = 0.667), and appropriate change following a training intervention (5.69 ± 8.9%).

CONCLUSIONS

The METT has the potential to provide a means to monitor progress, identify areas for improvement, and guide informed decision-making regarding individualization of cadet combat training plans.

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.

Cardiovascular Health Trajectories From Childhood Through Middle Age and Their Association With Subclinical Atherosclerosis

Importance

Cross-sectional measures of cardiovascular health (CVH) have been associated with cardiovascular disease in older age, but little is known about longitudinal trajectories in CVH and their association with subclinical atherosclerosis in middle age.

Objectives

To model long-term patterns in CVH starting in childhood and to assess their association with subclinical atherosclerosis in middle age.

Design, Setting, and Participants

This cohort study used data from 5 prospective cardiovascular cohort studies from the United States and Finland from 1973 to 2015. A total of 9388 participants aged 8 to 55 years had at least 3 examinations and were eligible for this study. Statistical analysis was performed from December 1, 2015, to June 1, 2019.

Exposures

Clinical CVH factors (body mass index, total cholesterol level, blood pressure, and glucose level) were classified as ideal, intermediate, or poor, and were summed as a clinical CVH score. Group-based latent class modeling identified trajectories in this score over time.

Main Outcomes and Measures

Carotid intima-media thickness (cIMT) was measured for participants in 3 cohorts, and high cIMT was defined as a value at or above the 90th percentile. The association between CVH trajectory and cIMT was modeled using both linear and logistic regression adjusted for demographics, baseline health behaviors, and baseline (or proximal) CVH score.

Results

Among 9388 participants (5146 [55%] female; 6228 [66%] white; baseline mean [SD] age, 17.5 [7.5] years), 5 distinct trajectory groups were identified: high-late decline (1518 participants [16%]), high-moderate decline (2403 [26%]), high-early decline (3066 [32%]), intermediate-late decline (1475 [16%]), and intermediate-early decline (926 [10%]). The high-late decline group had significantly lower adjusted cIMT vs other trajectory groups (high-late decline: 0.64 mm [95% CI, 0.63-0.65 mm] vs intermediate-early decline: 0.72 mm [95% CI, 0.69-0.75 mm] when adjusted for demographics and baseline smoking, diet, and physical activity; P < .01). The intermediate-early declining group had higher odds of high cIMT (odds ratio, 2.4; 95% CI, 1.3-4.5) compared with the high-late decline group, even after adjustment for baseline or proximal CVH score.

Conclusions and Relevance

In this study, CVH declined from childhood into adulthood. Promoting and preserving ideal CVH from early life onward may be associated with reduced CVD risk later in life.

Relationship between Homocysteine and Muscle Strength Decline: The Baltimore Longitudinal Study of Aging

Background

Decreased muscle strength is strongly associated with future mobility limitations in older adults. Homocysteine is a risk factor for vascular disease and may exacerbate muscle strength decline. The present study aimed to examine the association between homocysteine levels and muscle strength in adults aged 50 years or older.

Methods

Data were from 1,101 participants of The Baltimore Longitudinal Study of Aging between December 2004 and March 2015. Muscle strength was measured using grip strength. Mixed effects linear regression was used to estimate the association between homocysteine and muscle strength in men and women, separately.

Results

Total mean follow-up time was 4.7 ± 3.1 years, range from 0 to 10.1 years. Baseline mean grip strength was 39.9 kg for men and 25.5 kg for women. Grip strength declined over the follow-up time for both men and women. Among women, there was a significant inverse relationship between homocysteine and grip strength, where grip strength declined as a function of increasing homocysteine over time (β = -0.05, p = .031). Among men, an increase of 1 μmol/L in homocysteine was associated with -0.10 kg decrease in grip strength, though not significantly.

Conclusions

In this study of healthy older adults aged 50 years or older, higher homocysteine was related to lower muscle strength in women. This is the first study to characterize the relationship over a long follow-up period. Future research should focus on assessing homocysteine as a marker of physical function decline and translating the relationship into clinical and public health practice.

Proportion of Orofacial Clefts Attributable to Recognized Risk Factors

OBJECTIVE

Estimate the population attributable fraction (PAF) for a set of recognized risk factors for orofacial clefts.

DESIGN

We used data from the National Birth Defects Prevention Study. For recognized risk factors for which data were available, we estimated crude population attributable fractions (cPAFs) to account for potential confounding, average-adjusted population attributable fractions (aaPAFs). We assessed 11 modifiable and 3 nonmodifiable parental/maternal risk factors. The aaPAF for individual risk factors and the total aaPAF for the set of risk factors were calculated using a method described by Eide and Geffler.

SETTING

Population-based case-control study in 10 US states.

PARTICIPANTS

Two thousand seven hundred seventy-nine cases with isolated cleft lip with or without cleft palate (CL±P), 1310 cases with isolated cleft palate (CP), and 11 692 controls with estimated dates of delivery between October 1, 1997, and December 31, 2011.

MAIN OUTCOME MEASURES

Crude population attributable fraction and aaPAF.

RESULTS

The proportion of CL±P and CP cases attributable to the full set of examined risk factors was 50% and 43%, respectively. The modifiable factor with the largest aaPAF was smoking during the month before pregnancy or the first month of pregnancy (4.0% for CL±P and 3.4% for CP). Among nonmodifiable factors, the factor with the largest aaPAF for CL±P was male sex (27%) and for CP it was female sex (16%).

CONCLUSIONS

Our results may inform research and prevention efforts. A large proportion of orofacial cleft risk is attributable to nonmodifiable factors; it is important to better understand the mechanisms involved for these factors.

Vitamin B12 and Homocysteine Associations with Gait Speed in Older Adults: The Baltimore Longitudinal Study of Aging

OBJECTIVES

This study aimed to assess the independent associations of serum levels of vitamin B12 and plasma concentrations of homocysteine with gait speed decline.

DESIGN, SETTING, PARTICIPANTS

This study utilized longitudinal analysis of participants 50 years or older from The Baltimore Longitudinal Study of Aging, N=774.

MEASUREMENTS

Gait speed (m/s) was assessed using the 6-meter usual pace test. Vitamin B12 and homocysteine concentrations were collected using standard clinical protocols. Linear mixed effects regression was stratified by baseline age category (50-69, 70-79, and ≥80 years old).

RESULTS

Mean follow-up time for the total study sample was 5.4 ± 2.0 years. No association between vitamin B12 and gait speed decline over the follow-up time for any age group was found. Elevated homocysteine concentrations were associated with decline in gait speed after adjustment for covariates (50-69: β= -0.005, p=.057; 70-79: β= -0.013, p<.001, ≥80: β= -0.007, p=.054).

CONCLUSION

Homocysteine and vitamin B12 are inversely related, yet only homocysteine was associated with gait speed decline in this population of healthy older adults. Given these results, future research should be directed towards investigating the relationship in populations with greater variation in vitamin B12 concentrations and other mechanisms influencing homocysteine concentrations.

Adenovirus 36 antibody detection: Improving the standard serum neutralization assay

Adenovirus 36 (AdV36) causes weight gain in animal models, including non-human primates. In humans, AdV36-neutralizing antibodies are associated with adiposity; however, longitudinal studies in large populations are needed to clarify AdV36's contribution. The current gold standard for detection of AdV36-specific antibody is the serum neutralization assay (SNA), which requires long incubation times and highly trained personnel. The standard SNA was modified using an immunocytochemical (ICC) approach, which allows for a more rapid and objective assessment of AdV36 antibodies. Using the ICC assay, virus-infected cells were detected as early as day 1 (D1) and by D5 were detected in 100% of microtiter wells versus 20.3% of wells detected by observing the cytopathic effect. Further, human sera tested with the ICC assay at D5 had a sensitivity and specificity of 80.0% and 95.7%, respectively, when compared to the standard SNA read at D11. Thus, the ICC assay decreased assay incubation time, provided a more objective and easily interpreted assessment, and had a high degree of sensitivity and specificity in determining serological status. The more rapid and objective ICC method will make large population studies feasible, improve comparability among laboratories, and contribute to understanding the role of AdV36 in obesity.

Weight loss advice and prospective weight change among overweight firefighters

BACKGROUND

Obesity compromises firefighter safety, yet more than 70% of firefighters are overweight. Though healthcare professionals are encouraged to counsel overweight patients, the effectiveness of weight counseling is not consistent across studies.

OBJECTIVE

Examine longitudinal changes in cardiovascular risk factors and determine the role of healthcare professional weight loss advice on six-month weight changes among a national sample of male, overweight and obese firefighters.

METHODS

This study included baseline and six-month assessments of 757 firefighters. Medical and demographic data were collected using questionnaires. Investigators collected height, weight, percent body fat, waist circumference, blood pressure, and fasting serum samples (total cholesterol, high-density lipoprotein, low-density lipoprotein, glucose). Multilevel linear regression assessed the association between weight advice and outcomes.

RESULTS

Participants lost an average of 0.55 kg (95%CI: 0.17-0.93), and experienced significant improvements in systolic blood pressure (mean: 3.75 mm Hg; 95% CI: 2.35-5.14) and non-significant improvements in other clinical outcomes. Healthcare professional weight advice was not significantly associated with weight loss or other outcomes.

CONCLUSION

Similar to other studies, results show little benefit of low intensity weight loss counseling. Additional research is needed to identify effective and feasible weight management strategies to address firefighter obesity.

Alcohol use and caloric intake from alcohol in a national cohort of U.S. career firefighters

OBJECTIVE

Both media reports and preliminary research suggest that problem drinking is a concern in the U.S. fire service. However, no national epidemiological research has been conducted. This study presents the first national data on alcohol consumption patterns among firefighters.

METHOD

Data are from 954 male firefighters at 20 career fire departments. The departments covered 14 U.S. states, commonwealths, and/or territories and each of the four major U.S. Census Bureau Regions. Alcohol use was assessed through both surveys and, in a subsample, 24-hour dietary recall interviews from an off-duty day.

RESULTS

More than 85% of participants consumed alcohol, nearly half reported excessive drinking, and approximately one third reported episodic heavy use when off duty. Firefighters (in comparison with officers or chiefs) and those with fewer years of service had particularly high levels of alcohol intake. Among firefighters who drank, the energy derived from alcohol averaged 539 kcals, or nearly 18% of total energy. Twenty five percent of firefighters consumed more than 770 kcals from alcohol in a single day.

CONCLUSIONS

Given the high prevalence of excessive and episodic heavy drinking and the impact of alcohol on energy intake in this population, national surveillance programs and targeted prevention interventions for problem drinking in the U.S. fire service are critically needed.

Weight Advice Associated With Male Firefighter Weight Perception and Behavior

INTRODUCTION

The high prevalence of overweight and obesity threatens the health and safety of the fire service. Healthcare professionals may play an important role in helping firefighters achieve a healthy weight by providing weight loss counseling to at-risk firefighters. This study characterizes the impact of healthcare professional weight loss advice on firefighter weight perceptions and weight loss behaviors among overweight and obese male firefighters.

METHODS

A national sample of 763 overweight and obese male firefighters who recalled visiting a healthcare provider in the past 12 months reported information regarding healthcare visits, weight perceptions, current weight loss behaviors, and other covariates in 2011-2012. Analyzed in 2013, four unique multilevel logistic regression models estimated the association between healthcare professional weight loss advice and the outcomes of firefighter-reported weight perceptions, intentions to lose weight, reduced caloric intake, and increased physical activity.

RESULTS

Healthcare professional weight loss advice was significantly associated with self-perception as overweight (OR=4.78, 95% CI=2.16, 10.57) and attempted weight loss (OR=2.06, 95% CI=1.25, 3.38), but not significantly associated with reduced caloric intake (OR=1.26, 95% CI=0.82, 1.95) and increased physical activity (OR=1.51, 95% CI=0.89, 2.61), after adjusting for confounders.

CONCLUSIONS

Healthcare professional weight loss advice appears to increase the accuracy of firefighter weight perceptions, promote weight loss attempts, and may encourage dieting and physical activity behaviors among overweight firefighters. Healthcare providers should acknowledge their ability to influence the health behaviors of overweight and obese patients and make efforts to increase the quality and frequency of weight loss recommendations for all firefighters.

High-intensity Fitness Training Among a National Sample of Male Career Firefighters

Obesity and fitness have been identified as key health concerns among USA firefighters yet little is known about the current habits related to exercise and diet. In particular, high-intensity training (HIT) has gained increasing popularity among this population but limited quantitative data are available about how often it is used and the relationship between HIT and other outcomes. Using survey methodology, the current study evaluated self-reported HIT and diet practice among 625 male firefighters. Almost one-third (32.3%) of participants reported engaging in HIT. Body composition, as measured by waist circumference and percentage body fat, was significantly related to HIT training, with HIT participants being approximately half as likely to be classified as obese using body fat [odds ratio (OR) = 0.52, 95% confidence interval (CI) = 0.34-0.78] or waist circumference (OR = 0.61, 95% CI = 0.37-0.98). Those who engaged in HIT were more than twice as likely as those who did not (OR = 2.24, 95% CI = 1.42-3.55) to meet fitness recommendations. Findings highlight directions for future prevention and intervention efforts.

Prevalence and correlates of cell phone use among Texas drivers

Introduction

Cell phone use while driving restricts peripheral awareness and impairs reaction time. This study assessed the 3-year prevalence of cell phone use (CPU) of drivers and characteristics associated with its use in six cities across Texas, 2011–2013.

Methods

CPU and driver characteristics were observed among motor vehicles (n = 1280) stopped at major intersections in medical and academic campuses. A multivariable logistic regression model described the association between driver characteristics and CPU.

Results

The overall prevalence of any CPU was 18.7%. Any type of CPU and talking tended to decline, while texting seemed to increase from 2011 to 2013. CPU was more likely among female drivers (OR = 1.63; 95% CI = 1.21, 2.20), drivers < 25 years of age (OR = 4.12; 95% CI = 2.29, 7.39), and drivers without passengers (OR = 4.40; 95% CI = 2.82, 6.88).

Conclusion

Despite its dangers, CPU remains popular among Texas drivers. CPU and texting bans should target public health campaigns towards female and younger drivers.

•

Cell phone use and drivers were observed in Texas medical and academic campuses.

•

The overall prevalence of any cell phone use tended to decline from 2011 to 2013.

•

Texting appeared to increase from 2011 to 2013.

•

Cell phone use was more likely among females, those < 25 years and drivers alone.

•

Cell phone use and texting bans should target females and younger drivers.

Longer duration of combination antiretroviral therapy reduces the risk of Hodgkin lymphoma: A cohort study of HIV-infected male veterans

BACKGROUND

Hodgkin lymphoma (HL) incidence has increased since combined antiretroviral therapy (cART) introduction. It is unclear how different cART classes (e.g., protease inhibitors (PI), non-nucleoside reverse transcription inhibitors (NNRTI)) influence HL. This study aimed to determine the effects of cART duration on HL incidence among HIV-infected veterans.

METHODS

We performed a retrospective cohort study utilizing the Veterans Affairs HIV Clinical Case Registry (1985-2010). HL cases were identified using ICD-9 codes (201.4-9). cART, PI, and NNRTI duration was the aggregate number of treatment days delivered. Incidence rates (IR) and rate ratios (IRR) were calculated from Poisson regression models to examine the effects of cART duration on HL.

RESULTS

31,576 cART users contributed 288,736 person-years (PY) and 211 HL cases (IR=7.3/10,000 person-years). HL incidence decreased from 25.1/10,000 PY (95%CI=18.9-33.4) within the first year of cART to 0.6/10,000 PY (95%CI=0.3-1.6) after ≥ 10 years. In multivariable models, each additional year of cART was associated with decreased HL incidence (IRR=0.80; 95%CI=0.75-0.86); similar effects were observed in models assessing HL incidence by PI and NNRTI.

CONCLUSION

Our findings indicate long-term cART of any class is associated with decreased HL risk. High HL incidence directly following cART initiation supports a potential immune reconstitution mechanism in HIV-related HL. Further research is needed to evaluate the interaction between early cART, immune reconstitution, and HL.

An examination of the benefits of health promotion programs for the national fire service

BACKGROUND

Firefighters suffer from high prevalence of obesity, substandard fitness, and cardiovascular-related deaths. There have been a limited number of firefighter health promotion programs that have been developed and empirically-tested for this important occupational group. We evaluated the health of firefighters from departments with well-developed health promotion programs and compared them with those from departments not having such programs using a large national sample of career fire departments that varied in size and mission. We measured a broad array of important individual firefighter health outcomes (e.g., body composition, physical activity, and general and behavioral health) consistent with national fire service goals and addressed significant statistical limitations unaccounted for in previous studies.

METHODS

Using the approach of purposive sampling of heterogeneous instances, we selected and conducted a national evaluation of 10 departments already implementing wellness and fitness programs (Wellness Approach; WA) with 10 departments that did not (Standard). Participants were 1,002 male firefighters (WA n = 522; Standard n = 480) who underwent assessments including body composition, fitness, and general/behavioral health (e.g., injury, depressive symptoms).

RESULTS

Firefighters in WA departments were healthier than their Standard department counterparts. For example, they were less likely to be obese (adjusted [A]OR = 0.58; 95% CI = 0.41-0.82), more likely to meet endurance capacity standards for firefighting (AOR = 5.19; 95% CI = 2.49-10.83) and have higher estimated VO2max (40.7 ± 0.6 vs. 37.5 ± 1.3 for firefighters in Standard departments; p = 0.001). In addition, WA firefighter were substantially less likely to smoke (AOR = 0.30; 95% CI = 0.17-0.54) or ever have been diagnosed with an anxiety disorder (AOR = 0.27; 95% CI = 0.14-0.52) and they expressed higher job satisfaction across several domains. However, WA firefighters were somewhat more likely to have reported an injury to Workers' Compensation (AOR = 1.74; 95% CI = 1.05-2.90). It was notable that both groups evidenced high prevalence of smokeless tobacco use and binge drinking.

CONCLUSIONS

Firefighters in departments selected based on having strong wellness programs (WA) were healthier along a number of dimensions important to firefighter wellness and operational readiness. However, several health areas require greater attention including problematic alcohol consumption and smokeless tobacco use, suggesting that more emphasis on these behavioral health issues is needed in the fire service.

Long-term physical activity outcomes of home-based lifestyle interventions among breast and prostate cancer survivors

PURPOSE

Few studies have investigated long-term effects of physical activity (PA) interventions. The goal of this study was to evaluate whether or not increased levels of moderate to vigorous physical activity (MVPA) were maintained by cancer survivors 1 year after receipt of two home-based interventions.

METHODS

The FRESH START trial randomized 543 breast and prostate cancer survivors to 1-of-2 mailed print diet and exercise interventions: sequentially-tailored vs. standardized (attention control). Each arm received eight mailings over a 1-year period, with follow-up at 1 and 2 years. This analysis focuses solely on the 400 participants who had suboptimal levels of MVPA at baseline (measured by the 7-Day Physical Activity Recall) and who completed the 2-year study.

RESULTS

Median minutes of MVPA at baseline, 1-year and 2-year follow-up in the tailored intervention arm were as follows: 0, 90, and 60 min/week, respectively. The corresponding values in the attention control group were 0, 30, and 30 min/week. Significant improvements in MVPA from baseline to 2-year follow-up were observed in both study arms (p < 0.01). While significant between-arm differences were observed at 1-year follow-up (p < 0.01), there was only the suggestion of a trend (p = 0.08) at 2-year follow-up.

CONCLUSIONS

This study provides evidence that mailed-print exercise interventions result in significant and sustainable improvements in MVPA among newly diagnosed cancer survivors that are observed well after the intervention is complete. While tailored interventions, as compared to standardized materials, appear to produce superior improvements in MVPA initially, these differences diminish over time.

Modifiable barriers to cervical cancer screening adherence among working women in Mexico

AIMS

To determine predictors of adherence to cervical cancer screening guidelines among women working in Monterrey, Mexico. Cases (n = 94) were sexually active female store clerks working in Monterrey, Mexico, aged 18-64, who were not adherent to Official Mexican Standard cervical cancer screening guidelines; controls (n = 135) were adherent to guidelines. The outcome of interest was adherence to cervical cancer screening services according to national screening guidelines.

METHODS

Multivariate logistic regression analyzed knowledge factors and perceptions associated with adherence.

RESULTS

Having no or inaccurate knowledge of screening guidelines (odds ratio [OR] 11.1, 95% confidence interval [95% CI] 4.3-28.5) and no knowledge of Pap examination utility (OR 6.8, 95% CI 1.0-46.4) were associated with screening guideline nonadherence. Perceptions of fear/embarrassment (OR 16.2, 95% CI 5.1-51.5) and lower levels of spousal/partner acceptance (OR 5.8, 95% CI 1.3-25.3) of the Pap examination were associated with screening guideline nonadherence. Results were adjusted for age at initiation of sexual activity, civil status, level of education, use of family planning/birth control, and income.

CONCLUSIONS

Identification of knowledge factors and perceptions that predict screening guideline adherence can inform population-specific recommendations to increase screening and reduce cervical cancer morbidity and mortality among employed Mexican women.

Exercise among breast and prostate cancer survivors--what are their barriers?

INTRODUCTION

Despite proven benefits of regular physical activity, estimates indicate that few cancer survivors meet physical activity guidelines. The purpose of this paper is to identify and compare exercise barriers among cancer survivors, both cross-sectionally and longitudinally as they undergo home-based behavioral interventions.

METHODS

Data on a sample of 452 breast and prostate cancer survivors who completed the FRESH START trial were analyzed collectively, as well as separately by cancer type.

RESULTS

More total barriers (3.5 vs. 2.4; p < 0.01) were reported among breast cancer survivors compared with prostate cancer survivors. Commonly reported baseline exercise barriers among both groups were "too busy" (breast, 52% and prostate, 45%) and "no willpower" (breast, 51% and prostate, 44%). At baseline, breast cancer survivors who reported "no willpower" also reported 18.7 fewer minutes of physical activity compared with those not reporting this barrier (p < 0.01). Among prostate cancer survivors, this difference was 39.5 min (p < 0.01). Change in barriers was not associated with change in minutes of physical activity from baseline to post-intervention in either cancer survivor group.

CONCLUSIONS

This is the largest study evaluating barriers and physical activity over time among cancer survivors. There are similarities and differences that both need to be taken into consideration when promoting physical activity among subgroups of survivors.

IMPLICATIONS FOR CANCER SURVIVORS

Knowledge concerning barriers associated with reported physical activity may be helpful in designing optimally targeted physical activity interventions among breast and prostate cancer survivors.

A review of body size and breast cancer risk in Hispanic and African American women

Obesity is an epidemic in the United States, especially among Hispanics and African Americans. Studies of obesity and breast cancer risk have been conducted primarily in non-Hispanic whites. There have been few studies of the association between body mass index (BMI) or weight gain and the risk of breast cancer in minorities, and the results have been inconsistent. Because most studies are conducted primarily in non-Hispanic whites, the etiology of breast cancer in minorities is not well understood. The authors of the current report reviewed the literature on the association between obesity, weight, and weight gain and breast cancer in minorities using a combination of the Medical Subject Heading (MeSH) terms "obesity," "body mass index," "weight," "weight gain," "Hispanic," and "African American." Only publications in English and with both risk estimates and 95% confidence intervals were considered. Forty-five studies of body size and breast cancer risk in non-Hispanic whites were identified. After an exhaustive search of the literature, only 3 studies of body size and breast cancer were conducted in Hispanic women were identified, and only 8 such studies in African American women were identified. The results were inconsistent in both race/ethnicity groups, with studies reporting positive, inverse, and null results. Thus, as obesity rates among Hispanics and African Americans continue to rise, there is an urgent need to identify the roles that both obesity and adult weight gain play in the development of breast cancer in these minorities. Additional studies are needed to provide more understanding of the etiology of this disease and to explain some of the disparities in incidence and mortality.

Abstract A77: Association between obesity over the lifetime, adult weight gain, and breast cancer risk in Mexican-American women

Background: Obesity is an epidemic in the United States, and nearly one-third of American adults over the age of 20 are considered obese. Studies of obesity and breast cancer risk have been conducted primarily in non-Hispanic whites. While obesity decreases the risk of premenopausal breast cancer, it is positively associated with risk of postmenopausal disease. Studies also suggest that a change in weight leading to adult obesity increases the risk of postmenopausal breast cancer. There have been few studies of body mass index (BMI) or weight gain and risk of breast cancer in minorities, and the results have been inconsistent. The effect of obesity on breast cancer risk in Hispanic women is of great public health significance. Hispanics are the fastest-growing minority in the United States, and obesity rates among Hispanic women are high and continuing to rise. Hispanics have a lower incidence but higher mortality rate of breast cancer than non-Hispanic whites. Elucidating the role of obesity in breast cancer development in Hispanic women will provide more understanding of the etiology of this disease and perhaps explain some of the disparities in incidence and mortality. We hypothesized that in a study of Mexican-American women obesity would decrease the risk of premenopausal breast cancer but increase the risk in postmenopausal women. Further, we hypothesized that weight gain would increase the risk of breast cancer.

Methods: Using two ongoing cohort studies of Mexican-American women, we identified 155 women with incident breast cancer and 333 age-matched, healthy controls. In-person interviews were conducted on all study subjects, and medical records were abstracted for the cases to verify all cancer-related data. Self-reported weights at ages 15, 30, and at diagnosis (or at baseline for age-matched controls) were collected, and weight gain from age 15 to diagnosis/baseline was calculated. Logistic regression was used to calculate odds ratios. Exploratory analyses of effect measure modification by both menopausal status and hormone replacement therapy (HRT) use were conducted.

Results: There were no significant associations between BMI at any of the time points and breast cancer in Mexican-American women, regardless of menopausal status. However, there was a 7% reduction in the risk of breast cancer for every 5 kg of weight gained from age 15 to diagnosis/baseline (OR=0.93, 95% CI: 0.87-1.00). These results did not vary by menopausal status, but there was a non-significant decrease in risk in never-HRT users (OR=0.89, 95% CI: 0.78-1.01) and no association in ever-HRT users.

Conclusions: Obesity at three time points across the lifetime was not associated with breast cancer risk in Mexican-American women, while adult weight gain reduced the risk independently of menopausal status. These results are contradictory of those in non-Hispanic white women and suggest that the etiology of breast cancer may differ by race/ethnicity. Our study sample was small, but we intend to validate the results with a larger sample size. Research supported by Grant KG0901010, Susan G. Komen Breast Cancer Foundation, “A Transdisciplinary Training Program for Public Health Researchers and Practitioners Wanting to Impact Breast Cancer Disparities.”

Citation Information: Cancer Prev Res 2010;3(12 Suppl):A77.

Profiling lipoxygenase metabolism in specific steps of colorectal tumorigenesis

Lipoxygenases (LOX) are key enzymes for the oxidative metabolism of polyunsaturated fatty acids into biologically active products. Clinical data on comparative levels of various LOX products in tumorigenesis are lacking. Therefore, we examined the profiles of several LOX products (5-LOX, 12-LOX, 15-LOX-1, and 15-LOX-2) by liquid chromatography/tandem mass spectrometry in the major steps of colorectal tumorigenesis (normal, polyp, and cancer) in a clinical study of 125 subjects (49 with normal colon, 36 with colorectal polyps, and 40 with colorectal cancer) who underwent prospective colorectal biopsies to control for various potential confounding factors (e.g., diet, medications). Mean 13-hydroxyoctadecadienoic acid (13-HODE) levels were significantly higher in normal colon [mean, 36.11 ng/mg protein; 95% confidence interval (95% CI), 31.56-40.67] than in paired colorectal cancer mucosa (mean, 27.01 ng/mg protein; 95% CI, 22.00-32.02; P = 0.0002), and in normal colon (mean, 37.15 ng/mg protein; 95% CI, 31.95-42.34) than in paired colorectal polyp mucosa (mean, 28.07 ng/mg protein; 95% CI, 23.66-32.48; P < 0.001). Mean 13-HODE levels, however, were similar between the left (mean, 37.15 ng/mg protein; 95% CI, 31.95-42.35) and the right normal colon (mean, 32.46 ng/mg protein; 95% CI, 27.95-36.98; P = 0.09). No significant differences with regard to 12- or 15-hydroxyeicosatetraenoic acid or leukotriene B(4) levels were detected between normal, polyp, and cancer mucosae. 15-LOX-1 inhibited interleukin-1beta expression. This study establishes that reduced 13-HODE levels are a specific alteration in the LOX product profile associated with human colorectal tumorigenesis.

Psychosocial factors influencing calcium intake and bone quality in middle school girls

Calcium intake has been associated with promoting bone health in children and adolescents, thus preventing osteoporosis later in life. Behavior change such as increased calcium intake, as well as physiological factors such as bone quality, may be facilitated by psychosocial and environmental factors. The purpose of this study was to identify pathways by which psychosocial factors influence calcium intake and bone quality in middle school girls. The study design was cross-sectional. Baseline data from the Incorporating More Physical Activity and Calcium in Teens (IMPACT) study, collected in 2001-2003, were used. IMPACT was a 1.5-year nutrition and physical activity intervention study, designed to improve bone density in 717 middle school girls in Texas. Main outcome measures were calcium intake determined using mean milligrams of calcium consumed per day and number of glasses of milk consumed per day, and bone quality determined using a calcaneal stiffness index. Confirmatory factor analysis and path analysis were performed to identify the direct and indirect pathways used by various psychosocial factors such as knowledge, self-efficacy, outcome expectations, and milk availability at home, to influence calcium intake and bone quality. Results showed that knowledge of osteoporosis and calcium-rich foods had an indirect effect on calcium intake, with outcome expectations as the mediating variable (beta=.035 and beta=.03, respectively; P<0.05). Calcium self-efficacy had a significant indirect effect on calcium intake, with outcome expectations as the mediator (beta=.085, P<0.05). None of the variables significantly influenced bone quality. Thus, several direct and indirect pathways used to influence calcium intake among adolescent girls were identified. These findings are critical for the development of effective interventions to promote calcium intake in this population.

Abstract 2897: Profiling lipoxygenase metabolism in specific steps of colorectal tumorigenesis

Lipoxygenases (LOXs) are key enzymes for the oxidative metabolism of polyunsaturated fatty acids into products that influence cell signaling, structure, and metabolism. Previous data on comparative levels of various LOX products in human tumorigenesis are limited primarily to retrospectively collected surgical samples from cancer patients. Therefore, we examined LOX product profiles by liquid chromatography/tandem mass spectrometry in the major steps of colorectal tumorigenesis (normal, polyp, and cancer) in a clinical study of 125 subjects (49 with a normal colon, 36 with colorectal polyps, and 40 with colorectal cancer) who underwent prospective colorectal biopsies to control for various potential confounding factors (e.g. diet, medications). Mean 13-hydroxyoctadecadienoic acid (13-HODE) levels were significantly higher in normal colons (mean = 36.11 ng/mg protein, 95% confidence interval [CI]: 31.56-40.67) than in paired colorectal cancer mucosa (mean = 27.01 ng/mg protein, 95% CI: 22.00-32.02; P = 0.0002) and in normal colons (mean = 37.15 ng/mg protein, 95% CI: 31.95-42.34) than in paired colorectal polyp mucosa (mean = 28.07 ng/mg protein, 95% CI: 23.66-32.48; P &lt; 0.001). Mean 13-HODE levels, however, were similar between the left (mean = 37.15 ng/mg protein, 95% CI: 31.95-42.35) and right normal colons (mean = 32.46 ng/mg protein, 95% CI: 27.95-36.98; P = 0.09). No significant differences with regard to 12-hydroxyeicosatetraenoic acid (12-HETE), 15-HETE, or leukotriene B4 (LTB4) levels were detected between normal, polyp and cancer mucosa. Downregulation of 15-LOX-1 expression, the rate limiting enzyme for 13-HODE production, in human colorectal neoplastic mucosa was confirmed by quantitative real time PCR in a subset colorectal cancer patients for whom samples with adequate RNA quality were available. This study establishes that reduced 13-HODE levels are a specific alteration in the LOX product profile associated with human colorectal tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2897.

Antioxidant genes, diabetes and dietary antioxidants in association with risk of pancreatic cancer

To test the hypothesis that polymorphic variants of antioxidant genes modify the risk of pancreatic cancer, we examined seven single-nucleotide polymorphisms (SNPs) of genes coding for superoxide dismutase (SOD) 2, glutathione S-transferase alpha 4 (GSTA4), catalase and glutathione peroxidase in 575 patients with pancreatic adenocarcinoma and 648 healthy controls in a case-control study. Information on risk factors was collected by personal interview and dietary information was collected by a self-administered food frequency questionnaire. Genotypes were determined using the Taqman method. Adjusted odds ratio (AOR) and 95% confidence interval (CI) were estimated by unconditional logistic regression. No significant main effect of genotype was observed. A borderline significant interaction between diabetes and SOD2 Ex2+24T>C CT/TT genotype was observed (P(interaction) = 0.051); the AORs (95% CI) were 0.98 (0.73-1.32) for non-diabetics carrying the CT/TT genotype, 1.73 (0.94-3.18) for diabetics carrying the CC genotype and 3.49 (2.22-5.49) for diabetics carrying the CT/TT genotype compared with non-diabetics carrying the CC genotype. Moreover, the SOD2 -1221G>A AA genotype carriers had a significantly increased risk for pancreatic cancer among those with a low dietary vitamin E intake but decreased risk among those with a high vitamin E intake (P(interaction) = 0.002). There was a non-significant interaction between diabetes and GSTA4 Ex5-64G>A genotypes (P(interaction) = 0.078). No significant interaction between genotype with cigarette smoking or vitamin C intake was observed. These data suggest that genetic variations in antioxidant defenses modify the risk of pancreatic cancer in diabetics or individuals with a low dietary vitamin E intake.

Initiating BMI prevalence studies in Vietnamese children: changes in a transitional economy

BACKGROUND

Rapid changes in dietary patterns and lifestyles in Vietnam warrant monitoring trends of weight, height and body mass index (BMI) among children.

OBJECTIVE

To determine the trends of weight, height and BMI classification of Vietnamese children, 6-15 years of age, from 1992 to 2000 with reference to socioeconomic, urban and rural differences.

METHODS

Data in the Vietnam Living Standard Survey (1992-1993) and the General Nutrition Survey (2000) were collected from representative samples of children. Body mass index classification was determined using the International Obesity Task Force criteria to calculate the prevalence and trends in each survey, and in a pooled survey analysis.

RESULTS

Statistically significant increases were seen in children's mean weight, height and BMI between the two surveys: 2.1 kg for weight, 4 cm for height, and 0.28 kg/m2 for BMI. Increases in height were greater in rural than urban areas, and BMI increases were smaller in rural than urban areas.

CONCLUSIONS

The rising prevalence of children at risk of overweight in urban Vietnam is a concern that must be monitored to guide policy changes. The unchanging prevalence of rural underweight boys requires attention. A national nutrition program to address under- and overweight for children throughout primary school is needed.

Antibiotics taken for other illnesses and spontaneous clearance of Helicobacter pylori infection in children

PURPOSE

Factors that determine persistence of untreated Helicobacter pylori (H. pylori) infection in childhood are not well understood. We estimated risk differences for the effect of incidental antibiotic exposure on the probability of a detected clearance at the next test after an initial detected H. pylori infection.

METHODS

The Pasitos Cohort Study (1998-2005) investigated predictors of H. pylori infection in children from El Paso, Texas, and Juarez, Mexico. Children were screened for infection at 6-month target intervals from 6 to 84 months of age, using the 13C-urea breath test corrected for body-size-dependent variation in CO2 production. Exposure was defined as courses of any systemic antibiotic (systemic) or those with anti-H. pylori action (HP-effective) reported for the interval between initial detected infection and next test. Binomial regression models included country of residence, mother's education, adequacy of prenatal care, age at infection, and interval between tests.

RESULTS

Of 205 children with a test result and antibiotic data following a detected infection, the number of children who took > or =1 course in the interval between tests was 74 for systemic and 33 for HP-effective. The proportion testing negative at the next test was 66% for 0 courses, 72% for > or =1 systemic course, and 79% for > or =1 HP-effective course. Adjusted risk differences (95%CI) for apparent clearance, comparing > or =1 to 0 courses were 10% (1-20%) for systemic and 11% (0-21%) for HP-effective.

CONCLUSIONS

Incidental antibiotic exposure appears to influence the duration of childhood H. pylori infection but seems to explain only a small portion of spontaneous clearance.

A path analysis to identify the psychosocial factors influencing physical activity and bone health in middle-school girls

BACKGROUND

The purpose of this study was to identify pathways used by psychosocial factors to influence physical activity and bone health in middle-school girls.

METHODS

Baseline data from the Incorporating More Physical Activity and Calcium in Teens (IMPACT) study collected in 2001 to 2003 were used. IMPACT was a 1 1/2 years nutrition and physical activity intervention study designed to improve bone density in 717 middle-school girls in Texas. Structural Equations Modeling was used to examine the interrelationships and identify the direct and indirect pathways used by various psychosocial and environmental factors to influence physical activity and bone health.

RESULTS

Results show that physical activity self-efficacy and social support (friend, family engagement, and encouragement in physical activity) had a significant direct and indirect influence on physical activity with participation in sports teams as the mediator. Participation in sports teams had a direct effect on both physical activity (beta = 0.20, P < .05) and bone health and (beta = 0.13, P < .05).

CONCLUSION

The current study identified several direct and indirect pathways that psychosocial factors use to influence physical activity and bone health among adolescent girls. These findings are critical for the development of effective interventions for promoting bone health in this population.

Nutrient intake, physical activity, and CVD risk factors in children: Project HeartBeat!

BACKGROUND

Associations among dietary intake, physical activity, and cardiovascular disease (CVD) risk factors are inconsistent among male and female youth, possibly from lack of adjustment for pubertal status. The purpose of this report is to describe the associations of CVD risk factors among youth, adjusted for sexual maturation.

METHODS

Data analyzed in 2007 from a sumsample of 556 children aged 8, 11, and 14 years in Project HeartBeat!, 1991-1993, provide cross-sectional patterns of CVD risk factors by age and gender, adjusting for sexual maturation, within dietary fat and physical activity categories.

RESULTS

Girls consuming moderate- to high-fat diets were significantly less physically active than those consuming low-fat diets. Boys and girls consuming high-fat diets had higher saturated fat and cholesterol intakes than children in low-fat categories. Boys had no significant differences in physical activity, blood pressure, waist circumference, or plasma cholesterol levels across fat categories. Girls' plasma cholesterol levels showed no significant differences across fat categories. Dietary intake did not differ across moderate-to-vigorous physical activity (MVPA) categories within gender. There were no differences in BMI by fat or MVPA categories for either gender. Girls' waist circumference differed significantly by fat category, and systolic blood pressure differed significantly across fat and MVPA categories. Boys' fifth-phase diastolic blood pressure was significantly different across MVPA categories.

CONCLUSIONS

Girls consuming atherogenic diets were significantly less physically active than those with low fat intakes, whereas boys consuming high-fat diets did not show differences in physical activity measures. With the prevalence of overweight rising among youth, the impact of atherogenic diets and sedentary lifestyles on CVD risk factors is of concern to public health professionals.

Project HeartBeat! Concept, development, and design

Major cardiovascular disease (CVD) risk factors begin development in childhood and adolescence. Project HeartBeat! studied early development of these risk factors as growth processes. Growth, body composition, sexual maturation, major CVD risk factors, and cardiac structure and function were monitored every 4 months for up to 4 years among 678 children and adolescents (49.1% girls; 20.1% blacks) aged 8, 11, or 14 years at study entry. All resided in The Woodlands or Conroe TX. Interviews were conducted at entry and annually on diet, physical activity, and health history of participants and their families. Data were collected from 1991 to 1995, and study investigators continue data analysis and reporting. Overlap in ages at examination among three cohorts (aged 8-12, 11-15, and 14-18 years at baseline) and use of multilevel modeling methods permit analysis of some 5500 observations on each principal variable for the synthetic cohort from ages 8 to 18 years. The mixed-longitudinal design provides trajectories of change with age, for total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides; systolic, and fourth-phase and fifth-phase diastolic blood pressure, and left ventricular mass. These trajectories are then related to concurrent measures of multiple indices of body composition and sexual maturation and adjusted for energy intake and physical activity. The data provide valuable insights into risk factor development and suggest a fresh approach to understanding influences on blood lipids, blood pressure, and left ventricular mass during the period of childhood and adolescence, a period of dynamic change in these risk factors.

Sexual maturation affects diet-blood total cholesterol association in children: Project HeartBeat!

BACKGROUND

Cardiovascular disease (CVD) does not become clinically manifest until adulthood. However, children and young adults have evidence of atheromatous lesions and fatty streaks in their aortas and coronary vessels. Most longitudinal studies in children are not designed to evaluate the dynamics of change in CVD risk factors. There is a need to describe the trajectory of CVD risk factors as growth processes, to better understand their relationships. This study assesses the associations between dietary variables and blood total cholesterol concentration (BTCC) among children and adolescents aged 8-18 years after adjustment for sexual maturation.

METHODS

There were 678 boys and girls aged 8, 11, and 14 years at baseline who were followed for up to 4 years, allowing the creation of a synthetic cohort analytically, from ages 8-18 years. Multilevel modeling was used to longitudinally assess BTCC, dietary intake, Tanner stage, and BMI.

RESULTS

For every 1-mg/day increase in dietary cholesterol, BTCC increased by 0.012 mg/dL. However, no associations were evident between BTCC and dietary total fat, saturated fatty acids, polyunsaturated fatty acids, or monounsaturated fatty acids. In girls, none of the dietary variables was significantly associated with BTCC after controlling for Tanner stage for breast. In boys, with the exception of dietary cholesterol, no other dietary variable was significantly associated with BTCC after controlling for Tanner stage for genitalia.

CONCLUSIONS

Sexual maturation exerts a strong influence on BTCC in children and adolescents aged 8-18 years, obscuring most associations between diet and BTCC. The inclusion of sexual maturity stage is important in studies of blood lipids among children and adolescents.

Trajectories of fat mass index, fat free-mass index, and waist circumference in children: Project HeartBeat!

BACKGROUND

Body composition and fat distribution change dramatically during adolescence. Data based on longitudinal studies to describe these changes are limited. The aim of this study was to describe age-related changes in fat free-mass index (FFMI) and fat mass index (FMI), which are components of BMI, and waist circumference (WC) in participants of Project HeartBeat!, a longitudinal study of children.

METHODS

Anthropometric measurements and body composition data were obtained in a mixed longitudinal study of 678 children (49.1% female, 20.1% black), initially aged 8, 11, and 14 years, every 4 months for 4 years (1991-1995). Trajectories of change from ages 8 to 18 years were measured for FFMI, FMI, and WC. Because of the small number of observations for black participants, trajectories for this group were limited to ages 8.5-15 years.

RESULTS

Body mass index, FFMI, and WC increased steadily with age for all race-gender cohorts. However, in nonblack girls, FFMI remained constant after about age 16 years. For black boys and girls, FFMI was similar at age 8.5 years but increased more steeply for black boys by age 15 years. In girls, FMI showed an upward trend until shortly after age 14 years, when it remained constant. In boys, FMI increased between age 8 years and age 10 years, and then decreased.

CONCLUSIONS

The extent to which each component of BMI contributes to the changes in BMI depends on the gender, race, and age of the individual. Healthcare providers need to be aware that children who show upward deviation of BMI or BMI percentiles may have increases in their lean body mass rather than in adiposity.

Body mass index and risk, age of onset, and survival in patients with pancreatic cancer

CONTEXT

Obesity has been implicated as a risk factor for pancreatic cancer.

OBJECTIVE

To demonstrate the association of excess body weight across an age cohort and the risk, age of onset, and overall survival of patients with pancreatic cancer.

DESIGN, SETTING, AND PARTICIPANTS

A case-control study of 841 patients with pancreatic adenocarcinoma and 754 healthy individuals frequency matched by age, race, and sex. The study was conducted at a university cancer center in the United States from 2004 to 2008. Height and body weight histories were collected by personal interview starting at ages 14 to 19 years and over 10-year intervals progressing to the year prior to recruitment in the study.

MAIN OUTCOME MEASURES

The associations between patients' body mass index (BMI) and risk of pancreatic cancer, age at onset, and overall survival were examined by unconditional logistic regression, linear regression, and Cox proportional hazard regression models, respectively.

RESULTS

Individuals who were overweight (a BMI of 25-29.9) from the ages of 14 to 39 years (highest odds ratio [OR], 1.67; 95% confidence interval [CI], 1.20-2.34) or obese (a BMI > or = 30) from the ages of 20 to 49 years (highest OR, 2.58; 95% CI, 1.70-3.90) had an associated increased risk of pancreatic cancer, independent of diabetes status. The association was stronger in men (adjusted OR, 1.80; 95% CI, 1.45-2.23) by mean BMI from the ages of 14 to 59 years than in women (adjusted OR, 1.32; 95% CI, 1.02-1.70) and in ever smokers (adjusted OR, 1.75; 95% CI, 1.37-2.22) than in never smokers (adjusted OR, 1.46; 95% CI, 1.16-1.84). The population-attributable risk percentage of pancreatic cancer based on the mean BMI from the ages of 14 to 59 years was 10.3% for never smokers and 21.3% for ever smokers. Individuals who were overweight or obese from the ages of 20 to 49 years had an earlier onset of pancreatic cancer by 2 to 6 years (median age of onset was 64 years for patients with normal weight, 61 years for overweight patients [P = .02], and 59 years for obese patients [P < .001]). Compared with those with normal body weight and after adjusting for all clinical factors, individuals who were overweight or obese from the ages of 30 to 79 years or in the year prior to recruitment had reduced overall survival of pancreatic cancer regardless of disease stage and tumor resection status (overweight patients: hazard ratio, 1.26 [95% CI, 0.94-1.69], P = .04; obese patients: hazard ratio, 1.86 [95% CI, 1.35-2.56], P < .001).

CONCLUSIONS

Overweight or obesity during early adulthood was associated with a greater risk of pancreatic cancer and a younger age of disease onset. Obesity at an older age was associated with a lower overall survival in patients with pancreatic cancer.

Psychosocial, environmental and behavioral factors associated with bone health in middle-school girls

The purpose of this study was to identify the psychosocial, environmental and behavioral factors associated with calcium intake, physical activity and bone health in a cohort of adolescent girls. Baseline data (N = 718 girls, mean age: 11.6 +/-0.4 years) from the Incorporating More Physical Activity and Calcium in Teens (IMPACT) study conducted in Texas, 2001-03, were utilized for the analyses. Hierarchical linear regression was used to examine the associations of interest. Confounders adjusted for included ethnicity, menarchal status, body mass index and lactose intolerance. Several psychosocial and behavioral factors were significantly associated with bone quality. These included knowledge of calcium content of foods (beta = 0.08, P = 0.016), self-efficacy toward consuming calcium-rich foods (beta = 0.16, P = 0.047), physical activity self-efficacy (beta = 0.20, P = 0.002), physical activity outcome expectations (beta = 0.5, P = 0.004), family encouragement to do physical activity (beta = 0.96, P = 0.027), friend engagement in physical activity (beta = 1.3, P = 0.001) and participation in sports teams (beta = 1.7, P < 0.001). Self-efficacy, social support and participation in sports teams appear to be strongly associated with bone health in adolescent girls. Future health education/health promotion programs need to address these factors for effective primary prevention of osteoporosis in this population.

Nutrition knowledge predicts eating behavior of all food groups except fruits and vegetables among adults in the Paso del Norte region: Qué Sabrosa Vida

OBJECTIVE

To examine the association between nutrition knowledge and eating behavior in a predominantly Mexican American population on the Texas-Mexico border.

DESIGN

Cross-sectional using data from the baseline survey of the Qué Sabrosa Vida community nutrition initiative.

SETTING

El Paso and surrounding counties in Texas.

PARTICIPANTS

Data gathered in 2000 using random-digit dialing telephone survey. Response rate was 42.6% and final sample size was 963.

MAIN OUTCOME MEASURES

Knowledge of recommended servings of food items was the independent variable and number of servings of food items consumed was the dependent variable.

DATA ANALYSIS

Multiple logistic regression was used to examine the association between nutrition knowledge and eating behavior.

RESULTS

74% of the population was Mexican American. Nutrition knowledge was a significant predictor of eating behavior for grains (odds ratio [OR] = 6.42; 95% confidence interval [CI]: 2.4, 17.1), dairy (OR = 2.25; 95% CI: 1.5, 3.4), meats (OR = 2.02; 95% CI: 1.5, 2.8), beans (OR = 8.18; 95% CI: 5.1, 13.0), water (OR = 2.49; 95% CI: 1.7, 3.6), but not for fruits and (nonstarchy) vegetables (OR = 1.69; 95% CI: 0.89, 3.2).

CONCLUSIONS AND IMPLICATIONS

Nutrition knowledge predicts eating behavior for all food groups except fruits and vegetables. The role of cultural factors in eating behavior should be investigated to elucidate this finding. Results have implications for developing nutrition education programs for Mexican Americans.

Personality as a predictor of dietary quality in spouses during midlife

The authors evaluated the NEO Personality Inventory-Revised (NEO-PI-R) as a predictor of dietary quality in 850 married couples, focusing on associations among each participant's personality as a predictor of their own dietary quality and their spouses' dietary quality. Diet was based on a modified version of the US Department of Agriculture Healthy Eating Index. Openness was associated with self-ratings of dietary quality for wives (r = .28) and husbands (r = .27). Wives' levels of the characteristic openness were also related to their spouses' ratings of dietary quality (r = .22). The primary facets of openness accounting for the domain-level findings were O2-aesthetics and O4-actions. The remaining personality domains (neuroticism, extraversion, agreeableness, and conscientiousness) were not associated with self or spousal ratings of dietary quality (rs = .08-.09). Openness was associated with healthy eating habits--findings that may affect disease prevention during, midlife.

Menarchal status and calf circumference predict calcaneal ultrasound measurements in girls

PURPOSE

The purpose of this study was to predict calcaneal QUS measurements in healthy adolescent females as a function of anthropometric measures, pubertal stage and menarchal status.

METHODS

This was a secondary data analysis from a 2-year intervention designed to increase bone accretion. Simple Pearson correlation and Spearman's rank correlation analyses, followed by linear stepwise regression analyses were conducted.

SETTING

12 middle schools.

PARTICIPANTS

672 female students, baseline; 587 students at 18 months.

MAIN OUTCOME MEASURE

Calcaneal stiffness index (SI) by quantitative ultrasound.

RESULTS

Eighty percent of the subjects were premenarchal at baseline; 33% at 18 months. Although SI correlated with self-assessed pubic hair (rho = .21) and menarchal status (rho = .23, p < .01 for both) at baseline, the model for predicting SI included menarchal status, not pubic hair, and calf circumference, controlling for BMI (R(2) = .22, p < .01). At 18 months, SI correlated with self-assessed pubic hair (rho = .21) and menarchal status (rho = .25, p < .01 for both). The best model to predict SI included calf circumference and pubic hair stage (R(2) = .14, p < .01), and not menarchal status as 67% of the subjects at 18 months were postmenarchal.

CONCLUSIONS

In research assessing calcaneal SI in groups of adolescents, assessment of pubertal stage could be replaced with menarchal status and calf circumference when the majority of subjects are premenarchal. When the majority is postmenarchal, pubic hair stage and calf circumference together may be used to assess for pubertal maturation without menstrual status.

Dynamics of Helicobacter pylori infection in a US-Mexico cohort during the first two years of life

BACKGROUND

The Pasitos Cohort Study has followed children in El Paso, Texas and Ciudad Juarez, Mexico since 1998 to identify determinants of Helicobacter pylori infection. This paper describes patterns of acquisition and elimination of H. pylori infection in 468 children from birth to 24 months.

METHODS

Mothers were recruited during pregnancy at maternal-child clinics; children were targeted for follow-up examinations every 6 months after birth. H. pylori infection was detected using the 13C-urea breath test, corrected for age-dependent variation in CO2 production.

RESULTS

Test results were available for 359, 341, 269, and 215 children around target ages of 6, 12, 18, and 24 months, respectively. The person-time at risk of a first detectable infection was 7742 person-months; 128 first infections were detected, thus the incidence rate was 1.7% per month (95% confidence interval 1.4-2.0%). Rates were similar in boys and girls and on both sides of the border; evidence suggests, however, that this similarity could be due to selection bias. Among children with follow-up after a positive test, 77% tested negative at a later visit.

CONCLUSIONS

The initial acquisition of detectable H. pylori infection occurred at a rate of 20% per year among Pasitos Cohort children from birth to 24 months of age. A key finding, with implications for clinical, community health, and research settings, is that most of these infections did not persist. The transient nature of early H. pylori infection should be considered when designing research or contemplating therapeutic intervention for this age group.

Heritage retention and bean intake correlates to dietary fiber intakes in Hispanic mothers--Qué Sabrosa Vida

OBJECTIVE

To determine the correlation between fruit/vegetable and bean stage of change and heritage retention with fiber intake in Hispanic mothers.

DESIGN

Cross-sectional study design used baseline survey data from the Qué Sabrosa Vida nutrition intervention developed by the University of Texas School of Public Health, Human Nutrition Center (Houston, TX). Participants were recruited and data gathered from telephone surveys using random digit dial methodology ensuring proportional representation of demographic subgroups.

SUBJECTS

Hispanic mothers (N=293) responded to the baseline survey in El Paso, TX.

ANALYSES

Using SPSS version 11.0 (SPSS Inc, Chicago, IL), descriptive statistics, chi2 , correlations, and analyses of variance were used to determine the relationship of variables to fiber intake. Potential confounding variables included were grain stage of change, age, education level, and marital status.

RESULTS

Mean fiber intake for mothers was 21.9 g/day and mean age was 35.8 years. Chi2 of fruit/vegetable stage was P =.784. Chi 2 of bean stage, heritage retention score, age, and education to fiber intake were significant, P =.008, P =.004, P =.005, and P =.001, respectively. Bean stage, heritage retention score, age, and education level were significantly correlated. One-way analysis of variance of bean stage, heritage retention score, age, and education level by fiber intake were significant, P =.006, P =.001, P =.004, and P =.002, respectively.

CONCLUSIONS

Older Hispanic mothers in the action/maintenance bean stage with strong heritage retention score had greater fiber intakes than younger mothers in pre-action bean stage with weak heritage retention score. As education level increased fiber intake decreased. Encouragement of bean consumption and heritage retention may increase fiber intake in this Hispanic mother population.

The analysis of relapse-free survival curves: implications for evaluating intensive systemic adjuvant treatment regimens for breast cancer

Results of adjuvant dose intensification studies in patients with localised breast cancer have raised questions regarding the clinical usefulness of this treatment strategy. Here, we develop and fit a natural history model for the time to clinical tumour recurrence as a function of the number of involved lymph nodes, and derive plausible predictions of the effects of dose intensification under various conditions. The time to tumour recurrence is assumed to depend on the residual postoperative micrometastatic burden of tumour, the fractional reduction of residual tumour burden (RTB) by treatment, and the rate of regrowth of the RTB to a clinically detectable size. It is assumed that a proportion of micrometastatic tumours are unresponsive to adjuvant chemotherapy even at maximal dose intensity. Data fitted included the San Antonio Cancer Institute (SACI) database of untreated patients, and CALGB #9082, a study comparing a highly intensive and moderately intensity adjuvant regimen in patients with 10+ positive axillary nodes. The proportion of tumours unresponsive to maximally intensive adjuvant treatment is estimated to be 48% (29-67%). The estimated log kill for intermediate-dose therapy from CALGB #9082 was 6.5 logs, compared with 9 logs or greater for high-dose therapy. The model is consistent with a modest but nonnegligible advantage of dose intensification compared with standard therapies in patients with sensitive tumours who have 10+ positive axillary nodes, and suggests that much of this clinical benefit could be achieved using intermediate levels of treatment intensification. The model further suggests that, in patients with fewer than 10 involved axillary nodes, any advantage of treatment intensification over standard therapy would be much reduced, because in patients with smaller tumour burdens of sensitive tumour, a larger proportion of cures achievable with intensified therapy could be achieved as well with standard therapy.

Dietary carotenoids and genetic instability modify bladder cancer risk

In vitro and in vivo studies have shown that carotenoid supplementation is associated with decreased DNA damage, but the role of dietary carotenoids in cancer risk remains controversial because epidemiologic studies have yielded conflicting results. Limited data exist regarding the role of dietary carotenoids in the context of constitutional genetic instability in cancer risk. This case-control study estimated dietary carotenoid intake [microg/(kJ . d)] from a FFQ for 423 patients with bladder cancer and 467 healthy controls, and quantified baseline and benzo[a]pyrene diol epoxide (BPDE)- and gamma-radiation-induced DNA damage in the peripheral blood lymphocytes using the comet assay. Overall, intake of total carotenoids was lower (P < 0.01) for bladder cancer cases (mean +/- SD: 1273.4 +/- 688.9) compared with healthy controls (1501.3 +/- 791.5). When categorized into quartiles, there was an inverse association between increasing levels of carotenoid intake and bladder cancer risk with greatest protective effect [odds ratio (OR) = 0.56, 95% CI, 0.37-0.85] in the quartile with the highest level of intake. Baseline and mutagen-induced DNA damage was significantly higher in cases than in controls; when analyzed jointly with carotenoid intake, high DNA damage and low carotenoid intake were associated with the highest risk. For example, with high baseline DNA damage and low total carotenoid intake, the OR was 3.08 (95% CI, 1.64-5.77); with high baseline DNA damage and high total carotenoid intake, the risk was somewhat attenuated (OR = 2.49, 95% CI, 1.28-4.84). The risk was decreased further for low baseline DNA damage and low total carotenoid intake (OR = 2.18; 95% CI, 1.13-4.22). This study provides evidence of a preventive role for carotenoids in bladder cancer, and these data may have important implications for cancer prevention, especially for individuals susceptible to DNA damage.

Measuring the prevalence of overweight in Texas schoolchildren

OBJECTIVES

We describe results from year 1 of a surveillance system to monitor body mass index in children at the state level.

METHODS

A sample of 6630 children attending Texas public schools, weighted to represent 4th, 8th, and 11th grades within race/ethnic subpopulations, was assessed. Body mass index was calculated from measured height and weight; demographic information was obtained from a questionnaire.

RESULTS

Prevalence of overweight was 22.4%, 19.2%, and 15.5% for 4th-, 8th-, and 11th-grade students, respectively. Overweight prevalence was highest among Hispanic boys (29.5%-32.6%), fourth-grade Hispanic girls (26.7%), and fourth- and eighth-grade African American girls (30.8% and 23.1%, respectively). Eleventh-grade White/other girls had the lowest prevalence of overweight (5.5%).

CONCLUSIONS

These data confirm the increasing prevalence of overweight among US children, especially among Hispanic and African American students compared to White/other students and fourth-grade students relative to 8th- and 11th-grade students.

Modeling cellular processes with variational Bayesian cooperative vector quantizer

Gene expression of a cell is controlled by sophisticated cellular processes. The capability of inferring the states of these cellular processes would provide insight into the mechanism of gene expression control system. In this paper, we propose and investigate the cooperative vector quantizer (CVQ) model for analysis of microarray data. The CVQ model could be capable of decomposing observed microarray data into many different regulatory subprocesses. To make the CVQ analysis tractable we develop and apply variational approximations. Bayesian model selection is employed in the model, so that the optimal number processes is determined purely from observed micro-array data. We test the model and algorithms on two datasets: (1) simulated gene-expression data and (2) real-world yeast cell-cycle microarray data. The results illustrate the ability of the CVQ approach to recover and characterize regulatory gene expression subprocesses, indicating a potential for advanced gene expression data analysis.

Establishment of a binational cohort to study Helicobacter pylori infection in children

Chronic Helicobacter (H.) pylori infection, typically of childhood onset, causes upper digestive tract diseases of major impact among socioeconomically marginalized populations. This infection is common in children from ethnic minorities in the United States, and particularly so in immigrant children from Mexico. Prevention measures for H. pylori infection do not yet exist, given limited understanding of what causes either acute or persistent infection. To address this gap, we initiated the Pasitos Cohort Study to follow children from low-income families in the border region that includes El Paso County, Texas, and Ciudad Juarez, Chihuahua. The children were enrolled prior to birth, and are examined at 6-month intervals to observe the natural history of H. pylori infection, and to identify risk factors for acquisition, recurrence, and persistence. This report details the study methods, describes how the cohort was established, and discusses the challenges of compliance with follow up in the border setting. Between April 1998 and October 2000, 1,288 pregnant women were screened for eligibility; 807 of 994 eligible women consented to participate. Birth documentation was obtained for 615 infants, and 472 entered follow up. Successful follow up of this cohort requires resources, including a well-trained, dedicated staff, and incentives, to facilitate and motivate long-term participation. Future findings from this ongoing study will help to fill critical gaps in knowledge regarding the epidemiology of H. pylori infection, and will contribute to the identification of prevention strategies.

Helicobacter pylori infection in pregnant women from a U.S.-Mexico border population

Helicobacter pylori infection causes chronic digestive diseases that disproportionately affect Hispanics and other immigrant groups in the United States. Information on the epidemiology of H. pylori infection in pregnant women who reside along the U.S.-Mexico border is critical to understanding the dynamics of current H. pylori transmission patterns within families along the border. We describe the epidemiology of H. pylori infection in pregnant women recruited from Women, Infants, and Children (WIC) clinics in El Paso, Texas, and Mexican Social Security Institute maternal-child clinics in Ciudad Juarez, Mexico, from April 1998 to October 2000. We interviewed participants regarding environmental factors and tested their serum for IgG antibodies. We used logistic regression to estimate associations between environmental exposures and the odds of H. pylori prevalence. Definitive serological tests were available from 751 women. Seroprevalence was 74% in Juarez women and 56% in El Paso women. Prevalence increased with age, crowding, poor sanitation, and residence in Mexico, decreased with education, and was not associated with the woman's number of living children. In the U.S.-Mexico border region, women of reproductive age have a high prevalence of H. pylori infection, apparently related to poor socioeconomic conditions.

Determinants of geographic variation in Helicobacter pylori infection among children on the US-Mexico border

Rates of Helicobacter pylori infection are traditionally higher in developing countries than in developed countries, but the specific reasons for these differences are not fully clear. While chronic diseases resulting from H. pylori are generally of adult onset, chronic infection usually begins in childhood. In this cross-sectional study (1998-2000), the authors compared prevalences of H. pylori infection among children under age 6 years on both sides of the Rio Grande. Participants included 264 children of women from low-income families who were receiving services at health clinics in Juarez, Mexico, or El Paso, Texas, from April 1998 through October 2000. Data were collected through personal interviews and serologic testing for H. pylori antibodies. The crude odds ratio for H. pylori prevalence among Mexican children as compared with US children was 3.94 (95% confidence interval: 1.72, 9.06). After adjustment for covariates, the odds ratio decreased to 1.70 (95% confidence interval: 0.64, 4.52). The adjustments that produced the greatest reduction in the odds ratio for location were those for household crowding and maternal education. This study identified specific factors that may explain geographic variation in H. pylori prevalence among children.

Patterns of change in hostility from college to midlife in the UNC Alumni Heart Study predict high-risk status

OBJECTIVE

To examine hostility measured in college and patterns of change in hostility from college to midlife as predictors of high health-related risk later in midlife.

METHODS

Logistic regression models were used to test hostility/risk associations.

RESULTS

College hostility predicted being a current smoker, consuming more than two drinks of alcohol, low social support, achieving less than expected in career and in relationships, risk for depression, and appraisal of life changing for the worse in terms of family events at midlife. Change in hostility did not predict smoking and drinking; however, it did significantly predict social isolation, lower income (only for women), obesity, avoidance of exercise, high-fat diet, and negative changes in economic life, work life, and physical health events-all risk indicators measured during the next decade. Appraisals of social support, lowered expectations, risk for depression, and reports of family life changing for the worse were predicted at both time periods. When change in hostility was modeled with college hostility, all risk indicators were significantly predicted by college hostility.

CONCLUSIONS

High hostility in college and change in hostility from college to midlife predicts a full range of health risk indicators. When compared with the average population decline in hostility, gains in hostility at midlife are related to increased risk while declines in hostility are related to reduced risk. Higher midlife hostility is associated with increased odds of being in the higher risk group. Future research should focus on developing interventions to reduce hostility.