Early life risk factors and puberty implications for cancer prevention

Earlier age at puberty is a known risk factor for breast cancer and suspected to influence prostate cancer; yet few studies have assessed early life risk factors for puberty. The overall objectives was to determine the relationship between birth-weight-for-gestational-age (BWGA), weight gain in infancy and pubertal status in girls and boys at 10.8 and 11.8 years and who were born of preeclamptic (PE) and normotensive (NT) mothers. Data for this study were collected from hospital and public health medical records and at a follow-up visit at 10.8 and 11.8 years for girls and boys, respectively. We used stratified analysis and multivariable logistic regression modeling to assess effect measure modifier and to determine the relationship between BWGA, weight gain in infancy and childhood and pubertal status, respectively. ^ There was no difference in the relationship between BWGA and pubertal status by maternal PE status for girls and boys; however, there was a non-significant increase in the odds of having been born small-for-gestational-age (SGA) in girls who were pubertal for breast or pubic hair Tanner stage 2+ compared to those who B1 or PH1. In contrast, boys who were pubertal for genital and pubic hair Tanner stage 2+ had lower odds of having been born SGA than those who were prepubertal for G1 or PH1. ^ In girls who were pubertal for breast development, the odds of having gained one additional unit SD for weight was highest between 3 to 6 months and 6-12 months for those who were B2+ vs. B1. For pubic hair development, weight gain between 6-12 months had the greatest effect for girls of PE mothers only. In boys, there were no statistically significant associations between weight gain and genital Tanner stage at any of the intervals; however, weight gain between 3-6 months did affect pubic hair tanner stage in boys of NT mothers. This study provide important evidence regarding the role of SGA and weight gain at specific age intervals on puberty; however, larger studies need to shed light on modifiable exposures for behavioral interventions in pregnancy, postpartum and in childhood.^

Hypertension control and related variables among urban and rural adults in Taiwan

Literature on hypertension treatment has demonstrated that a healthy life style is one of the best strategies for hypertension control. In exploring the mechanisms of behavioral change for hypertension control, a comprehensive study based on the Transtheoretical Model was carried out in Taiwan during the summer of 2000 with a sample of 350 hypertensive adults living in Taipei urban and rural areas. ^ The relationships among stages of change, processes of change and demographic factors were analyzed for six health behaviors—low fat food consumption, alcohol use, smoking, physical activity, weight control, and routine blood pressure checkups. In addition, differences were assessed between urban and rural populations in changing their behavior for hypertension control. ^ The results showed that rural populations had more difficulties than urban populations in avoiding smoking and engaging in physical activity, and the processes of change being used by urban populations were significantly greater than rural populations. The study findings support a strong association between processes and stages of change. ^ Individuals who use more processes of change will be more inclined to move from precontemplation stage to maintenance stage. Counterconditioning, which is the substitution of alternatives for the problem behaviors, in this study, significantly helped people to change diet, engage in physical activity, and check blood pressure regularly. For example, counterconditioning is eating more vegetables instead of meat, or engaging in physical activity as a time to relax rather than another task to accomplish. ^ In addition, self-reevaluation was the most important process for helping people to engage in physical activity; and social liberation was the most important process for changing diet behavior. The findings in this study may be applied to improve health behaviors among rural populations with low income and low education; however, at the same time, the obesity problems among urban populations should be prevented to control hypertension in Taiwan. ^

Impact of a modified dietary plan on the health related quality of life of minority participants in the Women's Healthy Eating and Living (WHEL) Study

Advances in medical technology, in genetics, and in clinical research have led to early detection of cancer, precise diagnosis, and effective treatment modalities. Decline in cancer incidence and mortality due to cancer has led to increased number of long-term survivors. However, the ethnic minority population has not experienced this decline and still continues to carry a disparate proportion of the cancer burden. Majority of the clinical research including survivorship studies have recruited and continue to recruit a convenient sample of middle- to upper-class Caucasian survivors. Thus, minorities are underrepresented in cancer research in terms of both clinical studies and in health related quality of life (HRQOL) studies. ^ Life style and diet have been associated with increased risk of breast cancer. High vegetable low fat diet has been shown to reduce recurrence of breast cancer and early death. The Women's Healthy Eating and Living Study is an ongoing multi-site randomized controlled trial that is evaluating the high-vegetable low fat diet in reducing the recurrence of breast cancer and early death. The purpose of this dissertation was to (1) compare the impact of the modified diet on the HRQOL during the first 12-month period on specific Minorities and matched Caucasians; (2) identify predictors that significantly impact the HRQOL of the study participants; and (3) using the structural equation modeling assess the impact of nutrition on the HRQOL of the intervention group participants. Findings suggest that there are no significant differences in change in HRQOL between Minorities and Caucasians; between Minorities in the intervention group and those in the comparison group; and between women in the intervention group and those in the comparison group. Minority indicator variable and Intervention/Comparison group indicator variable were not found to be good predictors of HRQOL. Although the structural equation models suggested viable representation of the relationship between the antecedent variables, the mediating variables and the two outcome variables, the impact of nutrition was not statistically significant to be included in the model. This dissertation, by analyzing the HRQOL of minorities in the WHEL Study, attempted to add to the knowledge base specific to minority cancer survivors. ^

Adult weight gain and risk of colon cancer in men

Previous research supports the hypothesis that a "rich" diet (i.e., high in fat and low in fiber) increases the risk of colon cancer. Previous research also supports the hypothesis that physical inactivity increases the risk of colon cancer, perhaps because physical inactivity decreases gut motility, thereby increasing tee time that carcinogens are in contact with the intestinal mucosa. Habitual physical inactivity, combined with rich diet, ordinarily results in chronic energy imbalance and gain in weight, except when energy balance is modified by disease or factors such as cigarette smoking. Cigarette smokers typically stay lean because of effects of smoking on the resting metabolic rate as well as on efficiency of caloric intake and storage. Therefore, if physical inactivity and rich diet do increase the risk of colon cancer, then weight gain during young adulthood should be positively associated with incidence of colon cancer during later life, especially in nonsmokers.^ This hypothesis was investigated in a cohort of 2,059 randomly selected middle-aged men who were employed at the Western Electric Company in Chicago and were free of clinically diagnosed cancer at initial examination in 1958. Body mass index (BMI) in middle age was calculated from measured height and weight at the initial examination. BMI at age 20 was estimated from weight at age 20 as recalled at the initial examination and height as measured at the initial examination. Change in BMI between age 20 and middle age was estimated by subtracting the BMI at 20 from the BMI in middle age. Forty-nine incident cases of colon cancer were detected during 25 years (43,326 person-years) at risk. When stratified by level of change in BMI from age 20 to middle age ($\le$1.9, 2.0-3.9, 4.0-5.9, $\ge$6.0 kg/m$\sp2$), age-adjusted relative hazards of colon cancer in never-smokers were 1.00, 1.22, 2.31, and 5.01, respectively (p for trend = 0.008); corresponding values in ever-smokers were 1.00, 0.95, 0.77, and 0.87, These associations did not change appreciably after further adjustment for BMI at age 20, subscapular-triceps skinfold ratio, cigarette smoking, consumption of alcohol, energy, fat, and calcium.^ We also investigated the hypothesis that the risk of colon cancer was higher in men who were lean at age 20 and became fat by middle age (lean-to-fat) than in men who were fat at age 20 and stayed fat in middle-age (fat-to-fat). "Lean" was defined as BMI $<$24 kg/m$\sp2$ at age 20 and as BMI $<$27.0 kg/m$\sp2$ in middle age. Among never-smokers, in comparison to men who were lean at age 20 and in middle age (lean-to-lean), the age-adjusted relative hazard of colon cancer was 1.43 in the fat-to-fat group (95% confidence interval (CI) 0.37-5.52) and 3.36 in the lean-to-fat group (95% CI 1.21-9.37). This investigation provides new results on the magnitude of risk of colon cancer associated with weight gain during adulthood (from age 20 to middle age). This relation was obscured or underestimated in previous studies due to effect-modification by cigarette smoking. Finally, the result supports the idea that a life-style characterized by chronic energy imbalance during young adulthood increases risk of colon cancer. ^

Ozone and fine particulate matter association with CVD and COPD emergency room visits in Harris County, Texas: Spatiotemporal analysis

This study represents a secondary analysis of the merging of emergency room visits and daily ozone and PM2.5. Although the adverse health effects of ozone and fine particulate matter have been documented in the literature, evidence regarding the health risks of these two pollutants in Harris County, Texas, is limited. Harris County (Houston) has sufficiently unique characteristics that analysis of these relationships in this setting and with the ozone and industry issues in Houston is informative. The objective of this study was to investigate the association between the joint exposure to ozone and fine particulate matter, and emergency room diagnoses of chronic obstructive pulmonary disease and cardiovascular disease in Harris County, Texas, from 2004 to 2009, with zero and one day lags. ^ The study variables were daily emergency room visits for Harris County, Texas, from 2004 to 2009, temperature, relative humidity, east wind component, north wind component, ozone, and fine particulate matter. Information about each patient's age, race, and gender was also included. The two dichotomous outcomes were emergency room visits diagnoses for chronic obstructive pulmonary disease and cardiovascular disease. Estimates of ozone and PM2.5 were interpolated using kriging, in which estimates of the two pollutants were predicted from monitoring data for every case residence zip code for every day of the six years, over 3 million estimates (one of each pollutant for each case in the database). ^ Logistic regressions were conducted to estimate odds ratios of the two outcomes. Three analyses were conducted: one for all records, another for visits during the four months of April and September of 2005 and 2009, and a third one for visits from zip codes that are close to PM2.5 monitoring stations (east area of Harris County). The last two analyses were designed to investigate special temporal and spatial characteristics of the associations. ^ The dataset included all ER visits surveyed by Safety Net from 2004 to 2009, exceeding 3 million visits for all causes. There were 95,765 COPD and 96,596 CVD cases during this six year period. A 1-μg/m3 increase in PM2.5 on the same day was associated with a 1.0% increase in the odds of chronic obstructive pulmonary disease emergency room diagnoses, a 0.4% increase in the odds of cardiovascular disease emergency room diagnoses, and a 0.2% increase in the odds of cardiovascular disease emergency room diagnoses on the following day. A 1-ppb increase in ozone was associated with a 0.1% increase in the odds of chronic obstructive pulmonary disease emergency room diagnoses on the same day. These four percentages add up to 1.7% of ER visits. That is, over the period of six years, one unit increase for both ozone and PM2.5 (joint increase), resulted in about 55,286 (3,252,102 * 0.017) extra ER visits for CVD or COPD, or 9,214 extra ER visits per year. ^ After adjustment for age, race, gender, day of the week, temperature, relative humidity, east wind component, north wind component, and wind speed, there were statistically significant associations between emergency room chronic obstructive pulmonary disease diagnosis in Harris County, Texas, with joint exposure to ozone and fine particulate matter for the same day; and between emergency room cardiovascular disease diagnosis and exposure to PM2.5 of the same day and the previous day. ^ Despite the small association between the two air pollutants and the health outcomes, this study points to important findings. Namely, the need to identify reasons for the increase of CVD and COPD ER visits over the course of the project, the statistical association between humidity (or whatever other variables for which it may serve as a surrogate) and CVD and COPD cases, and the confirmatory finding that males and blacks have higher odds for the two outcomes, as consistent with other studies. ^ An important finding of this research suggests that the number and distribution of PM2.5 monitors in Harris County - although not evenly spaced geographically—are adequate to detect significant association between exposure and the two outcomes. In addition, this study points to other potential factors that contribute to the rising incidence rates of CVD and COPD ER visits in Harris County such as population increases, patient history, life style, and other pollutants. Finally, results of validation, using a subset of the data demonstrate the robustness of the models.^

Evidence of reliability and validity of IPAQ for Mexican-American adults

Physical activity is a key component of life-style modification process which helps to reduce the risk of developing chronic diseases. It is important to have accurate estimates of physical activity to identify sedentary populations where interventions might be helpful. The International Physical Activity Questionnaire (IPAQ) short version has been used to estimate physical activity in diverse populations. However, there is little literature depicting the use of the IPAQ short version in Mexican America population. This study addressed the predictive validity and test-retest reliability of the IPAQ short version in Mexican American adults. The analysis was performed on 97 participants enrolled in the Cameron County Hispanic Cohort. Individuals selected in this study were 18 years of age or older. The predictive validity was evaluated by studying the relationship between physical activity and biomarkers known to be correlated with physical activity, namely, TNF-α, Adiponectin, and HDL. Multiple linear regression analysis was performed to delineate predictive validity. To assess test-retest reliability, two IPAQ-short last seven days questionnaires were interviewer administered to the participants on the same day, approximately two hours apart. Test-Retest reliability of IPAQ was estimated by performing intraclass correlations between the readings at two different time periods. The study showed that the IPAQ – short version used in the above study had acceptable test-retest reliability in the Mexican American population. This study showed that the IPAQ – short version did not have acceptable predictive validity when looking at physical activity and TNF-α, Adiponectin, and HDL in this sample.^

Factors contributing to the attrition of women in the African-American Nutrition for Life study

Background. There is currently a push to increase the number of minorities in cancer clinical trials in an effort to reduce cancer health disparities. Overcoming barriers to clinical trial research for minorities is necessary if we are to achieve the goals of Healthy People 2010. To understand the unexpectedly high rate of attrition in the A NULIFE study, the research team examined the perceived barriers to participation among minority women. The purpose of this study was to determine if either personal or study-related factors influenced healthy pre-menopausal women aged 25-45 years to terminate their participation in the A NULIFE Study. We hypothesized that personal factors were the driving forces for attrition rates in the prevention trial.^ Methods. The target population consisted of eligible women who consented to the A NULIFE study but withdrew prior to being randomized (N= 46), as well as eligible women who completed the informed consent process for the A NULIFE study and withdrew after randomization (N= 42). Examination of attrition rates in this study occurred at a time point when 10 out of 12 participant groups had completed the A NULIFE study. Data involving the 2 groups that were actively engaged in study activities were not used in this analysis. A survey instrument was designed to query the personal and study-related factors that were believed to have contributed to the decision to terminate participation in the A NULIFE study.^ Results. Overall, the highest ranked personal reason that influenced withdrawal from the study was being “too busy” with other obligations. The second highest ranked factor for withdrawal was work obligations. Whereas, more than half of all participants agreed that they were well-informed about the study and considered the study personnel to be approachable, 54% of participants would have been inclined to remain in the study if it were located at a local community center.^ Conclusions. Time commitment was likely a major factor for withdrawal from the A NULIFE study. Future investigators should implement trials within participant communities where possible. Also, focus group settings may provide detailed insight into factors that contribute to the attrition of minorities in cancer clinical trials.^

Cardiovascular diseases risk factors during the first year of life

The pattern of change in cardiovascular risk factors, blood pressure (SBP and DBP) and plasma total cholesterol (TC), over time, their tracking and their relation to anthropometric measurements during the first year of life were investigated. Also, the effect of breast feeding on TC and the relationship of blood pressure measurements and family history of CVD risk factors were examined. One hundred five newborn term, healthy infants who were seen at a pediatric clinic in The Woodlands, Texas were followed longitudinally from 2 weeks to 1 year of age. TC, blood pressure, weight and length of the infants were measured at age 2 weeks, and again at 2, 4, 6, 9 and 12 months. In addition, family history, maternal and paternal, of CVD risk factors was obtained. Data analyses included only 40 infants who completed one year of follow up.^ At 2 weeks of age, the median value for TC was 23 mg/dl higher for females than for males. This difference disappeared as infants got older. For males, most of the increase in TC median levels, from 114 to 137 mg/dl, occurred between the ages of 2 weeks and 2 months, whereas for the female group, TC levels increased moderately, about 10 mg/dl, between 9 and 12 months of age. Tracking of TC was examined by using Spearman's correlation analysis. There were strong correlations between measurements taken as early as 2 weeks of age with later measurements. These correlations were stronger and more significant for males than for females (for males, r varied between 0.51 to 0.70, whereas for females, r varied between 0.11 to 0.70). The association of body measurements with TC is no more than modest and is closer for female infants than for male infants. Analysis, also, showed that infants who received breast milk had a TC mean value 47 mg/dl higher than that for infants who received formula milk only during the period of breast feeding and this difference disappeared by age 12 months.^ In both genders, most of the increase in blood pressure (about 10-15 mmHg in both SBP and DBP) occurred during the first 4 months of life. Most of the increase for male infants occurred during the first 2 months of life, while for females, the increase in SBP and DBP was between the age of 2 and 4 months. Neither SBP nor DBP track well during the first year of life and most of the correlations between measurements at different ages were not significant for either gender. The cross-sectional relationship of blood pressure measurements and selected body measurements was assessed. For females, only at age of 12 months did DBP have positive and significant correlations with weight, length and Quetelet index (r = 0.57, 0.60 and 0.57, respectively). There were no significant correlations between blood pressure and body measurements for males. Finally, analysis showed that maternal history of CV risk factors was significantly related to SBP in the female infant group, but not for males. For DBP, neither maternal nor paternal history was related. ^