Tracking of plasma lipids and lipoproteins, within-person and year-to-year variability in plasma cholesterol levels among participants from age 8 to 18 in Project HeartBeat!

Coronary heart disease remains the leading cause of death in the United States and increased blood cholesterol level has been found to be a major risk factor with roots in childhood. Tracking of cholesterol, i.e., the tendency to maintain a particular cholesterol level relative to the rest of the population, and variability in blood lipid levels with increase in age have implications for cholesterol screening and assessment of lipid levels in children for possible prevention of further rise to prevent adulthood heart disease. In this study the pattern of change in plasma lipids, over time, and their tracking were investigated. Also, within-person variance and retest reliability defined as the square root of within-person variance for plasma total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides and their relation to age, sex and body mass index among participants from age 8 to 18 years were investigated. ^ In Project HeartBeat!, 678 healthy children aged 8, 11 and 14 years at baseline were enrolled and examined at 4-monthly intervals for up to 4 years. We examined the relationship between repeated observations by Pearson's correlations. Age- and sex-specific quintiles were calculated and the probability of participants to remain in the uppermost quintile of their respective distribution was evaluated with life table methods. Plasma total cholesterol, HDL-C and LDL-C at baseline were strongly and significantly correlated with measurements at subsequent visits across the sex and age groups. Plasma triglyceride at baseline was also significantly correlated with subsequent measurements but less strongly than was the case for other plasma lipids. The probability to remain in the upper quintile was also high (60 to 70%) for plasma total cholesterol, HDL-C and LDL-C. ^ We used a mixed longitudinal, or synthetic cohort design with continuous observations from age 8 to 18 years to estimate within person variance of plasma total cholesterol, HDL-C, LDL-C and triglycerides. A total of 5809 measurements were available for both cholesterol and triglycerides. A multilevel linear model was used. Within-person variance among repeated measures over up to four years of follow-up was estimated for total cholesterol, HDL-C, LDL-C and triglycerides separately. The relationship of within-person and inter-individual variance with age, sex, and body mass index was evaluated. Likelihood ratio tests were conducted by calculating the deviation of −2log (likelihood) within the basic model and alternative models. The square root of within-person variance provided the retest reliability (within person standard deviation) for plasma total cholesterol, HDL-C, LDL-C and triglycerides. We found 13.6 percent retest reliability for plasma cholesterol, 6.1 percent for HDL-cholesterol, 11.9 percent for LDL-cholesterol and 32.4 percent for triglycerides. Retest reliability of plasma lipids was significantly related with age and body mass index. It increased with increase in body mass index and age. These findings have implications for screening guidelines, as participants in the uppermost quintile tended to maintain their status in each of the age groups during a four-year follow-up. The magnitude of within-person variability of plasma lipids influences the ability to classify children into risk categories recommended by the National Cholesterol Education Program. ^

Changes in serum lipids with change and fluctuation in body mass index and body fat distribution in Mexican Americans with type 2 diabetes

This dissertation was written in the format of three journal articles. Paper 1 examined the influence of change and fluctuation in body mass index (BMI) over an eleven-year period, on changes in serum lipid levels (total, HDL, and LDL cholesterol, triglyceride) in a population of Mexican Americans with type 2 diabetes. Linear regression models containing initial lipid value, BMI and age, BMI change (slope of BMI), and BMI fluctuation (root mean square error) were used to investigate associations of these variables with change in lipids over time. Increasing BMI over time was associated with gains in total and LDL cholesterol and triglyceride levels in women. Fluctuation of BMI was not associated with detrimental lipid profiles. These effects were independent of age and were not statistically significant in men. In Mexican-American women with type 2 diabetes, weight reduction is likely to result in more favorable levels of total and LDL cholesterol and triglyceride, without concern for possible detrimental effects of weight fluctuation. Weight reduction may not be as effective in men, but does not appear to be harmful either. ^ Paper 2 examined the associations of upper and total body fat with total cholesterol, HDL and LDL cholesterol, and triglyceride levels in the same population. Multilevel analysis was used to predict serum lipid levels from total body fat (BMI and triceps skinfold) and upper body fat (subscapular skinfold), while controlling for the effects of sex, age and self-correlations across time. Body fat was not strikingly associated with trends in serum lipid levels. However, upper body fat was strongly associated with triglyceride levels. This suggests that loss of upper body fat may be more important than weight loss in management of the hypertriglyceridemia commonly seen in type 2 diabetes. ^ Paper 3 was a review of the literature reporting associations between weight fluctuation and lipid levels. Few studies have reported associations between weight fluctuation and total, LDL, and HDL cholesterol and triglyceride levels. The body of evidence to date suggests that weight fluctuation does not strongly influence levels of total, LDL and HDL cholesterol and triglyceride. ^

Unintended pregnancy: Attitudes toward contraception of women obtaining abortions

Forty-nine percent of pregnancies in the United States are unintended and significant numbers of pregnancies are unintended for women of all ages. One possible reason for the high rate is that while 85% of women at risk for an unintended pregnancy use contraception, negative attitudes about the method used make them poor contraceptors. Negative attitudes may prevent the remaining 15% of women from using any method of birth control. This study examined adult women's attitudes toward contraception and its use to see if attitudes correlate with unintended pregnancy. ^ To obtain a sample of women experiencing unintended pregnancies, women obtaining therapeutic abortions were surveyed since almost all women obtaining therapeutic abortions are experiencing an unintended pregnancy. The study used a cross-sectional survey design and included 312 women obtaining abortions at the Planned Parenthood Surgical Services Clinic in Houston in the latter half of 1999. ^ The responses revealed a lack of knowledge about the safety and effectiveness of contraception, particularly for methods other than oral contraceptives and condoms. Thirty-four percent of the participants were uncomfortable buying contraception. While 71% of the participants said their physician recommended their use of contraception, 17% were unsure and 35% did not talk to their physician about contraception on a regular basis. ^ The attitudes of women using contraception were compared with those not using contraception and many differences were seen. Women not using contraception responded with more ‘unsure’ answers and believed contraception was more difficult to use. They felt planning ahead for the use of contraception interfered with the enjoyment of sex (p-value = 0.06). They were less likely to use contraception if their partner disapproved (p-value = 0.01) and more of them believed their church disapproved of contraception (p-value = 0.02). In comparison, women using contraception had negative attitudes about the safety of the pill (p-values = 0.01–0.08) and the effectiveness of the condom (p-value = 0.04). Therefore, the negative attitudes women using contraception had about contraception may interfere with their effective use of birth control. Those not using contraception were found to hold attitudes that may contribute to their non-use of contraception. ^

Association between temperament and physical activity in a population of minority women

Physical activity has been, and remains, a significant public health issue. Thus, increasing physical activity has been identified as a top priority according to Healthy People 2010. Various behavioral variables have been associated with participation in physical activity, including the Type A behavior pattern (TABP). This study was a secondary data analysis of the Women On The Move pilot study data and examined the relationship between Type A behavior with physical activity. The study population consisted of fifty-six (56) adult minority women 40 years of age and above. The Thurstone Activity Scale was adapted for use in this study to measure TABP. Physical activity behavior was measured using an accelerometer (Computer Science Application, [CSA]) and a physical activity diary. All study questions were examined using multiple linear regression analysis. In all analyses age, household income, and level of education were entered as covariates. The results found no association with TABP and exercise or physical activity. More research involving a larger, more active study population is recommended in order to more precisely determine the relationship of TABP and physical activity. ^

Stress and coping in African American grandparents who are raising grandchildren

Over the years, substantial increases have occurred in the number of children being raised by their grandparents. A small number of studies have reported that grandparents raising grandchildren experience an increase in stress due to the demands of caregiving. The primary objectives of this study were to: (1) determine the degree of stress in African American (AA) grandparents who are raising their grandchildren age 12 years or younger; (2) identify the variables pertaining to the demographic characteristics of the grandparent caregiver and characteristics of the caregiving situation; (3) identify the coping strategies reported by AA grandparents; and (4) identify the relative importance of demographic and situational variables pertaining to the grandparent caregiver and caregiving situation, and coping strategies in influencing the degree of stress experienced. ^ An exploratory, descriptive, cross sectional design was used to study stress and coping in 50 AA grandparents who ranged in age from 44–87 years (M = 63.12). Data were collected via one personal interview in January/February 2001 at area senior centers or churches which the grandparent attends in Harris County, Texas. Five home interviews were done as requested by grandparents. ^ The instruments used to measure stress and coping were the Parenting Stress Index developed by Abidin and Folkman and Lazarus' Ways of Coping Questionnaire. Results of the study found that the grandparents is this study were a highly stressed group. Ninety-four percent of the sample demonstrated a “clinically significant” level of stress. Situational variables associated with lower stress levels were use of counseling, use of special school programs such as tutoring and special education, and increased length of caregiving (>5 years). ^ The most frequently used coping strategies overall were seeking social support and positive reappraisal. Six coping strategies were significantly correlated to lower reported stress: positive reappraisal, accepting responsibility, confrontive coping, self-control, planful problem solving, and distancing. ^ The findings from this study have limited generalizability. Nonetheless, this study was useful in adding to the limited amount of literature on AA grandparents who are rearing their grandchildren. The results clearly suggest the need for affordable counseling, support groups, education related to available resources, stress management, and interventions that increase the use of coping strategies found to reduce perceived stress. Future research should investigate levels of stress in AA and other grandparent caregivers longitudinally, as well as focus on stress and coping in grandparents raising grandchildren with special needs. ^

Long-term central venous catheter-related candidemia: A new approach towards diagnosis and management

A case-series analysis of approximately 811 cancer patients who developed Candidemia between 1989 and 1998 and seen at M. D. Anderson Cancer Center, was studied to assess the impact and timing of central venous catheter (CVC) removal on the outcome of fungal bloodstream infections in cancer patients with primary catheter-related Candidemia as well as secondary infections. ^ This study explored the diagnosis and the management of vascular catheter-associated fungemia in patients with cancer. The microbiologic and clinical factors were determined to predict catheter-related Candidemia. Those factors included, in addition to basic demographics, the underlying malignancy, chemotherapy, neutropenia, and other salient data. Statistical analyses included univariate and multivariate logistic regression to determine the outcome of Candidemia in relation to the timing of catheter removal, type of species, and to identify predictors of catheter-related infections. ^ The conclusions of the study aim at enhancing our mastery of issues involving CVC removal and potentially will have an impact on the management of nosocomial bloodstream infections related to timing of CVC removal and the optimal duration of treatment of catheter-related Candidemia. ^

Cervical cancer screening in Hispanic women as compared with other ethnic groups on an urban campus

Although Pap screening has decreased morbidity and mortality from cervical cancer, reported statistics indicate that among ethnic groups, Hispanic women are one of the least likely to follow screening guidelines. Human papillomavirus (HPV), a major risk factor for cervical cancer, as well as pre-cancerous lesions, may be detected by early Pap screening. With a reported 43% prevalence of HPV infection in college women, regular Pap screening is important. The purpose of this descriptive, cross-sectional survey was to examine self-reported cervical cancer screening rates in a target population of primarily Mexican-American college women, and to discover if recognized correlates for screening behavior explained differences in screening rates between this and two other predominant groups on the University of Houston Downtown campus, non-Hispanic white and African-American. The sample size consisted of 613 women recruited from summer 2003 classes. A survey, adapted from an earlier El Paso study, and based on constructs of the Health Belief Model (HBM), was administered to women ages 18 and older. It was found that although screening rates were similar across ethnic groups, overall, the Hispanic group obtained screening less frequently, though this did not reach statistical significance. However, a significant difference in lower screening rates was found in Mexican American women ages <25. Additionally, of the predicted correlates, the construct of perceived barriers from the HBM was most significant for the Mexican American group for non-screening. For all groups, knowledge about cervical cancer was negatively correlated with ever obtaining Pap screening and screening within the past year. This implies that if health counseling is given at the time of women's screening visits, both adherence to appropriate screening intervals and risk factor avoidance may be more likely. Studies such as these are needed to address both screening behaviors and likelihood of follow-up for abnormal results in populations of multicultural, urban college women. ^

Cystoscopy and the development of invasive bladder cancer in patients presenting with superficial urinary bladder cancer

The objective of this study was to determine the impact of different follow-up cystoscopy frequencies on time to development of invasive bladder cancer in a cohort of 3,658 eligible patients 65 and older with an initial diagnosis of superficial bladder cancer between 1994 and 1998. Bladder cancer patients in the Surveillance, Epidemiology, and End Results (SEER)-Medicare database were used as the study population. ^ It was hypothesized that superficial bladder cancer patients receiving less frequent cystoscopy follow-up would develop invasive bladder cancer sooner after initial diagnosis and treatment than patients seen more frequently for cystoscopy follow-up. Cox Proportional Hazard Regression revealed that patients seen for cystoscopy every 3 or more months were 83–89% less likely to develop invasive cancer than patients seen every 1 to 2 months. A comparison of the 2 groups (1 to 2 months vs. 3≥ months) revealed that the 1 to 2 month group may have had more aggressive disease, and they are seen more frequently as a result. ^ These findings suggest that there are two groups of superficial bladder cancer patients: those at high risk of developing invasive bladder cancer and those at low risk. Patients who developed invasive bladder cancer sooner after initial diagnosis and treatment were seen more frequently for cystoscopy follow-up. The recommendation is that cystoscopy should be based on disease status at 3 months. Standardized schedules give all patients the same number of cystoscopies regardless of their risk factors. This could lead to unnecessary cystoscopies in low risk patients, and fewer than optimal cystoscopies in high risk patients. ^

The effect of alcohol consumption on mortality among idiosyncratic drug induced liver injury (IDILI) patients

Severe liver injury (SLI) due to drugs is a frequent cause of catastrophic illness and hospitalization. Due to significant morbidity, mortality, and excess medical care costs, this poses a challenge as a public health problem. The role of associated risk factors like alcohol consumption in contributing to the high mortality remains to be studied. This study was conducted to assess the impact of alcohol use on mortality in IDILI patients, while adjusting for age, gender, race/ethnicity, and education level. The data from this study indicate only a small excess risk of death among IDILI patients using alcohol, but the difference was not statistically significant. The major contribution of this study to the field of public health is that it excludes a large hazard of alcohol consumption on the mortality among idiosyncratic drug induced liver injury (IDILI) patients. ^

Predictors of participation in genetic testing for hereditary breast and ovarian cancer

Up to 10% of all breast and ovarian cancers are attributable to mutations in cancer susceptibility genes. Clinical genetic testing for deleterious gene mutations that predispose to hereditary breast and ovarian cancer (HBOC) syndrome is available. Mutation carriers may benefit from following high-risk guidelines for cancer prevention and early detection; however, few studies have reported the uptake of clinical genetic testing for HBOC. This study identified predictors of HBOC genetic testing uptake among a case series of 268 women who underwent genetic counseling at The University of Texas M. D. Anderson Cancer Center from October, 1996, through July, 2000. Women completed a baseline questionnaire that measured psychosocial and demographic variables. Additional medical characteristics were obtained from the medical charts. Logistic regression modeling identified predictors of participation in HBOC genetic testing. Psychological variables were hypothesized to be the strongest predictors of testing uptake—in particular, one's readiness (intention) to have testing. Testing uptake among all women in this study was 37% (n = 99). Contrary to the hypotheses, one's actual risk of carrying a BRCA1 or BRCA2 gene mutation was the strongest predictor of testing participation (OR = 15.37, CI = 5.15, 45.86). Other predictors included religious background, greater readiness to have testing, knowledge about HBOC and genetic testing, not having female children, and adherence to breast self-exam. Among the subgroup of women who were at ≥10% risk of carrying a mutation, 51% (n = 90) had genetic testing. Consistent with the hypotheses, predictors of testing participation in the high-risk subgroup included greater readiness to have testing, knowledge, and greater self-efficacy regarding one's ability to cope with test results. Women with CES-D scores ≥16, indicating the presence of depressive symptoms, were less likely to have genetic testing. Results indicate that among women with a wide range of risk for HBOC, actual risk of carrying an HBOC-predisposing mutation may be the strongest predictor of their decision to have genetic testing. Psychological variables (e.g., distress and self-efficacy) may influence testing participation only among women at highest risk of carrying a mutation, for whom genetic testing is most likely to be informative. ^

Adherence to a lifestyle physical activity program: Trends over time and associations with processes of change and physical activity

Research on lifestyle physical activity interventions suggests that they help individuals meet the new recommendations for physical activity made by the Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine (ACSM). The purpose of this research was to describe the rates of adherence to two lifestyle physical activity intervention arms and to examine the association between adherence and outcome variables, using data from Project PRIME, a lifestyle physical activity intervention based on the transtheoretical model and conducted by the Cooper Institute of Aerobics Research, Dallas, Texas. Participants were 250 sedentary healthy adults, aged 35 to 70 years, primarily non-Hispanic White, and in the contemplation and preparation stages of readiness to change. They were randomized to a group (PRIME G) or a mail- and telephone-delivered condition (PRIME C). Adherence measures included attending class (PRIME G), completing a monthly telephone call with a health educator (PRIME C), and completing homework assignments and self-monitoring minutes of moderate- to vigorous physical activity (both groups). In the first results paper, adherence over time and between conditions was examined: Attendance in group, completing the monthly telephone call, and homework completion decreased over time, and participants in PRIME G were more likely to complete homework than those in PRIME C. Paper 2 aimed to determine whether the adherence measures predicted achievement of the CDC/ACSM physical activity guideline. In separate models for the two conditions, a latent variable measuring adherence was found to predict achievement of the guideline. Paper 3 examined the association between adherence measures and the transtheoretical model's processes of change within each condition. For both, participants who completed at least two thirds of the homework assignments improved their use of the processes of change more than those who completed less than that amount. These results suggest that encouraging adherence to a lifestyle physical activity intervention, at least among already motivated volunteers, may increase the likelihood of beneficial changes in the outcomes. ^

Assessing perceptions of environmental risk and environmental justice and their impacts on neighborhood attachment in a predominately Hispanic community

This study examines and relates concepts from environmental risk perception and environmental justice and focuses on the perception of environmental problems, their consequent health risks and their impact on neighborhood attachment in a predominately Hispanic community along the U.S.-Mexico border. The findings indicate that the perception of environmental problems in the immediate area varies by problem and demographic subgroup. Ethnicity and income have the highest number of statistically significant associations across ten environmental problems. This result lies in the fact that Hispanics in El Paso County and those with low annual incomes live in neighborhoods that are faced with more severe environmental problems. Thus the findings lend support to the environmental justice claim that the poor and minorities bear the brunt of environmental degradation. ^ The findings also provide evidence that public perception of health risks from an environmental problem is influenced by the perceived severity of an environmental problem in the immediate area. Those who believe the problem is serious on a local level are the ones who are most likely to believe that they could become ill or injured from that problem and that the illness/injury will be serious. ^ The findings of this study also indicate that the young, Hispanics, those who perceive considerable environmental problems in their neighborhood, those who believe that their neighborhood has more environmental problems than others, and those who are angry about those problems are most likely to want to move from their neighborhood. ^ Efforts need to be made to enact policies and programs designed to reduce the environmental hazards in disadvantaged Hispanic communities along the U.S.-Mexico border. Future environmental education campaigns need to complement community-based projects with the media. Programs that involve and empower the community, particularly the youth, in improving the neighborhood could provide a sense of control and pride within their community in solving these problems. These neighborhood improvement efforts could also lead to the development and strengthening of social ties within the community, as well as enhanced community cohesiveness in tackling these problems. ^

The identification of child abuse in Harris County in 1998

Characteristics of child abuse cases are not well known. In this study I collected data on 70 child abuse cases that were reported to Children's Protective Services in Harris County in 1998. The purpose of this study was to determine the factors in Harris County that lead to the identification of physical and sexual abuse. In order to answer the questions of who, what, where and when relative to the discovery of abuse I applied the same questionnaire (see Appendix) to each of 35 Sexual Abuse case reports and to each of 35 Physical Abuse/Neglect case reports. Answers to the first four questions were arranged by frequency distribution to show the predominant reporter, the 10 most common indicators, the most common locale, and the most frequent timing. Tables of the age, sex, and ethnicity of the children indicate the identity of those whose victimization was most reported. In addition the relationship between the form questions and the characteristics of the children was explored. A comparison of Sexual Abuse cases with Physical Abuse/Neglect cases was conducted and the results were analyzed and recorded in the Tables. ^ Child maltreatment often has negative short and long term effects on children's mental health and development. Suicide, violence, delinquency, drug and alcohol abuse and other forms of criminality are frequently child abuse related. Early detection and treatment helps to alleviate the myriad mental and physical ailments that untreated victims present as adults. This translates into medical dollar savings. ^ The long term objectives of my research were to reduce the number of undetected and unreported child abuse cases in Harris County by formulating better educational programs and literature for medical professionals and other personnel who are in contact with children. ^

Temporal variations of dyspnea, fatigue, and lung function in chronic lung disease

Background. Research investigating symptom management in patients with chronic obstructive pulmonary disease (COPD) largely has been undertaken assuming the homeostatic construct, without regard to potential roles of circadian rhythms. Temporal relations among dyspnea, fatigue, peak expiratory flow rate (PEFR) and objective measures of activity/rest have not been reported in COPD. ^ Objectives. The specific aims of this study were to (1) explore the 24-hour patterns of dyspnea, fatigue, and PEFR in subjects with COPD; (2) examine the relations among dyspnea, fatigue, and PEFR in COPD; and (3) examine the relations among objective measures of activity/rest and dyspnea, fatigue, and PEFR in COPD. ^ Methods. The repeated-measures design involved 10 subjects with COPD who self-assessed dyspnea and fatigue by 100 mm visual analog scales, and PEFR by peak flow meter in their home 5 times a day for 8 days. Activity/rest was measured by wrist actigraphy. Single and population mean cosinor analyses and correlations were computed for dyspnea, fatigue, and PEFR; correlations were done among these variables and activity/rest. ^ Results. Circadian rhythms were documented by single cosinor analysis in 40% of the subjects for dyspnea, 60% for fatigue, and 60% for PEFR. The population cosinor analysis of PEFR yielded a significant rhythm (p < .05). The 8-day 24-hour means of dyspnea and fatigue was moderately correlated (r = .48, p < .01). Dyspnea and PEFR, and fatigue and PEFR, were weakly correlated in a negative way (r = −.11, p < .05 and r = −.15, p < .01 respectively). Weak to moderate correlations (r = .12–.34, p < .05) were demonstrated between PEFR and mean activity level measured up to 4 hours before PEFR measurement. ^ Conclusions. The findings suggest that (1) the dyspnea and fatigue experienced by COPD patients are moderately related, (2) there is a weak to modest positive relation between PEFR and activity levels, and (3) temporal variation in lung function may not affect the dyspnea and fatigue experienced by patients with COPD. Further research, examining the relations among dyspnea, fatigue, PEFR, and activity/rest is needed. Replication of this study is suggested with a larger sample size. ^

Atlas of cancer mortality in the United Arab Emirates aided by application of geographic information system methods

The aim of this study was to determine cancer mortality rates for the United Arab Emirates (UAE) and to create an atlas of cancer mortality for the UAE. This atlas is the first of its kind in the Gulf country and the Middle East. Death certificates were reviewed for a period from January 1, 1990 to December 31, 1999 and cancer deaths were identified. Cancer mortality cases were verified by comparing with medical records. Age-adjusted cancer mortality rates were calculated by gender, emirate/medical district and nationality (UAE nationals and overall UAE population). Individual rates for each emirate were compared to the overall rate of the corresponding population for the same cancer site and gender. Age-adjusted rates were mapped using MapInfo software. High rates for liver, lung and stomach cancer were observed in Abu Dhabi, Dubai and the northern emirates, respectively. Rates for UAE nationals were greater compared to the overall UAE population. Several factors were suggested that may account for high rates of specific cancers observed in certain emirates. It is hoped that this atlas will provide leads that will guide further epidemiologic and public health activities aimed at preventing cancer. ^