Biomedical subjects

W S Poston

Publications and source records attributed to W S Poston.

At least 19 recordsLinked to original sources

PubMed2001

Blood pressure and symptoms of depression and anxiety: a prospective study.

This study investigated whether symptoms of depression and anxiety were related to the development of elevated blood pressure in initially normotensive adults. The study's hypothesis was addressed with an existing set of prospective data gathered from an age-, sex-, and weight-stratified sample of 508 adults. Four years of follow-up data were analyzed both with logistic analysis, which used hypertension (blood pressure > or =140 mm Hg systolic or 90 mm Hg diastolic) as the dependent variable, and with multiple regression analysis, which used change in blood pressure as the dependent variable. Five physical risk factors for hypertension (age, sex, baseline body mass index, family history of hypertension, and baseline blood pressure levels) were controlled for in the regression analyses. Use of antidepressant/antianxiety and antihypertensive medications were controlled for in the study. Of the 433 normotensive participants who were eligible for our study, 15% had missing data in the logistic regression analysis focusing on depression (n = 371); similarly, 15% of the eligible sample had missing data in the logistic regression using anxiety as the psychological variable of interest (n = 370). Both logistic regression analyses showed no significant relationship for either depression or anxiety in the development of hypertension. The multiple regression analyses (n = 369 for the depression analysis; n = 361 for the anxiety analysis) similarly showed no relationship between either depression or anxiety in changes in blood pressure during the 4-year follow-up. Thus, our results do not support the role of depressive or anxiety symptoms in the development of hypertension in our sample of initially normotensive adults.

Adult↗

PubMed2001

Lifestyle treatments in randomized clinical trials of pharmacotherapies for obesity.

OBJECTIVE: This meta-analysis evaluated the types of lifestyle treatments used in published obesity drug studies and assessed their contribution to weight losses associated with pharmacological interventions. RESEARCH METHODS AND PROCEDURES: Randomized, placebo-controlled, double-blind clinical trials of anti-obesity agents that are/were Food and Drug Administration-approved for the treatment of obesity (both prescription and over-the-counter), and drugs that are Food and Drug Administration-approved and are used off-label for obesity were included. Studies were located by computer searches of databases (e.g., Medline, PsychInfo) and reviewing tables of content/reference sections of journals, abstracts, previous reviews, past empirical studies, relevant book chapters, and recent issues of journals that regularly publish obesity research. In addition, a number of individuals who regularly publish in the obesity literature were asked to provide personal lists of obesity-drug studies. Based on the above criteria, a total of 108 randomized clinical trials were located. RESULTS: Balanced-deficit diets, low-calorie diets, and self-monitoring were the most used lifestyle treatments in published obesity studies. They were incorporated into 40.7%, 25%, and 23.1% of pharmacotherapy studies, respectively. Physical activity and other behavioral or psychotherapeutic interventions rarely were used. A substantial portion of weight loss experienced by patients was attributable to both "placebo effects" and to the lifestyle treatments. DISCUSSION: Obesity-pharmacotherapy trials do not use lifestyle treatments with the frequency expected based on the official positions of most professional organizations concerned with the comprehensive management of obesity.

Anti-Obesity Agents↗

PubMed2001

Determining the amount of physical activity needed for long-term weight control.

OBJECTIVE: To evaluate prospectively the influence of habitual physical activity on body weight of men and women and to develop a model that defines the role of physical activity on longitudinal weight change. DESIGN AND SETTING: Occupational cohort study conducted for a mean of 5.5 y. SUBJECTS: A total of 496 (341 male and 155 female) NASA/Johnson Space Center employees who completed the 3 month education component of the employee health-related fitness program and remained involved for a minimum of 2 y. MEASUREMENTS: Body weights were measured at baseline (T1) and follow-up (T2), and habitual physical activity was obtained from the mean of multiple ratings of the 11-point (0-10) NASA Activity Scale (NAS) recorded quarterly between T1 and T2. Other measures included age, gender, VO(2 max) obtained from maximal treadmill testing, body mass index (BMI), and body fat percentage. RESULTS: Multiple regression demonstrated that mean NAS, T1 weight, aging and gender all influence long-term T2 weight. T1 age was significant for the men only. Independently, each increase in mean NAS significantly (P<0.01) reduced T2 weight in men (b=-0.91 kg; 95% CI:-1.4 to-0.42 kg) and women (b=-2.14 kg; 95% CI:-2.93 to-1.35 kg). Mean NAS had a greater effect on T2 weight as T1 weight increased, and the relationship was dose-dependent. CONCLUSIONS: Habitual physical activity is a significant source of long-term weight change. The use of self-reported activity level is helpful in predicting long-term weight changes and may be used by health care professionals when counseling patients about the value of physical activity for weight control.

Adult↗

PubMed2001

Genetic bottlenecks, perceived racism, and hypertension risk among African Americans and first-generation African immigrants.

The complexity of factors influencing the development of hypertension (HTN) in African Americans has given rise to theories suggesting that genetic changes occurred due to selection pressures/genetic bottleneck effects (ie, constriction of existing genetic variability) over the course of the slave trade. Ninety-nine US-born and 86 African-born health professionals were compared in a cross-sectional survey examining genetic and psychosocial predictors of HTN. We examined the distributions of three genetic loci (G-protein, AGT-235, and ACE I/D) that have been associated with increased HTN risk. There were no significant differences between US-born African Americans and African-born immigrants in the studied genetic loci or biological variables (eg, plasma renin and angiotensin converting enzyme activity), except that the AGT-235 homozygous T genotype was somewhat more frequent among African-born participants than US-born African Americans. Only age, body mass index, and birthplace consistently demonstrated associations with HTN status. Thus, there was no evidence of a genetic bottleneck in the loci studied, ie, that US-born African Americans have different genotype distributions that increase their risk for HTN. In fact, some of the genotypic distributions evidenced lower frequencies of HTN-related alleles among US-born African Americans, providing evidence of European admixture. The consistent finding that birthplace (ie, US vs Africa) was associated with HTN, even though it was not always significant, suggests potential and unmeasured cultural, lifestyle, and environmental differences between African immigrants and US-born African Americans that are protective against HTN.

Adult↗

PubMed2001

Negative stress and the outcome of treatment for binge eating.

This study investigated the ability of negatively versus positively perceived stress to predict outcome of treatment for binge eating disorder (BED). Participants were 62 obese women satisfying the DSMIV research criteria for BED. Stress was measured using an instrument based on the Recent Life Change Questionnaire (RLCQ). Participants experiencing high negative stress during the study period reported a binge eating frequency three times greater than that reported by subjects experiencing low negative stress (2.14 vs. 0.65 binge-days/week). Negative stress predicted how fast an individual would reduce binge eating and demonstrated more predictive power than positive stress.

Journal Article↗

PubMed2000

Successful management of the obese patient.

Obesity is a chronic disease that affects a substantial number of Americans. Obesity significantly increases a person's risk of cardiovascular diseases and morbidity. Modification of lifestyle behaviors that contribute to obesity (e.g., inappropriate diet and inactivity) is the cornerstone of treatment. Behavior modification involves using such techniques as self-monitoring, stimulus control, cognitive restructuring, stress management and social support to systematically alter obesity-related behaviors. In addition, adjunctive pharmacotherapy can play an important role in the routine medical management of obesity.

Anti-Obesity Agents↗

PubMed2000

Does personality or psychopathology predict disability in chronic pain patients?

PURPOSE: The purpose of this study was to evaluate the usefulness of personality characteristics, depression and personality disorders in predicting disability status in pain patients one year later. METHOD: Subjects were 250 volunteer chronic pain patients. The baseline evaluation consisted of the Karolinska Scales of Personality and psychiatric evaluation of depression and personality disorders using standardized diagnostic instruments. Disability status was assessed by insurance record review one year after the evaluation. RESULTS: The results suggest that baseline personality traits and psychopathology (i.e. depression or personality disorders) were not useful predictors of disability status in pain patients with one-year follow-up. CONCLUSIONS: These data suggest that personality characteristics and psychopathology are probably not important disability predictors in chronic pain patients.

Adult↗

PubMed2000

Where do diets, exercise, and behavior modification fit in the treatment of obesity?

Obesity is a significant public health concern that affects a growing number of people in the United States and throughout the world. While substantial advances have been made in the development of new pharmacotherapies and in understanding the biological underpinnings (e.g., genetics and physiology) of obesity, lifestyle modification, which involves the application of behavior modification principles to alter eating and activity patterns, is the foundation of any comprehensive obesity management. The purpose of this article is to provide a practical overview of the benefits of dietary and activity change and to review behavior modification principles that have been used successfully in obesity management.

Behavior Therapy↗

PubMed2000

Scientific and legal issues in fenfluramine/dexfenfluramine litigation.

Fenfluramine and dexfenfluramine were popular and widely used antiobesity agents until they were withdrawn from the market in 1997. Even though early research appeared to demonstrate their safety, serious concerns were raised about these medications. Primary pulmonary hypertension (PPH) was a known side effect, but it was believed that the health benefits of weight loss compensated for the risk of PPH. With widespread use of these agents, 2 other conditions--valvular heart disease and neurotoxicity--were reported as potential side effects. In this paper, we review the evidence for these adverse events and whether the current data meet federal and Texas legal standards for admissibility. We discuss also the basis for health claims against physicians, and the scientific and legal challenges faced by both plaintiffs and defendants.

Anti-Obesity Agents↗

PubMed2000

Lower hypertension prevalence in first-generation African immigrants compared to US-born African Americans.

Both genetic and environmental factors have been hypothesized to explain the higher prevalence of hypertension in US African Americans compared to populations still residing in western Africa. Studies of first-generation immigrants can help to identify risk factors for increased chronic disease expression in the developed world. Since we could identify no prior studies of hypertension in African immigrants to the United States, we conducted a cross-sectional survey of African-born and US-born African-American health professionals to compare the two groups for the prevalence of hypertension (blood pressure > or = 140/90 mm Hg or use of antihypertensive medication) and risk factors for hypertension (body mass index, lifestyle factors, and psychosocial variables hypothesized to relate to hypertension). Subjects were registered pharmacists and nurses recruited by mail. For the 182 individuals who completed study measurements (95 US-born and 87 African-born), the unadjusted odds ratio for hypertension associated with birthplace was 2.16 (95% CI = 1.12, 3.98). After adjustment for body mass index and age, the OR for birthplace was 1.92 (95% CI = 0.92, 4.00). No lifestyle or psychosocial variables were associated with hypertension prevalence. We conclude that there is a lower prevalence of hypertension in first-generation African immigrants that cannot be readily explained by the environmental effects measured in this study. Larger scale studies with African immigrants could advance understanding of the causes of the increased hypertension prevalence in US-born African Americans.

Africa↗

PubMed1999

Personality and the prediction of weight loss and relapse in the treatment of obesity.

OBJECTIVE: This prospective study examined whether stable personality traits, as measured by the Karolinska Scales of Personality (KSP), predicted initial weight loss or long-term maintenance in obesity patients. METHOD: The KSP was administered to 102 obese patients prior to entering an 8-week weight loss program. Patients were weighed again at the end of treatment and at 3- and 12-month follow-up. RESULTS: The KSP did not predict initial weight loss after the 8-week program. Several of the KSP scales (Muscle Tension, Monotony Avoidance, Suspicion, and Guilt) had weak associations with 12-month relapse status. Weight gain at the 3-month follow-up was the strongest predictor of 12-month relapse status (O.R. = 0.46; 95% C.I. = 0.32, 0.66). DISCUSSION: Personality traits, as measured by the KSP, do not appear to be important predictors of initial weight loss or 12-month relapse status. Personality assessment may not substantially contribute to predicting treatment outcome in obesity research.

Adult↗

PubMed1999

Obesity is an environmental issue.

Obesity is an environmental issue. Societies that are transitioning to westernized lifestyles are experiencing substantial increases in its prevalence. The primary environmental determinants of obesity are high calorie intake and low levels of activity. Socioeconomic status and place of residence are important contributors. These factors together comprise an obesogenic or 'toxic' environment where the development of obesity is the expected course for humans leading lifestyles incompatible with their evolutionary development. Only by addressing and modifying the toxic environment will we be able to stem the obesity epidemic.

Animals↗

PubMed1999

Early identification of Mexican American children who are at risk for becoming obese.

OBJECTIVE: To describe the problem of obesity in Mexican American children and provide a method for identifying Mexican American children at risk for obesity. DESIGN: Cross-sectional and retrospective cohort study. SUBJECTS: Mexican American children, ages 5-11 (kindergarten (K)-5th grade) were studied in cross-sectional (girls = 463, boys = 448) and retrospective (girls = 124, boys = 92) samples. MEASUREMENTS: Weights (kg) and heights (cm) were extracted from each child's school medical records. Measurements were made by the school nurses (one nurse per school). Body mass index (BMI [w/h2]) was calculated from obtained weights and heights. RESULTS: The prevalence of obesity in the cross-sectional sample was 27.4% for girls and 23.0% for boys. The highest prevalence was noted in 4th grade for both the girls (32.4%) and boys (43.4%). The 5 year incidence rates derived from the retrospective sample were 17.7% for girls and 21.1% for boys. The largest increase in the number of girls becoming obese was observed between K and 1st grade (15.6%). The largest increase for boys was found between the 1st and 2nd grades (13.2%). Logistic regression parameters were calculated to estimate the probability of becoming obese in 5th grade given a child's K BMI. Using the generated equation, BMIs in K equal to 16.5, 20.9, and 23.7 would have a 21.0%, 70.0%, and 91.0% probability of being obese by 5th grade. CONCLUSION: This study provides schools with a simple procedure for identifying Mexican American children at risk for obesity. This procedure may assist in the development and implementation of interventions aimed at averting the onset of obesity in this population.

Body Mass Index↗

PubMed1999

The challenge of diet, exercise and lifestyle modification in the management of the obese diabetic patient.

Type 2 diabetes is associated with many comorbid medical conditions including obesity, neuropathy, microvascular pathology and atherosclerotic arterial disease. Due to its complications and chronicity, reducing risk factors such as obesity and sedentary lifestyle through lifestyle modification is crucial to the long-term health of patients with type 2 diabetes. Patients must learn how to adopt lifelong, low-fat eating habits and regular activity patterns, with formal treatments focusing on weight loss, increased physical activity and low-fat, low-saturated fat diets. In this article we review the efficacy of lifestyle modification programmes for obese diabetic patients. In addition, we discuss barriers to lifestyle changes and methods for improving long-term adherence. Finally, we present information on how this approach has been adapted to a group of Mexican Americans in the USA, a population at high risk for type 2 diabetes, obesity and sedentary lifestyle.

Diabetes Complications↗

PubMed1999

An examination of body weight standards and the association between weight and health behaviors in the United States Air Force.

This study examined the weight standards used by the U.S. Air Force and tested whether Air Force personnel who exceed the maximum allowable weight standard are more likely to engage in health risk behaviors compared with individuals who do not exceed current Air Force weight standards. Participants were 32,144 individuals who completed basic military training from August 1995 to August 1996. Compared with body mass levels known to predict increased health risks, the Air Force maximum allowable weight standards were found to be more stringent for women than for men. Furthermore, exceeding the maximum allowable weight standard of the weight management programs did not consistently indicate that an individual engaged in a less healthy lifestyle than other airmen. Perhaps other risk factors, such as cigarette smoking, may be more closely linked to negative health consequences than body weight.

Adolescent↗

PubMed1998

The predictive validity of the Diet Readiness Test in a clinical population.

OBJECTIVE: To evaluate the psychometric properties, including the factorial and predictive validity, of the Diet Readiness Test (DRT) in a clinical population. METHOD: The DRT was administered to 132 women who participated in an obesity and binge eating treatment study. RESULTS: The DRT demonstrated adequate internal consistency. The DRT's proposed factor structure was not supported. Neither the DRT subscales nor the derived factors predicted changes in weight, binge eating, or exercise. DISCUSSION: The DRT did not demonstrate factorial or predictive validity in this study. Based on the DRT's cutoff criteria, 100% of the sample was considered not ready to begin a weight loss program, suggesting that the DRT may have limited utility with clinical populations.

Adult↗

PubMed1998

What is the role of cognitive-behavior therapy in patient management?

This review summarizes the role of cognitive-behavior therapy (CBT) in obesity treatment. Although not a specific intervention per se, CBT is the systematic application of principles of social cognitive theory to modify behaviors that are thought to contribute to or maintain obesity. Most forms of CBT include the use of five strategies: self-monitoring and goal setting; stimulus control for the modification of eating style, activity, and related habits; cognitive restructuring techniques that focus on challenging and modifying unrealistic or maladaptive thoughts or expectations; stress management; and social support. The use of these strategies in comprehensive obesity programs has been helpful in improving short-term weight losses, but long-term success remains elusive, even though these strategies are predictors of long-term weight loss maintenance. Given that obesity is a chronic condition, not unlike hypertension or diabetes, CBT interventions will need to focus on broader treatment outcomes, such as improved metabolic profiles, quality of life, psychological functioning, and physical fitness. In addition, new methods for delivering CBT interventions should be explored, including home-based programs and combination with adjunctive pharmacotherapy delivered in primary care centers.

Cognitive Behavioral Therapy↗

PubMed1998

D4 dopamine receptor gene exon III polymorphism and obesity risk.

Many genes have been identified that may play a role in increasing individual susceptibility to obesity. Reduced dopamine function appears to play a role in dysfunctional eating patterns and may predispose some individuals to obesity. The long version of the D4 dopamine receptor gene (D4DR) has been shown to alter receptor function and reduce intracellular response to dopamine. It also has been associated with novelty-seeking-related personality traits that are found with greater frequency in obese individuals. We examined the association between the long alleles of the D4DR and obesity in a sample of 115 obese patients participating in a weight management program. No direct relationship was found between the D4DR and body mass or novelty-seeking-related personality traits. We constructed four models of increased obesity risk that included combinations of traditional risk factors (i.e., long-term history of obesity, parental obesity, a body mass index > 40) and elevations on the novelty-seeking-related scales of the Karolinska Scales of Personality. There was a significant increase in the frequency of the D4DR long alleles in individuals defined as high risk using the combination of novelty-seeking-related personality traits, severe obesity (i.e., BMI > 40), and any other traditional risk factor, but not with the traditional risk factors alone. These preliminary data suggest a potential role for the D4DR gene in increasing obesity susceptibility.

Adult↗