SOCIAL AND BIOLOGICAL DETERMINANTS OF SHORT-TERM GROWTH VELOCITY AMONG PRESCHOOLERS OF RURAL GUATEMALA: A PATH ANALYSIS APPROACH (WEIGHT-GAIN, IRON DEFICIENCY, GASTROINTESTINAL SYMPTOMS)

This dissertation develops and tests through path analysis a theoretical model to explain how socioeconomic, socioenvironmental, and biologic risk factors simultaneously influence each other to further produce short-term, depressed growth in preschoolers. Three areas of risk factors were identified: child's proximal environment, maturational stage, and biological vulnerability. The theoretical model represented both the conceptual framework and the nature and direction of the hypotheses. Original research completed in 1978-80 and in 1982 provided the background data. It was analyzed first by nested-analysis of variance, followed by path analysis. The study provided evidence of mild iron deficiency and gastrointestinal symptomatology in the etiology of depressed, short-term weight gain. Also, there was evidence suggesting that family resources for material and social survival significantly contribute to the variability of short-term, age-adjusted growth velocity. These results challenge current views of unifocal intervention, whether for prevention or control. For policy formulations, though, the mechanisms underlying any set of interlaced relationships must be decoded. Theoretical formulations here proposed should be reassessed under a more extensive research design. It is suggested that studies should be undertaken where social changes are actually in progress; otherwise, nutritional epidemiology in developing countries operates somewhere between social reality and research concepts, with little grasp of its real potential. The study stresses that there is a connection between substantive theory, empirical observation, and policy issues. ^

Is obesity associated with increased symptoms of psychiatric morbidity among Indian adolescents?

The relationship between obesity and mental health disorders has not been explored among adolescents in India. Although evidence from western countries has failed to demonstrate conclusive associations, a tremendous increase in the prevalence of obesity and overweight among urban adolescents in India, along with an absolute lack of studies into mental health of Indian adolescents, necessitate the need for research in this population. This present study used data collected from 861 urban 6th and 8th graders from Delhi, India and tested for the associations of weight status with psychiatric symptomatology and other weight related behaviors. The Strengths and Difficulties questionnaire (SDQ) was used to collect data on psychiatric symptoms. Falling into the overweight or obese category was hypothesized to be associated with borderline or abnormal scores on the SDQ scales. Results indicated a high prevalence for overweight/obesity among the population (>30%). No significant associations were demonstrated between weight status and borderline/abnormal SDQ scores on all the scales. However, significant associations were found between sedentary behaviors (screen time >2 hrs daily), positive and negative weight-control behaviors and borderline/abnormal SDQ scores on various scales. In light of these new findings, a further exploration of the relationship in this population is indicated.^

Attention-deficit hyperactivity disorder symptoms and lead exposure in children: A systematic review of literature

Blood lead levels > 10 µg/dL are known to affect various areas of the brain that influence behavior and cause many other health problems in children. As a result, the Centers for Disease Control and Prevention (CDC) set the blood lead action level at 10 µg/dL. However, recent research provides evidence that blood lead levels <10 µg/dL also may lead to behavioral problems in children. With the recent increase in diagnosis of Attention-Deficit Hyperactivity Disorder (ADHD) in children in the U.S. it is important to determine possible environmental toxins such as lead that may play a role in causing ADHD symptoms. The aim of this systematic review of the literature was to identify recent published studies that examine an association between blood lead levels < 10 µg/dL and ADHD symptoms in children in order to summarize their findings and describe major gaps in the literature. Although available research is limited, the articles reviewed indicate that blood lead at levels much below the CDC action level of 10 µg/dL may affect a child's level of attention, hyperactivity, impulsivity and ADHD diagnosis. Additional prospective research is warranted in order to inform the revision of current blood lead action levels as well as better elucidate the relationship between lead and ADHD diagnoses.^

Prevalence of symptoms of neurotoxicity and potential occupational pesticide and solvent exposures among high school students in Starr County, Texas: A pilot study

Numerous harmful occupational exposures affect working teens in the United States. Teens working in agriculture and other heavy-labor industries may be at risk for occupational exposures to pesticides and solvents. The neurotoxicity of pesticides and solvents at high doses is well-known; however, the long term effects of these substances at low doses on occupationally exposed adolescents have not been well-studied. To address this research gap, a secondary analysis of cross-sectional data was completed in order to estimate the prevalence of self-reported symptoms of neurotoxicity among a cohort of high school students from Starr County, Texas, a rural area along the Texas-Mexico border. Multivariable linear regression was used to estimate the association between work status (i.e., no work, farm work, and non-farm work) and symptoms of neurotoxicity, while controlling for age, gender, Spanish speaking preference, inhalant use, tobacco use, and alcohol use. The sample included 1,208 students. Of these, the majority (85.84%) did not report having worked during the prior nine months compared to 4.80% who did only farm work, 6.21% who did only non-farm work, and 3.15% who did both types of work. On average, students reported 3.26 symptoms with a range from 0-16. The most commonly endorsed items across work status were those related to memory impairment. Adolescents employed in non-farm work jobs reported more neurotoxicity symptoms than those who reported that they did not work (Mean 4.31; SD 3.97). In the adjusted multivariable regression model, adolescents reporting non-farm work status reported an average of 0.77 more neurotoxicity symptoms on the Q16 than those who did not work (P = 0.031). The confounding variables included in the final model were all found to be factors significantly associated with report of neurotoxicity symptoms. Future research should examine the relationship between these variables and self-report of symptoms of neurotoxicity.^

Stressful life events and their contributions to symptoms of anxiety and depression in adolescents

There are several innovative aspects to this thesis that extend our current knowledge of the relations between stress and psychiatric symptoms in adolescents. First, distal and proximal stressors are differentiated. This approach allows one to specifically examine the role of early childhood stressors as well as stressors experienced more recently as they impact the expression of depression and anxiety during adolescence. Second, a state-of-the-art assessment instrument was used to examine proximal stressors, helping to distinguish several aspects of stress, including objective stress and subjective stress. Third, the parent study from which these data were derived was designed to examine the role of familial risk for depression and related risk factors for the initial development of depression and alcohol use disorders. This allowed for a very thorough collection of demographic characteristics of the study population. Accordingly, this thesis examines the initial prodromal expression of anxiety and depressive symptoms as they are originally expressed prior to the development, if any, of a full-blown psychiatric disorder.^

Analysis of symptoms of rural workers exposed to pesticides

This cross-sectional study was conducted in southern Minas Gerais, in two counties: São Gonçalo do Sapucaí and Silvianópolis. Presented as objective to verify the important variables associated with the occurrence of symptoms of subacute intoxication related to pesticides exposure. A questionnaire was dedicated to a sample of 412 workers. An analysis of non-conditional logistic regression was applied gradually. The likelihood ratio method was used to define the significant variables in the final model. Of the analysed population, 59.2% reported symptoms typical of subacute intoxication. Of the respondents, 91.5% reported knowing the deleterious effects associated with exposure to pesticides. The adjusted model was found with the significant variables: being male that presented Prevalence Odds Ratio (POR) adjusted . PORof 0.54 (95% CI 0.36 to 0.81), already hospitalized for poisoning with pesticides, POR of 3.26 (95% CI 1.08 to 9.82), living in the rural area of residence., POR of 2.17 (95% CI 1.20 to 3.93) and type of employment relationship or temporary employment, POR of 2.32 (95% CI 1.08 to 4.95).

Slater revisited: 6 year follow up study of patients with medically unexplained motor symptoms

Objective: To investigate psychiatric and neurological morbidity, diagnostic stability, and indicators of prognosis in patients previously identified as having medically unexplained motor symptoms.