Adolfo Chávez

Bio: Adolfo Chávez is an academic researcher from National Institute of Nutrition, Hyderabad. The author has contributed to research in topics: Population & Malnutrition. The author has an hindex of 18, co-authored 44 publications receiving 1185 citations.

Prevalence and age at development of enamel hypoplasias in Mexican children.

Abstract: Enamel hypoplasias, deficiencies in enamel thickness resulting from disturbances during the secretory phase of enamel development, are generally believed to result from nonspecific metabolic and nutritional disruptions. However, data are scarce on the prevalence and chronological distribution of hypoplasias in populations experiencing mild to moderate malnutrition. The purpose of this article is to present baseline data on the prevalences and chronological distributions of enamel hypoplasias, by sex and for all deciduous and permanent anterior teeth, in 300 5 to 15-year-old rural Mexican children. Identification of hypoplasias was aided by comparison to a published standard (Federation Dentaire Internationale: Int. Dent. J. 32(2):159−167, 1982). The location of defects, by transverse sixths of tooth crowns, was used to construct distributions of defects by age at development. One or more hypoplasias were detected in 46.7% (95% CI= 40.9−52.5%) of children. Among the unworn and completely erupted teeth, the highest prevalence of defects was found on the permanent maxillary central incisors (44.4% with one or more hypoplasias), followed by the permanent maxillary canine (28.0%) and the remaining permanent teeth (26.2 to 22.2%) Only 6.1% of the completely erupted and unworn deciduous teeth were hypoplastic. The prevalence of enamel defects on the permanent teeth was up to tenfold greater than that found in studies of less marginal populations that used the FDI method. The prevalence of defects in transverse zones suggests a peak frequency of hypoplasias during the second and third years for the permanent teeth, corresponding to the age at weaning in this group. In the deciduous teeth, a smaller peak occurs between 30 and 40 weeks post gestation. The frequency of defects after three years of age is slightly higher in females than males, suggesting a sex difference in access to critical resources.

Iron, vitamin B-12 and folate status in Mexico: associated factors in men and women and during pregnancy and lactation.

Abstract: To determine the prevalence and causes of anemia in rural Mexico, blood samples and longitudinal dietary data were collected from 187 women, some pregnant and then lactating, and from 72 men. Blood was used to measure anemia, mean cell volume, and plasma ferritin, folate and vitamin B-12. Anemia was found in 33% of the men, 54% of nonpregnant, nonlactating women, 35% of pregnant women and 41% of lactating women, and varied by season. Low iron stores (ferritin) accompanied anemia in only 8% of men compared with 38-67% of women. Low meat intake and poor dietary iron bioavailability were associated with anemia in women. There were no cases of low plasma folate. Low plasma vitamin B-12 was common in all groups, and the incidence increased from 15% at 7 mo of pregnancy to 30% at 7 mo of lactation. Vitamin B-12 was lower in the plasma and milk of anemic lactating women than in plasma and milk of non-anemic lactating women and was classified as deficient in 62% of breast milk samples.

An analytical approach for exploring the importance of dietary quality versus quantity in the growth of Mexican children.

Abstract: The average annual intake of specific nutrients, foods, food groups, and proxies for nutrient bioavailability of 87 Mexican preschoolers and 110 schoolchildren were compared with their anthropometr...

The relationship between social support and physiological processes: a review with emphasis on underlying mechanisms and implications for health.

Abstract: In this review, the authors examine the evidence linking social support to physiological processes and characterize the potential mechanisms responsible for these covariations. A review of 81 studies revealed that social support was reliably related to beneficial effects on aspects of the cardiovascular, endocrine, and immune systems. An analysis of potential mechanisms underlying these associations revealed that (a) potential health-related behaviors do not appear to be responsible for these associations; (b) stress-buffering effects operate in some studies; (c) familial sources of support may be important; and (d) emotional support appears to be at least 1 important dimension of social support. Recommendations and directions for future research include the importance of conceptualizing social support as a multidimensional construct, examination of potential mechanisms across levels of analyses, and attention to the physiological process of interest.

Applied Longitudinal Data Analysis for Epidemiology: A Practical Guide

Abstract: This book discusses the most important techniques available for longitudinal data analysis, from simple techniques such as the paired t-test and summary statistics, to more sophisticated ones such as generalized estimating of equations and mixed model analysis A distinction is made between longitudinal analysis with continuous, dichotomous and categorical outcome variables The emphasis of the discussion lies in the interpretation and comparison of the results of the different techniques The second edition includes new chapters on the role of the time variable and presents new features of longitudinal data analysis Explanations have been clarified where necessary and several chapters have been completely rewritten The analysis of data from experimental studies and the problem of missing data in longitudinal studies are discussed Finally, an extensive overview and comparison of different software packages is provided This practical guide is essential for non-statisticians and researchers working with longitudinal data from epidemiological and clinical studies

The Duke-UNC Functional Social Support Questionnaire. Measurement of social support in family medicine patients.

Abstract: A 14-item, self-administered, multidimensional, functional social support questionnaire was designed and evaluated on 401 patients attending a family medicine clinic. Patients were selected from randomized time-frame sampling blocks during regular office hours. The population was predominantly white, female, married, and under age 45. Eleven items remained after test-retest reliability was assessed over a 1- to 4-week follow-up period. Factor analysis and item remainder analysis reduced the remaining 11 items to a brief and easy-to-complete two-scale, eight-item functional social support instrument. Construct validity, concurrent validity, and discriminant validity are demonstrated for the two scales (confidant support--five items and affective support--three items). Factor analysis and correlations with other measures of social support suggest that the three remaining items (visits, instrumental support, and praise) are distinct entities that may need further study.

Evidence-Based Nutrition Principles and Recommendations for the Treatment and Prevention of Diabetes and Related Complications

Abstract: Historically, nutrition principles and recommendations for diabetes and related complications have been based on scientific evidence and diabetes knowledge when available and, when evidence was not available, on clinical experience and expert consensus. Often it has been difficult to discern the level of evidence used to construct the nutrition principles and recommendations. Furthermore, in clinical practice, many nutrition recommendations that have no scientific supporting evidence have been and are still being given to individuals with diabetes. To address these problems and to incorporate the research done in the past 8 years, this 2002 technical review provides principles and recommendations classified according to the level of evidence available. It reviews the evidence from randomized, controlled trials; cohort and case-controlled studies; and observational studies, which can also provide valuable evidence (1,2), and takes into account the number of studies that have provided consistent outcomes of support. In this review, nutrition principles are graded into four categories based on the available evidence: those with strong supporting evidence, those with some supporting evidence, those with limited supporting evidence and those based on expert consensus. Evidence-based nutrition recommendations attempt to translate research data and clinically applicable evidence into nutrition care. However, the best available evidence must still be moderated by individual circumstances and preferences. The goal of evidence-based recommendations is to improve the quality of clinical judgments and facilitate cost-effective care by increasing the awareness of clinicians and patients with diabetes of the evidence supporting nutrition services and the strength of that evidence, both in quality and quantity. Before 1994, the American Diabetes Association’s (ADA’s) nutrition principles and recommendations attempted to define an “ideal” nutrition prescription that would apply to everyone with diabetes (3,4,5). Although individualization was a major principle of all recommendations, it was usually done within defined …