Bernardo Hernández

La investigación sobre apoyo social en salud: situación actual y nuevos desafíos

On the borderline between sociology and psychology, the concept of social support has made it possible to develop a whole research tradition aimed at explaining some of the differences existing in the distribution of mental and physical disease. The concept of social support itself, however, still presents some ambiguities which must be clarified. These problems are discussed and it is showed and shows that the topic can be enriched with the contribution of the social sciences. Different definitions of the concept itself, are briefly analysed and the complexity and multidimensional character of social support are highlighted. The association between social support and health is discussed. The differences and implications of the direct effect model and the buffering effect model are addressed, and the relevance of the construct of social support is enhanced. The need to study social support not only as a likely determinant of some forms of disease, but also as a dependent variable, is brought out. Some recent developments in the study of factors associated with the availability of social support are discussed. It is shown that social support is a product of certain social factors which can be clearly identified by sociological analysis. In order to illustrate this point, the structural determinants of a specific dimension of social support-attention-are discussed. The importance of structural variables like social class and gender in attempting to explain the differential distribution of certain forms of social support is emphasized. It is proposed, on the theoretical level, that the intersection between two related autonomous constructs-social class and social support-may better explain those aspects of these concepts that are of importance to observed heterogeneity in the distribution of mental and physical health. Different theoretical and methodological approaches to the understanding of the determinants of social support and its effect on health are suggested.

Peak bone mineral area density and determinants among females aged 9 to 24 years in Mexico

Introduction: Peak bone mineral area density is the amount of bone tissue present when skeletal maturation is completed. The exact age at which bone accumulation reaches a plateau varies with skeletal region. In Mexico and other Latin American countries, there are very few reports on bone mineral area density at early age. Material and methods: A cross-sectional study of 461 females between 9 and 24xa0years of age in Cuernavaca, Mexico, distributed proportionately by age group, determined the bone mineral density (BMD) in femur, lumbar spine, and subcranial skeleton, using a Hologic 4500-Series A osteodensitometer. The peak bone mineral area density (PBM) was determined by using the sigmoid growth model defined by Raymond-Pearl (CSRP). Cohort comparisons among different age groups were developed to evaluate BMD in three skeletal regions, with the Dunnett test, comparing the slopes of BMD by each age stratum. Also, the primary determinants of BMD were evaluated through models of multiple linear regression. Results: The timing of PBM is highly site specific with some skeletal regions reaching PBM earlier: beginning with the femur, and later reaching the lumbar spine and subcranial skeleton. Using a multivariate model, age and body weight were important predictors of BMD in the three anatomical regions studied (p<.001). The percentage of fat is associated in an inversely proportionate manner (p<.005), as independent predictors for BMD in the lumbar spine. The age of the onset of menstruation is also a predictor of BMD in the lumbar spine (p<0.05); vigorous activity is an important predictor in the subcranial skeleton (p<0.001). Discussion: For Mexican females in the state of Morelos, the BMD are similar to that reported in a number of ethnic groups. In mestizo females the timing of PBM is highly site specific with some skeletal regions acquiring PBM earlier: specifically, in the femoral region where PBM rapidly reached a plateau. In Mexico, early strategies for preventing osteoporosis should be focused on promoting physical activity and appropriate eating habits (control of obesity, among others) during the puberty stage.

Chronic disease risk factors among healthy adolescents attending public schools in the state of Morelos, Mexico

BACKGROUNDnLittle research (and fewer interventions) has been done on longitudinal exposure to risk factors for chronic diseases in young people in Latin America, including Mexico, although chronic diseases constitute the first cause of death in Mexico. Our objective was to document the prevalence of chronic disease risk factors among adolescents as a baseline measurement for a cohort study and to develop educational interventions.nnnMETHODSnQuestionnaires, blood samples, and anthropometric measurements were collected from 13,293 public school students of both sexes, ages 11-24 years in Morelos, Mexico. This constitutes the baseline measurement for a cohort study. Twenty focus groups and 10 in-depth interviews were done with girls aged 12-17 years. Two educational interventions promoting physical activity and sexual health were designed.nnnRESULTSnPrevalence of obesity was 21.2%. On average, participants spent 0.5 h/day on vigorous physical activity and 3.7 h/day watching television. Sexual initiation was reported by 14.5% (girls = 9.1%, boys = 21.5%); 52.3% of whom reported using condoms. Young women demonstrated correct condom use and perceived themselves at risk for HIV/AIDS but did not have condom negotiation skills. Prevalence of experimenting with tobacco was 15.1% (girls = 10.4%, boys = 21.1%); current smoking was 14.4% (girls = 10.6%) and boys = 19.2%), while 6.3% of participants reported monthly intoxication with alcohol, and 4.5% reported past and 2.1% reported current illegal drug use.nnnCONCLUSIONSnResults indicate substantial exposure to risk factors for chronic diseases and reproductive health problems in this population. The study will generate interventions and constitutes initiation of a longitudinal study able to explore causal associations between risk factors and chronic diseases in this population.

A Study on Maternal Mortality in Mexico Through a Qualitative Approach

This report presents the main qualitative results of a verbal autopsy study carried out in three states of Mexico, which aimed at identifying the factors associated with maternal mortality that could be subject to modifications through concrete interventions. By reviewing death certificates issued in 1995, it was possible to identify 164 households where a maternal death had occurred. One hundred forty-five of these households were visited, and a precoded questionnaire was completed to explore socioeconomic and living conditions, as well as causes of death. An open-ended question to prompt the relatives to narrate all the facts that led to the maternal deaths was included in the questionnaire. This study presents an analysis of that question, focusing on the delays in the care-seeking process and organized according to the model of the three delays: in deciding to seek care, in reaching a care facility, and in actually receiving care after arrival. Additionally, problems related to quality of care are examined. For analysis of the accounts, structural, interactional/community, and subjective variables were identified that allowed refining of our understanding of the problem of maternal deaths. Finally, based on the findings of the study, this article presents a series of recommendations, highlighting that interventions should address the early stages of a complication and focus on decreasing the various forms of inequality (gender and socioeconomic) associated with the occurrence of maternal deaths.

Current wheezing, puberty, and obesity among mexican adolescent females and young women.

Background. Studies suggest an association between obesity and asthma. This may be modified by the physiological changes of puberty. We aim to explore the relation between overweight and current asthma among Mexican adolescent females and young women and evaluate how puberty may modify this association. Methods. Adolescent females (n = 6944) and young women aged 11–24 years provided data. Current asthma was defined as wheezing in the last 12 months and obesity by body mass index (BMI). Puberty was defined by age at menarche. The association of obesity and current wheezing was evaluated by using logistic regression adjusting for confounders. The impact of puberty was studied by using stratified analysis by age at menarche. Results. The prevalence of current wheezing was 16.2% (95% CI 15–17). Compared with girls of normal weight (BMI 15 to ≥ 85 percentile), obese girls (BMI ≥ 95 percentile) had an increased risk of current wheezing of 19% (OR = 1.19; 95% CI 0.97–1.46). After stratifying by age at menarche, we observed that this increased risk was only present in girls with menarche at 11 years old or younger (1.31%; 95% CI 1.01–1.73). Conclusions. The association between obesity and asthma seems to be greater among girls with early puberty, suggesting the role of female hormones.