Luis Ortiz-Hernández

Computer use increases the risk of musculoskeletal disorders among newspaper office workers

BACKGROUND Our objectives were to estimate prevalence of musculoskeletal disorders among office workers at a newspaper in Mexico City, analyze the relationship between musculoskeletal disorders and use of the personal computer (PC) and associated ergonomic factors in the aforementioned population, and to analyze the modifying effect that psychosocial factors have on the relationship between ergonomic factors and musculoskeletal disorders and extant jobs at the newspaper. METHODS A total of 73% (218 of 298) of office workers at a newspaper were studied. Information was collected by a questionnaire completed by participants. Cases for work-related musculoskeletal disorder in hands (WMSD-H), upper extremity (WMSD-UE), and back (WMSD-B) were established. Working conditions, computer use, and ergonomic and psychosocial factors were studied as independent variables. To study the relationship between musculoskeletal disorders and independent variables, prevalence ratios adjusted for potential confounders (sex, age, educational level, and marital status) were estimated. RESULTS Risk of musculoskeletal disorders was greater among workers at the newspaper who used computers, those involved in editing work, and those who adopted uncomfortable positions. The modifying effect of psychosocial factors was observed only in the relationship between ergonomic factors and WMSD-B because among workers with control over work, WMSD-B risk was reduced by the greater number of work breaks. Among workers without social support, increase in number of postures and rotation/inclination of the neck was associated with substantial risk increase, while amid workers under psychological demand number of PC tasks and number of rest pauses were associated with increase in WMSD-B risk. CONCLUSIONS The findings of our study showed that PC use increased risk of developing musculoskeletal disorders (WMSD-H and WMSD-UE). Such an increase is mediated by ergonomic factors such as mouse use, remaining seated for prolonged periods, adoption of inadequate or uncomfortable postures, performing certain PC tasks, and psychosocial factors.

The association of sexual orientation with self-rated health, and cigarette and alcohol use in Mexican adolescents and youths

Evidence of health inequities associated with sexual orientation has been gathered for industrialized countries. The situation for lesbians, gay males, and bisexuals (LGB) from middle- or low-income countries may be worse than those in industrialized nations. Here, we analyze the relationship of sexual orientation with self-rated health and cigarette and alcohol use among a representative sample of Mexican adolescents and youths between the ages of 12 and 29 years, in order to explore whether this association is mediated by discrimination and violence. Three dimensions of sexual orientation (affective attraction, sexual behavior, and identity) were assessed. The outcomes were self-rated health and cigarette and alcohol use. Compared to heterosexuals, LGB youths more frequently smoked >or=6 cigarettes per day, reported having experienced family violence, having crimes perpetrated against them, and having experienced violations of their rights. Among males, gays and bisexuals exhibited a higher risk of poor health than heterosexuals. Compared to heterosexual women, lesbians and bisexual women were more likely to consume alcohol. Many differences in self-rated health and substance use according to sexual orientation were explained by having experienced discrimination and violence. We concluded that lesbian and bisexual females have a higher prevalence of cigarette and alcohol use. It is necessary to develop policies and programs aimed at the reduction of substance abuse among LGB youths (focusing on females who engage in sexual contact with persons of the same gender) and to work against discrimination and violence experienced by LGB people, particularly against non-heterosexual males.

Efectos de la violencia y la discriminación en la salud mental de bisexuales, lesbianas y homosexuales de la Ciudad de México

The objectives of this study were to estimate the prevalence of suicidal ideation, suicide attempts, mental disorders, and alcoholism in bisexuals, lesbians, and gays in Mexico City and analyze the possible relationship between violence, discrimination, and the mental health of these population groups. A questionnaire was administered to 506 bisexuals, lesbians, and gays attending support organizations and institutions. Eight forms of discrimination and fourteen forms of violence based on sexual orientation were researched. The study found the following prevalence rates: 39.0% suicidal ideation, 15.0% suicide attempts, 27.0% mental disorders, and 18.0% alcoholism. Prevalence of alcoholism was 21.0% among bisexual and lesbian women, which is higher than in other women. Discrimination was correlated with suicide attempts and mental disorders, whereas violence was a risk factor for suicidal ideation, suicide attempts, mental disorders, and alcoholism. Violence and to a lesser extent discrimination suffered by bisexuals, lesbians, and gays are associated with psychological distress, and policies are needed to counter this situation.

Publicidad de alimentos en la programación de la televisión mexicana: ¿los niños están más expuestos?

Objective. To evaluate food advertisements on broadcast television channels in Mexico City. Material and Methods. Between July and October, 2007 programming by the 11 broadcast channels (N=11) in Mexico City was recorded during one weekday and one weekend day. The length of advertisements (N = 9178), types of products, and nutritional content of foods advertised were analyzed. Results. The time devoted to food products advertising was greater during children’s television than during programming targeted to the general audience (25.8 vs. 15.4%). The foods more frequently advertised were sweetened beverages, sweets and cereals with added sugar. Calorie, carbohydrate and fat contents were higher in foods advertised during children’s shows. The two most common marketing strategies were to offer some kind of gift and to link the item to positive emotions. Conclusion. The findings of this research indicate the need for an effective system to regulate advertising directed towards children and adolescents.

Food consumption in Mexican adolescents

OBJECTIVE To examine the relationship between demographic and socioeconomic factors and food consumption in Mexican adolescents. METHODS A representative sample (n=7218) of Mexican adolescents (12-19 years old) was analyzed. Independent variables included age, gender, and main activity of the adolescents; gender and age of the head of household; socioeconomic position; size of town (rural, semiurban, or urban); and area of residence. The consumption frequency of 13 food groups was assessed. Through multivariate logistic regression models, the effect of independent variables over consumption frequency was evaluated. RESULTS Among Mexican adolescents only one-third consumed fruits and vegetables daily, a little less than one-half consumed dairy products daily, one-third drank soft drinks daily, and one-fifth consumed sweets and salty snacks. Males reported higher consumption of legumes. Age increase was associated with higher frequency of milk consumption. Adolescents who worked and those who neither studied nor worked consumed fruits, sweets, and salty snacks less frequently. Eating fruits, vegetables, cereals, dairy products, bread, starchy vegetables, red meat, white meat, and fast food decreased with regard to socioeconomic position; on the other hand, the lower socioeconomic strata had more frequent consumption of legumes and soft drinks. CONCLUSIONS There are groups of adolescents who are less likely to consume healthy foods (such as fruits, vegetables, and dairy products). Socioeconomic and cultural processes that can explain the differences observed are discussed.

Sociodemographic factors associated with physical activity in Mexican adults.

OBJECTIVE To estimate the physical activity level among Mexican adults and to establish the sociodemographic variables that may be linked to active lifestyles. DESIGN Data from a cross-sectional survey were analysed. Physical activity was assessed using the short version of the International Physical Activity Questionnaire. The independent variables were sex, age, socio-economic status and size of town. Ordinal regression models were fitted to assess the association of physical activity levels with sociodemographic factors. SETTING Fieldwork was conducted from November 2002 through April 2003; the non-response rate was 3.1%. SUBJECTS Data from a national representative sample (n 38,746) of Mexican adults aged >18 years old were analysed. RESULTS Almost 60% of the population was classified into the high physical activity level. Women were less active than men in rural areas; in urban areas, the opposite trend was observed. In women, higher socio-economic status was associated with less physical activity, while among men there were no differences. People from rural and urban areas had a higher probability of engaging in physical activity than those from cities. In urban localities and cities, respondents of low socio-economic status had a lower probability of engaging in physical activity. CONCLUSIONS Using a validated instrument to measure physical activity, we found that the prevalence of active lifestyle among Mexican adults was high. The socio-economic and gender inequalities are different according to size of town (i.e. an effect modifier), which must be considered in the design of policies and programmes to promote physical activity.

Violence against bisexuals, gays and lesbians in Mexico City.

Abstract An essential premise of this work is that three dominant ideologies explain oppression against BGL, as a result of a gender system: adhesion to gender stereotypes, androcentrism and heterosexism.Three hundred eighteen bisexual and gay males (BG) and 188 bisexual and lesbian females (BL) were surveyed. By means of a self-applied questionnaire, variables of interest were researched. The following trends were observed: an important number of men and women interviewed suffered violence in their childhood and adolescence because they defied gender stereotypes, and not because of their sexual orientation; BG males were more often victims of violence than BL females. Within the BG group, those who challenged gender stereotypes were more frequently attacked than those who did not; men were identified as aggressors more frequently than women; and in the BG group, gender stereotype transgression was associated with the perception of suffering violence in the future.

Riesgos y daños a la salud derivados del uso de videoterminal

OBJETIVO: Evaluar la relacion de danos a la salud con el uso de videoterminal, riesgos laborales y factores psicosociales en trabajadores de un diario informativo. MATERIAL Y METODOS: En 1998 se estudio una muestra representativa (n=68) de una poblacion de 218 trabajadores de un diario informativo de la Ciudad de Mexico. Se presentan los resultados obtenidos a partir de una encuesta de autoaplicacion, los cuales fueron comparados posteriormente con datos de examenes clinicos. La hipotesis de esta investigacion sustenta que, tanto el uso actual como la exposicion acumulada de videoterminal, se asocian con mayor riesgo de presentar padecimientos visuales, musculo-esqueleticos y dermatologicos; trastornos mentales y psicosomaticos, y fatiga general. Los resultados fueron analizados en funcion de diferentes riesgos laborales: (riesgo visual, trabajo sedentario, uso de mouse, riesgo postural, calor excesivo y hacinamiento) y factores psicosociales derivados de la organizacion del trabajo (demandas psicologicas, control sobre el trabajo y apoyo social). Para valorar su relacion con los danos derivados del uso de videoterminal, se estimaron razones de prevalencias ajustadas por confusores potenciales (edad, sexo y escolaridad). RESULTADOS: Las mujeres presentaron prevalencias mas elevadas de trastornos musculo-esqueleticos en la mayoria de los danos investigados, y las diferencias fueron significativas entre ambos sexos para dermatitis y eczema seborreico. El uso de videoterminal se asocio con mayor riesgo de fatiga neurovisual, trastornos musculo-esqueleticos en manos y extremidades superiores, dermatitis y eczema seborreico. De los riesgos laborales, los mas asociados con trastornos fueron el uso de mouse y el riesgo postural. Los factores psicosociales se relacionaron principalmente con los padecimientos de naturaleza psicologica (trastornos mentales, psicosomaticos y fatiga general). CONCLUSIONES: Con el uso intensivo de videoterminal los padecimientos investigados son frecuentes, en especial, los trastornos musculo-esqueleticos en manos. Ademas, el enriquecimiento de las tareas y el propio control del proceso laboral tuvieron efecto protector contra los trastornos psicosomaticos y la fatiga patologica.

Racism and mental health among university students in Mexico City

OBJECTIVE To assess whether differences exist in experiences of discrimination, perceptions of physical attractiveness, socioeconomic position, and mental health according to students skin color. MATERIALS AND METHODS The population included students from a public university in Mexico City. The following three groups were created based on skin color: white, light brown, and brown. By means of regression models, we evaluated whether differences in mental health according to skin color could be due to experiences of discrimination, perceptions of physical attractiveness, and/or socioeconomic position. RESULTS Students with brown skin had lower levels of self-esteem and vitality and higher levels of fatigue and alcohol consumption. These differences were explained by more frequent experiences of discrimination and because students with brown skin perceived themselves as less attractive. CONCLUSIONS This is one of the first studies to document the possible effects of racism on mental health among the urban population. Verification of these findings in representative samples is required.

Application of Body Mass Index to Schoolchildren of Mexico City

Background: The validity of body mass index (BMI)-for-age for obesity diagnosis in Latin-American children may be limited due to observed cases of overweight without obesity (i.e. body fat excess), possibly due to certain physical characteristics. In the current study, we investigated whether the usefulness of BMI-for-age in the diagnosis of obesity among Mexican schoolchildren is modified by height, trunk length, muscle mass, body frame, or waist circumference. Methods: Our study cohort comprised 1,015 schoolchildren (aged 6–11 years) from Mexico City. Obesity diagnostics were derived from three classifications of BMI-for-age: percentiles of BMI according to the references of the Centers of Disease Control (CDC), the National Center for Health Statistics and the International Obesity Task Force. The area under the curve (AUC, through receiver-operating characteristic curves) and optimal cutoff points (by Youden index) of each classification were calculated. Body fat percentage, triceps skinfold thickness and blood pressure were used as standards. AUC and optimal cutoff point analysis were stratified according to height-for-age, sitting height, elbow breadth, arm muscle area (AMA) and waist circumference. Results: For the general population, the CDC reference had the highest values of AUC (0.94 for triceps skinfold thickness and 0.96 for body fat percentage), and the optimal cutoff point was the 85th percentile. Among schoolchildren with large body frames (measured through elbow breadth) or with high muscle mass (assessed by AMA), the optimal cutoff point was the 95th percentile of the CDC reference. Conclusions: Our results suggest that the percentile cutoff to define obesity in children with high muscle mass or a large body frame should be the 95th percentile, while the 85th percentile can still be used for the other children.