Smoking Dependence, Time-Discounting, and Sustained Cessation Behavior: A Longitudinal Study of Predominantly Light Smokers.

INTRODUCTION: This study aimed to assess whether two established psychosocial predictors of smoking abstinence, nicotine dependence and time-discounting, also apply to a population of predominantly cigarette light smokers, which is the dominant pattern of smoking in countries like Mexico. Relatively infrequent smoking is increasingly prevalent, yet still harmful, making it important to understand the predictors of cessation in this population. AIMS AND METHODS: Mexican adult smokers recruited from an online consumer panel were surveyed every 4 months between November 2018 and July 2020. We considered respondents who reported a quit attempt in between surveys (n = 1288). Dependence was measured with a 10-item version of the Wisconsin Inventory of Smoking Dependence Motives (WISDM). Time-discounting was assessed with five branching questions about hypothetical reward scenarios. Logistic models regressed sustained quit attempts (≥30 days of abstinence) at time t + 1 on study variables at time t. RESULTS: We found strong interitem reliability (α = 0.92) and intraindividual consistency of our brief WISDM (ρ = 0.68), but moderate intraindividual consistency of the time-discounting measure (ρ = 0.48). Forty-eight percent of the sample reported sustained quit attempts, and 79% were non-daily or light daily smokers (≤5 cigarettes per day). Smokers with higher WISDM-10 had lower odds of sustained quitting and this result remained when controlling for smoking frequency and the Heaviness of Smoking Index (adjusted odds ratio [AOR] = 0.768). Time-discounting was unassociated with sustained quitting. CONCLUSIONS: Our findings suggest that a brief, 10-item multidimensional measure of dependence is useful for predicting sustained quitting in a context of relatively light smoking; time-discounting appears less relevant, although our results are not conclusive because of the low test-retest reliability of our measure. IMPLICATIONS: Given the increase in non-daily and light daily cigarette smoking in many countries, including in Mexico, and the health risks this still poses, it is important to understand the predictors of cessation among relatively light smokers. The WISDM-10 multidimensional measure seems to be a good instrument to assess dependence and predict successful quitting in this population, and possibly more appropriate than physical dependence measures. As such, it could help design and target more suitable cessation treatments for non-daily and daily light cigarette smokers. While this study did not find time-discounting to be a relevant predictor of smoking abstinence, future studies should explore other measures.

Aceptabilidad de propuestas de regulación de los Sistemas Electrónicos de Administración de Nicotina entre consumidores en México.

OBJETIVO: Explorar la aceptabilidad de la actual prohibición de Sistemas Electrónicos de Administración de Nicotina (SEAN) y cuatro propuestas regulatorias (prohibición de saborizantes, espacios libres de emisiones, edad mínima para compra y prohibición de promociones) entre usuarios de nicotina. Material y métodos. Estudio transversal de panel realizado en fumadores y vapeadores mexicanos (no-viembre 2018-marzo 2020). Mediante análisis de regresión logística se estimaron razones de momios ajustadas (RMa) para evaluar la asociación entre las variables independientes y el apoyo a la prohibición y cuatro propuestas regulatorias. RESULTADOS: El apoyo de la prohibición fue de 20%. El nivel de aceptación de las propuestas fue de 21% prohibición de sabores, 23.2% prohibición de promociones, 40.5% espacios libres de emisiones, y 47.9% edad mínima para compra. Con-clusiones. En México existe un rechazo generalizado de los usuarios de nicotina a la prohibición de los SEAN, y mayor aceptación sobre regulación de espacios libres de emisiones y edad mínima de compra.

Why Smoke Flavor Capsule Cigarettes? Preferences and Perceptions Among Adult Smokers in Mexico.

INTRODUCTION: Flavor capsule cigarettes are rapidly gaining global market share, particularly in Latin America; however, little is known about consumer profiles and perceptions since the diffusion of this product innovation has become more widespread. AIMS AND METHODS: This paper compares profiles and perceptions of smokers who prefer flavor capsule cigarettes and those who do not in Mexico. We analyzed data from six online surveys of adult Mexican smokers (n = 4488) from 2018-2020. Participants identified their preferred brand variety characteristics (no capsule; one capsule; two capsules), and reported perceptions of their brand varieties' flavor, smoothness, harmfulness, and whether they smoke to control their appetite. Separate multinomial logistic models regressed preferred cigarette type on sociodemographic and smoking-related variables, as well as perceived benefits on preferred cigarette type, adjusting for covariates. RESULTS: Most participants preferred capsule cigarettes (single capsule = 47.5%; double capsule = 12.9%). Flavor capsule users reported that their preferred varieties mostly tasted like menthol/mint (59% of single capsule users and 23% of double capsule users), cucumber (12% and 27%, respectively) or berries (10% and 22%, respectively). Females were more likely than males to prefer either single or double capsule cigarettes (AOR = 2.26 and 2.01, respectively). Preference for flavor capsules was also higher among younger smokers, e-cigarette users, those who smoke less frequently, and those who recently tried or plan to quit. Smokers who preferred capsules were more likely than non-capsule smokers to perceive their cigarettes as smoother, less harmful, and to smoke to control their appetite. CONCLUSIONS: The high prevalence of capsule use and widespread perceptions of the benefits of capsules over traditional cigarettes may help explain why tobacco control policies have not reduced smoking prevalence in Mexico. IMPLICATIONS: Flavor capsules are rapidly growing in popularity in many countries around the world, including Mexico. This study found that more Mexican adult smokers prefer brand varieties with capsules (60%) than without capsules (40%), that flavor capsule use strongly correlates with menthol cigarette use, and that perceived flavors of capsules range widely. Flavor capsule smokers have more positive smoking expectancies (eg, lower risk perceptions, dietary control) than noncapsule smokers. Capsules appeal particularly to women, young adults, less frequent smokers, and those who recently tried to quit. Policies should consider banning flavors in cigarettes, including capsules and other filter innovations.

Soft drink and non-caloric soft drink intake and their association with blood pressure: the Health Workers Cohort Study.

BACKGROUND: A few prospective studies have investigated the potential association of soft drink and non-caloric soft drink intake with high blood pressure using methods that adequately consider changes in intake over time and hypertensive status at baseline. OBJECTIVE: To prospectively examine the association of soft drink and non-caloric soft drink intake with systolic and diastolic blood pressure in a sample of Mexican adults, overall and by hypertension status. METHODS: We used data from the Health Workers Cohort Study spanning from 2004 to 2018 (n = 1,324 adults). Soft drink and non-caloric soft drink intake were assessed with a semiquantitative food frequency questionnaire. We fit multivariable-adjusted fixed-effects models to test the association of soft drink and non-caloric soft drink intake with systolic and diastolic blood pressure. The models were adjusted for potential confounders and considering the potential modifying effect of hypertension status at baseline. RESULTS: A one-serving increase in soft drink intake was associated with a 2.08 mm Hg (95% CI: 0.21, 3.94) increase in systolic blood pressure and 2.09 mm Hg (95% CI: 0.81, 3.36) increase in diastolic blood pressure over ten years. A stronger association between soft drink intake and diastolic pressure was observed among participants with versus without hypertension at baseline. We found no association between non-caloric soft drink intake and blood pressure. CONCLUSIONS: Our findings support the hypothesis that soft drink intake increases blood pressure. While further studies should be conducted to confirm our findings, food policies and recommendations to limit soft drink intake are likely to help reduce blood pressure at the population level. We probably did not find an association between non-caloric soft drink intake and blood pressure because of the low consumption of this type of beverage in the cohort. More studies will be needed to understand the potential effect of non-caloric beverages on blood pressure.

Exposure to e-cigarette advertising and provaping websites, and the social acceptability of their use among nicotine users.

Objectives: To evaluate the prevalence of exposure to Internet communications on and advertising of electronic cigarettes (e-cigarettes) and their association with perceptions of the social acceptability of e-cigarettes in Mexico. Methods: Data were analyzed from eight surveys (2018-2021) of an online sample of Mexican adult (> 18 years) smokers and dual users (of combustible and electronic cigarettes). Self-reported exposure to e-cigarette advertising across various marketing channels was assessed, as well as visits to e-cigarette websites. Logistic regression analysis was used to evaluate the association between perceptions of the social acceptability of e-cigarette use and level of advertising exposure and visits to e-cigarette websites. Results: The Internet and outside e-cigarette stores were where exposure to advertising most occurred, as reported by 47.4% and 46.8% of respondents, respectively. Respondents who noticed e-cigarette advertisements on the Internet (adjusted odds ratio (OR) 1.43, 95% confidence intervals (CI) 1.25, 1.63), outside e-cigarette stores (adjusted OR 1.31, 95% CI 1.14, 1.50), and in temporary outlets (adjusted OR 1.16, 95% CI 1.01, 1.34), and those who visited e-cigarette websites (adjusted OR 1.48, 95% CI 1.25, 1.76) were more likely to perceive e-cigarettes as socially acceptable. Noticing advertisements across more channels was also associated with higher perceived social acceptability of e-cigarette use. Conclusions: Being exposed to e-cigarette marketing, either online or through traditional marketing channels, is associated with perceived social acceptability of e-cigarette use, as is contact with provaping sites. Regulatory options to avoid the proliferation of promotional websites disguised as opinion or user sites need to be considered.

Screen-Based Sedentary Behaviors and Their Association With Metabolic Syndrome Components Among Adults in Mexico.

INTRODUCTION: Approximately 25% of the adult population worldwide and 49.8% of Mexican adults have metabolic syndrome. Metabolic syndrome is the result of unhealthy dietary and sleeping patterns, sedentary behaviors, and physical inactivity. The objective of our study was to evaluate the association between sedentary behaviors as screen-based sedentary time (SBST) and each component of metabolic syndrome among adults who participated in the Mexico National Survey of Health and Nutrition Mid-way 2016. METHODS: We analyzed sociodemographic, clinical, and physical activity data from 3,166 adults aged 20 years or older. The International Physical Activity Questionnaire was used to evaluate sedentary behavior. SBST was obtained by counting minutes per week spent watching television, playing video games, and interacting with computers and smartphones. We used Poisson regression to estimate the prevalence ratio of time in front of screens as a continuous variable and its association with metabolic syndrome. RESULTS: The mean (SD) hours per day of SBST in men was 3.6 (0.4) and in women was 2.8 (0.2). The prevalence of metabolic syndrome was 59.6%. In men, the risk for metabolic syndrome increased 4% (P < .05) for each hour of SBST. Similarly, for each hour of SBST, the risk of abdominal obesity increased by 4% (P < .01). In women, we observed that the risk of hypertension or high-density lipoprotein cholesterol deficiency increased for each hour of SBST, and the risk of abdominal obesity increased for each hour of SBST in those who were inactive. CONCLUSION: Sedentary behavior based on screen time is associated with metabolic syndrome and its components among Mexicans, depending on hours of sleep. Current public health policies should consider strategies for reducing SBST.

Understanding adherence of hypertensive patients in Mexico to an exercise-referral scheme for increasing physical activity.

Among the strategies developed thus far for promoting physical activity (PA), exercise-referral schemes (ERs) have gained in popularity as an effective means of preventing secondary health conditions such as hypertension. However, information on the factors affecting adherence to these programs is limited. Using a mixed-methods approach, we undertook the present study to determine the factors associated with adherence to a specific ER aimed at increasing PA among the hypertensive patients in a Social Security institution in Mexico. Data were obtained through semi-structured questionnaires and interviews as well as from the clinical records of participants. For the quantitative component, multinomial regression analysis estimated the factors behind the varying levels of adherence. For the qualitative component, we performed a content analysis based on the health belief model. According to our findings, 80% of participants who began the ER exhibited high levels of adherence. Older age and being female were the key demographic characteristics of those showing increased adherence. Meanwhile, financial issues, the investment of time required, low perception of the benefits of PA, lack of confidence in being able to achieve changes in lifestyle, and a reluctance to acknowledge the seriousness of their health condition were the principal factors among those who did not join the program or exhibited low levels of adherence. Our findings can serve as a basis for designing PA interventions that take into account individual, cultural and administrative elements in their efforts to improve adherence to PA programs for those suffering from chronic conditions such as hypertension.

Profile and patterns of dual use of e-cigarettes and combustible cigarettes among Mexican adults.

OBJECTIVE: To describe the profile and patterns of dual uses (n=954) and exclusive cigarette users (n=2 070) and determine the correlates of more frequent e-cigarette use among dual users and their reasons for e-cigarette use. MATERIALS AND METHODS: An online survey of Mexican adult smokers. Logistic models regressed dual-use (exclusive smoking vs. dual user) on sociodemographic, smoking varia-bles and substance use behaviors. We conducted censorial binomial models to estimate the correlates of frequency of e-cigarette use among dual users. RESULTS: Dual users were younger had higher education (AOR=2.22) and higher levels of smoking dependence (AOR=1.31), preferred cigarettes with flavor capsules (AOR=1.58) and had recently attempted to quit smoking (AOR=1.38). Marijuana use and being daily smokers were correlates of higher frequency of use among dual users. CONCLUSION: Dual users had a higher risk profile than exclusive smokers, which was even more prominent in dual-users who used e-cigarettes frequently.

Diet, physical activity, obesity and related cancer risk: strategies to reduce cancer burden in the Americas.

With increased globalization, Latin America is experiencing transitions from traditional lifestyle and dietary practices to those found in higher income countries. Healthy diets, physical activity and optimal body fat can prevent approximately 15% of cancers in low-income and 20% in high-income countries. We discuss links between diet, obesity, physical activity and cancer, emphasizing strategies targeting children to decrease risk of obesity, control obesity-related risk factors, and reduce sedentary lifestyles, as this will have high impact on adult cancer risk. We focus on individual behaviors, economic, cultural and societal changes that may guide future interventions in the Americas.

América Latina está experimentando transiciones desde estilos de vida tradicional y prácticas dietéticas a las de países de ingresos altos. Las dietas saludables, la actividad física y la grasa corporal óptima pueden prevenir aproximadamente el 15% de cánceres en países de bajos ingresos y 20% en países de ingresos altos. Discutimos los vínculos entre la dieta, obesidad, actividad física y cáncer; haciendo hincapié en estrategias dirigidas a niños, para disminuir el riesgo de obesidad y reducir la vida sedentaria. Nos enfocamos en comportamientos individuales, cambios económicos, culturales y sociales que pueden guiar futuras intervenciones en las Américas.

Preventive health services and physical activity improve health-related quality of life in Mexican older adults.

OBJECTIVE: To evaluate the combined use of IMSS preventive health services (PHS) and the practice of physical activity (PA) in order to determine their association with the perceived health-related quality of life (HRQoL) of older adults. MATERIALS AND METHODS: A survey-based cross-sectional study was conducted at nine primary health care units (PHCUs) in Mexico City. The 36-Item Short-Form Health Survey evaluated the HRQoL, while PA and PHS use were assessed through self-report. Linear regression analyses were performed to determine the relationship between these three variables. RESULTS: Of the 1 085 older adults who participated in the study, 36.8% used PHS, and 23.3% reported that they engage in PA. After controlling for possible effects due to sociodemographic and health differences, we found that participants who were physically active and used PHS reported better perceived HRQoL scores. CONCLUSIONS: The combined use of preventive practices such as the use of PHS and the practice of PA can help improve the perceived HRQoL of older adults.

OBJETIVO: Determinar la asociación del uso combinado de servicios de salud preventiva (SSP) y la práctica de la actividad física (AF) sobre la calidad de vida relacionada con la salud (CVRS) de los adultos mayores en México. MATERIAL Y MÉTODOS: Estudio transversal en unidades de atención primaria. La percepción de CVRS fue evaluada a través del instrumento SF-36; el nivel de AF, y el uso de SSP, a través de auto-reporte. Se realizaron análisis de regresión lineal para determinar la relación entre estas tres variables. RESULTADOS: De los 1 085 adultos mayores que participaron en el estudio, 36.8% usaron SSP y 23.3% informaron practicar AF. Los adultos mayores físicamente activos y que usaban SSP re- portaron una mejor puntuación de CVRS percibida, ajustando por variables de salud y sociodemográficas. CONCLUSIONES: Prácticas preventivas como la actividad física en conjunto con el uso de servicios preventivos pueden ser útiles para mejorar la percepción de CVRS de los adultos mayores.

Physical activity and calorie intake mediate the relationship from depression to body fat mass among female Mexican health workers.

BACKGROUND: Depression is a foremost cause of morbidity throughout the world and the prevalence of depression in women is about twice as high as men. Additionally, overweight and obesity are major global health concerns. We explored the relationship between depression and body fat, and the role of physical activity and diet as mediators of this relationship in a sample of 456 adult female Mexican health workers. METHOD: Longitudinal and cross-sectional analyses using data from adult women of the Health Workers Cohort Study (HWCS) Measures of body fat mass (kg from DEXA), dietary intake (kcal from FFQ), leisure time activity (METs/wk) and depression (CES-D) were determined in two waves (2004-2006 and 2010-2011). We explored the interrelation between body fat, diet, leisure time, physical activity, and depression using a cross-lagged effects model fitted to longitudinal data. We also fitted a structural equations model to cross-sectional data with body fat as the main outcome, and dietary intake and physical activity from leisure time as mediators between depression and body fat. RESULTS: Baseline depression was significantly related to higher depression, higher calorie intake, and lower leisure time physical activity at follow-up. From our cross-sectional model, each standard deviation increase in the depression score was associated with an average increase of 751 ± 259 g (± standard error) in body fat through the mediating effects of calorie intake and physical activity. CONCLUSIONS: The results of this study show how depression may influence energy imbalance between calories consumed and calories expended, resulting in higher body fat among those with a greater depression score. Evaluating the role of mental conditions like depression in dietary and physical activity behaviors should be positioned as a key research goal for better designed and targeted public health interventions. TRIAL REGISTRATION: The HealthWorkers Cohort Study (HWCS) has been approved by the Institutional IRB. Number: 2005-785-012.

Comparison of quality of life among community-dwelling older adults with the frailty phenotype.

PURPOSE: To compare the perception of the quality of life (QOL) of community-dwelling older adults with the phenotype of frailty. METHODS: Cross-sectional analysis of baseline data of the "Cohort of Obesity, Sarcopenia and Frailty of Mexican Older Adults" (COSFOMA). Operationalization of frailty was carried out using the phenotype as follows: weight loss, self-report of exhaustion, low physical activity, slow gait, and weakness. QOL was measured using two scales: World Health Organization Quality of Life of Older Adults (WHOQOL-OLD), which is a specific instrument for the elderly population, and Short Form-36 Health Survey (SF-36), a generic instrument to evaluate the QOL related to health. One-way analyses of variance were conducted to assess the differences among the three phenotypes of frailty and QOL perception. RESULTS: There were 1252 older adult participants who were analyzed; 11.2% (n = 140) had frailty, 50.3% (n = 630) pre-frailty and 38.5% (n = 482) were not frail. The mean (±SD) total score of the WHOQOL-OLD according to the phenotype of frailty was 60.3 (13.9) for those with frailty, 67.4 (12.7) pre-frailty and 72.4 (11.2) not frail (ANOVA, p < 0.001). The mean (±SD) of the SF-36 of the physical and mental component measures the sum, 38.9 (9.9) and 41.9 (11.3) with frailty, 45.7 (9.1) and 46.6 (9.8) pre-frailty, and 49.6 (7.3) and 49.4 (7.9) not frail, respectively (ANOVA, p < 0.001). CONCLUSIONS: Frailty is observed in 1/10 community-dwelling older adults. Those with frailty and pre-frailty had a lower perception of QOL compared with those who were not frail.

Influence of mealtime habits on the risk of weight gain and obesity in Mexican adults.

OBJECTIVE: To prospectively examine the extent to which mealtime habits influences the risk of weight gain and obesity in Mexican adults. DESIGN: We performed a prospective cohort study. The Mealtime Habits Quality (MHQ) scale was used for assessing participants' MHQ; the outcomes of interest were gain ≥5 % of body weight, developing overweight/obesity and abdominal obesity, after 7 years of follow-up. In order to estimate the independent effect of MHQ on anthropometric indicators, generalized linear models were computed to obtain adjusted relative risks (95 % CI). SETTING: The state of Morelos, Mexico. SUBJECTS: Mexican adults (n 837) aged 18-70 years participating in a cohort study. RESULTS: Compared with participants classified in the higher MHQ category, individuals in the middle and lower MHQ groups had a 4·1 (2·5, 6·7) and 6·2 (3·9, 9·7) fold greater risk of gain ≥5 % of body weight, respectively; 6·6 (2·8, 15·5) and 8·6 (3·7, 19·8) fold greater risk of becoming overweight/obese, respectively; and 3·8 (2·0, 7·3) and 5·3 (2·8, 9·8) fold greater risk of developing abdominal obesity, respectively. CONCLUSIONS: This study provides evidence about the influence of a set of mealtime habits on obesity indicators, showing that greater adherence to unadvisable mealtime habits increases the risk of developing unhealthy anthropometric indicators. Since the meal is one of the most important sources of food intake, and consequently weight status, the MHQ scale can be a useful population tool to predict weight gain and obesity.

Health workers cohort study: methods and study design.

OBJECTIVE:: To examine different health outcomes that are associated with specific lifestyle and genetic factors. MATERIALS AND METHODS:: From March 2004 to April 2006, a sample of employees from three different health and academic institutions, as well as their family members, were enrolled in the study after providing informed consent. At baseline and follow-up (2010-2013), participants completed a self-administered questionnaire, a physical examination, and provided blood samples. RESULTS:: A total of 10 729 participants aged 6 to 94 years were recruited at baseline. Of these, 70% were females, and 50% were from the Mexican Social Security Institute. Nearly 42% of the adults in the sample were overweight, while 20% were obese. CONCLUSION:: Our study can offer new insights into disease mechanisms and prevention through the analysis of risk factor information in a large sample of Mexicans.

Perceived health status and cardiometabolic risk among a sample of youth in Mexico.

PURPOSE: To examine differences in self-reported perceived mental and physical health status, as well as known cardiometabolic risk factors in a sample of normal weight, overweight, and obese Mexican youths. METHODS: Cross-sectional analysis of 164 youths aged 11-18 years recruited in Cuernavaca, Mexico. Participants completed a self-administered questionnaire that included measures of generic and weight-specific quality of life, perceived health, physical function, depressive symptoms, and body shape satisfaction. Height, weight, and waist circumference were measured, and body mass index (BMI) was determined. Fasting blood samples from participants yielded levels of glucose, triglycerides, and cholesterol (total, HDL, and LDL). RESULTS: Nearly 50 % of participants were female, 21 % had a normal BMI, 39 % were overweight, and 40 % were obese. Obese youths reported significantly lower measures of perceived health status (PHS) and showed an increase in cardiometabolic risk, compared with normal weight youths. Physical functioning, generic and weight-specific QoL were inversely associated with BMI, waist circumference, and glucose. Depressive symptoms were positively correlated with BMI, waist circumference, glucose levels, and HDL cholesterol. No correlation was found between PHS and cardiometabolic risk measures after controlling for BMI. CONCLUSIONS: In this sample of Mexican youths, obesity was associated with a significantly lower PHS and increased cardiometabolic risk.

Recreational physical activity is inversely associated with asymptomatic gallstones in adult Mexican women.

BACKGROUND AND RATIONALE: Epidemiologic research suggests that physical activity (PA) reduces the risk of chronic diseases including gallstones. OBJECTIVE: This study explores the association between recreational physical activity (RPA) and risk of asymptomatic gallstones (AG) in adult Mexican women. MATERIAL AND METHODS: We performed a cross-sectional analysis of women from the Health Workers Cohort Study. The study population included Mexican women aged 17-94 years, with no history of gallstone (GS) or cholecystectomy. A self-administered questionnaire was used to collect information on weight change, gynecological health history, cholesterol-lowering medications and diuretics, history of diabetes mellitus type 2 (DM2), PA and diet. PA was calculated in minutes/day, minutes/week and Metabolic Equivalents (METs)/week. Gallstone diagnosis was performed using real-time ultrasonography. The association between RPA and risk of AG was evaluated using multivariate logistic regression models. Results. Of the 4,953 women involved in the study, 12.3% were diagnosed with AG. The participants with AG were significantly older, had a higher body mass index, and had a higher prevalence of DM2 than those without AG. The participants with > 30 min/day of RPA had lower odds of AG (OR = 0.80; 95% CI: 0.65-0.97; P = 0.03), regardless of other known risk factors for gallstone disease. Furthermore, we observed an inverse relationship between RPA time and AG risk, especially in women doing more than 150 min a week of RPA (OR = 0.76; 95%CI: 0.61- 0.95; P = 0.02). CONCLUSION: These findings support the hypothesis that RPA may protect against AG, although further prospective investigations are needed to confirm this association.

Exercise-referral scheme to promote physical activity among hypertensive patients: design of a cluster randomized trial in the Primary Health Care Units of Mexico's Social Security System.

BACKGROUND: Although the benefits of physical activity (PA) on to prevent and manage non-communicable diseases are well known, strategies to help increase the levels of PA among different populations are limited. Exercise-referral schemes have emerged as one effective approach to promote PA; however, there is uncertainty about the feasibility and effectiveness of these schemes in settings outside high-income countries. This study will examine the effectiveness of a scheme to refer hypertensive patients identified in Primary Health Care facilities (PHCU) of the Mexican social security institution to a group PA program offered in the same institution. METHODS AND DESIGN: We will describe the methods of a cluster randomized trial study designed to evaluate the effectiveness of an exercise referral scheme to increasing physical activity in hypertensive patients compared to a non-referral scheme. Four PHCU were selected for the study; the PHCU will take part as the unit of randomization and sedentary hypertensive patients as the unit of assessment. 2 PHCU of control group (GC) will provide information to hypertensive patients about physical activity benefits and ways to increase it safely. 2 PHCU of intervention group (IG) will refer patients to sports facilities at the same institution, to follow a group-based PA program developed to increase the PA levels with a designed based on the Transtheoretical Model and Social Cognitive Theory. To evaluate the effects of the intervention as well as short-term maintenance of the intervention's effects, PA will be assessed at baseline, at 24 and 32 weeks of follow-up.The main outcome will be the difference before and after intervention in the percentage of participants meeting recommended levels of PA between and within intervention and control groups. PA will be measured through self-report and with objective measure by accelerometer. DISCUSSION: This study will allow us to evaluate a multidisciplinary effort to link the primary care and community-based areas of the same health care system. Our findings will provide important information about the feasibility and effectiveness of an exercise-referral scheme and will be useful for decision-making about the implementation of strategies for increasing PA among hypertensive and other clinical populations in Mexico and Latin America. TRIAL REGISTRATION: Clinicaltrials.gov Identifier: NCT01910935. Date of registration: 07/05/2013.

Accuracy of body fat percent and adiposity indicators cut off values to detect metabolic risk factors in a sample of Mexican adults.

BACKGROUND: Although body fat percent (BF%) may be used for screening metabolic risk factors, its accuracy compared to BMI and waist circumference is unknown in a Mexican population. We compared the classification accuracy of BF%, BMI and WC for the detection of metabolic risk factors in a sample of Mexican adults; optimized cutoffs as well as sensitivity and specificity at commonly used BF% and BMI international cutoffs were estimated. We also estimated conditional BF% means at BMI international cutoffs. METHODS: We performed a cross-sectional analysis of data on body composition, anthropometry and metabolic risk factors(high glucose, high triglycerides, low HDL cholesterol and hypertension) from 5,100 Mexican men and women. The association between BMI, WC and BF%was evaluated with linear regression models. The BF%, BMI and WC optimal cutoffs for the detection of metabolic risk factors were selected at the point where sensitivity was closest to specificity. Areas under the ROC Curve (AUC) were compared among classifiers using a non-parametric method. RESULTS: After adjustment for WC, a 1% increase in BMI was associated with a BF% rise of 0.05 percentage points (p.p.) in men (P<0.05) and 0.25 p.p. in women (P<0.001). At BMI=25.0 predicted BF% was 27.6±0.16 (mean±SE) in men and 41.2±0.07 in women. Estimated BF% cutoffs for detection of metabolic risk factors were close to 30.0 in men and close to 44.0 in women. In men WC had higher AUC than BF% for the classification of all conditions whereas BMI had higher AUC than BF% for the classification of high triglycerides and hypertension. In womenBMI and WC had higher AUC than BF% for the classification of all metabolic risk factors. CONCLUSIONS: BMI and WC were more accurate than BF% for classifying the studied metabolic disorders. International BF% cutoffs had very low specificity and thus produced a high rate of false positives in both sexes.

Risk factors for cardiovascular disease among Mexican-American adults in the United States and Mexico: a comparative study.

OBJECTIVE: To compare cardiovascular disease (CVD) risk factors in a cohort of Mexican health workers with representative samples of US-born and Mexico-born Mexican-Americans living in the US. MATERIALS AND METHODS: Data were obtained from the Mexican Health Worker Cohort Study (MHWCS) in Mexico and the National Health and Nutrition Examination Survey (NHANES) IV 1999-2006 in the US. Regression analyses were used to investigate CVD risk factors. RESULTS: In adjusted analyses, NHANES participants were more likely than MHWCS participants to have hypertension, high total cholesterol, diabetes, obesity, and abdominal obesity, and were less likely to have low HDL cholesterol and smoke. Less-educated men and women were more likely to have low HDL cholesterol, obesity, and abdominal obesity. CONCLUSIONS: In this binational study, men and women enrolled in the MHWCS appear to have fewer CVD risk factors than US-born and Mexico-born Mexican-American men and women living in the US.