Sugar-Sweetened Beverages Consumption and Breast Cancer in Premenopausal and Postmenopausal Women

BACKGROUND

The consumption of sugar-sweetened beverages (SSB), of which Mexico is a large consumer, has been associated with the risk of breast cancer. We assessed the association between SSBs consumption and breast cancer risk in pre- and postmenopausal women.

METHODS

We performed a multicenter population-based case-control study in Mexico City, Monterrey, and Veracruz. We recruited 1,000 cases and 1,074 controls; all participants were pre- or postmenopausal women between 35 and 69 years of age. Diet before symptoms onset was assessed using a food frequency questionnaire. We conducted a multivariable-adjusted conditional logistic regression analysis stratified by menopausal status.

RESULTS

For premenopausal women, after adjusting for matching characteristics, total energy intake and all potential confounders, the odds of having breast cancer in women who drank one or more SSBs servings per day showed 1.78 times the odds of those who drank one or fewer SSBs servings per month [OR = 1.78; 95% confidence interval (CI), 1.06-3.01]. For postmenopausal women, the corresponding model was not statistically significant (OR = 1.38, 95% CI, 0.84-2.25). We also observed higher consumption of SSBs among pre- than in postmenopausal women (23.3% and 17.4%, respectively among controls in the highest consumption category (≥1 per day).

CONCLUSIONS

Our results suggest that SSBs consumption increases the risk of developing breast cancer, particularly in premenopausal women.

IMPACT

Given the consumption of SSBs, of which Mexico is a large consumer, these results can support public policies to discourage the consumption of SSBs.

Effect of Vitamin D Supplementation on (25(OH)D) Status in Children 12-30 Months of Age: A Randomized Clinical Trial

Vitamin D (VD) deficiency (serum 25(OH)D < 50 nmol/L) affects 27.3% of preschool children in Mexico. The purpose of this study was to assess the effect of vitamin D supplementation at different doses on serum 25(OH)D concentrations in preschool children. In a randomized control trial, 222 children 12-30 months old were randomly assigned to one of four treatment groups: (1) Vitamin D2 (Ergocalciferol) 400 IU/day (n = 56); (2) Vitamin D2 (Ergocalciferol) 800 IU/day (n = 55); (3) Vitamin D3 (Cholecalciferol) 1000 IU/day (n = 56); or (4) multiple micronutrients (MM) non-VD (n = 55). Supplements were given five days/wk for three months. Serum 25(OH)D was measured at baseline and after three months. At baseline, mean serum 25(OH)D was 58.9 ± 12.6 nmol/L and 23.4% were VD-deficient. There was a statistically significant increase in serum concentrations of 25(OH)D (range across groups: +8.2 to +17.3 nmol/L). Additionally, the prevalence of vitamin D deficiency decreased after three months: for D2 400 IU, -9.0%; for D2 800 IU, -11.0%; for D3 1000 IU, -18.0%; and for MM non-VD, -2.8% (p < 0.05). No adverse effects were observed. VD supplementation for three months was effective for increasing serum 25(OH)D concentrations and for reducing VD deficiency in preschool children. The highest efficacy was observed by giving 1000 IU D3/d.

Dietary Sodium and Potassium Intake: Data from the Mexican National Health and Nutrition Survey 2016

Population studies have demonstrated an association between sodium and potassium intake and blood pressure levels and lipids. The aim of this study was to describe the dietary intake and contribution of sodium and potassium to the Mexican diet, and to describe its association with nutrition status and clinical characteristics. We analyzed a national survey with 4219 participants. Dietary information was obtained with a 24-h recall. Foods and beverages were classified according to level of processing. The mean intake (mg/d) of Na was 1512 in preschool children, 2844 in school-age children, 3743 in adolescents, and 3132 in adults. The mean intake (mg/d) of K was 1616 in preschool children, 2256 in school-age children, 2967 in adolescents, and 3401 in adults. Processed and ultra-processed foods (UPF) contribute 49% of Na intake in preschool children, 50% in school-age children, 47% in adolescents, and 39% in adults. Adults with high Na intake had lower serum concentrations of cholesterol, HDL-c, and LDL-c. A significant proportion of the Mexican population has a high intake of Na (64-82%) and low K (58-73%). Strategies to reduce Na and increase K intake need to reduce the possibility of having high BP and serum lipid disturbances.

Etiology of Anemia in Older Mexican Adults: The Role of Hepcidin, Vitamin A and Vitamin D

Anemia in older adults is a growing public health issue in Mexico; however, its etiology remains largely unknown. Vitamin A deficiency (VAD) and vitamin D deficiency (VDD) have been implicated in the development of anemia, though by different mechanisms. The aim of this study is to analyze the etiology of anemia and anemia-related factors in older Mexican adults. This is a cross-sectional study of 803 older adults from the southern region of Mexico in 2015. The anemia etiologies analyzed were chronic kidney disease (CKD), nutritional deficiencies (ND), anemia of inflammation (AI), anemia of multiple causes (AMC) and unexplained anemia (UEA). VAD was considered to be s-retinol ≤ 20 μg/dL, and VDD if 25(OH)D < 50 nmol/L. IL-6 and hepcidin were also measured. Multinomial regression models were generated and adjusted for confounders. Anemia was present in 35.7% of OA, independent of sex. UEA, CKD, AI and ND were confirmed in 45%, 29.3%, 14.6% and 7% of older adults with anemia, respectively. Hepcidin and log IL-6 were associated with AI (p < 0.05) and CKD (p < 0.001). VAD was associated with AI (p < 0.001), and VDD with ND and AMC (p < 0.05). Log-IL6 was associated with UEA (p < 0.001). In conclusion, anemia in older adults has an inflammatory component. VAD was associated to AI and VDD with ND and AMC.

Breakfast Frequency and Diabetes Incidence in a Cohort of Middle-Age Women

Objectives

To examine the relation between breakfast frequency and incidence of diabetes in middle-aged women.

Methods

The Mexican Teacher´s Cohort is a prospective study in women. We included 71,373 participants at baseline (2006–2008). Participants were classified according to breakfast frequency 0, 1–3, 4–6, or 7 d/wk; and meal frequency 1–2, 3–4, or ≥5 meals/d. Diabetes was self-reported. We used Cox proportional hazards models to calculate hazard ratios (HR) and 95% confidence intervals (CI) to estimate the association between breakfast frequency and diabetes incidence. Models were adjusted for sociodemographic and lifestyle confounders that are associated with breakfast consumption and are risk factors for diabetes. Stratified analyses were performed for age, birth weight, indigenous background, and physical activity.

Results

We identified 3,613 new diabetes cases during a median of 2.2 years of follow-up. Prevalence of daily breakfast consumers was 25%. After adjustment for known risk factors for diabetes, compared to 0 d/wk, women who eat daily breakfast had 12% lower rate of diabetes (HR = 0.88; 95% CI 0.78, 0.99; p-trend = 0.0018). One day additional per week having breakfast decreased the risk of diabetes (HR = 0.98; CI 0.97, 0.99). In stratified analysis, women with indigenous background who consumed breakfast 4–6 d/wk and 7 d/wk vs. 0 d/wk shown lower risk (HR = 0.68; 95% CI 0.47, 0.98) and HR = 0.76; 95% CI 0.76 (0.51, 1.15) respectively; p-interaction = 0.197).

Conclusions

Daily breakfast was associated with a lower incidence of diabetes, independently of dietary and lifestyle factors. Likely effect modifiers as ethnicity warrants more research. Daily breakfast consumption is a potential component of diabetes prevention.

Funding Sources

This work is supported by the American Institute for Cancer Research (05B047) and Consejo Nacional de Ciencia y Tecnología (CONACyT) grant S0008-2009-1: 000000000115312.

Vitamin D status in Mexican women at reproductive age, Ensanut 2018-19

OBJECTIVE

To describe the prevalence of deficiency (VDD) and insufficiency (VDI) of vitamin D (VD), by sociodemo-graphic factors, obesity and physical activity in a probabilistic sample of Mexican women participating in Ensanut 2018-19.

MATERIALS AND METHODS

In 1 262 women aged 20 to 49 years, the prevalence of VDD/IVD was estimated and the factors associated with it were evaluated with a multinomial regression model.

RESULTS

The prevalence of VDI was 46.1% and of VDD was 31.6%. The probability of present-ing VDI and VDD was higher for residents of urban areas, in tertiles 2 and 3 of socioeconomic status, and with obesity, while was lower in women with moderate physical activ-ity.

CONCLUSION

The prevalence of vitamin D in Mexican women continues to be a public health problem in Mexico despite the high availability of sunlight in the country. It is necessary to promote healthy sun exposure in the population and consider fortifying foods with vitamin D.

Breakfast Frequency Is Inversely Associated with Weight Gain in a Cohort of Mexican Women

BACKGROUND

Food timing affects circadian rhythms involved in weight control. Regular consumption of breakfast may affect body weight.

OBJECTIVE

We examined the relation between breakfast frequency with weight change in middle-age women over a 3-y period.

METHODS

We used data from 65,099 nonpregnant women aged >20 y participating in the Mexican Teachers' Cohort (MTC) who at baseline (2006-2008) were cancer free and for whom self-reported breakfast frequency at baseline was available. We analyzed body weight change between baseline and the first follow-up (2011) according to breakfast frequency. Participants were classified according to baseline breakfast frequency 0, 1-3, 4-6, or 7 d/wk and meal frequency 1-2, 3-4, or ≥5 meals/d. We used linear and modified Poisson regression to analyze body weight change as a continuous variable and for weight gain ≥5 kg (yes/no), respectively. Models were adjusted for sociodemographic and lifestyle confounders.

RESULTS

At baseline, 25% of participants were daily breakfast consumers and 18.4% of women increased ≥5 kg between 2008 and 2011. The prevalence of weight gain ≥5 kg among daily breakfast consumers was 7% lower than among those who skipped breakfast (prevalence ratio: 0.93; 95% CI: 0.89, 0.97; P-trend = 0.02). The association was stronger among normal-weight women at baseline with a corresponding estimate of 0.87 (95% CI: 0.79, 0.97; P-trend = 0.02).

CONCLUSION

Daily breakfast consumption was inversely associated with weight gain ≥5 kg over 3 y in middle-aged Mexican women. Regular breakfast may be an important dietary factor for body weight change.

Effect of Milk-Based Infant Formula Fortified with PUFAs on Lipid Profile, Growth and Micronutrient Status of Young Children: A Randomized Double-Blind Clinical Trial

BACKGROUND

Polyunsaturated fatty acids (PUFAs) are essential to child growth and development.

OBJECTIVE

To assess the effect of PUFAs-fortified infant formula on lipid profile, growth and micronutrient status in children 12 to 30 months old.

METHODS

This study is a double-blind randomized controlled clinical trial. Two study groups were assessed: (a) milk-based infant formula with micronutrients and PUFAs (PUFAs) and (b) milk-based infant formula with micronutrients, no PUFAs added (Non-PUFAs). Children received prepared formula (240 mL) twice a day, according to the color-code assigned to each infant. Anthropometric measurements and venous blood samples were taken at each day-care center at baseline, and again after four months. Total serum lipid extraction was 0.5 mL. Samples were treated and modified by the Folch method and analyzed with gas chromatography.

RESULTS

Changes in serum lipid profile (expressed as % FA) between baseline and four months showed a statistically significant increase in docosahexaenoic acid (DHA) (0.22 vs. -0.07, p < 0.05) and Alpha-Linoleic acid (0.08 vs. 0.02, p < 0.05) in infants who consumed PUFAs-fortified formula compared to Non-PUFAs-fortified formula. Infants increased their length/height-for-age Z-score: median change for the PUFAs group was 0.16 (95% CI = 0.08, 0.28) and 0.23 (95% CI = 0.14, 0.33) for Non-PUFAs, with no differences between groups. Median folate level was significantly higher among the PUFAs group compared to Non-PUFAs: -0.87 (95% CI = -1.38, -0.44) and -3.83 (95% CI = -4.65, -3.03) respectively. Consumption of both supplements was adequate and stable during the intervention.

CONCLUSION

A significant improvement was observed in the lipid profile of children who received the PUFAs-fortified milk-based formula.

Cardiovascular Risk Factors and Their Association with Vitamin D Deficiency in Mexican Women of Reproductive Age

Based on a nationally representative sample of young Mexican women aged 20 to 49 years (n = 3260), we sought to explore whether cardiovascular risk factors and acute myocardial infarction (AMI) were associated with vitamin D deficiency (VDD, defined as 25-OH-D <50 nmol/L). To this end, we obtained sociodemographic, serum and anthropometric data from the 2012 National Health and Nutrition Survey (ENSANUT 2012). Analyses were developed through logistic regression models adjusted for potential confounders. The prevalence of VDD was significantly higher in obese women (42.5%, 95% CI; 37.3–47.9) compared to women with a normal body mass index (29.9%, 95% CI; 23.5–37.1, p = 0.05), in those with high total cholesterol (TC) (45.6% 95% CI; 39.4–51.9) compared to those with normal TC levels (33.9%, 95% CI 30–38.1, p = 0.03), and in those with insulin resistance (IR) (44%, 95% CI; 36.9–51.7) or type 2 diabetes mellitus (T2DM) (58.6%, 95% CI 46.9–69.4) compared to those with normal glycemia (no insulin resistance: 34.7%, 95% CI; 30.9–38.8, p = 0.04 and no T2DM: 34.9%, 95% CI 31.4–38.6, p < 0.001). Utilizing individual models to estimate cardiovascular risk according to VDD, we found that the odds of being obese (odds ratio, OR: 1.53, 95% CI 1.02–2.32, p = 0.05), or having high TC levels (OR: 1.43, 95% CI; 1.05–2.01, p = 0.03), T2DM (OR: 2.64, 95% CI; 1.65–4.03, p < 0.001), or IR (OR: 1.48, 95% CI 1.04–2.10, p = 0.026) were significantly higher in women with VDD (p < 0.05). Odds were not statistically significant for overweight, high blood pressure, sedentarism, AMI, high serum concentration of triglycerides, homocysteine, or C-reactive protein models. In conclusion, our results indicate that young Mexican women with VDD show a higher prevalence of cardiovascular risk factors.

Serum Retinol but Not 25(OH)D Status Is Associated With Serum Hepcidin Levels in Older Mexican Adults

1) Background: Elevated hepcidin levels have been linked to anemia of inflammation (AI). Retinol deficiency has shown to upregulate hepcidin expression in animals, while conflicting evidence links VD status with hepcidin concentration in humans. The purpose of the study is to explore if VA and VD status are associated with hepcidin concentrations in older Mexican adults (OA). 2) Methods: A cross-sectional study was conducted in summer 2015, using serum samples from 783 fasting OA ages 60 and above residents from Campeche and Yucatán. VA deficiency (VAD) was defined as serum retinol concentration <20 μg/dL and VD deficiency (VDD) as 25(OH)D <50 nmol/L. The log-hepcidin was the outcome variable expressed as continuous and tertiles of its distribution. Linear and ordinal regression models were used. 3) Results: VAD was present in 3.4% and VDD in 9.5% of OA. Log-retinol was inversely associated with log-hepcidin (coeff.: -0.15, 95%CI: -0.2, -0.09). VAD status shown a higher probability than non-VAD for higher hepcidin tertiles (OR = 2.15, 95%CI: 1.24, 3.74). VDD states was not associated with hepcidin in the linear (coeff.: 0.16, 95%CI: -0.02, 0.34) nor the ordinal model (OR = 0.74, 95%CI: 0.42, 1.28). 4) Conclusions: VAD, but not VDD, status was inversely associated with hepcidin concentrations in OA.

Dietary intake and adequacy of energy and nutrients in Mexican older adults: results from two National Health and Nutrition Surveys

Objective:

To describe energy and nutrient intakes and their adequacies in older Mexican adults participating in the National Health and Nutrition Survey (Ensanut) 2006 and 2012.

Materials and methods:

Dietary information was obtained through a semiquantitative food frequency questionnaire (SFFQ) from 526 adults 60 y and older participating in Ensanut 2012 and 3 326 in Ensanut 2006 in Mexico. Quantile and logistic regression models were used to obtain medians and marginal effects of each nutrient, adjusting by confounders and survey design.

Results:

Dietary intake of energy and nutrients was similar in both surveys. Most common micronutrients at risk of dietary deficiency were, for vitamins: A, B-12, C, D and folate, and for minerals: calcium, iron and zinc, in both surveys. Excessive intake of sugar and saturated fat and low fiber intake were common.

Conclusions:

Diet in older Mexican adults is low in micronutrient essentials, and excessive in fat and sugar. Attention to the diet in this age group through targeted interventions is necessary to promote a healthy diet.

Papel de las enfermedades infecciosas en el desarrollo de la esclerosis múltiple: evidencia científica

Introducción

La esclerosis múltiple (EM) es el trastorno inflamatorio más común del sistema nervioso central (SNC) y la causa principal de discapacidad neurológica en adultos jóvenes. Los factores ambientales e infecciosos han sido fuertemente asociados al incremento de la ocurrencia de la enfermedad, hasta más del doble, en los últimos 10 años. En este artículo de revisión se describen los principales hallazgos reportados sobre la relación entre ciertas infecciones virales y bacterianas con la aparición y progresión de la EM.

Métodos

Se realizó un plan metodológico de búsqueda de artículos científicos relacionados con infección y EM, mediante la búsqueda de artículos científicos, principalmente publicados en inglés, en las plataformas virtuales de Pubmed, Medline y Cochrane. Para la búsqueda se utilizaron como palabras claves (términos MeSH): «virus, bacteria, autoimmune disease of the nervous system, multiple sclerosis». Se eligieron artículos publicados en revistas indexadas durante los últimos 15 años.

Resultados

Estudios epidemiológicos sugieren que la EM tiene un componente etiológico infeccioso que origina un proceso inflamatorio que puede contribuir a la iniciación o exacerbación de la enfermedad. Particularmente, la infección viral y los eventos de desmielinización en el SNC puede deberse a la penetración de un virus como el virus Epstein-Barr (EBV), a través del torrente sanguíneo, específicamente hacia el SNC. Por otro lado, las infecciones bacterianas crónicas pueden causar procesos de desmielinización en el SNC que agravan la enfermedad de EM.

Conclusiones

Este estudio contribuye a aportar evidencia científica donde se demuestra la multicausalidad implicada en la ocurrencia de la EM. Aún falta desarrollar más estudios epidemiológicos que demuestren y comprueben la relación y la implicación de agentes virales y bacterianos en el origen, el desarrollo y la severidad de la enfermedad.

Consumption of fruits and vegetables and health status of Mexican children from the National Health and Nutrition Survey 2012

OBJECTIVE

To characterize the current consumption of fruits and vegetables based on the international recommendations, as well as its relationship to certain variables of interest in Mexican children aged 6 to 12 years.

MATERIALS AND METHODS

Adherence to the international recommendations for the consumption of fruits and vegetables was estimated based on data from the 2012 National Health and Nutrition Survey (Ensanut 2012). Logistic regression models were developed.

RESULTS

Only 34.4% of children met the recommendations. Their age (years) (OR:074; p< 0.01) and the fact that they lived in the Central (OR:2.48; p< 0.01) or Southern (OR:2.66; p< 0.01) regions of Mexico or in Mexico City (OR:2.37; p< 0.01) versus the Northern region were significantly associated with adherence. An interaction was observed between the educational level of the head of the family and his or her kinship with the child.

CONCLUSIONS

Only 3 out of every 10 Mexican children meet the recommendations; therefore, the implementation of a public policy with the appropriate legislation, financing and regulation is required.

[Antioxidant use as dietary therapy in patients with multiple sclerosis]

INTRODUCTION

Multiple sclerosis is an immune-mediated disease that produces chronic inflammation and neural degeneration. The disease progresses with acute attacks that result in myelin inflammation. This in turn increases oxidative stress and favors the appearance of reactive oxygen species. Reactive oxygen species damage neural cells causing apoptosis. The etiology of multiple sclerosis remains unknown and current therapy is aggressive and expensive. Recently, complementary and alternative medicine therapies have been proposed to control pathogenesis and symptoms of this disease. It is believed that these therapies help slow the progression of multiple sclerosis and improve survival.

METHODS

We conducted a MEDLINE/PubMed search using the following MeSH terms: diet, multiple sclerosis, antioxidants. We selected the main articles containing multiple sclerosis and diet.

RESULTS

We analyzed three case control studies that evaluated different dietary approaches in multiple sclerosis. For this review, we also included five experimental studies that studied the efficacy of lipoic acid in humans and rodents in diseases like multiple sclerosis, experimental autoimmune encephalomyelitis, and breast cancer.

Does food insecurity compromise maternal dietary zinc or energy intake in favor of her child, in rural poor Mexican households?

OBJECTIVE

To analyze quantitative indicators of food insecurity (FI), and estimate if FI modifies the association between maternal and child Zinc and energy intake as evidence for maternal dietary compromise in favor of her child.

MATERIAL AND METHODS

Cross-sectional study (n=2 563), data derived from baseline impact evaluation of the Mexican Programa de Apoyo Alimentario. Quantitative indicators of FI were:Household food storage, maize and/or bean production, food expenditure, and spatial access to food markets. We evaluated percentage adequacy of energy (PAE) and Zinc (PAZn) intake. Multiple linear regression model was fitted to estimate the association between maternal and child PAE and PAZn.

RESULTS

Child PAE and PAZn were positively associated with those of their mothers. None of the FI indicators modified the association between maternal and child PAE and PAZn.

CONCLUSIONS

No evidence of maternal dietary compromise in favor of her child was observed using four quantitative indicators of FI in central-southern rural Mexican househods.

Identifying pesticide use patterns among flower growers to assess occupational exposure to mixtures

OBJECTIVES

Exposure assessment to a single pesticide does not capture the complexity of the occupational exposure. Recently, pesticide use patterns analysis has emerged as an alternative to study these exposures. The aim of this study is to identify the pesticide use pattern among flower growers in Mexico participating in the study on the endocrine and reproductive effects associated with pesticide exposure.

METHODS

A cross-sectional study was carried out to gather retrospective information on pesticide use applying a questionnaire to the person in charge of the participating flower growing farms. Information about seasonal frequency of pesticide use (rainy and dry) for the years 2004 and 2005 was obtained. Principal components analysis was performed.

RESULTS

Complete information was obtained for 88 farms and 23 pesticides were included in the analysis. Six principal components were selected, which explained more than 70% of the data variability. The identified pesticide use patterns during both years were: 1. fungicides benomyl, carbendazim, thiophanate and metalaxyl (both seasons), including triadimephon during the rainy season, chlorotalonyl and insecticide permethrin during the dry season; 2. insecticides oxamyl, biphenthrin and fungicide iprodione (both seasons), including insecticide methomyl during the dry season; 3. fungicide mancozeb and herbicide glyphosate (only during the rainy season); 4. insecticides metamidophos and parathion (both seasons); 5. insecticides omethoate and methomyl (only rainy season); and 6. insecticides abamectin and carbofuran (only dry season). Some pesticides do not show a clear pattern of seasonal use during the studied years.

CONCLUSIONS

The principal component analysis is useful to summarise a large set of exposure variables into smaller groups of exposure patterns, identifying the mixtures of pesticides in the occupational environment that may have an interactive effect on a particular health effect.

Simulation model of the impact of biofortification on the absorption of adequate amounts of zinc and iron among Mexican women and preschool children

BACKGROUND

Biofortification is an agricultural process that attempts to increase the iron and zinc content of staple food crops. Improving the absorption of zinc and iron could contribute to reducing the high rates of deficiency of these micronutrients in developing-country settings.

OBJECTIVE

To simulate the effects of biofortification of staple food crops (maize, wheat, rice, and beans) on the absorption of zinc and iron among women and children in Mexico.

METHODS

We analyzed dietary data from the 1999 Mexican National Nutrition Survey. On the basis of the intake of the four staple food crops and the increase in zinc and iron content that could be achieved by conventional breeding in the short term, the prevalence of inadequacy in the amounts of absorbed zinc and iron was determined. The mean increase in the amounts of absorbed zinc and iron was compared according to rural and urban residence and according to region of the country.

RESULTS

In rural areas, simulated biofortification of maize resulted in a reduction in the prevalence of absorption of inadequate amounts of zinc of 47% in children and 56% in women but had no effect on the prevalence of absorption of inadequate amounts of iron. The increase in zinc absorption was greater in rural populations and in the Central and Southern regions (p < .05).

CONCLUSIONS

Biofortification of maize could significantly improve zinc absorption among children and women in Mexico living in areas most vulnerable to zinc deficiency. Studies of the biological impact of biofortified maize on zinc status are warranted.

Epidemiologic panorama of colorectal cancer in Mexico, 1980-1993

INTRODUCTION

Colorectal cancer is the third cause of cancer-related death in the world, with 468,000 estimated deaths in 1993. In some countries mortality rates have started to decline, and survival rates have increased. In this study performed in Mexico, information is presented on the increase in mortality from this form of cancer, especially in more economically developed areas.

METHODS

The mortality trend for colorectal cancer was evaluated and standardized by five-year age groups in the period 1980 to 1993. Also, the standardized mortality ratio was calculated for Mexico's 32 states, as was the possible association between mortality and indicators of rurality level and fertility rates in the different regions of Mexico.

RESULTS

In the period studied, 18,962 deaths were officially reported. The average age of death was 66 years. The mortality rate among women (1.8) was significantly higher than among men (1.55 per 100,000 inhabitants). Mortality from colorectal cancer grew by 100 percent in both genders (beta = 0.089; P < 0.001), especially in the age group 34 and younger, in the 45 to 49 age group, and in the older than 75 age group (P < 0.05). The standardized mortality ratio was greater in the states in the north of Mexico. Finally, an inverse correlation was observed throughout Mexico between the rurality index (r = -0.60; P < 0.001) and the fertility rates (r = -0.43; P < 0.05) and mortality from colorectal cancer.

CONCLUSIONS

In this study, there is evidence that mortality from this cancer is higher in geographic areas with greater socioeconomic development, similar to regional patterns observed in other countries. In Mexico, the coming years will see a serious epidemic in mortality from this disease; therefore, immediate attention must be given to identifying the profile of high-risk subjects and implementing early cancer detection measures.

[Methodological aspects of measuring injuries from traffic accidents at the site of occurrence]

Traffic accidents are a well-known public health problem worldwide. In Mexico research into risk factors for motor involving vehicles accidents and their consequences has recently been taken into account. The relevant literature does not normally describe the methodological aspects involved in the collection of primary data, since most studies have used secondary data the good quality and validity of which are assumed. The paper presented seeks to discuss and share with researchers in this field, some of the methodological aspects to be considered in the attempt to recreate the scene of the accident and obtain information approximating to reality. The measurements in situ of, such traffic accident variables as injury, use of seat belt, speed and alcohol intake are discussed.