Eduardo Salazar-Martínez

14-day triple, 5-day concomitant, and 10-day sequential therapies for Helicobacter pylori infection in seven Latin American sites: a randomised trial

BACKGROUND Evidence from Europe, Asia, and North America suggests that standard three-drug regimens of a proton-pump inhibitor plus amoxicillin and clarithromycin are significantly less effective for eradication of Helicobacter pylori infection than are 5-day concomitant and 10-day sequential four-drug regimens that include a nitroimidazole. These four-drug regimens also entail fewer antibiotic doses than do three-drug regimens and thus could be suitable for eradication programmes in low-resource settings. Few studies in Latin America have been done, where the burden of H pylori-associated diseases is high. We therefore did a randomised trial in Latin America comparing the effectiveness of four-drug regimens given concomitantly or sequentially with that of a standard 14-day regimen of triple therapy. METHODS Between September, 2009, and June, 2010, we did a randomised trial of empiric 14-day triple, 5-day concomitant, and 10-day sequential therapies for H pylori in seven Latin American sites: Chile, Colombia, Costa Rica, Honduras, Nicaragua, and Mexico (two sites). Participants aged 21-65 years who tested positive for H pylori by a urea breath test were randomly assigned by a central computer using a dynamic balancing procedure to: 14 days of lansoprazole, amoxicillin, and clarithromycin (standard therapy); 5 days of lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant therapy); or 5 days of lansoprazole and amoxicillin followed by 5 days of lansoprazole, clarithromycin, and metronidazole (sequential therapy). Eradication was assessed by urea breath test 6-8 weeks after randomisation. The trial was not masked. Our primary outcome was probablity of H pylori eradication. Our analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, registration number NCT01061437. FINDINGS 1463 participants aged 21-65 years were randomly allocated a treatment: 488 were treated with 14-day standard therapy, 489 with 5-day concomitant therapy, and 486 with 10-day sequential therapy. The probability of eradication with standard therapy was 82·2% (401 of 488), which was 8·6% higher (95% adjusted CI 2·6-14·5) than with concomitant therapy (73·6% [360 of 489]) and 5·6% higher (-0·04% to 11·6) than with sequential therapy (76·5% [372 of 486]). Neither four-drug regimen was significantly better than standard triple therapy in any of the seven sites. INTERPRETATION Standard 14-day triple-drug therapy is preferable to 5-day concomitant or 10-day sequential four-drug regimens as empiric therapy for H pylori infection in diverse Latin American populations. FUNDING Bill & Melinda Gates Foundation, US National Institutes of Health.

Anogenital distance in human male and female newborns: a descriptive, cross-sectional study

BackgroundIn animal studies of the effects of hormonally active agents, measurement of anogenital distance (AGD) is now routine, and serves as a bioassay of fetal androgen action. Although measurement of AGD in humans has been discussed in the literature, to our knowledge it has been measured formally in only two descriptive studies of females. Because AGD has been an easy-to-measure, sensitive outcome in animals studies, we developed and implemented an anthropometric protocol for measurement of AGD in human males as well as females.MethodsWe first evaluated the reliability of the AGD measures in 20 subjects. Then measurements were taken on an additional 87 newborns (42 females, 45 males). All subjects were from Morelos, Mexico.ResultsThe reliability (Pearson r) of the AGD measure was, for females 0.50, and for males, 0.64. The between-subject variation in AGD, however, was much greater than the variation due to measurement error. The AGD measure was about two-fold greater in males (mean, 22 mm) than in females (mean, 11 mm), and there was little overlap in the distributions for males and females.ConclusionThe sexual dimorphism of AGD in humans comprises prima facie evidence that this outcome may respond to in utero exposure to hormonally active agents.

Nutritional determinants of epithelial ovarian cancer risk: a case-control study in Mexico

Background: Variations in the incidence of cancer can be influenced by diet and specific lifestyles. In the last years, diet has been evaluated as an important factor in the development of ovarian cancer, even though the results have not been consistent. Dietary factors related to the risk of ovarian cancer in Mexican women were evaluated. Methods: A case-control study in Mexico City was done during 1995–1997 in a social security hospital, evaluating 84 new cases of ovarian cancer and 629 controls. A validated questionnaire with 116 items about the frequency and type of food intake was used. The analysis of nutrients was done with the residual method adjusted for total energy intake and other predictor variables through logistic regression methods. Also, partition models estimated the total caloric intake for other sources. Results: The nutrients negatively associated with ovarian cancer in the highest versus the lowest tertile were retinol (OR 0.52; p for trend = 0.03) and vitamin D (OR 0.43; 95% CI 0.23–0.80; p = 0.01; residual model). Additionally, carbohydrates were positively associated (partition model: OR 1.08; 95% CI 1.00–1.15), and tortilla intake did not show an association with ovarian cancer (OR 0.96; 95% CI 0.78–1.17). Conclusions: The diet of the Mexican population is rich in carbohydrates; in Mexico corn intake is the main energy source. On the other hand, vitamins such as retinol and vitamin D were shown to be associated with this neoplasm in a protective way; nevertheless, further studies are necessary to allow us to corroborate our results. This is the first attempt in our country that relates the Mexican diet to ovarian cancer.

Case-control study of diabetes, obesity, physical activity and risk of endometrial cancer among Mexican women.

AbstractObjectives: Obesity, hypertension and diabetes are closely associated with endometrial cancer (EC). This study evaluates the relationship between diabetes and risk of EC on the basis of obesity. Methods: A case–control study was carried out in Mexico City from 1995 to 1997. Eighty-five histologically confirmed cases were compared with 668 population-based controls obtained through frequency matching. Diabetes status, weight, height and other factors were determined through personal interviews among both cases and controls. Results: Compared to women without diabetes, those with diabetes had an adjusted odds ratio of 3.6 (95% CI = 1.7, 7.4) for EC. This association was modified by body mass index (p interaction < 0.001). Compared to non-overweight and non-diabetic women, non-overweight (OR = 3.9, 95% CI = 0.88, 18.0) and overweight (OR = 5.9, 95% CI = 1.6, 21.1) diabetic women had a non-significant elevated risk of EC. However, elevated risk estimates were observed for obese diabetic women (OR = 8.0, 95% CI = 2.8, 22.7). Conclusions: Our results strongly suggest an interaction effect between obesity and diabetes that significantly increases the risk of EC. This, in turn, may explain the growing number of new EC cases recently observed in developing countries with reduced birth rates and an increased incidence of both obesity and diabetes mellitus.

Prevalence and determinants of male partner violence against Mexican women: a population-based study

OBJECTIVE To determine the prevalence of and risk factors for violence against women, inflicted by their male partners, in a representative sample of women residing in the metropolitan area of Cuernavaca Morelos, Mexico. MATERIAL AND METHODS A population-based study was conducted from June to September 1998, among 1,535 women aged 15 to 49 years. Principal components analysis was used to determine the domains of violence that served as the dependent variable. Polynomial logistic regression models were used to estimate odds ratios (OR), with 95% confidence intervals (CI). RESULTS Prevalence of low-moderate level violence was 35.8%, while prevalence of severe violence was 9.5%. The lifetime prevalence of reported rape was 5.9%. The main factors associated with violence were socio-economic status (OR=0.57; 95% CI=0.34-0.95); education level, both of the women studied (test for trend p=0.01) and of the male partner (test for trend p=0.002); number of years living with partner (OR=2.63; 95% CI=1.55-4.45), alcohol use (OR=2.56; 95% CI=2.02-3.25), illegal drug use by partner (OR=6.17; 95% CI=2.37-16.03); violence during childhood (OR=3.40; 95% CI=2.23-5.18), and a history of rape (OR=5.89; 95% CI=2.78-12.5). CONCLUSIONS Study findings confirm that violence against women is a prevalent phenomenon in Mexico. Awareness-raising campaigns about male partner violence should bring this important issue to the front of public discussion. Such efforts will help assure that future generations do not experience partner violence to the extent that contemporary Mexican women do.

Risk of recurrent Helicobacter pylori infection 1 year after initial eradication therapy in 7 Latin American communities.

IMPORTANCE The long-term effectiveness of Helicobacter pylori eradication programs for preventing gastric cancer will depend on recurrence risk and individual and community factors. OBJECTIVE To estimate risk of H. pylori recurrence and assess factors associated with successful eradication 1 year after treatment. DESIGN, SETTING, AND PARTICIPANTS Cohort analysis of 1463 randomized trial participants aged 21 to 65 years from 7 Latin American communities, who were treated for H. pylori and observed between September 2009 and July 2011. INTERVENTIONS Randomization to 1 of 3 treatment groups: 14-day lansoprazole, amoxicillin, and clarithromycin (triple therapy); 5-day lansoprazole and amoxicillin followed by 5-day lansoprazole, clarithromycin, and metronidazole (sequential); or 5-day lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant). Participants with a positive (13)C-urea breath test (UBT) 6 to 8 weeks posttreatment were offered voluntary re-treatment with 14-day bismuth-based quadruple therapy. MEASUREMENTS Recurrent infection after a negative posttreatment UBT and factors associated with successful eradication at 1-year follow-up. RESULTS Among participants with UBT-negative results who had a 1-year follow-up UBT (n=1091), 125 tested UBT positive, a recurrence risk of 11.5% (95% CI, 9.6%-13.5%). Recurrence was significantly associated with study site (P = .03), nonadherence to initial therapy (adjusted odds ratio [AOR], 2.94; 95% CI, 1.31-6.13; P = .01), and children in the household (AOR, 1.17; 95% CI, 1.01-1.35 per child; P = .03). Of the 281 with positive posttreatment UBT results, 138 completed re-treatment, of whom 93 tested UBT negative at 1 year. Among the 1340 who had a 1-year UBT, 80.4% (95% CI, 76.4%-83.9%), 79.8% (95% CI, 75.8%-83.5%), and 77.8% (95% CI, 73.6%-81.6%) had UBT-negative results in the triple, sequential, and concomitant groups, respectively (P = .61), with 79.3% overall effectiveness (95% CI, 77.1%-81.5%). In a single-treatment course analysis that ignored the effects of re-treatment, the percentage of UBT-negative results at 1 year was 72.4% (95% CI, 69.9%-74.8%) and was significantly associated with study site (P < .001), adherence to initial therapy (AOR, 0.26; 95% CI, 0.15-0.42; P < .001), male sex (AOR, 1.63; 95% CI, 1.25-2.13; P < .001), and age (AOR, 1.14; 95% CI, 1.02-1.27 per decade; P = .02). One-year effectiveness among all 1463 enrolled participants, considering all missing UBT results as positive, was 72.7% (95% CI, 70.3%-74.9%). CONCLUSIONS AND RELEVANCE One year after treatment for H. pylori infection, recurrence occurred in 11.5% of participants who had negative posttreatment UBT results. Recurrence determinants (ie, nonadherence and demographics) may be as important as specific antibiotic regimen in determining the long-term success of H. pylori eradication interventions. Study findings are relevant to the feasibility of programs for the primary prevention of gastric cancer in high-incidence regions of Latin America. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01061437.

Factores pronósticos relacionados con la supervivencia del cáncer de mama

Objective. To evaluate prognostic factors for breast cancer in Mexican women. Material and Methods. Four hundred and thirty two women with breast cancer, admitted from 1990 to 1999 to the General Hospital of Mexico, were included to evaluate their survival using the Kaplan-Meier technique and Cox proportional hazard method. Results. Overall 5-year survival was 58.9%. The shortest survival rate corresponds to the clinical stage (IIIB, 47.5%; IIIA, 44.2%; and IV, 15%), the haematological metastasis (21.4%) and surgical edges with positive tumor (12.5%). Lymph node-positive (RR, 1.9; IC95%, 1.3-2.8), clinical stage IV (RR, 14.8; IC95%, 5.539.7) and surgical edges with positive tumor (RR, 2.4; IC95%, 1.2-4.8) were the central prognostic factors. Conclusions. These results give consistency to diagnostic and therapeutic criteria for women with breast cancer who receive medical attention in Mexico, taking into consideration the charac teristics of the tumor –such as extension, clinical stage and status of the lymph nodes– before making a decision as to the initial therapy.

Body mass index associated with elevated blood pressure in Mexican school-aged adolescents.

OBJECTIVE To evaluate the relationship between blood pressure and body mass index among adolescents. METHODS A 14-month period cross-sectional study was carried out among 2387 adolescents attending public schools in the state of Morelos, Mexico between 2005 and 2007. We measured blood pressure during four visits, obtaining elevated blood pressure prevalence according to the guidelines for children and adolescents of the United States National Educational Program on High Blood Pressure (at least three visits needed to assess elevated blood pressure on the basis of 95th percentile specific for gender, age and height). We used specific body mass index percentiles for age and gender. We employed multiple linear and Cox proportional hazards models to identify factors related to elevated blood pressure. RESULTS The overall prevalence of elevated blood pressure was 3.9%. Multiple linear models showed that overweight subjects had systolic and diastolic blood pressures that were 5.1 and 2.5 mmHg higher, respectively, compared with adolescents with a normal body mass index, while obese subjects had 11.3 and 6.2 mmHg higher levels, respectively. Cox proportional hazards models indicated high risk of elevated blood pressure among overweight (RR, 3.6; 95%CI, 1.5-8.5) and obese subjects (RR, 14.2; 95%CI, 7.2-27.75) compared with adolescents with a normal body mass index. CONCLUSION Our results suggest that a higher body mass index is associated with elevated systolic and diastolic blood pressure levels, indicating the importance of incorporating strategies for ongoing screening and for promoting educational programs on healthy lifestyles to prevent hypertension in adolescents.

Estudios epidemiológicos de casos y controles. Fundamento teórico, variantes y aplicaciones

establece la concepcionmoderna de este tipo de estudios, presentando las basesteoricas que establecen la estrecha relacion que existeentre este tipo de diseno y los estudios tradicionalesde cohorte.Con estos antecedentes es posible afirmar que in-formacion derivada de diferentes estudios de casos ycontroles ha sido notoriamente util para modificarpoliticas de salud y avanzar en el conocimiento medi-co. A este respecto, los estudios de casos y controles sehan empleado exitosamente para evidenciar la asocia-cion entre consumo de cigarrillos y el riesgo de cancerde pulmon,

Ensayos clínicos aleatorizados: variantes,métodos de aleatorización, análisis,consideraciones éticas y regulación

(1) Centro de Investigacion en Salud Poblacional. Instituto Nacional de Salud Publica. Cuernavaca, Morelos, Mexico.(2) Instituto Mexicano del Seguro Social, Delegacion Morelos. Cuernavaca, Morelos, Mexico.(3) Departamento de Metodologia de la Investigacion. Instituto Nacional de Pediatria. Mexico, DF, Mexico.(4) Servicio de Pediatria, Hospital General de Mexico, Secretaria de Salud. Mexico, DF, Mexico.(5) Investigador independiente. Mexico, DF, Mexico. Mexico, DF, Mexico.