ABSTRACT
OBJETIVO: Evaluar el efecto de la actividad física moderada (en horas por semana y METs-hora por semana) sobre el riesgo de cáncer de mama (CM). MATERIAL Y MÉTODOS: Se trata de la primera fase de un estudio multicéntrico de casos y controles con base poblacional que se desarrolló en el Distrito Federal, Monterrey y Veracruz, México, en el año 2004. Se analizaron 58 casos y 58 controles pareados a los casos por quinquenio de edad, y pertenencia al sistema de salud; participaron tres hospitales del Instituto Mexicano del Seguro Social, tres del Instituto de Seguridad Social al Servicio de los Trabajadores del Estado y tres de la Secretaría de Salud. RESULTADOS: En mujeres posmenopáusicas se observó una reducción del riesgo de CM por cada hora semanal adicional de actividad física moderada (RM= 0.91; IC95 por ciento 0.85-0.97); en mujeres premenopáusicas, la disminución del riesgo no tuvo significancia estadística (RM= 0.99; IC95 por ciento 0.94-1.05) (p= 0.048, modificación de efecto). CONCLUSIONES: La actividad física reduce el riesgo de CM en mujeres mexicanas posmenopáusicas.
OBJECTIVE: To evaluate the effect of moderate physical activity (hours per week and METs hours per week) on the risk of breast cancer (BC) in Mexican women. MATERIAL AND METHODS: This is the initial stage of a case control multicentric study based in the Federal District, Monterrey and Veracruz, Mexico, during 2004. Fifty eight cases paired to 58 control cases on quinquennium of age, and belonging to the health system were analyzed: three hospitals from the IMSS, three from ISSSTE and three from SS participated. RESULTS: In postmenopausal women, there was a reduction of the risk in BC by every additional hour per week of moderate physical activity (RM= 0.91; IC95 percent 0.85-0.97); in premenopausal women, the reduction of the risk was not statistically significant (RM= 0.99; IC95 percent 0.94-1.05) (p= 0.048, effect modification). CONCLUSIONS: Moderate physical activity reduces the risk of BC in postmenopausal Mexican women.
Subject(s)
Female , Humans , Middle Aged , Breast Neoplasms/epidemiology , Motor Activity , Case-Control Studies , Mexico , Risk FactorsABSTRACT
The purpose of this study was to examine the effects of walking 10,000 steps/day on the body composition, blood pressure, blood biochemical parameters and physical fitness. Sixty-one women, aged 56.0±5.3 yrs (mean±SD), participated in a hyperlipemia prevention program. The length of the program was 90-min and it was performed one time per week for 3 months. The program consisted of stretching and aerobic exercise (cycle exercise, walking or aerobic rhythmic gymnastics). The participants were asked to walk 10,000 steps/day or more during the program. The number of steps and physical activity (PA) were monitored using a single-axis accelerometer during the program. PA was categorized into three activity levels, namely light (L), moderate (M) and vigorous (V) PA. After 3 months in the program, the participants were divided into two groups according to the average number of steps taken daily during the program : one group (GA) walked more than 10,000 steps/day, while the other (GB) walked below 10,000 steps/day. The time spent in LPA, MPA and VPA in GA were significantly longer than in GB (LPA : 79.4±19.2 min VS 58.2±10.0 min, MPA : 38.5±9.6 min VS 21.6±6.1 min, VPA : 6.3±4.9 min VS 2.6±2.0 min, p<0.001). Decreases in the percent body fat (p<0.001), body fat mass (p<0.001), fasting glucose (p<0.001), hemoglobin A1c (p=0.026), and triglyceride (p=0.036) and an improved performance when balancing on one leg while standing with eyes closed (p=0.027) were found respectively after the program for GA. These findings indicated that GA affected the percent body fat (p=0.036), body fat mass (p=0.040) and fasting glucose (p=0.009). According to a stepwise multiple regression analysis, the time spent in MPA showed a significantly negative correlation with the change in the body fat mass (p=0.025), and the change in the body fat mass showed a significantly positive correlation with the change in the fasting glucose (p<0.001), hemoglobin A1c (p=0.002) and triglyceride (p<0.001). We thus concluded that walking 10,000 steps/day resulted in an increased amount of time spent in MPA, and thus leading to decrease in the amount of body fat. This decrease in body fat is also considered to contribute to improvement in the coronary risk factor profiles.