The effect of insulin resistance on breast cancer risk in Latinas of Mexican origin.

BACKGROUND: Conclusive evidence has yet to emerge regarding the association between markers of hyperinsulinemia and breast cancer. We determined the effect of insulin resistance (IR) on breast cancer risk in Latinas of Mexican origin who did not have a direct family history of breast cancer and had not been previously diagnosed with prediabetes or diabetes. METHODS: This was a case-control study in which a case (n=124) was defined as a patient with a recent histopathologic diagnosis of breast cancer and a control (n=197) was defined as a participant who had recently undergone a mammography and had either a Breast Imaging, Reporting & Data System (BI-RADS)-1 or a BI-RADS-2 score. Plasma glucose, insulin, and glycated hemoglobin (HbA1c) levels were measured. IR was determined by using the homeostasis model assessment (HOMA-IR) criterion. Odds ratios (OR) and 95% confidence intervals (CI) were determined using unconditional binary logistic regression analysis. RESULTS: IR was detected in 33.9% of cases and 41.6% of controls, based on a HOMA-IR ≥3.5. Although multivariate analysis did not show any association between IR and breast cancer risk (OR 0.56, 95% CI 0.31-1.01), it showed that an HbA1c ≥5.7% increased the risk of breast cancer (OR 3.41, 95% CI 1.93-6.01), regardless of menopausal status. CONCLUSIONS: The findings suggest that IR had no effect on breast cancer risk; however HbA1c increased the risk in Latinas of Mexican origin who had not been diagnosed previously with prediabetes or diabetes and had no direct family history of breast cancer. Prospective studies are required to establish the impact of IR over time.

Prediabetes, diabetes, and risk of breast cancer: a case-control study.

BACKGROUND AND AIMS: Although underlying mechanisms have been described to account for the association between prediabetes and diabetes with breast cancer, reported results have been inconsistent. We undertook this study to determine whether prediabetes and diabetes are risk factors for breast cancer in Mexican women with no family history of breast cancer in the mother, daughters, or sisters. METHODS: A case-control study was carried out during 2011-2013. "Case" referred to patients with a histopathological diagnosis of breast cancer (incident and primary cases) (n = 240); "controls" were those with a BI-RADS 1 or 2 mammography result (n = 406). Categorization of prediabetes and diabetes was based on self-reporting or fasting glucose and glycated hemoglobin blood sampling results. Reproductive and sociodemographic data were collected by interview. Odds ratios (ORs) and 95% confidence intervals (CI) were calculated using multivariate unconditional binary logistic regression analysis. RESULTS: Prediabetes increased the risk of breast cancer in postmenopausal women (adjusted OR 2.08, 95% CI 1.10-3.96) as did diabetes (adjusted OR 2.85, 95% CI 1.55-5.26). A history of diabetes preceding breast cancer by ≥7 years and <7 years were both associated with an increased risk for breast cancer (adjusted OR 2.80, 95% CI 1.40-5.60 and 3.00, 95% CI 1.50-5.90, respectively). CONCLUSIONS: This is the first study in Mexico evaluating prediabetes and diabetes as breast cancer risk factors in women with no first-degree relatives with breast cancer. Our findings suggest that women with prediabetes and diabetes should be considered a more vulnerable population for early breast cancer detection.

Moderate-intensity physical activity ameliorates the breast cancer risk in diabetic women.

OBJECTIVE: To evaluate the association between self-reported diabetes and the risk of breast cancer (BC) and its interaction with moderate-intensity physical activity in pre- and postmenopausal Mexican women. RESEARCH DESIGN AND METHODS: A population-based case-control study was conducted using 1,000 incident case subjects and 1,074 control subjects. Blood samples and information on health, diet, physical activity, and anthropometric measurements were obtained. RESULTS: The association between diabetes and BC risk decreased with increasing tertiles of moderate-intensity physical activity (odds ratio [OR] = 4.9 [95% CI 2.3-10.8]; 3.0 [1.3-6.9]; and 1.0 [0.1-9.2], respectively, for each tertile) (test for interaction = 0.04). Compared with the women in the lowest tertiles, increased risk was observed in those premenopausal women with the highest serum C-peptide, IGF-1, and IGF-1 binding protein 3 levels. CONCLUSIONS: Moderate-intensity physical activity can substantially ameliorate the increased BC risk in diabetic women.

Diabetes and pregnancy.

Diabetes in pregnant women is associated with an increased risk for maternal and neonatal morbidities and remains a significant medical challenge. Fortunately, the prognosis has changed dramatically, related to an increased clinical awareness of the potential risks for the mother and the infant, better health care and intensive treatment strategies to maintain the closest to normal metabolic milieu. Diabetes and pregnancy may be divided into pregestational diabetes (women previously diagnosed with type 1 or type 2 diabetes) and gestational diabetes defined as any glucose intolerance detected during pregnancy that has evolved from a diagnosis associated with the metabolic risk of type 2 diabetes to a clinical condition associated with higher risks for maternal and perinatal morbidity. Early diagnosis of gestational diabetes is an important step to improve outcomes and systematic or selective screening with the OGTT should be established. Associated with the global epidemic in diabetes, pregnancy associated with diabetes is saturating high-risk obstetric clinics and neonatal intensive care units, becoming a heavy burden to the health care systems around the world.

Diabetes y embarazo en México / Pregnancy and diabetes in Mexico

Objetivo. Conocer algunas características de diabetes pregestacional y gestacional en México. Material y métodos: Revisamos la literatura mexicana de pacientes con diabetes mellitus (DM) y embarazo que emplearon los criterios de clasificación propuestos por el National Diabetes Data Group (NDDG) y la Organización mundial de la Salud, así como los estudios para identificar DMG en embarazadas normales empleando carga de glucosa. Resultados. Hubo cinco series de DM y embarazo con un total de 689 pacientes: 331 de DM pregestacional tipo 2 y 32 de tipo 1; las otras 326 pacientes (47 por ciento) se clasificaron como DM gestacional (DMG) identificadas por cuadro clínico con hiperglucemia o por hiperglucemia de ayuno (> 140 mg/dL) cuando menos en dos ocasiones. El patrón de distribución de los tipos 1 y 2 fue similar en las series. Las principales complicaciones maternas fueron toxemia (18 por ciento) polihidramnios (10 por ciento) e infección de vías urinarias (6 por ciento), y las perinatales fueron muerte (7 por ciento), de las cuales 46 por ciento fueron intrauterinas y 54 por ciento neonatales. Hubo malformaciones congénitas en 6 por ciento de los niños, 25 por ciento de macrosomia y 8 por ciento de prematurez. En la reevaluación en el puerperio de 71 casos de DMG, hubo 48 (68 por ciento) con DM tipo 2, una tipo 1, tres (4 por ciento) con intolerancia a la glucosa (IG) y 19 (27 por ciento) con respuesta normal. Hubo seis estudios de detección de DMG en embarazadas normales con una prevalancia de 4 a 11 por ciento; tres de ellos corresponden a la ciudad de Monterrey con un total de 2,338 mujeres con prevalencia de 5.3 por ciento versus 10.5 a 11 por ciento en los otros estudios. La evaluación de 26 mujeres en el peurperio identificó a tres con DM tipo (12 por ciento), cinco con IG (19 por ciento) y 18 (69 por ciento) con respuesta normal. Conclusiones. La DM pregestacional de tipo 2 es la diabetes que con más frecuencia se asocia a embarazo y se acompaña de un incremento en las morbilidades materna y fetal. La DMG son tipo 2 mayoritariamente. La aparición de DMG ocurre en una proporción signficativa de 4 a 11 por ciento de la población obstétrica mexicana, las cuales tienen en su mayoría una respuesta normal en el puerperio. Se requiere una myor participación en la diabetes del embarazo, así como el escutrinio sistemático de embarazadas normales con el fin de proporcionar una mejor atención obstétrica