Obesity is very common in American society and is a risk factor for breast cancer in...

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Obesity is very common in American society and is a risk factor for breast cancer in postmenopausal women. One mechanism explaining why obesity is a risk factor is that it may raise estrogen levels in women. In particular, one type of estrogen, serum estradiol, is a strong risk factor for breast cancer. To better assess these relationships, researchers studied a group of 151 African Amer can and 60 Caucasian postmenopausal women. Adiposity was measured in two different ways (a) by body-mass index (BMI) - weight (kg)/Height2(m2) and also (b) by the waist-hip ratio (WHR) = waist circumference/hip circumference. BMI is a measure of overall adiposity, 1 whereas WHR is a measure of abdominal adiposity. In addition, a complete hormonal profile was obtained, including serum estradiol (ES 1). Finally, other breast-cancer risk factors were also assessed among these women, including (1) ethnicity (ETHNIC = 1 if African American, = 0 if Caucasian), (2) age (ENTAGE), (3) parity (NUMCHILD = number of children), (4) age at first birth (AGEFBO), (5) any children (ANY KIDS = 1 if yes, =0 if no), (6) age at menarche (AGEMNRCH = age when menstrual periods began). please explain the process of how to answer the below questions in R (a) is there a crude association between either measure of adiposity (BMI, WHR) considered separately, and serum estradiol? Present the scatterplots of each variable, and the correlation coefficients, and discuss any concerns. (b) Are these relationships similar for Caucasian and African Ameri can women? Fit a model that will answer this question. (c) Do the relationships between adiposity measures and serum estra diol persist after controlling for the other breast-cancer risk factors in list items 1 to 6? (d) One debate in the breast-cancer literature whether overall adiposity (BMI) or central (abdominal) adiposity (WHR) is a better indicator of breast cancer risk. Perform analyses to inform the debate as to which measure of adiposity is more closely related to serum estradiol either crudely or after adjusting for other breast cancer risk factors. (e) Are there differences between estradiol levels for African American women and Caucasian women after controlling for obesity? Obesity is very common in American society and is a risk factor for breast cancer in postmenopausal women. One mechanism explaining why obesity is a risk factor is that it may raise estrogen levels in women. In particular, one type of estrogen, serum estradiol, is a strong risk factor for breast cancer. To better assess these relationships, researchers studied a group of 151 African Amer can and 60 Caucasian postmenopausal women. Adiposity was measured in two different ways (a) by body-mass index (BMI) - weight (kg)/Height2(m2) and also (b) by the waist-hip ratio (WHR) = waist circumference/hip circumference. BMI is a measure of overall adiposity, 1 whereas WHR is a measure of abdominal adiposity. In addition, a complete hormonal profile was obtained, including serum estradiol (ES 1). Finally, other breast-cancer risk factors were also assessed among these women, including (1) ethnicity (ETHNIC = 1 if African American, = 0 if Caucasian), (2) age (ENTAGE), (3) parity (NUMCHILD = number of children), (4) age at first birth (AGEFBO), (5) any children (ANY KIDS = 1 if yes, =0 if no), (6) age at menarche (AGEMNRCH = age when menstrual periods began). please explain the process of how to answer the below questions in R (a) is there a crude association between either measure of adiposity (BMI, WHR) considered separately, and serum estradiol? Present the scatterplots of each variable, and the correlation coefficients, and discuss any concerns. (b) Are these relationships similar for Caucasian and African Ameri can women? Fit a model that will answer this question. (c) Do the relationships between adiposity measures and serum estra diol persist after controlling for the other breast-cancer risk factors in list items 1 to 6? (d) One debate in the breast-cancer literature whether overall adiposity (BMI) or central (abdominal) adiposity (WHR) is a better indicator of breast cancer risk. Perform analyses to inform the debate as to which measure of adiposity is more closely related to serum estradiol either crudely or after adjusting for other breast cancer risk factors. (e) Are there differences between estradiol levels for African American women and Caucasian women after controlling for obesity?

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