Physical Activity and Breast Cancer Risk in Postmenopausal Women:the SHAPE Study

Study Overview
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Brief Summary
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Purpose of the SHAPE study is to examine the effects of an 1-year exercise programme on endogenous hormone levels associated with breast cancer among sedentary postmenopausal women and whether a decrease in intra-abdominal fat is associated with a lowering of these hormone levels.

Detailed Description
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Physical activity has been associated with a decreased risk for breast cancer. The biological mechanism(s) underlying the association between physical activity and breast cancer is not clear. Most prominent hypothesis is that physical activity may protect against breast cancer through reduced lifetime exposure to endogenous hormones. Another hypothesis is that physical activity prevents overweight and abdominal adiposity. In this intervention study, 189 sedentary postmenopausal women who are aged 50-69 years are randomly allocated to an intervention or a control group. The intervention consists of an 1-year moderate-to-vigorous intensity aerobic and strength training exercise programme. Participants allocated to the control group are requested to retain their habitual exercise pattern. Primary study parameters measured at baseline, at four months and at 12 months are: serum concentrations of endogenous estrogens, endogenous androgens, sex hormone binding globulin and insulin. Other study parameters include: amount of total and abdominal fat, weight, BMI, body fat distribution, physical fitness, blood pressure and lifestyle factors. This study will contribute to the body of evidence relating physical activity and breast cancer risk and will provide insight into possible mechanisms through which physical activity might be associated with reduced risk of breast cancer in postmenopausal women.

Official Title
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Physical Activity and Breast Cancer Risk in Postmenopausal Women: the SHAPE Study

Conditions
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Breast Cancer

Intervention / Treatment
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* Behavioral: Physical activity


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Women aged 50 -69 year > 12 months since last menses Non-smokers (at least 12 months) Sedentary Knowledge of the Dutch language Agreement to be randomly assigned to either the exercise intervention or control group Informed consent to participate in all screening and study activities Exclusion Criteria: Use of hormone replacement or oral contraceptives in past 6 months Morbidly obese (BMI > 40) BMI < 22 Currently on or planning to go on a strict diet Ever diagnosed with breast cancer Diagnosis of other types of cancer in the past 5 years Diabetes mellitus or other endocrine related diseases Disorders or diseases (locomotor, optical, neurological, mental) that might impede the participation in the exercise programme Alcohol or drug abuse Maintenance use of corticosteroids Use of beta blockers

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 69 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Intervention/Treatment |
| --- |
|Behavioral: Physical activity|nan|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum concentrations of endogenous estrogens: estradiol (total, free), estrone, estrone sulfate |  |  | 
| Serum concentrations of endogenous androgens: testosterone, androstenedione |  |  | 
| Serum concentrations of sex hormone binding globulin |  |  | 
| Serum concentrations of fasting insulin |  |  | 
| Insulin sensitivity |  |  | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Amount of total body fat and intra-abdominal fat |  |  | 
| Weight |  |  | 
| Body Mass Index (BMI) |  |  | 
| Body fat distribution |  |  | 
| Waist to hip ratio |  |  | 
| Physical Fitness |  |  | 
| Blood pressure |  |  | 
| Lifestyle parameters (covariates) |  |  | 
| Exercise behaviour (habitual physical activity, past week activity, physical activity in the past) |  |  | 
| Diet (daily caloric intake; percent daily calories from fat, carbohydrates and proteins) |  |  | 
| Alcohol consumption |  |  | 
| Medication use |  |  | 
| Reproductive factors |  |  | 
| Medical history |  |  | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Physical activity, Sex steroid hormones, Breast cancer risk, Intervention study, Postmenopausal women