An Exercise RCT Targeting African-American Women With Metabolic Syndrome and High Risk for Breast Cancer

Overview

Among African-American women, in whom metabolic syndrome (MetS) is very prevalent and breast cancer mortality rates are high, it is hypothesized that intervening on MetS to improve the MetS profile may prove to be a means to reduce breast cancer risk. Specific recommendations for breast cancer prevention are now focused on maintaining a healthy weight via increased physical activity levels, and losing weight if overweight or obese. This pilot project compares two exercise interventions: a supervised facility-based and a home-based exercise intervention to a control group in African-American women with metabolic syndrome who are at high risk for breast cancer. This study is a 6-month three-arm RCT to assess the impact of the exercise interventions on biomarkers related to obesity, insulin-related pathways, inflammation, hormones, and micro-RNAs. The specific aim of the proposed study is to compare the impact of a supervised facility-based and a home-based exercise intervention on obesity, metabolic syndrome and known breast cancer biomarkers in postmenopausal African-American women with metabolic syndrome who are at increased risk of breast cancer.

1. To assess the impact of exercise on biomarkers related to obesity, insulin-related pathways, inflammation, hormones, and microRNAs. 2. The primary aim of this study is to compare the effect of 2 types of exercise interventions (supervised and self-directed compared to control) on biological parameters related to breast cancer development. It is important to understand if participants in this study respond better to an exercise program they are able to engage in on their own (self-directed) or if participating in an exercise program under supervision is preferred. A study by Pinto utilized a home-based exercise program among breast cancer survivors and commented that the home-based program has several advantages including 1) mitigating transportation and scheduling difficulties, and 2) is less expensive than supervised programs. Another study compared the effect of a supervised exercise program to a self-directed exercise group and a control group on physical functioning and health-related quality of life among breast cancer survivors and found that participants in the self-directed exercise group improved their physical functioning to a somewhat greater degree than the supervised group. The authors proposed that one reason for this result could be attributed to the fact that the self-directed program included many features thought to comprise effective home training including the following: baseline fitness evaluations, written guidelines for home exercise, education about pulse checking/heart rate guidelines, daily activity logs and bi-weekly telephone calls by the exercise specialist. In the current study, we plan to employ features similar to the self-directed exercise program in an effort to determine if the self-directed group improves to a greater extent than the control group and better or comparable to the supervised group. An added feature of the current study is that we will administer a participant satisfaction questionnaire to assess each participant's experience in their respective groups. This information will, in part, help us to plan future studies. All participants will complete a baseline assessment prior to randomization, as indicated in Table 1 in the attached grant proposal; follow-up measures will also be conducted as indicated in that table. Participants will be required to provide a medical clearance from their health care provider or a nurse practitioner. 3. \* Rationale and justification for study (i.e. historical background, investigator's personal experience, pertinent medical literature, etc.): In the United States, breast cancer is the most commonly diagnosed cancer in women, other than non-melanoma skin cancer, and is the second most common cause of cancer deaths among women. Several risk factors have been identified that increase breast cancer risk, some of which are non-modifiable (e.g., age, family history, and race) and some of which are modifiable (e.g., physical activity, body weight, dietary habits, and alcohol intake). Breast cancer rates, which are increasing worldwide, parallel the increases in lifestyle diseases including Type 2 diabetes, obesity, and metabolic syndrome (MetS). MetS represents a cluster of risk factors associated with increased risk of cardiovascular diseases, and includes several components individually related to breast cancer etiology, i.e., central obesity, hypertension, hyperglycemia, and low high-density lipoprotein cholesterol. However, recent studies have suggested that MetS is underdiagnosed in African-American women because they are less likely to have decreased HDL or increased triglycerides as compared to women of other races/ethnicities. Breast cancer is hormone related and thus, the effects of established risk factors for the disease, including obesity, differ before to after menopause. Among African-American women, in whom MetS is very prevalent and breast cancer mortality rates are high, it is hypothesized that intervening on MetS to improve the MetS profile may prove to be a means to reduce breast cancer risk. The American Cancer Society (ACS) and the International Agency for Research on Cancer of the World Health Organization now both recommend regular physical activity as a strategy for women to reduce their risk of developing breast cancer. Specific recommendations for breast cancer prevention, which initially emphasized diet, are now focused on maintaining a healthy weight throughout life by balancing caloric intake while increasing caloric expenditure via increased physical activity levels, and losing weight if overweight or obese. Obesity itself is a major public health problem and is associated with increased postmenopausal breast cancer incidence and mortality. Our proposed pilot project compares two exercise interventions: a supervised facility-based and a home-based exercise intervention to a control group in African-American women with metabolic syndrome who are at high risk for breast cancer (based on the CARE model).This study is a 6-month three-arm RCT to assess the impact of the exercise interventions on biomarkers related to obesity, insulin-related pathways, inflammation, and hormones. The specific aim of the proposed study is to compare the impact of a supervised facility-based and a home-based exercise intervention on obesity, metabolic syndrome and known breast cancer biomarkers in postmenopausal African-American women with metabolic syndrome who are at increased risk of breast cancer.