Association of Sedentary Behavior with Salivary Estradiol Level Among African-american Women Who Are Overweight

Purpose: Recent studies have reported that sedentary behavior may have multiple adverse health outcomes in adults, and is related to elevated levels of estradiol that are associated with breast cancer, ovarian cancer, and endometrial cancer. A growing body of research has assessed the association of sedentary behavior with estradiol levels, however, few studies have been in African-American (AA) overweight women who are disproportionally diagnosed with cancer. The objective of this study was to assess the association of self-reported sedentary behavior of AA overweight women with salivary estradiol level. Methods: We recruited 263 AA overweight (BMI [greater than] 25, mean BMI 36.8 (SD 8.5), mean age 49.4 (SD 11.6) years) women from a faith-based weight reduction program from 2014-2016 in Dallas, Texas. Approximately 4mL of saliva was collected over four consecutive weeks. Saliva was stored in a sub 800C freezer and sent to a lab to assay. Weekly sedentary behavior was collected with a valid and reliable survey for weekdays and weekends that included hours of sitting to watch television, working on the computer, riding in a car, bus, or train, and other sitting practices. We used Pearson’s-correlation and linear models to estimate the unadjusted and adjusted association of sedentary behavior with estradiol level. Results: Average weekly sedentary time was 40.6 hours (SD = 17.5). The range of estradiol level was 0.50 pg/mL to 3.50 pg/mL with mean 1.13 pg/mL (SD = 0.55). Sedentary time was positively associated with estradiol level (correlation coefficient = 0.18, p2= 8.4%, p Conclusions: Self-reported sedentary hours for AA overweight women were less than the national average (5.8 hours in this study vs. 7.7 hours nationally, per day). We found that sedentary time was a predictive factor for estradiol level, and higher sedentary time was associated with elevated estradiol levels. Future research should further explore how sedentary behavior and elevated estradiol levels influence cancer risk in AA women.