Neighborhood Walkability and Sex Hormone Levels in Women

Abstract

BACKGROUND AND AIM: Neighborhood walkability (NW) has been linked to increased physical activity. Engaging in regular exercise is associated with lower levels of sex hormones in women. However, little is known about the effects of NW on female sex hormones. We conducted a cross-sectional study to evaluate the association between NW and circulating levels of sex hormones in pre- and postmenopausal women. METHODS: We included a total of 802 premenopausal and 629 postmenopausal women in the New York University Women’s Health Study (NYUWHS) who were healthy controls from previous nested case-control studies in which sex hormone levels had been measured. Baseline residential addresses were geo-coded and the Built Environment and Health Neighborhood Walkability Index (BEH-NWI) was derived. Measurements from serum samples collected at recruitment were available for androstenedione, testosterone, dehydroandrosterone sulfate (DHEAS), estradiol and estrone (postmenopausal women), and sex hormone-binding globulin (SHBG). Generalized Estimating Equations were implemented to assess the association between BEH-NWI and sex hormone levels. RESULTS:One standard deviation (SD) increment in BEH-NWI was associated with 4.2 percent (95% CI 1.6-6.7) and 8.9 percent (95% CI 5.8-11.9) lower DHEAS concentrations in premenopausal and postmenopausal women, respectively, adjusting for individual and neighborhood level factors. One SD increment in BEH-NWI was also related to a 4.3 percent (95% CI 1.1-7.3) lower level of testosterone and a 6.7 percent (95% CI: 4.6-8.8) higher level of SHBG in postmenopausal women, adjusting for covariates. These associations remained significant after controlling additionally for BMI. BEH-NWI was not associated with estradiol, estrone, or androstenedione concentrations. CONCLUSIONS:Our findings suggest that NW is associated with lower concentrations of DHEAS in both pre- and postmenopausal women, as well as lower testosterone and higher SHBG in postmenopausal women, independent of BMI. KEYWORDS: walkability, urban health, other (sex steroid hormones), other (women’s health)