The aim of this study was to determine whether there is an association between leukocyte telomere length (LTL), and estrogen level, oxidative stress, cardiovascular disease (CVD) risk factors, and cardiorespiratory fitness (CRF) in pre-and postmenopausal obese women. Fifty-four obese women (premenopausal, n= 25; postmenopausal, n= 29) were selected to participate in this study. The outcome measurements in the pre-and postmenopausal groups were compared using independent t-tests and Pearson correlation analysis. The estrogen level (P< 0.001), LTL (P< 0.05), high-density lipoprotein level (P< 0.05), and CRF (P< 0.001) were higher in premenopausal women than in postmenopausal women. The body fat percentage (P< 0.05) and triglyceride concentration (P< 0.05) were lower in premenopausal women than in postmenopausal women. There were no significant associations between LTL, CVD risk, CRF, and oxidative stress and antioxidant enzyme activity in premenopausal women. The body mass index (BMI) and body fat percentage in postmenopausal women were negatively associated with LTL (P< 0.05). When all women were considered (i.e., both pre-and postmenopause), the BMI, percentage of fat, and waist circumference had a negative association with LTL (P < 0.05), and estrogen levels were positively associated with LTL (P< 0.05). Decreased estrogen levels after menopause, a pivotal factor in the biology of aging, and obesity were more associated with shorter telomere lengths in pre-and postmenopausal women than aerobic capacity and other CVD risk factors
