Association between hot flashes severity and oxidative stress among Mexican postmenopausal women: a cross-sectional study

Abstract

36Objective: To assess the association between hot flashes (HFs) severity and oxidative stress (OS) 37 in Mexican postmenopausal women. 38 Methods: A cross-sectional study was carried out with perimenopausal women aged 40-59 years 39 community-dwelling from Mexico City, Mexico. They participated in Menopause and Oxidative 40 Stress Project. The baseline sample consisted of 476 women recruited to participate; 161 women 41were excluded due to different reasons. Hence, 315 women were selected to establish two groups, 42 a) 145 premenopausal women (yet with menstrual bleeding), and b) 170 postmenopausal women 43 (without menses). All women were free of cardiovascular, kidney, hepatic or cancer disease, and 44 without antioxidant supplement intake for at least six months prior to the beginning of the study; 45 none had previously received hormone therapy. As OS markers, we measured plasma 46 malondialdehyde using the TBARS assay, erythrocyte superoxide dismutase (SOD) and 47 glutathione peroxidase (GPx), uric acid, and total antioxidant status; also, we calculated 48 SOD/GPx ratio, antioxidant gap and an oxidative stress score ranging from 0 to 7. The HFs were 49 evaluated using the Menopause Rating Scale. The women completed Spanish version of the 50 Athens Insomnia Scale, Zung Self-Rating Anxiety Scale and Zung Self-Rating Depression Scale 51 and a questionnaire of pro-oxidant factors. 52Results: Stress score increased with HFs severity (mild 2.9±0.23, moderate 3.1±0.21 and severe 53 3.8±0.18, p<0.01) in postmenopausal women. We observed a positive correlation between HFs 54 severity and stress score, r=0.247 (p=0.001) in postmenopausal women; other test scores were not 55 correlated. Severe HFs were a risk factor for OS (OR=3.37, 95%CI: 1.20-9.51, p<0.05) in an 56 adjusted multivariate analysis by different postmenopausal symptoms and pro-oxidant factors; we 57 did not see any association in premenopausal women. 3 58 Conclusion: Our findings suggest an association between HFs severity and OS in Mexican 59 postmenopausal women. 60 Introduction 63 Menopause, an expected event in a woman's life, is commonly defined as a 12-month 64 period of amenorrhea [1] or hypoestrogenism (estrogen level < 25 pg/mL) due to ovarian 65 senescence; therefore, the postmenopausal period may be considered the beginning of the aging 66 process in women. Postmenopausal aging is produced by a series of endocrinological changes 67 that lead to the erratic production of estrogens (mainly estradiol) that eventually bring to low 68 estrogen (E2) level [2] and is associated with multiple symptoms including vasomotor symptoms 69 that interfere with daily activities and sleep. The most distressing symptoms of menopausal 70 transition are hot flashes (HFs). They occur in over 75% of menopausal women [3]. Recently, it 71 was highlighted that moderate/severe HFs continue, on average, for nearly 5 years after 72 menopause, and more than one third of women experience moderate/severe HFs 10 years or more 73 after menopause [4]; however, HFs onset or ...