SERUM LEVELS OF OXIDATIVE STRESS PARAMETERS IN POSTMENOPAUSAL VERSUS FERTILE WOMEN OF KUTAHYA CITY, TURKEY

Abstract

Background: Decreased concentration of both oestrogen hormone and vitamin D in postmenopausal period may lead to oxidative stress, lipid peroxidation, dyslipidaemia, osteoporosis, and cardiovascular diseases. The objectives of this study were to determine and compare the serum levels of oxidative stress parameters; TOS, TAS, OSI, PON-1, ARYL in postmenopausal and fertile women of Kutahya city, Turkey. Materials & Methods: This cross-sectional study was conducted at Department of Biochemistry, Faculty of Medicine, Kutahya University of Health Sciences, Kutahya, Turkey from July, 2016 to December, 2016. Kutahya is a city in western Turkey, with population of 237,804 as per 2011 estimates. Two samples were drawn from this population with consecutive technique. Study group included 40 menopausal women, while control group included 40 healthy fertile women. After overnight fasting, venous blood samples were collected, centrifuged, aliquoted into a polystyrene tube, and aliquots were stored at -80°C until measurement for total oxidant status (TOS), total antioxidant status (TAS), paraoxonase-1 (PON-1), and arylesterase (ARYL) measurements were made. Levels of TOS, TAS, OSI, PON-1, ARYL were five research variables on ratio scale. ‘Normal’ data were described by mean, range and SD and skewed data by median, Q1, Q3 and IQR with 95% confidence intervals. For normal data, independent-samples t-test and for skewed data Mann–Whitney U test was used for hypotheses testing. Results: Serum total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly higher (p-value .015 & .003 respectively), and serum paraoxonase-1 (PON-1) and arylesterase (ARYL) levels were significantly lower in postmenopausal than fertile women (p-value <.0001 & .0005 respectively), with no statistical difference for serum total antioxidant status (TAS) levels between the two groups (p-value .186). Conclusion: Postmenopausal period is associated with oxidative stress and decreased antioxidant defence. HDL-c-dependent PON-1 and ARYL activities are also reducing due to a decrease of HDL-c with menopause. Elevated levels of TOS and OSI, decreased levels of PON-1 and ARYL may lead to various life-threatening diseases such as cardiovascular disorders or cancer.