177 - Non-Enzymatic Antioxidant Response in Postmenopausal Women with Decreased Muscle Strength

Abstract

Background Menopause is the beginning of aging in woman due to loss of ovarian follicular function that produces an abrupt drop in estrogen levels as well as body and biochemical changes like muscle strength loss and oxidative stress (OS). Objective To determinate OS biomarkers in postmenopausal women with low muscle strength. Methods We carried out a cross-sectional study with 42 premenopausal [PRE] (47.8±1.9 years) and 48 postmenopausal [POS] women (53.9±2.3 years) from Mexico City. We measured as OS biomarkers: plasma lipoperoxides (LPO) by the TBARS assay, serum uric acid (UA) using a Cobas© C111 analyzer, erythrocyte superoxide dismutase (SOD) and glutathione peroxidase (GPx), and total plasma antioxidant status (TAS) with Randox kits, and we calculated SOD/GPx ratio and antioxidant gap. Handgrip strength was measured with a dynamometer; also we measured weight and height and we calculated the body mass index (BMI). An alternative cut-off value of handgrip strength <20 kg was defined according the Sarcopenia European consensus. Results We found that PRE women had good strength and 20 (42%) of the POS women had low handgrip strength; 83 (92%) of the all women were obese (BMI >25 kg/m2). LPO levels were higher, and SOD and GPx activities were lower in POS women with low muscle strength compared with PRE women (control group), although only GPx had low activity statistically significant (58.6±2.9 vs. 69.2±.1 U/gHb, p<0.05). Non-enzymatic antioxidants were statistically higher (p<0.05) in POS women with low muscle strength than control group: TAS 1262±48.2 vs. 1147±29.9 μmol/L, UA 296±21.8 vs. 265±9.5 μmol/L, and GAP 502±46.1 vs. 395±28.4 μmol/L. Conclusion Our findings suggest that there is a non-enzymatic antioxidant response in postmenopausal women with decreased muscle strength. This work was supported by grant UNAM-IN224115.