Effects of hormonal replacement therapy on oxidative stress and total antioxidant capacity in postmenopausal hemodialysis patients

Abstract

Background: Oxidative stress is known to be implicated in the pathogenesis of atherosclerotic cardiovascular disease. Many studies have demonstrated that hormone replacement therapy (HRT) has beneficial effects on oxidation injury in postmenopausal women with normal renal function. In this study, we examined the effects of HRT on plasma malondialdehyde (MDA) level and total antioxidant capacity (TAC) in postmenopausal hemodialysis women. Methods: We randomly assigned 70 postmenopausal women on maintenance hemodialysis into either a HRT group or a control group. Oral conjugated estrogen (0.625 mg) combined with medroxyprogesterone acetate (2.5 mg) was given daily for 12 weeks in HRT group. Plasma MDA, TAC, albumin, uric acid and C-reactive protein (CRP) were measured before, 4 and 12 weeks after the start of medication in the HRT group. In the control group, the same parameters were measured without HRT. Results: There was no difference in baseline values between the two groups. In the control group (n = 32), all these parameters showed no change at 4 and 12 weeks. HRT decreased MDA from 1.32 (0.55-1.88) μM to 1.08 (0.44-1.50) μM (p < 0.001) at 4 weeks and to 1.11 (0.50-1.37) μM (p < 0.001) at 12 weeks (n = 33). TAC was not changed at 4 weeks, however, it decreased from 1.59 (1.27-2.00) mM to 1.45 (1.08-1.65)mM (p < 0.05) at 12 weeks. The albumin, uric acid and CRP levels were not changed significantly after HRT. Conclusions: These results suggest that HRT has a favorable effect on oxidative stress in postmenopausal women with ESRD as in the general population.