Iodine levels are associated with oxidative stress and antioxidant status in pregnant women with hypertensive disease

BACKGROUND The antioxidant function of iodine and iodine deficiency as a risk factor of preeclampsia have been previously reported. AIM To analyze the association between iodine deficiency, oxidative stress and antioxidant status with hypertensive disease of pregnancy (HPD). METHOD Fifty-seven pregnant women were recruited in the last trimester of pregnancy; 20 were diagnosed with hypertensive disease (HPD) of pregnancy and 37 were normotensive pregnant women. Urinary iodine concentration (UIC), TSH, free T4 (fT4), total antioxidant status (FRP), superoxide dismutase (SOD), catalase (CAT), and oxidative stress (TBARS) were evaluated by colorimetric methods. RESULTS UIC median for all pregnant women was 151.9 µg/l. The UIC for pregnant women with HPD was 50-149 µg/l, compared to 150-249 µg/l in normotensive women. No significant differences in levels of TSH and fT4 in normotensive pregnant compared with HPD women were found. Pregnant women with HPD had significant high levels of TBARS, and significant low levels of FRP, SOD, CAT and UIC compared to normotensive pregnant. In addition, pregnant women with optimal levels of UIC had a higher SOD activity (r = 0.354, p = 0.011), while iodine deficiency was associated with HPD (r = -0,281, p = 0.039). Similarly, pregnant women with HPD had a significant negative association with SOD activity (r = -0.702, p = 0.005), CAT (r = -0.409, p = 0.002), and FRP (r = -0.624, p = 0.003), and a positive association with TBARS (r = 0.744, p = 0.001). CONCLUSION Iodine contributes to redox balance during pregnancy; its deficiency is associated with HPD. This study shows the importance of iodine during pregnancy.