The role of antioxidant & oxidative status in the protection against altitude‐associated reductions in uterine artery (UA) blood flow & fetal growth afforded by Andean ancestry

Abstract

Objective: To determine the role of antioxidant & oxidative status in the protection of uterine artery blood flow (UAVF) & fetal growth at high altitude in Andean populations. Methods: Erythrocyte catalase (CAT) & superoxide dismutase (SOD), plasma isoprostanes (8‐ISO‐PGF‐2α) & UA VF were measured at 20 & 36w of pregnancy & and in the non‐pregnant state in Andean (AND) & European (EUR) women at low (LA, 416m) or high (HA, 3600m) altitude. CAT, SOD & 8‐iso‐PGF‐2α were assessed by spectrometry, UA VF by Doppler ultrasound & birth weight (BW) by medical records review. Data was analyzed by t‐tests, 1‐ & 2‐way ANOVA. Results: At LA, ancestry had no effect on CAT or SOD. AND had higher CAT (20 & 36w p<0.05) & SOD activity (36w p<0.05) than EUR at HA. At HA, UA diameter and UA VF were greater in AND than EUR. Altitude decreased BW in AND (p<0.05) and EUR (p<0.01), and at HA EUR ancestry reduced BW (β= − 0.238 p<0.05). Small‐for‐gestational age (SGA) infants occurred 2‐times more frequently at HA than LA in EUR. SOD was lower at 20w in SGA at both altitues, or HA alone (all p<0.05). In EUR, CAT tended to be lower at 20w in SGA. 8‐ISO‐PGF2α reduced UA diam (p<0.05) & UA VF (p<0.01) in all women. Conclusion: Elevated endogenous antioxidant activity may contribute to the protection against altitude‐associated reductions in UA blood flow & fetal growth afforded by Andean ancestry. NIH HL079647,AHA 0610129Z & NSF BCS‐064719.