Potential role for elevated maternal enzymatic antioxidant status in Andean protection against altitude-associated SGA

Abstract

Oxidative stress has been implicated in the uteroplacental ischemia characteristic of preeclampsia and small-for-gestational-age (SGA) birth, both of which are more common at high (>2500 m) vs low altitude. Since Andeans are protected relative to Europeans from the altitude-associated rise in SGA, we asked whether alterations in maternal antioxidant status or oxidative stress contributed to their protection. Enzymatic antioxidant (erythrocyte catalase and superoxide dismutase [SOD]) activity and a plasma marker of lipid peroxidation (8-iso-PGF2α) were measured during pregnancy and in the non-pregnant state in Andean or European residents of low (400 m) or high altitude (3600–4100 m). Pregnancy and altitude increased catalase and/or SOD activity to a greater extent in Andeans than Europeans. 8-iso-PGF2α levels were independent of altitude and pregnancy. SOD was lower in mothers of SGA infants at weeks 20 and 36. Our findings are consistent with the possibility that elevated enzymatic antioxidant activity contributes to Andean protection against altitude-associated SGA.

Keywords::

• Adaptation
• fetal growth restriction
• hypoxia
• oxidative stress

Acknowledgements

We would like to acknowledge all the women who generously donated their time for this project. Our appreciation is also extended to the many physicians who helped with numerous aspects of the study: Fernando Armaza, Diva Bellido, José L. Casanova, Pilar Garcia, Jose Luis Pablo Lopez, Jessica Pardo, Julio Roca, Jessika Schaymann, Lilian Toledo, Mercedes Villena, and Elizabeth Zelada. We are also grateful for the technical help provided by Mabel Agramonte, Ana-Maria Alarcón, Marta Aguilar, Esteban Alanoca, Hugo Aquino, Ruliana Arce, Marta Cardenas, Dolly Condori, Maria Elena Gira, Cristina Gonzáles, Ida Gonzales, Jennifer Hageman, Jost Klawitter, Freddy Lamachi, Damon Maes, Zaida Martinez, Lourdes Mavrich, Gene and Rosann McCullough, Caterina Romero, Tita Sanchez, and Wilmar Velasquez. We would also like to thank the following hospitals or clinics for their participation: CEMES, Clinica Siraní, Caja Nacional de Salud, Clinica Centro Integral de Educación Sexual and Clinica Grupo Médico Solidario.

Declaration of Interest: NIH HLBI-079647, HLBI-060131 and TW-01188 (LGM); as well as an AHA pre-doctoral fellowship (CGJ), an NSF doctoral dissertation improvement grant (CGJ) and an NSF graduate research fellowship (MJW).