028 - Relationship Between Maternal Plasma Carotenoids and Fetal/Infant Kidney Parenchymal Thickness

Publication Number: 28.6249

Anum Akbar, University of nebraska Medical center, Omaha, NE, United States; Rebecca Drakowski, University of Nebraska Medical Center, Papillion, NE, United States; Taija Hahka, University of Nebraska Medical Center, LINCOLN, NE, United States; Rebekah Rapoza, University of Nebraska Medical Center, Omaha, NE, United States; Colman I. Freel, University of Nebraska College of Medicine, Omaha, NE, United States; Matthew VanOrmer, University of Nebraska Medical Center, Omaha, NE, United States; Melissa Thoene, University of Nebraska College of Medicine, Omaha, NE, United States; Corrine Hanson, University of Nebraska Medical Center, Omaha, NE, United States; Ann L. Anderson Berry, University of Nebraska College of Medicine, OMAHA, NE, United States

Background: Despite the importance of vitamin A (retinol) in kidney development, the impact of compounds with pro-vitamin A activity (α-carotene, β-carotene, and β-cryptoxanthin) on kidney size has not been examined. Furthermore, non-provitamin A carotenoids (lutein, lycopene, and lutein+zeaxanthin) are known for their antioxidant properties, yet their role in infant kidney development remains unexplored.

Objective: To investigate the association between maternal carotenoid status (both pro-vitamin A and non-provitamin A) with fetus and infant kidney parenchymal thickness, an important surrogate measurement for the lifetime number of nephrons and renal filtration capacity.

Design/Methods: An IRB-approved study enrolled pregnant women at 18-20 weeks of gestation. Infant parenchymal thickness was measured by ultrasound during the anatomy scan and within 48-72 hours after birth. Maternal blood samples were collected between 24-28 weeks gestation (n=79) and again at the time of delivery (n=79). Plasma samples were analyzed using HPLC and LC-MS/MS for total concentrations of α-carotene, β-carotene,β -cryptoxanthin, lycopene, and lutein+zeaxanthin. Spearman’s correlation was conducted to evaluate the relationships between maternal carotenoid levels and fetal/infant parenchymal thickness. Linear regression analysis was performed adjusting for maternal hypertension, diabetes, and smoking status. A p-value of < 0.05 was considered statistically significant.

Results: 111 subjects were included in the analysis. Fetal right kidney parenchymal thickness was correlated at 24-28 weeks with maternal provitamin A carotenoids, α-carotene (r = -0.347, p = 0.003) and β-carotene (r = -0.254, p = 0.033), as well as non-provitamin A carotenoids lycopene (r = -0.349, p = 0.003) and the combined lutein+zeaxanthin levels (r = 0.289, p = 0.015) Table 1. However, after adjusting for confounders, fetal right kidney parenchymal thickness remained significantly associated only with maternal lycopene ( r= -0.292, p = 0.018). Similarly, fetal left kidney parenchymal thickness was correlated with α-carotene (r = -0.323, p = 0.006) and lycopene (r = -0.314, p = 0.008), and these associations remained significant after adjusting for confounders (α-carotene: r =- 0.257, p = 0.048; lycopene: r = -0.251, p = 0.047). In contrast, no correlations were found between infant kidney parenchymal thickness (right or left) and maternal carotenoids at delivery.

Conclusion(s): Fetal kidney size may be associated with maternal serum carotenoid levels during pregnancy, but no associations were found between infant kidney size and maternal carotenoids measured at birth.

Table 1: Spearman’s correlation between fetal kidney parenchymal thickness and maternal plasma carotenoids concentration at 24-28 weeks of gestation