Effect of fetal apolipoprotein L1 genotype and vitamin D deficiencies on preeclampsia risk

Background: Preeclampsia is a hypertensive disorder in pregnancy known to increase the risk of mortality and other pregnancy-related issues, such as prematurity. Currently, there no known prophylactics or treatment options available for preeclampsia. More research is needed to better understand factors that increase preeclampsia risk. Vitamin D deficiency is consistently associated with developing preeclampsia. In addition to micronutrient deficiency, the presence of two fetal apolipoprotein L1 high-risk variants are also associated with preeclampsia risk. We hypothesized that a potential additive effect between high-risk apolipoprotein L1 genotype status and nutritional deficiencies would place individuals at a higher risk of developing preeclampsia.

Objective (s): The objective of this study was to determine the risk of developing preeclampsia in African American women with vitamin D deficiency and maternal/fetal high-risk apolipoprotein L1 genotype.

Study design: This was a case-control study using a subset of 999 African American mother and infant pairs collected from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood cohort in Memphis, TN. We performed multiple logistic regression to examine the association of preeclampsia with 2nd and 3rd trimester vitamin D concentrations. Concentrations were dichotomized into high or low categories. Vitamin D deficiency was defined as a concentration less than 20 ng/mL. Further analyses assessed whether maternal or fetal apolipoprotein genotype status modified the association between vitamin D association and preeclampsia. The reference group included individuals with both high vitamin D and low-risk apolipoprotein genotype.

Results: Pregnancies with low vitamin D in the 3rd trimester were at an increased risk for preeclampsia (odds ratio 2.10; 95 % confidence interval 1.09-4.12; P-value, 0.03). Risk for preeclampsia was greatest among pregnancies with fetal high-risk genotype and low vitamin D levels in the 2nd trimester (odds ratio, 2.79; 95 % confidence interval, 1.06-6.83; P-value, 0.03) and 3rd trimester (odds ratio 6.40; 95 % confidence interval 2.07-19.18; P-value, <0.01).

Conclusion(s): Our significant findings suggest that the risk of preeclampsia associated with low vitamin D levels, especially during the 3rd trimester, is magnified by the presence of fetal high-risk apolipoprotein L1 genotype.