Maternal vitamin D status in preeclampsia: seasonal changes are not influenced by placental gene expression of vitamin D metabolizing enzymes.

Carolin Lechtermann,Alexandra Gellhaus,Michael M Schündeln,Ralf Herrmann,Markus Schmidt,Corinna Grasemann,Berthold P Hauffa,Ana Claudia Zenclussen

doi:10.1371/journal.pone.0105558

Carolin Lechtermann, Alexandra Gellhaus + Show 6 more

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https://doi.org/10.1371/journal.pone.0105558

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Abstract

Preeclampsia, a hypertensive disorder in pregnancy develops in 2–8% of pregnancies worldwide. Winter season and vitamin D deficiency have been associated with its onset.ObjectiveTo investigate the influence of season on maternal vitamin D status and placental vitamin D metabolism.Methods25-OH vitamin D and 1,25-(OH)2 vitamin D were measured in maternal serum obtained during the winter or summer months from 63 pregnant women at delivery (43 healthy, 20 preeclampsia). In a subgroup, mRNA expression of CYP24A1 (24-hydroxylase), CYP27B1 (1α-hydroxylase) and VDR (vitamin D receptor) were quantified by real time PCR in placental samples of 14 women with normal pregnancies and 13 with preeclampsia.ResultsIn patients with preeclampsia,25-OH vitamin D levels were lower, but differed significantly from controls only in summer (18.21±17.1 vs 49.2±29.2 ng/mL, P<0.001), whereas 1,25-(OH)2 vitamin D levels were significantly lower only in winter (291±217 vs 612.3±455 pmol/mL, P<0.05). A two-factorial analysis of variance produced a statistically significant model (P<0.0001) with an effect of season (P<0.01) and preeclampsia (P = 0.01) on maternal 25-OH vitamin D levels, as well as a significant interaction between the two variables (P = 0.02). Placental gene expression of CYP24A1, CYP27B1, and VDR did not differ between groups or seasons. A negative correlation between placental gene expression of CYP24A1 and CYP27B1 was observed only in healthy controls (r = −0.81, P<0.0001).SummaryPatients with preeclampsia displayed lower vitamin D serum levels in response to seasonal changes.The regulation of placental CYP24A1, but not of the VDR or CYP27B1 might be altered in preeclampsia.

Highlights

Preeclampsia, a hypertensive disorder of pregnancy, affects about 2–8% of pregnancies worldwide [1]
Summary: Patients with preeclampsia displayed lower vitamin D serum levels in response to seasonal changes.The regulation of placental CYP24A1, but not of the vitamin D receptor (VDR) or CYP27B1 might be altered in preeclampsia
Maternal 1,25 -(OH)2 vitamin D levels were differently affected by season than 25-OH vitamin D levels: While no seasonal changes were detected in healthy controls (612.36455.7 in winter vs.748.56462 pmol/L in summer), patients with preeclampsia had significantly lower 1,25-(OH)2 vitamin D levels in the winter compared to the summer months (2916217 vs 8156478 pmol/L, P,0.01), and compared to the levels of healthy controls (P, 0.01) (Figure 1)

Summary

Introduction

Preeclampsia, a hypertensive disorder of pregnancy, affects about 2–8% of pregnancies worldwide [1]. The development of preeclampsia is linked to altered vitamin D metabolism [2], and might be a result from placental dysfunction [24]. The underlying cause of the development of preeclampsia remains elusive. The onset of preeclampsia is more frequent during winter months, which in tropical countries corresponds to the rain season, than during any other season [3]. Since vitamin D deficiency is more frequent during winter months, these findings point towards a potential role of vitamin D in the development of preeclampsia. Studies found lower 25-OH vitamin D serum levels as well as lower 1,25-(OH) vitamin D levels in patients with preeclampsia compared to healthy pregnant women of the same gestational age [2]

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