Arginine and Asymmetric Dimethylarginine in Pregnant Women With Major Depression

OBJECTIVE: Depression has been associated with vascular dysfunction, which may be of particular relevance in pregnancy. Asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and L-arginine play a critical role in vascular function. The objective of this study was to investigate differences in ADMA, SDMA, and L-arginine among pregnant women with major depression compared with pregnant women without depression. METHODS: A case-control study was conducted in 21 depressed pregnant women and 42 matched controls. Maternal plasma ADMA, SDMA, and L-arginine were quantified, as well as C-reactive protein and urine excretion of ADMA, SDMA, L-arginine, and Arginase I. RESULTS: Plasma L-arginine and ADMA levels were significantly lower in the first trimester in women with depression (mean [standard deviation = 37.0 [9.2] and 0.298 [0.06] μM, respectively) compared with matched controls (42.1 [11.4] and 0.336 [0.08] μM, p = .004 and p = .002, respectively) and across pregnancies (p < .001 both). Depressed pregnant women had higher levels of plasma C-reactive protein (7.5 [3.7] versus 5.1 [4.0] μg/ml, p = .027), but no differences in urine excretion of ADMA, SDMA, or L-arginine, or plasma levels of Arginase I (p > .10). CONCLUSIONS: Pregnant women with depression show lower plasma levels of L-arginine and ADMA. These differences are not explained by urinary excretion or Arginase I levels. The mechanism responsible for the observed differences in depressed pregnant women requires further research.