Plasma and urinary free amino acid concentrations in preeclamptic women in northern Nigeria

Background: Preeciampsia/eciampsia is one of the major causes of maternal and fetal mortality in Nigeria and many other countries in sub-Saharan Africa. We determined if serum and urine concentrations of amino acids were abnormal in women with this disorder of pregnancy in Gombe, Nigeria. Methods: Free amino acids were measured in serum and urine of women (ages, 15 to 40 years) with preeclampsia/eclampsia (n = 3 7) and their pregnant age and gestational age matched controls (n = 16). Results: The concentrations of 19 of the 20 serum amino acids that are common in proteins were not significantly different between the control and preeclamptic groups. Phenylalanine was increased in the preeclamptic women compared to the controls (p < 0.05); however, the difference between the two values was small (119 vs. 104 umol/l, respectively). The concentrations of urine free amino acids were indexed to urine creatinine (i.e., nmol/mg creatinine). Five amino acids were significantly elevated in the urine of preeclamptic patients vs. the control group: proline (100%, p < 0.05), the branched amino acids, valine (80%, p < 0.05), leucine (61 %, p < 0.05), isoleucine (49%, p = 0.01), and methionine (52%, p < 0.005). On the other hand, the concentrations of a nutritionally non-essential amino acid, glycine (p = 0.01), and an essential amino acid, histidine (p = 0.01), were both reduced by about one-third in the urine of the preeclamptic women. Conclusions: Our findings indicate that there are disturbances in urinary amino acid excretion but not in the serum amino acid profile in the preeclamptic patients. The degree of aminoaciduria is probably not sufficient to significantly affect overall nitrogen balance or precipitate a deficiency of one or more of the essential amino acids. (C) 2004 Elsevier B.V. All rights reserved.