Thiol status and antioxidant capacity in women with a history of severe pre-eclampsia.

Objective: To investigate a possible mechanism that could lead to the subsequent development of cardiovascular diseases (CVD) in women with a history of severe pre-eclampsia.

Design: Case-control study.

Setting: University Medical Centre Nijmegen, The Netherlands.

Sample: Non-pregnant women with a history of severe pre-eclampsia (n= 131) and women with an uncomplicated obstetric history (n= 94).

Methods: Total plasma levels of cysteine (tCys), homocysteine (tHcy), cysteinylglycine (tCysGly) and glutathione (tGSH), the free-to-oxidised ratio of these thiols in whole blood, the glucose-6-phosphate dehydrogenase (G6PDH) enzyme activity and antioxidant capacity were assessed at least 6 months following last pregnancy.

Main Outcome Measure: Oxidative stress and antioxidant status.

Results: Women with a history of severe pre-eclampsia showed higher levels (mean [SD]) of tHcy (13.1 [5.0] versus 11.5 [4.8] micromol/L; P= 0.018) and tCysGly (37.5 [5.6] versus 34.0 [5.8] micromol/L; P= 0.0001) compared with controls, whereas tCys was lower (232 [31] versus 242 [39]; P= 0.029). The lower free-to-oxidised ratio of homocysteine (2.3 [0.8] versus 2.9 [1.0], P= 0.0001) among women with a history of severe pre-eclampsia as compared with control subjects might indicate a higher oxidant status for homocysteine. Previous severe pre-eclamptic patients had also a higher antioxidant capacity as compared with controls (0.79 [0.14] versus 0.74 [0.11] mmol Fe2+/L, P= 0.002).

Conclusion: Since women with a history of severe pre-eclampsia showed elevated total homocysteine levels, which is an independent risk factor for CVD, and higher oxidised homocysteine levels in whole blood, these women may have an enhanced risk for the subsequent development of cardiovascular-related problems in later life.