The Assessment of Copeptin and Brain Natriuretic Peptide Levels as Biomarkers in Hypertensive Disorders of Pregnancy

Hypertensive disorders of pregnancy associated with potentially fatal outcomes are common obstetrics occurrences. Early diagnosis, management and prediction of outcomes are challenges to be surmounted especially in developing countries. Biomarkers are emerging as useful tools for diagnosis and prognostication in varying health conditions. Elevated levels of serum copeptin and Brain Natriuretic Peptide (BNP) are associated with adverse perinatal outcomes and may serve as potential biomarkers utilized during routine antenatal care.

To determine the level and clinical value of copeptin and BNP as biomarkers of hypertensive disorders of pregnancy among Nigerian pregnant women.

This case-control study comprised 156 consenting pregnant women equally grouped into those with chronic hypertension (CH), gestational hypertension (GH), and preeclampsia (PE) as cases and normotensives as controls. Pregnant women were recruited from the antenatal clinic, University College Hospital, Nigeria. Blood pressures were measured and blood (10ml) was drawn from patients, serum and plasma obtained accordingly while other data were collected using interviewer administered questionnaire and medical records. Serum copeptin and plasma BNP levels were measured using enzyme-linked immunosorbent assay. Data was analysed with SPSS version 20.0 and statistical significance was set at p < 0.05.

The mean levels of SBP and DBP were significantly higher in CH (155.41±2.14; 102.36±2.0 mmHg), GH (150.49±0.82; 98.67±0.56 mmHg), and PE (153.92±1.47; 98.92±0.61 mmHg), compared to controls (101.85±1.9; 66.77±1.24 mmHg). Mean serum copeptin and plasma BNP were significantly higher in women with GH (21.25±1.31pmol/L; 223.05±14.95pg/mL) and PE (22.47±1.01pmol/L; 253.99±17.69pg/mL) compared with controls (9.05±1.01pmol/L; 48.63±2.50pg/mL) (p<0.05). There was no significant difference in the mean levels of copeptin and BNP in CH compared with controls (p>0.05). The ROC curve for copeptin gave an AUC of 0.829 (p= 0.000) with a cut off value of 10.15pmol/ L while the AUC for BNP was 0.902 (p= 0.000) with a cut off value of 50.81pg/mL.

Serum copeptin and plasma BNP levels were significantly higher in GH and PE and may be used as markers of hypertensive disorders of pregnancy among Nigerian pregnant women.