Renal markers in normal and hypertensive disorders of pregnancy in Indian women: a pilot study

BACKGROUND Altered renal function is an essential component of the pathophysiological process in pre-eclampsia. Kidneys play an important role in the turnover of low molecular weight substances such as creatinine, uric acid and cystatin C. The present study was undertaken if these serum markers were characteristically altered in Indian pregnant women. METHODS Serum levels were therefore determined in samples from 69 healthy women at term as well as in 27 samples of patients with Pregnancy induced hypertension (PIH) and in 20 patients with pre-eclampsia (PE). RESULTS The levels of all three components were significantly higher in pre-eclamptic patients when compared to healthy controls with the mean ± SD being 1.47 ± 0.9 vs. 1.06 ± 0.2 for cystatin C, 0.95 ± 0.2 vs. 0.67 ± 0.1 for creatinine and 6.13 ± 1.8 vs. 4.28 ±1.1 for uric acid respectively. In PIH cystatin C was significantly higher, 1.25 ± 0.9 unlike creatinine, 0.67 ± 0.14 and uric acid, 4.30 ± 1.0. Receiver operating characteristic (ROC) plots demonstrated that the diagnostic accuracy of serum creatinine was superior to serum uric acid and serum cystatin C and serum uric acid was better than serum cystatin C. CONCLUSION The maternal serum cystatin C, creatinine and uric acid were all significantly elevated at the end of pregnancy in pre-eclampsia compared to those of healthy pregnant women. If this rise in the above markers during early pregnancy could predict the onset of PIH/PE, needs to be investigated.