Angiotensin sensitivity test revisited

Abstract

Objective: To determine the validity of a single angiotensin sensitivity test as predictor of pregnancy-induced hypertension with special reference to the dietary sodium intake at the time of testing.

Methods: The angiotensin sensitivity test was successfully performed at 32 weeks' gestation in 104 women. In 90 of these women, the 24-h urinary sodium-creatinine ratio was known. Using an effective pressure dose of 10 ng/kg/min as the cutoff level, test characteristics were assessed in both the total population and after subdivision into a sodium restricted (n = 23) and an unrestricted diet group (n = 67).

Results: The incidence of pregnancy-induced hypertension was 13.4%. The number of positive angiotensin sensitivity tests was 7.5%. Test characteristics showed poor sensitivity (22.2%) and high specificity (94.8%); positive and negative predictive values were 40.0% and 88.7%, respectively. None of the sodium-restricted women was angiotensin sensitive. Sodium restriction did not have a significant influence on sensitivity, specificity, and predictive values of the test.

Conclusion: The angiotensin sensitivity test is not an appropriate screening test to predict hypertensive disorders of pregnancy. No significant effect of dietary sodium restriction was found.