Introduction We aimed to assess renin, aldosterone, and cortisol in the
early stages of pregnancy-induced hypertension (PIH), i. e., at the time
of diagnosis.
Methods During the postural test, we measured aldosterone, renin [Liason
DiaSorin Inc. (Italy)], as well as cortisol, sodium, potassium, and 24-h urinary
sodium and potassium excretion in 62 women with newly diagnosed PIH, 70 healthy
women during the 3rd trimester of pregnancy, and in 22 healthy non-pregnant
women.
Results In all groups, there was a significant increase in aldosterone and
renin in upright versus supine posture (p<0.01). Both supine and upright
aldosterone concentrations were higher in healthy pregnant women than in women
with PIH and the lowest in healthy not-pregnant [supine
(median±intequartile range): 25.04±18.4 ng/dL,
18.03±12.58 ng/dL, and
7.48±4.78 ng/dL, p<0.001, upright:
31.60±21.32 ng/dL,
25.11±13.15 ng/dL, and
12.4±12.4 ng/dL, p<0.001, for healthy pregnant,
pregnant with PIH, and non-pregnant, respectively]. Supine renin concentrations
were higher only in healthy pregnant (p<0.001), while in the upright
position, there was a difference only between healthy pregnant and women with
PIH (p=0.002). Both in supine and upright positions, there was no
difference in the aldosterone-to-renin ratio between healthy pregnant women and
women with PIH, though, in both groups, the ratio was higher than in
non-pregnant women (p<0.001). Morning cortisol concentrations and 24-h
urinary sodium excretion were lower in women with PIH than in healthy pregnant
(p<0.001, p=0.002, respectively).
Conclusion Hyperaldosteronism is not involved in the etiology of PIH. In
PIH, there is also a tendency towards lower sodium excretion and lower morning
cortisol concentrations.