Zinc deficiency and
cadmium toxicity have both been implicated in
hypertension during pregnancy. The goals of this study were twofold: first, to assess the different
zinc indices (plasma, red blood cell
zinc, heat-labile
alkaline phosphatase, and placental
zinc) in normotensive and hypertensive parturients to determine whether they are altered in the different types of
hypertension that occur during pregnancy; second, to assess whole-blood
cadmium and placental
cadmium with regard to
hypertension and
zinc status. Patients were diagnosed as having chronic
hypertension or
preeclamptic toxemia and were then further divided into groups on the basis of smoking status. Each patient was matched with a normal control subject based on age, parity, and smoking status. Forty-three hypertensive patients and their matched control subjects were studied. No differences were found in the various
zinc indices between chronic hypertensive parturients and normal control subjects. However, in parturients with
preeclamptic toxemia, the plasma
zinc level was 19% lower than in control subjects (p less than 0.02); these patients had the lowest plasma
zinc level of the three groups. Placental
zinc was also 12% lower in patients with
preeclamptic toxemia than in control subjects (p less than 0.04). Whole-blood
cadmium and placental
cadmium levels did not differ between control subjects or hypertensive patients. However, a significant positive correlation was found between whole-blood
cadmium and plasma
zinc levels in
preeclamptic toxemia (r = 0.53; p less than 0.05). The results support a marginal
zinc deficiency in parturients with
preeclamptic toxemia but not in those with chronic
hypertension. The role of
cadmium in the cause of
preeclamptic toxemia remains unclear.