R. Swaminathan

Maternal thyroid hormones and outcome of pre-eclamptic pregnancies

Summary. Plasma concentrations of total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3), thyroid‐stimulating hormone (TSH), plasma albumin and urate were measured in 39 proteinuric pre‐eclamptic patients presenting before labour. Preeclamptic patients had significantly lower FT4 and higher TSH concentrations compared with values in third trimester normotensive pregnancies. There was a significantly higher frequency of lower TT4, TT3 and high TSH levels in the subgroup of pre‐eclamptic patients who had low‐birthweight babies. Thyroid hormone concentrations were not correlated with gestation at delivery or birthweight but, with the exception of FT4, were correlated with plasma albumin and urate concentrations. Plasma TSH correlated with birthweight and with plasma urate. The results suggest that mild biochemical hypothyroidism may be found in proteinuric pre‐eclampsia, and the concentrations of TT4, TT3, FT3 and TSH may reflect the severity of pre‐eclampsia.

Thyroid function in pre‐eclampsia

Summary. Thyroid function was studied in 24 proteinuric pre‐eclamptic patients and 24 gestation‐matched controls. The pre‐eclamptic patients had significantly lower mean total (TT4) and free thyroxine (FT4), and thyroxine‐binding globulin (TBG) concentrations, and the concentration of thyroid‐stimulating hormone was significantly higher. The mean total triiodothyronine (TT3) concentration, however, was similar to the controls. This is at variance with the classical low T3 syndrome reported previously for pre‐eclamptic patients. Compared to the controls, 33·3% and 29·2% of the pre‐eclamptic patients had low TT4 and TT3 concentrations respectively. Pre‐eclamptic patients with low TT4/ TT3 had significantly higher plasma urate concentrations. Thyroid hormone concentrations may reflect the severity of pre‐eclampsia.

Differences in Erythrocyte Cation (Sodium) Transport Between Chinese and Non Chinese Males

Erythrocyte sodium content, sodium pump activity (ouabain sensitive efflux rate, efflux rate constant, ouabain binding sites and Na+, K+-ATPase activity), sodium-lithium countertransport and sodium-potassium cotransport activities were measured in 10 European males, 11 non Chinese Asian males and 12 Chinese males. There were no differences between the 3 groups in any of the measurements of active transport. The sodium-lithium countertransport was higher and sodium-potassium cotransport (measured as lithium-potassium cotransport) was lower in Chinese compared to either the Europeans or non Chinese Asians. There were no differences in counter and cotransport activities between the Europeans and non Chinese Asians. Multiple regression analysis showed that the co and countertransport pathways contribute little to the maintenance of erythrocyte sodium content in healthy subjects.

Plasma and erythrocyte zinc and birth weight in pre-eclamptic pregnancies

SummaryPlasma and erythrocyte zinc concentrations in 45 proteinuric pre-clamptic Chinese women were measured. There was no difference in either the plasma or erythrocyte zinc concentration between pre-eclamptic patients with and without intrauterine growth retardation. There was no correlation between either plasma or erythrocyte zinc concentration with the gestation at delivery, birth weight, mean arterial pressure and plasma albumin concentration. On the other hand, both plasma albumin concentration and mean arterial pressure were significantly correlated to birth weight, and the mean arterial pressure was also significantly higher in patients with intrauterine growth retardation. Plasma and erythrocyte zinc are not useful as indices of severity in pre-eclampsia.

Plasma and erythrocyte zinc concentrations in pre-eclampsia

Plasma and erythrocyte zinc concentrations were measured in 28 Chinese pre-eclamptic women and 28 controls matched for parity, race and gestation. There were no differences in either the plasma or erythrocyte zinc concentrations between pre-eclamptic and control groups, although the mean birth weight (p less than 0.001) and period of gestation (p less than 0.001) at delivery in the control group were significantly higher. In the pre-eclamptic patients, those delivering before 37 weeks or those who gave birth to low birth weight (less than 2500 g), babies had a significantly higher plasma urate concentration (p less than 0.02) compared to the pre-eclamptic patients with better fetal outcome. However, the plasma and erythrocyte zinc concentrations between these subgroups were not significantly different. Our results suggest that zinc deficiency is unlikely to play a significant role in pre-eclampsia in our patients, and that measurement of plasma and erythrocyte zinc concentrations is of doubtful clinical value in the management of pre-eclampsia.

Changes in Erythrocyte and Plasma Zinc Concentrations in Pregnancy

In a group of normal pregnant women, erythrocyte and plasma zinc concentrations were assessed at 8, 15, 25 and 35 weeks. Erythrocyte zinc concentration showed an increasing trend with a peak value at 25 weeks, although the increase did not reach a significant level. Plasma zinc concentration showed a significant decrease with the lowest value at 35 weeks. Erythrocyte and plasma zinc concentrations were not correlated, and there was no correlation between either of these concentrations and human chorionic gonadotrophin at 8-15 weeks. The value of zinc measurements in the management of complicated pregnancies is discussed.

A Longitudinal Study of Changes in Erythrocyte Zinc Concentration in Hyperemesis gravidarum

Erythrocyte zinc concentration and plasma thyroid hormones were measured in 32 patients admitted to hospital because of hyperemesis gravidarum. At presentation, 8 patients had elevated total and free thyroxine concentrations. The initial erythrocyte zinc concentration in these 8 patients was not different from the others, but in 5 of them, a transient drop in the erythrocyte zinc concentration was observed 2-12 weeks later, and which returned to normal towards the end of pregnancy. The lowest erythrocyte zinc concentration in the hyperthyroxinaemic group (171.0 +/- 31.7 mumol/l of RBC) was significantly lower than that of the normothyroxinaemic group (214.2 +/- 33.9 mumol/l of RBC) (p less than 0.01). This indicates that hyperthyroxinaemia in patients with hyperemesis gravidarum represents true hyperthyroidism, but is different from classical thyrotoxicosis in that the elevation of thyroid hormones is transient.

Zinc concentration in umbilical cord tissue and cord plasma in appropriate-for-gestational-age babies

Zinc concentration in cord plasma was determined in 148 healthy appropriate-for-gestational-age babies delivered at various gestational ages. Zinc concentration in cord tissue was also determined in 62 of these babies. There was a significant rise in the cord tissue zinc concentration just after the 35th week of gestational age; thereafter the levels remained relatively unchanged. The cord plasma zinc concentration decreased slightly with increasing gestational age, but these changes were not significant. There was a statistically significant positive correlation between cord tissue zinc concentration and birth weight. No correlation was found between cord plasma zinc concentration and birth weight or cord tissue zinc concentration.

Second-Trimester Thyroid Function and Pregnancy Outcome in Mothers with Hyperthyroidism

Thyroid function at 24-28 weeks gestation was compared between 26 mothers with hyperthyroidism (16 on antithyroid treatment and 10 in remission without treatment) and 15 normal pregnant controls. There was no difference in the total and free thyroxine (TT4 and FT4) or in the total and free triiodothyronine (TT3 and FT3) concentrations, but the erythrocyte zinc (RBC Zn) concentration was significantly lower in the study group (187.3 +/- 46.6 mumol/l RBC versus 223.6 +/- 3.7 mumol/l RBC, p less than 0.01). In the study group, both birth weight and gestation at delivery were significantly correlated with TT3 (r = -0.500, p less than 0.02 and r = -0.460, p less than 0.05, respectively) as well as with RBC Zn (r = 0.473, p less than 0.02 and r = 0.573, p less than 0.01, respectively). The results suggest that plasma concentration of TT3 and of RBC Zn at 24-28 weeks gestation may be helpful prognostic factors in the management of pregnant patients with hyperthyroidism.

Serum C-Reactive Protein Levels in Patients with Cervical Neoplasia

Serum C-reactive protein (CRP) levels were determined by enzyme immunoassay in 56 patients with invasive carcinoma of the cervix, 34 patients with cervical dysplasia and 24 women with no evidence of cervical pathology. The logarithmic CRP values were significantly higher in patients with invasive carcinoma when compared with the controls (p less than 0.05). Measurement of serum CRP in cancer patients grouped according to their clinical stages failed to reveal any relationship with the extent of the disease.