Pattern of thyroid hormones in mildly protein-deficient women in area endemic for goiter
Centanni, M.; Scaccini, C.; Maiani, G.; Andreoli, M.; Taffese, S.; Ferro-Luzzi, A.
Nutrition 7(6): 417-420
1991
ISSN/ISBN: 0899-9007 PMID: 1802231 Document Number: 386717
The components of retinol circulating complex were measured in 23 non-pregnant and 5 pregnant Ethiopian women living in a severely iodine-deficient area exposed to marginal chronic protein malnutrition, half of whom exhibited goiter. Transthyretin, retinol and retinol-binding protein were 31+or-8 mg/100 ml, 36+or-6 micro g/100 ml and 3.1+or-0.6 mg/100 ml, respectively. No differences in circulating thyroid hormone (TH) pattern were found among goitrous and non-goitrous women. In non-pregnant women, the circulating TH pattern was characterized by a low total thyroxine (TT4, 53 ng/ml), whereas free T4 (FT4, 0.5 ng/100 ml) was below the lower level of the range. Thyroid-stimulating hormone and free triiodothyronine (FT3) were in the normal range, and total triiodothyronine (TT3) was at the upper level of the range. The pregnant women exhibited the expected increase in total TH's (TT3 3.0 and TT4 96 ng/ml), respectively, whereas the free fractions were equal to those of the non-pregnant women (FT3 2.5 pg/ml, FT4 0.6 ng/100 ml). In the whole group, the T3-T4 ratio was 3.4 x 10-2, i.e., twice the normal ratio. No antibodies against thyroid structures were detected. It is concluded that the circulating TH pattern of these marginally malnourished women differs from that reported for subjects with pure protein-energy malnutrition or exposed to chronic I2 deficiency only. Even in the presence of low TT4 and FT4, the hypophysis-thyroid axis has remained unchanged. The normal levels of TT3 and FT3 may account for the normal thyroid-hypophysis feedback.