Thyroid Peroxidase Antibodies in Mexican-Born Healthy Pregnant Women, in Women with Type 2 Or Gestational Diabetes Mellitus, and in their Offspring

Abstract

ObjectiveTo search for differences in the frequency of thyroid peroxidase antibodies (TPO-Ab) among 150 pregnant Mexican women who were healthy, had type 2 diabetes mellitus (DM), or had gestational diabetes mellitus (GDM). MethodsFifty healthy women, 50 women with type 2 DM, and 50 women with GDM were studied at delivery. In addition, 142 of their offspring were included in the study. TPO-Ab were determined by enzyme immunoassay, and total triiodothyronine, free thyroxine, and thyroid-stimulating hormone (thyrotropin) were measured by radioimmunoanalysis. ResultsTPO-Ab were ≤70 U/mL (negative) in 50% of the healthy women and in 60% and 60% of women with type 2 DM and GDM, respectively (no significant difference). TPO-Ab were 71 to 250 U/mL (slightly positive) in 40% of healthy women and in 30% and 34% of women with type 2 DM and GDM, respectively (no significant difference). TPO-Ab were ≥251 U/mL (strongly positive) in 10% of healthy women and in 10% and 6% of women with type 2 DM and GDM, respectively. One healthy woman had subclinical hypothyroidism, and the rest were euthyroid. The newborn offspring of these Mexican women were euthyroid and had similar frequencies of TPO-Ab (all had TPO-Ab <250 U/mL). Conclusion(1) The frequency of TPO-Ab ≥251 U/mL was similar in pregnant Mexican women with GDM in comparison with those who were healthy or had type 2 DM. (2) The similar high frequencies of slightly positive TPO-Ab in the three groups of pregnant women can partially be explained by the existence of an ethnic factor, the very strong family history of DM in a substantial percentage of them, and the use of a more sensitive and specific assay for detection of TPO-Ab. (Endocr Pract. 2000; 6:244-248)