Research Information System
23rd European Congress of Endocrinology 2021, Antalya, Turkey, 22 - 26 May 2021, pp.202
Introduction
Gestational diabetes mellitus (GDM) may frequently be overcome by
nutrition therapy alone, but insulin regimen may be necessary in about 30
% of the patients with GDM. It was known that thyroid hormones were
associated with glucose metabolism. Therefore, we aimed to investigate
the association of fT4 level with insulin requirement in euthyroid pregnant
women with GDM.
Materials and methods
We consecutively included euthyroid patients with GDM, and excluded those
with thyroid dysfunction or any previous history of use of levothyroxine
or antithyroid drug. The diagnosis of GDM was based on ADA criteria.
Demographic features, previous history of GDM, gestational hypertension,
insulin requirement (absent vs present or basal vs intensive regimen) and
dose, nutrition and exercise adherence, and HbA1c, TSH, fT4, fT3, 25(OH)
vitamin D3 levels were analyzed. We grouped the patients according to fT4
levels: lower than mid-normal (group A) vs upper than mid-normal (group
B), or lower than normal range vs in normal range. We assessed the patients
in 3rd trimester after 34th weeks of the pregnancy.
Results
Of total (n = 228), insulin was necessary in 58 patients. Insulin use was more
frequent in the patients with fT4 level lower than normal range than those
with normal fT4 (P = 0.003, OR:5.69 (95% CI 1.60–20.24)). Number of
insulin injections was higher in group A than group B (0.022). fT4 level was
not associated with insulin dose, HbA1c level, previous history of GDM, or
diet adherence.
Conclusion
Lower fT4 level even in normal range may worsely affect glucose
metabolism in euthyroid pregnant women with GDM. Our findings suggest
that euthyroid hypothyroxinemia in pregnancy may be associated with
difficulty in control of hyperglycemia. GDM would be an indication for
treatment with levothyroxine in euthyroid hypothyroxinemia.