[Frequency of increased thyrotropin in women with hyperprolactinemia]

Hypothyroidism has been associated to hyperprolactinemia. The aim was to establish the frequency of high thyrotropin (TSH) levels in women with hyperprolactinemia.

Retrospective, observational, open, and non-controlled study, which included all the non-pregnant women whose prolactin (PRL) and TSH levels were measured between January 1 and December 31, 2014.

437 women were studied. The most frequent diagnoses that motivated PRL measurement were: infertility (31.7%), polycystic ovary syndrome (18.7%), and amenorrhea (7.8%). In the whole group TSH levels were 2.5 ± 2.7 µUl/mL and those of PRL 16.5 ± 13.2 ng/dL. From the total of women, those with normal PRL levels, 1.4% had low TSH levels, 76.6% normal and 7.5% high, while in those with high PRL levels 0.7% had low TSH levels 12.6% normal and 1.1% high. Of those 374 patients with normal PRL, 6 (1.6%) had low TSH levels, 335 (89.6%) normal TSH levels, and 33 (8.8%) high TSH levels. Of those 63 patients with high PRL, 3 (4.8%) had low TSH levels, 55 (87.3%) normal TSH and 5 (7.9%) high TSH levels.

In this study it was not possible to document that the proportion of patients with high TSH was greater in those with hyperprolactinemia.