Hyperprolactinemia in association with subclinical hypothyroidism

Background: Hyperprolactinemia is the most common endocrine disorder in hypothalamic-pituitary axis and has been reported in variable levels in patients with overt primary hypothyroidism. We decided to determine the prevalence of hyperprolactinemia and clinical related symptoms in subclinical hypothyroidism patients. Methods: In this cross sectional study, prolactin levels of 481 subclinical hypothyroid patients were assessed. Prolactin measurement was performed using chemiluminescent immunoassay. Data were collected and analyzed. Results: Sixty-two (13%) patients were males and 419 (87%) were females. The mean age of the patients was 32.53 +/- 10.13 years. Ninty-eight patients (91 females 7 males) had high prolactin. Prevalence of hyperprolactinemia in subclinical hypothyroidism was 20.4%. (11% in men and 22% in women, p=0.05). There was no correlation between the serum TSH and prolactin level. Clinical symptom prevalence was not different between patients with and without hyperprolactinemia. Conclusion: This study showed that prevalence of hyperprolactinemia in subclinical hypothyroidism is notable and this disorder is more common in female subclinical hypothyroidism than the men.