Prolactin hormone is believed to have direct and indirect effects on bone and mineral metabolism1. In vitro studies have shown that high prolactin level is directly associated with decreased bone formation and increased bone resorption2. Also indirectly, hyperprolactinemia is associated with supressed sex hormone levels, primarily due to hypogonadotropic hypogonadism which also has an adverse impact on bone health3. Two of the commonest causes of hyperprolactinemia are drug induced hyperprolactinemia and primary hypothyroidism4,5. Anti-psychotics are some of the commonest drugs implicated to cause hyperprolactinemia. Many a times patients have to take these medicines for extended periods of time for the underlying neurologic condition, thus exposing the patients to long standing hyperprolactinemia. In a systematic review, evaluating data from 1360 patients (15 studies) with schizophrenia on anti-psychotics and drug induced hyperprolactinemia, a significant inverse correlation was noted between serum prolactin and bone mineral density (BMD)6. Prolactinoma is a rare but an important cause of hyperprolactinemia. Hyperprolactinemia in people living with prolactinomas is often very severe (as compared to drug induced hyperprolactinemia) and long standing2. Hence it may be hypothesised that people living with prolactinomas are likely to have impaired bone mineral metabolism with poor bone mineral health, which may be worse than what is noted in the setting of drug induced hyperprolactinemia. Several studies have been published evaluating bone mineral metabolism in people living with prolactinomas7, 8, 9, 10.

However, to date, no systematic review is available which has holistically analysed and summarized the impact of hyperprolactinemia in the setting of prolactinomas on bone mineral metabolism. Hence the aim of this systematic review and meta-analysis was to evaluate bone mass in hyperprolactinemia due to prolactinomas.