Endocrine Abstracts

Introduction: A few studies have examined the effect of Hormone replacement therapy (HRT) on serum Prolactin level (PRL) in postmenopausal women. It has been demonstrated that HRT can trigger a stimulatory response on PRL secretion. However, the significance of this is yet to be further evaluated given the great variation in PRL concentration during menopause which has not been fully meticulously examined.

Case reports: We present 3 cases of postmenopausal women who were found to have high PRL while being investigated for a variety of symptoms and other endocrinological conditions and presentations. The patients were on different HRT preparations for a variable length of time. We discuss the implications of high prolactin in this age group, the variability and scarcity in the available literature and the possible treatment strategies. Case 1: A lady in her early 50s with a chronic history of PMR on steroids. She was referred to our clinic to investigate the HPA axis for secondary adrenal insufficiency. Tests revealed raised Prolactin level with no clear cause. MRI pituitary and the anterior pituitary profile were normal. She was not on any other medication. Case 2: A lady in her late 50s who presented to her GP with severe symptoms of menopause and was started on HRT. The dose was gradually increased. She was found to have raised prolactin level and referred to our clinic. MRI pituitary and anterior pituitary profile were normal apart from the raised Prolactin. Case 3: a 60-year-old lady who has been on long term HRT which was only recently discontinued. She continued to suffer from hot flushes and excessive sweating. She was referred to our clinic for further investigation. Pituitary profile, urinary 5HIAA, urinary Metanephrines were normal apart from the raised prolactin. CT CAP and MRI pituitary were all normal.

Discussion and conclusion: PRL can vary significantly during menopause. The incidence of Hyperprolactinaemia decreases with age. The commonest cause for raised PRL in menopause is Macroprolactinomas. Exogenous oestrogen could play a crucial role in Prolactin secretion. High PRL is associated with obesity, dyslipidaemia and insulin resistance. Some studies have also shown adverse effect on bone density. HRT dose adjustment and Dopamine agonists are among the treatment strategies. Some studies, however, argue that as the patient is usually asymptomatic, treatment might not need to be introduced but long-term monitoring is warranted.