Endocrine Abstracts

Background

Prolactinomas are the most frequent type of hormone-secreting pituitary adenomas. Prolactin(PRL)-receptor mediates intracellular signaling pathways that contribute to weight gain, dyslipidemia, impaired fasting glucose (IFG), type 2 diabetes mellitus (T2DM) and cardiovascular disease, parameters that improve along with PRL level control on dopamine agonist (DA) therapy.

Aim

To assess metabolic disturbances in prolactinomas at diagnosis and during follow-up.

Methods

Fifty-seven patients with prolactinomas (aged 50.2 ± 17.6 years, 37 M:20 W median PRL 838.45 mg/l) were retrospectively assessed for weight, lipids, fasting glycemia, blood pressure, cardiovascular events. Evaluation was made at baseline, at 6, 12 and 24 months after DA treatment (1–7 mg/week cabergoline/7.5–30 mg/day bromocriptine). Nadir PRL on therapy was 0.2 mg/l. Serum PRL was measured by chemiluminescence.

Results

At the time of diagnosis, 27.3% were overweight and 52.7% obese. Weight excess was significantly more prevalent in men (89.2%) vs. women (55), P < 0.01 and in macroprolactinoma (83.7%) vs. microprolactinoma (37.5%), P < 0.01. Nine subjects had central hypothyroidism, 46 central hypogonadism and 5 panhypopituitarism. Initial BMI (29.8 ± 5.4 kg/m²) significantly decrease both at 6-months (29.1 ± 4.6 kg/m², P = 0.04) and 24-months (28.9 ± 5.6 kg/m², P = 0.01). Maximum decrease in BMI (0.7 kg/m²) occurred at 6-months, despite the fact that only 63.2% had achieved disease control. At the time of diagnosis, 65.3% had dyslipidemia. Initial cholesterol level was 208.3 ± 40.7 mg/dl and significantly decreased both at 6-months (185.1 ± 39.6 mg/dl, P < 0.01) and 24-months (183.5 ± 44.04 mg/dl, P < 0.01). Significant decrease was also observed in LDL-cholesterol and triglyceride levels from 127.3 ± 38.9 mg/dl and 165.3 ± 135.3 mg/dl at baseline to 106.2 ± 28.8 mg/dl(P = 0.05) and 133.1 ± 77.4 mg/dl(P = 0.01) at 6-months and to 106.9 ± 31.4 mg/dl and 115.5 ± 72.8 mg/dl, respectively at 24-months (P < 0.01). HDL-cholesterol levels were similar at 6-months, but significantly lower at 24-months compared to baseline (42.3 ± 9.9 mg/dl vs. 49.1 ± 44 mg/dl, P = 0.04). Nine of 37 dyslipidemic patients (24.3%) received statin. Arterial hypertension (26.31%, n = 15) and chronic coronary syndrome (CCS) (10.5%, n = 6) prevalence was similar at the time of diagnosis and at 24-months: 29.8% (n = 17) patients with hypertension and 12.3% (n = 7) patients with CCS. At baseline, 21.8% (n = 12) had IFG and 5.3% (n = 3) DM. At 24-months evaluation, the prevalence of IFG and DM was 7.3% (n = 4) and 3.6% (n = 2), respectively.

Conclusion

Two years dopamine agonists treatment improved metabolic parameters in prolactinoma patients, with weight loss, decrease in total and LDL-cholesterol and triglycerides. Long term follow-up, larger studies are necessary to assess cardiovascular risk of patients with PRM, in order to stratify therapeutic intervention and to reduce associated mortality.