Introduction: Cabergoline is the treatment of choice for prolactinomas. However, 10-20% of prolactinomas are resistant to cabergoline. Metformin, a biguanide widely used in the treatment of diabetes mellitus, has been shown to reduce prolactin secretion in various pituitary tumor cell lineages both in vitro and in vivo and in human pituitary adenomas in vitro. The aim of this study is to test the effects of metformin addition to cabergoline treatment on prolactin levels in patients with resistant prolactinomas. Subjects and Methods: This is a prospective study performed in an outpatient clinic in a reference center. Ten adult patients (26-61 y) with prolactinomas (7M), persistent hyperprolactinemia (38-386 ng/mL) under cabergoline treatment (2-7 mg/week) for at least six months (6-108 mo), features of metabolic syndrome and not taking metformin were included. Metformin (1.0-2.5 g v.o./d) was given according to patients´ tolerance. Cabergoline doses were kept unchanged. Serum prolactin levels were measured before and after short- (30-60 d) and long- term (120-180 d) metformin treatment. Results: Mean prolactin levels did not show any significant changes (148 ± 39 ng/ml vs 138 ± 42 ng/ml vs 133 ± 39 ng/ml, before, at 30-60 days, and at 120-180 days, respectively, P=0.196) after metformin (mean dose: 1.25 g/day; range: 1.0-2.0 g/day). No patient reached a normal prolactin level during metformin treatment. Two patients were considered partial responders for exhibiting prolactin decreases ≥50% at a single time point during metformin. Conclusion: Metformin addition to ongoing high dose cabergoline treatment in patients with cabergoline-resistant prolactinomas failed to show a consistent inhibitory effect in serum prolactin levels.


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耐卡麦角林催乳素瘤对二甲双胍的催乳素反应：一项试点研究

简介：卡麦角林是泌乳素瘤的首选治疗方法。然而，10-20% 的泌乳素瘤对卡麦角林有抗药性。二甲双胍是一种广泛用于治疗糖尿病的双胍，已被证明可减少体外和体内各种垂体肿瘤细胞谱系以及体外人垂体腺瘤中催乳素的分泌。本研究的目的是测试二甲双胍和卡麦角林治疗对耐药催乳素瘤患者催乳素水平的影响。受试者和方法：这是一项在参考中心的门诊进行的前瞻性研究。十名成年患者（26-61 岁）患有催乳素瘤（7M）、持续性高催乳素血症（38-386 ng/mL），接受卡麦角林治疗（2-7 毫克/周）至少六个月（6-108 个月），包括代谢综合征和未服用二甲双胍的特征。根据患者的耐受性给予二甲双胍（1.0-2.5 g vo/d）。卡麦角林剂量保持不变。在短期（30-60 天）和长期（120-180 天）二甲双胍治疗前后测量血清催乳素水平。结果：平均催乳素水平未显示任何显着变化（分别为 148 ± 39 ng/ml vs 138 ± 42 ng/ml vs 133 ± 39 ng/ml，分别在之前、30-60 天和 120-180 天， P=0.196) 服用二甲双胍后（平均剂量：1.25 g/天；范围：1.0-2.0 g/天）。在二甲双胍治疗期间，没有患者达到正常催乳素水平。两名患者在二甲双胍期间的单个时间点表现出催乳素降低≥50%，被认为是部分反应者。结论：