Efficacy of cabergoline add-on therapy in patients with acromegaly resistance to somatostatin analogs treatment and the review of literature

ABSTRACT Objective: It is reported that adding cabergoline to somatostatin analog (SSA) normalizes IGF-1 levels approximately in one-third of patients with acromegaly. We investigated the effect of combination therapy and potential predictors of response in patients with acromegaly who do not respond to SSA therapy alone. Subjects and methods: Fifty acromegaly patients (M/F 23/27, mean age 50.88 ± 12.34 years) were divided into two groups as the active and control groups in this connection. Before and after treatment, we not only evaluated serum GH and IGF-1 levels and tumor size but also analyzed the factors relevant to the effect of the combined therapy. Results: Adding cabergoline to SSA treatment led to IGF-1 normalization in 42% (21/50) of patients. Mean GH levels decreased from 2.64 ± 1.79 to 1.34 ± 0.99 ng/mL (p < .0001) and IGF-1 levels decreased from 432.92 ± 155.61 to 292.52 ± 126.15 ng/mL (p < .0001). GH and IGF-1 reduction in percent (%) were significantly higher in the controlled group (63% to 40%, p = 0.023 and 45% to 19%, p = 0.0001). Moreover, tumor size decrease was significantly higher in controlled group (-3.6 cm to -1.66 cm, p = 0.005). Conclusions: According to the results of our study, the addition of cabergoline to SSA normalized IGF-1 levels in a considerable amount of acromegaly patients with a moderately elevated IGF-1 level, regardless of serum PRL levels. Besides, cabergoline treatment was also influential in patients with higher IGF-1 levels despite a lower remission rate.

Efficacy of cabergoline add-on therapy in patients with acromegaly resistance to somatostatin analogs treatment and the review of literature.

Objective: It is reported that adding cabergoline to somatostatin analog (SSA) normalizes IGF-1 levels approximately in one-third of patients with acromegaly. We investigated the effect of combination therapy and potential predictors of response in patients with acromegaly who do not respond to SSA therapy alone. Methods: Fifty acromegaly patients (M/F 23/27, mean age 50.88 ± 12.34 years) were divided into two groups as the active and control groups in this connection. Before and after treatment, we not only evaluated serum GH and IGF-1 levels and tumor size but also analyzed the factors relevant to the effect of the combined therapy. Results: Adding cabergoline to SSA treatment led to IGF-1 normalization in 42% (21/50) of patients. Mean GH levels decreased from 2.64 ± 1.79 to 1.34 ± 0.99 ng/mL (p < .0001) and IGF-1 levels decreased from 432.92 ± 155.61 to 292.52 ± 126.15 ng/mL (p < .0001). GH and IGF-1 reduction in percent (%) were significantly higher in the controlled group (63% to 40%, p = 0.023 and 45% to 19%, p = 0.0001). Moreover, tumor size decrease was significantly higher in controlled group (-3.6 cm to -1.66 cm, p = 0.005). Conclusion: According to the results of our study, the addition of cabergoline to SSA normalized IGF-1 levels in a considerable amount of acromegaly patients with a moderately elevated IGF-1 level, regardless of serum PRL levels. Besides, cabergoline treatment was also influential in patients with higher IGF-1 levels despite a lower remission rate.

Evaluation of atherosclerosis after cessation of cabergoline therapy in patients with prolactinoma.

OBJECTIVE: The aim of the study was to determine whether atherosclerotic risk markers exist at the moment and after withdrawal of cabergoline (CAB) therapy in patients who had taken a suitable dose of CAB therapy for a suitable period of time before cessation of CAB. METHODS: This study was designed as prospective cross-sectional. Out of a total of 115 patients with prolactinoma, 42 non-obese women with microprolactinoma, who met the Pituitary Society criteria (2006) for the withdrawal of long-term CAB therapy, and 30 healthy patients participated in our study. The number of patients excluded from the study were as follows: 34 patients with tumor shrinkage of less than 50%; 10 who received DA treatments for less than 2 years; 9 who were treated with bromocriptine; and 20 who had diabetes mellitus, hypertension, hyperlipidemia, obesity, renal disease, coronary arterial disease, or were tobacco smokers. The patients were evaluated for anthropometric, metabolic, and inflammatory parameters at the time of cessation of CAB therapy and at the 3rd and 12th months after the withdrawal of CAB therapy. Endothelial dysfunction was determined by flow-mediated dilation (FMD) of the brachial artery and carotid intima media thickness (IMT), which were assessed by high resolution ultrasonography (USG) by the same practitioner. RESULTS: At the moment of cessation of CAB therapy, the FMD percentage in patients with prolactinoma was worse than that in healthy controls (p=0.0029). After the withdrawal of CAB treatment, fibrinogen (p=0.036), mean platelet volume (MPV) (p<0.001), carotid IMT (p=0.041), and high-density lipoprotein cholesterol (HDL C) (p=0.048) were worse in the relapse patients than those in the remission patients. Furthermore, only MPV values were found to be significantly related to a relapse of hyperprolactinemia among all atherosclerotic risk markers [area under the curve: 0.830 (95% CI 0.685-0.974) (p<0.001)]. CONCLUSION: Unfavorable cardiovascular risk profiles are a problem for patients with prolactinoma during cessation and after CAB withdrawal.