BMI and Metabolic Profile in Patients With Prolactinoma Before and After Treatment With Dopamine Agonists

Abstract

Hyperprolactinemia might be related to weight gain, metabolic syndrome (MS), and insulin resistance (IR). Treatment with dopamine agonist (DA) has been shown to reduce body weight and improve metabolic parameters. The objectives of this study were to determine the prevalence of obesity, overweight, MS, and IR in patients with prolactinoma before and after therapy with DA and to evaluate the relation between prolactin (PRL), body weight, fat distribution, leptin levels, IR, and lipid profile before treatment. In addition, we investigated the correlation of the reduction in PRL levels with weight loss and metabolic profile improvement. Twenty‐two patients with prolactinoma completed 6 months of treatment with DA. These patients were submitted to clinical (BMI, waist circumference, blood pressure (BP)), laboratory evaluation (leptin, glucose, low‐density lipoprotein (LDL)‐cholesterol, and triglyceride (TG) levels) and abdominal computed tomography (CT) before and after treatment. The statistical analyses were done by nonparametric tests. At the beginning of the study, the prevalence of obesity, overweight, MS, and IR was 45, 27, 27, and 18%, respectively. After 6 months of treatment with DA, PRL levels normalized, but no significant difference in BMI was observed. However, there was a significant decrease on homeostasis model assessment of insulin resistance (HOMAIR) index, glucose, LDL‐cholesterol, and TG levels. This study suggests a possible involvement of prolactinoma on the prevalence of obesity. We should consider that DA may be effective on improving metabolic parameters, and we speculate that a period longer than 6 months of treatment is necessary to conclude whether this drug can interfere in the body weight of patients with prolactinoma.

Association Between Prolactin and Incidence of Cardiovascular Risk Factors in the Framingham Heart Study

“…In humans with prolactinomas, weight gain is often a prominent feature and is reversible with prolactin‐lowering therapy 4. Other metabolic abnormalities seen in prolactinomas include insulin resistance and dyslipidemia 5. In animal models, prolactin promotes accrual of visceral adipose tissue (VAT) 6.…”

Prolactinoma-associated obesity treated with bupropion and methylphenidate

“…Notably, abnormalities of the circadian rhythm of prolactin secretion rather than the baseline prolactin level has been associated with weight increase [Doknic et al 2002], which might explain some inconsistencies in the literature mentioned above [Greenman et al 1998;Delgrange et al 1999;dos Santos Silva et al 2011]. As the somatotropin levels were normalized at the point of treatment, we did not substitute this hormone.…”

“…Still, the exact mechanism of the association of prolactinoma and obesity is insufficiently understood and studies on obesity after normalization of prolactin levels show inconsistent results [Greenman et al 1998;Delgrange et al 1999;dos Santos Silva et al 2011]. However, both standard pharmacological treatments for prolactinoma and cognitive-behavioural treatment often fail to reduce patients' weight [Doknic et al 2002;dos Santos Silva et al 2011].…”

“…However, both standard pharmacological treatments for prolactinoma and cognitive-behavioural treatment often fail to reduce patients' weight [Doknic et al 2002;dos Santos Silva et al 2011]. Overall, there is a considerable need for effective clinical options to address obesity associated with pituitary tumours and to elucidate the relationship between central and peripheral dopamine effects on adipogenesis including the role of prolactin.…”

Prolactinoma

“…Alguns autores encontraram melhora nos parâmetros relacionados à resistência insulínica (índice HOMA-IR, glicemia, LDL-colesterol e níveis de triglicérides) após seis meses de tratamento com agonistas dopaminérgicos, associados (18,19) ou não (20) à redução da porcentagem de gordura corporal em homens.…”