The effects of hyperprolactinemia on bone and fat

Metabolic Syndrome Components in Patients with Pituitary Adenoma

Pituitary adenomas are benign tumors of the anterior portion of the pituitary gland (adenohypophysis), representing the 25% of all the tumor alterations. Pituitary adenomas are classified by the type of hormone secreted, cellularity, size, and structural alterations by the hormonal segregation. The diagnosis consists on the histopathological identification of cell types and the image-guided by magnetic resonance or tomography; the treatment can be both pharmacological and surgical. Metabolic Syndrome is the set of clinical conditions that increase the risk of cardiovascular diseases with an estimated prevalence of 25% worldwide. The alterations of metabolic syndrome are obesity, hypertension, dyslipidemia, insulin resistance, and diabetes mellitus type II. Pituitary adenomas and metabolic syndrome have an important relationship, hormone-secreting by pituitary adenomas affects a myriad of signaling pathways, which allows a favorable environment for the appearance of the metabolic syndrome. Moreover, patients with pituitary adenomas are shown to have an improvement in metabolic parameters after the medical/surgical treatment. The objective of this review is to explore the possible mechanisms through which PAs contributes to MetSx.

The Gender-Specific Association of DRD2 Polymorphism with Metabolic Syndrome in Patients with Schizophrenia

Background: Metabolic syndrome is widespread in patients with schizophrenia receiving long-term antipsychotic therapy. Dopamine D2 receptors play an important role in mediating both the therapeutic actions of antipsychotics and their side effects. The present study examined the association of two polymorphisms of the DRD2 gene with metabolic syndrome in patients with schizophrenia. Methods: We examined 517 patients from several regions of Siberia (Russia) with a clinical diagnosis of schizophrenia. Genotyping of two single nucleotide polymorphisms rs1799732 and rs4436578 of the dopamine D2 receptor gene (DRD2) was performed in a population of 471 patients. The results were analyzed using chi-square tests. Results: Functional polymorphism rs1799732 of the DRD2 gene is associated with drug-induced metabolic syndrome in women with schizophrenia. Conclusions: Our results show that the DRD2 gene may be involved in the pathogenesis of metabolic disorders in patients with schizophrenia. Further analysis of possible genetic markers will allow for personalized treatment with minimal side effects and optimal efficacy. This which seems relevant in light of the recent focus on improving the quality of life and ensuring a high level of social adaptation of patients with schizophrenia.

Proton pump inhibitors therapy and risk of hyperprolactinemia with associated sexual disorders

Proton pump inhibitors (PPIs) are the most widely prescribed medications in the world. According to numerous studies, PPIs have been linked to hyperprolactinemia, which can lead to a variety of sexual and reproductive issues. This review summarizes the effects of numerous PPIs on the blood prolactin levels and associated sexual dysfunctions, which have an effect on the patient's life quality and fertility. The study is taken into account all the available resources till January 31, 2021. Out of total 364, only 27 relevant resources were involved in this review. In certain studies, short-term PPIs use has been shown to have little or no effect on the blood prolactin and other reproductive hormones levels. PPIs have been linked to the development of hyperprolactinemia in several case studies with varying degrees of the blood prolactin levels increase seen in individuals taking PPI alone or in combination with medications, like prokinetics. The relative risk of the sexual consequences development, such as gynecomastia, has been documented using lansoprazole and omeprazole in various cohort studies. On the other hand, other bits of data are insufficient to establish a definite relationship that can turn a possibility into certainty. The majority of the literature data is comprising of double-blind, randomized, crossover studies, case reports, and adverse drug reaction incidents reported to various pharmacovigilance centers. To investigate this link, high-quality studies in patients taking PPIs for a longer time period are needed. We conclude this article with a comprehensive discussion of the hyperprolactinemia clinical implications and the PPIs' function.

Italian Association of Clinical Endocrinologists (AME) and International Chapter of Clinical Endocrinology (ICCE). Position statement for clinical practice: prolactin-secreting tumors

Prolactinomas are the most frequent pituitary adenomas. Prolactinoma may occur in different clinical settings and always require an individually tailored approach. This is the reason why a panel of Italian neuroendocrine experts was charged with the task to provide indications for the diagnostic and therapeutic approaches that can be easily applied in different contexts. The document provides 15 recommendations for diagnosis and 54 recommendations for treatment, issued according to the GRADE system. The level of agreement among panel members was formally evaluated by RAND-UCLA methodology. In the last century, prolactinomas represented the paradigm of pituitary tumors for which the development of highly effective drugs obtained the best results, allowing to avoid neurosurgery in most cases. The impressive improvement of neurosurgical endoscopic techniques allows a far better definition of the tumoral tissue during surgery and the remission of endocrine symptoms in many patients with pituitary tumors. Consequently, this refinement of neurosurgery is changing the therapeutic strategy in prolactinomas, allowing the definitive cure of some patients with permanent discontinuation of medical therapy.

The interplay between prolactin and cardiovascular disease

Hyperprolactinemia can be caused by several conditions and its effects on the hypothalamic-pituitary-gonadal axis are understood in more detail. Nevertheless, in recent decades, other metabolic effects have been studied and data pointed to a potential increased cardiovascular disease (CVD) risk. A recent study showed a decrease in total and LDL- cholesterol only in men with prolactinoma treated with dopamine agonists (DA) supporting the previous results of a population study with increased CVD risk in men harboring prolactinoma. However, other population studies did not find a correlation between prolactin (PRL) levels and CVD risk or mortality. There is also data pointing to an increase in high-density lipoprotein levels, and decreases in triglycerides, carotid-intima-media thickness, C-reactive protein, and homocysteine levels in patients with prolactinoma on DA treatment. PRL was also implicated in endothelial dysfunction in pre and postmenopausal women. Withdrawal of DA resulted in negative changes in vascular parameters and an increase in plasma fibrinogen. It has been shown that PRL levels were positively correlated with blood pressure and inversely correlated with dilatation of the brachial artery and insulin sensitivity, increased homocysteine levels, and elevated D-dimer levels. Regarding possible mechanisms for the association between hyperprolactinemia and CVD risk, they include a possible direct effect of PRL, hypogonadism, and even effects of DA treatment, independently of changes in PRL levels. In conclusion, hyperprolactinemia seems to be associated with impaired endothelial function and DA treatment could improve CVD risk. More studies evaluating CVD risk in hyperprolactinemic patients are important to define a potential indication of treatment beyond hypogonadism.

Metabolic effects of prolactin and the role of dopamine agonists: A review

Prolactin is a polypeptide hormone that is well known for its role in reproductive physiology. Recent studies highlight its role in neurohormonal appetite regulation and metabolism. Elevated prolactin levels are widely associated with worsening metabolic disease, but it appears that low prolactin levels could also be metabolically unfavorable. This review discusses the pathophysiology of prolactin related metabolic changes, and the less commonly recognized effects of prolactin on adipose tissue, pancreas, liver, and small bowel. Furthermore, the effect of dopamine agonists on the metabolic profiles of patients with hyperprolactinemia are discussed as well.

The Relationship Between Bone and Reproductive Hormones Beyond Estrogens and Androgens

Reproductive hormones play a crucial role in the growth and maintenance of the mammalian skeleton. Indeed, the biological significance for this hormonal regulation of skeletal homeostasis is best illustrated by common clinical reproductive disorders, such as primary ovarian insufficiency, hypothalamic amenorrhea, congenital hypogonadotropic hypogonadism, and early menopause, which contribute to the clinical burden of low bone mineral density and increased risk for fragility fracture. Emerging evidence relating to traditional reproductive hormones and the recent discovery of newer reproductive neuropeptides and hormones has deepened our understanding of the interaction between bone and the reproductive system. In this review, we provide a contemporary summary of the literature examining the relationship between bone biology and reproductive signals that extend beyond estrogens and androgens, and include kisspeptin, gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, prolactin, progesterone, inhibin, activin, and relaxin. A comprehensive and up-to-date review of the recent basic and clinical research advances is essential given the prevalence of clinical reproductive disorders, the emerging roles of upstream reproductive hormones in bone physiology, as well as the urgent need to develop novel safe and effective therapies for bone fragility in a rapidly aging population.

Hyperprolactinemia in the postmenopause: versions and contraversions

The prevalence of hyperprolactinemia in postmenopausal women is unknown and has been estimated as infrequent by many studies. Prolactinomas found after menopause are usually macroadenomas and remain unrecognized for a long time due to atypical clinical signs or their absence. The growth potential of prolactinomas persists after menopause, most of them are invasive and accompanied by high prolactin levels. Treatment with dopamine agonists is usually long-term, the goals of which are to reduce tumor size, normalize prolactin levels and the negative effects of hyperprolactinemia. Treatment with cabergoline makes it possible to achieve remission of the disease in the first years after discontinuation, however, the proportion of relapses in postmenopausal women increases 5 years after discontinuation of the drug. Remission of prolactinomas is not evident in postmenopausal women. The modern management of patients with prolactinoma and/or hyperprolactinemia does not have clear positions in the postmenopausal period. Controversial issues remain: an ambiguous relationship between prolactin levels and breast cancer, there are no convincing conclusions on the improvement of bone mineral density and/or a decrease in the risk of fractures with normalization of prolactin levels, there are no data on metabolic parameters after the end of treatment with dopamine agonists, conflicting information about the relationship of prolactin levels and the severity of the manifold manifestations of the climacteric syndrome. The use of estrogen-progestin drugs in women with hyperprolactinemia/prolactinomas is also not well understood. Thus, the problem of hyperprolactinemia in the perimenopausal and postmenopausal period is underestimated and requires additional research, as well as the development of diagnostic and therapeutic strategies for potential benefits in terms of weight loss, improving insulin sensitivity, reducing the risk of fractures, maintaining sexuality and psycho-emotional well-being.

Clinical Management of Hypertriglyceridemia in the Prevention of Cardiovascular Disease and Pancreatitis

Purpose of Review

Hypertriglyceridemia (HTG) is common and is a significant contributor to atherosclerosis and pancreatitis risk. Specific HTG treatments have had variable success in reducing atherosclerosis risk. Novel therapies for severe HTG treatment and pancreatitis risk reduction are likely to be available soon. These novel therapies are expected to have broader applications for more moderate HTG and atherosclerosis risk reduction as well.

Recent Findings

NHANES 2012 data has confirmed a reduction in average triglyceride (TG) levels in the US population. Dietary modification and weight reduction when needed remain the core treatment elements for all individuals with HTG, while statin therapy is a foundational pharmacologic care for atherosclerotic cardiovascular disease (ASCVD) event risk reduction. In addition, the REDUCE-IT study provides evidence for additional benefit from the use of high-dose icosapent ethyl (IPE) on top of background medical therapy in adults with moderate HTG and ASCVD or type 2 diabetes mellitus (T2D) and additional ASCVD risk factors. However, treatment with eicosapentaenoic acid (EPA) combined with docosahexanoic acid (DHA) did not reduce ASCVD in a similar population studied in the STRENGTH trial. Furthermore, novel therapeutics targeting PPAR-ɑ, as well as ApoC-III and AngPTL3, effectively lower TG levels in individuals with moderate and severe HTG, respectively. These treatments may have applicability for reducing risk from ASCVD among individuals with chylomicronemia; in addition, ApoC-III and AngPTL3 treatments may have a role in treating individuals with the rare monogenic familial chylomicronemia syndrome (FCS) at risk for acute pancreatitis (AP).

Summary

Residual ASCVD risk in individuals treated with contemporary care may be due in part to non-LDL lipid abnormalities including HTG. The findings from REDUCE-IT, but not STRENGTH, confirm that consumption of high-dose EPA may reduce ASCVD risk, while combination therapy of EPA plus DHA does not reduce ASCVD in a similar population. TG lowering likely reduces ASCVD risk in individuals with HTG, but ASCVD risk is multifactorial; the added benefit of IPE to contemporary preventive therapy is the consequence of differential non-TG biologic properties between the two fatty acids. Acute pancreatitis is more difficult to study prospectively since it is less common; however, TG lowering is likely critical for the care of at-risk individuals. Additional benefit from novel therapy that has an impact on this otherwise refractory condition is anticipated.

Hyperprolactinemia after menopause: Diagnosis and management

Most prolactinomas are diagnosed in women of reproductive age and are generally microadenomas. Prolactinomas diagnosed in postmenopausal women are less common and are not usually associated with the typical syndrome induced by prolactin excess, including infertility and oligo-amenorrhea. This implies that the diagnosis of prolactinomas after menopause may be delayed and require greater clinical effort. Limited data are available on the management and prognosis of prolactinomas in postmenopausal women. However, the physiologic decline of prolactin levels during menopause and the lack of fertility concerns, which represent specific indications for medical treatment with dopamine agonists, might require a careful reassessment of therapeutic management in such patients. Postmenopausal women with microprolactinoma may be successfully withdrawn from medical therapy with dopamine agonists, whereas in those with macroprolactinomas greater caution is advisable before dopamine agonists are discontinued, considering the potential, although rare, tumor enlargement. This review focuses on the diagnostic challenges and therapeutic management of prolactinomas in postmenopausal women.

Hyperprolactinemia in Adults with Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a rare neurodevelopmental genetic disorder typically characterized by body composition abnormalities, hyperphagia, behavioural challenges, cognitive dysfunction, and hypogonadism. Psychotic illness is common, particularly in patients with maternal uniparental disomy (mUPD), and antipsychotic medications can result in hyperprolactinemia. Information about hyperprolactinemia and its potential clinical consequences in PWS is sparse. Here, we present data from an international, observational study of 45 adults with PWS and hyperprolactinemia. Estimated prevalence of hyperprolactinemia in a subset of centres with available data was 22%, with 66% of those related to medication and 55% due to antipsychotics. Thirty-three patients were men, 12 women. Median age was 29 years, median BMI 29.8 kg/m², 13 had mUPD. Median prolactin was 680 mIU/L (range 329–5702). Prolactin levels were higher in women and patients with mUPD, with only 3 patients having severe hyperprolactinemia. Thyroid function tests were normal, 24 were treated with growth hormone, 29 with sex steroids, and 20 with antipsychotic medications. One patient had kidney insufficiency, and one a microprolactinoma. In conclusion, severe hyperprolactinemia was rare, and the most common aetiology of hyperprolactinemia was treatment with antipsychotic medications. Although significant clinical consequences could not be determined, potential negative long-term effects of moderate or severe hyperprolactinemia cannot be excluded. Our results suggest including measurements of prolactin in the follow-up of adults with PWS, especially in those on treatment with antipsychotics.

Impact of primary medical or surgical therapy on prolactinoma patients' BMI and metabolic profile over the long-term

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High prolactin (PRL) levels are associated with weight gain and impaired metabolic profiles.

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Long-term control of hyperprolactinemia can be attained by first-line surgery and medical therapy.

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Normalization of PRL improves patients’ BMI and fasting glucose levels.

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Marginal changes in patients’ metabolic profiles are noted regardless of the primary therapy.

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Not dopamine agonists per se, but rather the control of hyperprolactinemia plays a role in metabolic profile alterations.

Objectives

High prolactin levels have been associated with weight gain and impaired metabolic profiles. While treatment with dopamine agonists (DAs) has been shown to improve these parameters, there is a lack of surgical series on its comparative effect in prolactinoma patients.

Methods

In this retrospective, comparative study, consecutive patients with a prolactinoma were enrolled if treated with first-line transsphenoidal surgery (TSS) or with DAs. Patients with prolactinomas of Knosp grade >2 and those with a follow-up <24 months were excluded, as were patients with missing laboratory metabolic parameters at baseline and over the long-term. Effects of either treatment on BMI and the metabolic profile were analyzed, and independent risk factors for long-term obesity were calculated.

Results

Primary treatment was TSS for 12 patients (40%) and DAs for 18 patients (60%). At diagnosis, no significant differences between the two cohorts were observed with regard to adenoma size, Knosp grading, baseline prolactin (PRL) levels, prevalence of hypogonadism, or laboratory metabolic parameters. Mean follow-up was 51.9 months (range, 24–158). Over the long-term, both TSS and DAs led to the control of hyperprolactinemia (92% vs. 72%) and hypogonadism (78% vs. 83%) in the majority of patients. While a significant decrease in patients’ BMI and fasting glucose were observed, changes in the lipid profile were marginal and independent of the treatment modality. At baseline, increased BMI—but not the primary treatment strategy—was an independent predictor of long-term obesity.

Conclusions

Over the long-term, patients’ BMI and FG improve, but changes in the metabolic profile are marginal and independent of the primary treatment. It is presumable that not DAs per se, but rather the control of hyperprolactinemia plays a role in patients’ metabolic profile alterations.

Morbid Obesity Due to Prolactinoma and Significant Weight Loss After Dopamine Agonist Treatment

Objective

Morbid obesity may be related to a prolactinoma, although uncommon, and can lead to adverse effects like insulin resistance and metabolic syndrome. Recent research suggests that hyperprolactinemia causes an abnormal lipid profile, weight gain, and cardiovascular diseases. Moreover, high prolactin levels lead to decreased testosterone production by disrupting 17-b-estradiol synthesis. Our objective was to present a case of prolactinoma with morbid obesity, hypogonadism, and then significant weight loss after dopamine agonist treatment.

Methods

The clinical course, in addition to serial laboratory and imaging results, are presented. These include prolactin levels, testosterone levels, thyroid function tests, blood sugar levels, and serial lipid profiles.

Results

In this report, we discuss a case of 30-year-old male with prolactin-secreting macroadenoma with clinical features of hypogonadism, hypothyroidism, and morbid obesity. He showed marked improvement in obesity and hypogonadism with dopamine agonist therapy supplemented with clomiphene citrate.

Conclusion

Prolactinomas with morbid obesity can be successfully treated contingent upon proper medication and compliance with medications. Insulin resistance, hypogonadism, prolactin levels, body mass index, and tumor size all improved by regular follow-up and treatment adherence.

Persistent bone impairment despite long-term control of hyperprolactinemia and hypogonadism in men and women with prolactinomas

While prolactinoma patients have high bone turnover, current data are inconclusive when it comes to determining whether correction of hyperprolactinemia and associated hypogandism improves osteodensitometric data in men and women over the long term. In a large cohort of including 40 men and 60 women, we studied the long-term impact of prolactinoma treatment on bone mineral density (BMD) in men versus women, assessed adverse effects of a primary surgical or medical approach, and evaluated data for risk factors for impaired BMD at last follow-up using multivariate regression analyses. Median duration of follow-up was 79 months (range 13–408 months). Our data indicate that the prevalence of impaired BMD remained significantly higher in men (37%) than in women (7%, p < 0.001), despite the fact that hyperprolactinemia and hypogonadism are under control in the majority of men. We found that persistent hyperprolactinemia and male sex were independent risk factors for long-term bone impairment. Currently, osteoporosis prevention and treatment focus primarily on women, yet special attention to bone loss in men with prolactinomas is advised. Bone impairment as “end organ” reflects the full range of the disease and could become a surrogate marker for the severity of long-lasting hyperprolactinemia and associated hypogonadism.

Metabolic functions of prolactin: Physiological and pathological aspects

Prolactin is named after its vital role of promoting milk production during lactation, although it has been implicated in multiple functions within the body, including metabolism and energy homeostasis. Prolactin has been hypothesised to play a key role in driving many of the adaptations of the maternal body to allow the mother to meet the physiological demands of both pregnancy and lactation, including the high energetic demands of the growing foetus followed by milk production to support the offspring after birth. Prolactin receptors are found in many tissues involved in metabolism and food intake, such as the pancreas, liver, hypothalamus, small intestine and adipose tissue. We review the literature examining the effects of prolactin in these various tissues and how they relate to changes in function in physiological states of high prolactin, such as pregnancy and lactation, and in pathological states of hyperprolactinaemia in the adult. In many cases, whether prolactin promotes healthy metabolism or leads to dysregulation of metabolic functions is highly dependent on the situation. Overall, although prolactin may not play a major role in regulating metabolism and body weight outside of pregnancy and lactation, it definitely has the ability to contribute to metabolic function.

Long-Term Effects of Fatherhood on Morphology, Energetics, and Exercise Performance in California Mice (Peromyscus californicus)

In male mammals that provide care for their offspring, fatherhood can lead to changes in behavioral, morphological, and physiological traits, some of which might constitute trade-offs. However, relatively little is known about these changes, especially across multiple reproductive bouts, which are expected to magnify differences between fathers and nonreproductive males. We evaluated consequences of fatherhood in the monogamous, biparental California mouse (Peromsycus californicus) across seven consecutive reproductive bouts. We compared breeding adult males (housed with sham-ovariectomized females) with two control groups: nonbreeding males (housed with ovariectomized females treated with estrogen and progesterone to induce estrous behavior) and virgin males (housed with untreated ovariectomized females). At five time points (before pairing, early postpartum of the first litter, late postpartum of the second litter, early postpartum of the sixth litter, and late postpartum of the seventh litter or comparable time points for nonbreeding and virgin males), we measured males' body composition, hematocrit, predatory aggression, resting metabolic rate, maximal oxygen consumption (V˙O2 max⁡), grip strength, and sprint speed. We also weighed organs at the final time point. We predicted that fathers would have lower relative body fat and lower performance abilities compared with control groups and that these effects would become more pronounced with increasing parity. Contrary to predictions, breeding and control males differed in surprisingly few measures, and the number and magnitude of differences did not increase with parity. Thus, our expectations regarding trade-offs were not met. As reported in studies of single reproductive events, these results suggest that fatherhood has few costs in this species when housed under standard laboratory conditions, even across multiple reproductive bouts.

Hyperprolactinemic African elephant (Loxodonta africana) females exhibit elevated dopamine, oxytocin and serotonin concentrations compared to normal cycling and noncycling, low prolactin elephants†

Many zoo elephants do not cycle normally, and for African elephants, it is often associated with hyperprolactinemia. Dopamine agonists successfully treat hyperprolactinemia-induced ovarian dysfunction in women, but not elephants. The objective of this study was to determine how longitudinal dopamine, serotonin, and oxytocin patterns in African elephants are related to ovarian cycle function. We hypothesized that dopamine concentrations are decreased, while oxytocin and serotonin are increased in non-cycling, hyperprolactinemic African elephants. Weekly urine and serum samples were collected for eight consecutive months from 28 female African elephants. Females were categorized as follows: (1) non-cycling with average prolactin concentrations of 15 ng/ml or greater (HIGH; n = 7); (2) non-cycling with average prolactin concentrations below 15 ng/ml (LOW; n = 13); and (3) cycling with normal progestagen and prolactin patterns (CYCLING; n = 8). Both oxytocin and serotonin were elevated in hyperprolactinemic elephants. Thus, we propose that stimulatory factors may play a role in the observed hyperprolactinemia in this species. Interestingly, rather than being reduced as hypothesized, urinary dopamine was elevated in hyperprolactinemic elephants compared to CYCLING and LOW prolactin groups. Despite its apparent lack of regulatory control over prolactin, this new evidence suggests that dopamine synthesis and secretion are not impaired in these elephants, and perhaps are augmented.

Patterns of prolactin secretion

Prolactin is pleotropic in nature affecting multiple tissues throughout the body. As a consequence of the broad range of functions, regulation of anterior pituitary prolactin secretion is complex and atypical as compared to other pituitary hormones. Many studies have provided insight into the complex hypothalamic-pituitary networks controlling prolactin secretion patterns in different species using a range of techniques. Here, we review prolactin secretion in both males and females; and consider the different patterns of prolactin secretion across the reproductive cycle in representative female mammals with short versus long luteal phases and in seasonal breeders. Additionally, we highlight changes in the pattern of secretion during pregnancy and lactation, and discuss the wide range of adaptive functions that prolactin may have in these important physiological states.

The role of prolactin in co-ordinating fertility and metabolic adaptations during reproduction

Mammalian pregnancy and lactation is accompanied by a period of infertility that takes place in the midst of a sustained increase in food intake. Indeed, successful reproduction in females is dependent on co-ordination of the distinct systems that regulate reproduction and metabolism. Rather than arising from different mechanisms during pregnancy and lactation, we propose that elevations in lactogenic hormones (predominant among these being prolactin and the placental lactogens), are ideally placed to influence both of these systems at the appropriate time. We review the literature examining the impacts of lactogens on fertility and energy homeostasis in the virgin state, during pregnancy and lactation and potential long-term impacts of reproductive experience. Taken together, the literature indicates that duration and pattern of lactogen exposure is a vital factor in the ability of these hormones to alter reproduction and food intake. Transient increases in prolactin, as typically seen in healthy virgin females and males, are unable to exert lasting impacts. Importantly, both suppression of fertility and increased food intake are only observed following exposure to chronically-elevated levels of lactogens. Physiologically, the only time this pattern of lactogenic secretion is maintained in the healthy female is during pregnancy and lactation, when co-ordination between these regulatory systems emerges. This article is part of the special issue on 'Neuropeptides'.

Body self-image disturbances in women with prolactinoma

Objective:

To evaluate body dissatisfaction and distorted body self-image in women with prolactinoma.

Methods:

Body dissatisfaction and distorted body self-image were evaluated in 80 women with prolactinoma. All patients were in menacme, 34% had normal body mass index (BMI), and 66% were overweight. Most patients (56.2%) had normal prolactin (PRL) levels and no hyperprolactinemia symptoms (52.5%). The Body Shape Questionnaire (BSQ) was used to assess the patients’ dissatisfaction with and concern about their physical form, and the Stunkard Figure Rating Scale (FRS) was used to assess body dissatisfaction and distorted body self-image. The patients were divided according to PRL level (normal vs. elevated) and the presence or absence of prolactinoma symptoms.

Results:

The normal and elevated PRL groups had similar incidences of body dissatisfaction and distorted body self-image. However, symptomatic patients reported a higher incidence of dissatisfaction than asymptomatic patients. Distorted body self-image was less common among symptomatic patients.

Conclusion:

Symptomatic patients showed higher body dissatisfaction, but lower body self-image distortion. The presence of symptoms may have been responsible for increased body awareness. The perception of body shape could have triggered feelings of dissatisfaction compared to an ideal lean body. Therefore, a distorted body self-image might not necessarily result in body dissatisfaction in women with prolactinomas.

Prolactin and human weight disturbances: A puzzling and neglected association

Weight gain at the outset of prolactinomas in many women is well documented. Yet, this symptom is absent from the clinical descriptions of the disease in textbooks and reviews. This omission is almost certainly due to the absence of a physiological explanation for the phenomenon, as prolactin is not a recognized fat promoting hormone. In this review we present the clinical evidence for a relationship between prolactin and fat accumulation and address some possible mechanisms involved. We put forward the hypothesis that prolactin is a component of a neuroendocrine program - maternal subroutine - aimed at optimizing the care of the young through the production of milk, promotion of maternal behavior and increase in the metabolic efficiency of the mother. These adaptations can enable her to face the extraordinary metabolic expenses of pregnancy and nursing, especially during times of suboptimal environmental conditions. We emphasize the uniqueness of prolactin in that it is a hormone that is tonically inhibited and which has its major effects on the regulation of an inter-individual (the mother - offspring dyad), rather than an intra-individual, system. This approach opens a window to consider the possibility of external events as regulators of this system. It also allows addressing a variety of hitherto unexplained findings reported in the literature. Examples include: association of prolactinomas with paternal deprivation and with stressful life events; pseudocyesis; acute life event-driven episodes of galactorrhea; episodes of rapid weight gain following a life event; prolactin surges (without associated cortisol surges) following some psychological stresses.

Different Cabergoline Effect on Metabolic and Anthropometric Parameters in Female Prolactinoma Patients Versus Idiopathic Hyperprolactinemia Patients

BACKGROUND

Hyperprolactinemia can lead to weight gain, insulin resistance, abnormal glucose homeostasis and dyslipidemia. Reversibility of these changes after normalization of prolactin with dopamine agonists is still controversial and needs more clarification.

OBJECTIVE

We aimed to: 1) evaluate and compare metabolic and anthropometric profile in female with newly diagnosed prolactin-secreting adenoma versus female idiopathic hyperprolactinemic patients; 2) compare the effects of one year cabergoline therapy on the metabolic profile and anthropometric parameters (by using visceral adiposity index as index for evaluation of adipose tissue dysfunction) in females with prolactinoma to female idiopathic hyperprolactinemic patients.

PATIENTS AND METHODS

We enrolled 40 female patients with newly diagnosed prolactinoma and 40 female patients with idiopathic hyperprolactinemia, who were matched according to: age; weight; BMI; waist; and prolactin levels. We enrolled the participants in this study at the time of diagnosis before therapy and they were followed up for 12 months.

RESULTS

Cabergoline therapy had significant favorable effects on metabolic and anthropometric parameters, visceral adiposity index and in all patients (apart from HDLc in prolactinoma patients). Cabergoline therapy was significantly more effective in patient with idiopathic hyperprolactinemia than prolactinoma patients with regard to BMI, waist circumference, HDLc and visceral adiposity index despite normalization of prolactin levels in both groups.

CONCLUSION

12 months of Cabergoline treatment improved most of the anthropometric and metabolic parameters, and visceral adiposity index as a marker for adipose tissue dysfunction in both idiopathic hyperprolactinemia and prolactinoma patients. However, Cabergoline treatment was more effective in idiopathic hyperprolactinemic than prolactinoma patients.

Hyperprolactinemia/Prolactinomas in the Postmenopausal Period: Challenges in Diagnosis and Management

Hyperprolactinemia is not a common finding in postmenopausal women. Prolactinomas detected after menopause are usually macroadenomas. Due to atypical clinical features they may remain unrecognized for a long period of time. Interestingly the growth potential of prolactinomas remains after menopause. Most tumors are invasive and present with high prolactin levels. They respond to medical treatment with dopamine agonists in terms of prolactin normalization, tumor shrinkage, and improvement in pituitary function. Treatment with dopamine agonists is usually long term. Reducing doses of cabergoline to the lowest that keeps prolactin levels normal prior to withdrawal is proposed to patients with macroprolactinomas who normalize prolactin after > 5 years of treatment and who do not have cavernous sinus invasion. Cabergoline can achieve a high percentage of remission maintenance in the first years after withdrawal. However, the percentage of relapse-free patients 5 years after withdrawal is significantly lower. Besides recurrent hyper-prolactinemia in a subgroup of macroprolactinomas after a long-interval tumor regrowth may be detected. Menopause cannot ensure remission of the tumor so long-term surveillance is suggested. In patients with microadenomas data on long-term remission rates (normalization of prolactin and disappearance of the tumor) after suspension of treatment with dopamine agonists are highly variable. The current strategy for microprolactinomas is not to treat hyperprolactinemia in menopause if it recurrs after discontinuation of dopamine agonists. This is based on: (1) reports that elevated prolactin levels may normalize in some women after menopause, (2) the fact that the association between prolactin levels and breast cancer is inconsistent in postmenopausal women, (3) the lack of clinical evidence that normalization of prolactin levels in postmenopausal women improves bone mineral density or reduces the risk of fracture, and (4) the fact that, concerning the metabolic syndrome, no data are available on metabolic parameters after suspension of treatment with dopamine agonists. For a change in strategy, i.e., for the potential benefits from treatment of hyperprolactinemia in the postmenopausal period with dopamine agonists concerning weight loss, improved insulin sensitivity, decreased fracture risk, and improved sexuality, more evidence is needed.

The value of prolactin in predicting prolactinοma in hyperprolactinaemic polycystic ovarian syndrome

BACKGROUND

To identify a serum prolactin (PRL) cut-off value indicative of a PRL-producing adenoma in women with polycystic ovarian syndrome (PCOS) and hyperprolactinaemia and characterize such patients.

MATERIALS AND METHODS

In the present retrospective case-control study, the medical records of 528 PCOS women were reviewed. Pituitary magnetic resonance imaging (MRI) was performed in PCOS patients with PRL levels ≥94.0 ng/mL and/or symptoms suspicious of a pituitary adenoma (PA). Prolactinoma diagnosis was made in the presence of an MRI-identifiable PA with biochemical and radiological response to dopamine agonists. Receiver operating characteristic (ROC) curve analysis was performed to determine a serum PRL threshold that could identify hyperprolactinaemic PCOS subjects with prolactinomas. Clinical, metabolic and endocrine parameters were also analysed.

RESULTS

Among 528 patients with PCOS, 60 (11.4%) had elevated PRL levels. Of 44 (73.3%) patients who had pituitary imaging, 19 had PAs, 18 normal MRI and 7 other abnormalities. Patients harbouring prolactinomas had significantly higher PRL levels compared to patients without adenomas (median PRL 95.4 vs 49.2 ng/mL, P < .0001). A PRL threshold of 85.2 ng/mL could distinguish patients with prolactinomas with 77% sensitivity and 100% specificity [Area Under the curve (AUC) (95%) 0.91(0.8-1.018), P = .0001]. PCOS women with prolactinomas were younger and had lower LH levels compared to women without prolactinomas.

CONCLUSIONS

In women with PCOS, PRL levels exceeding 85.2 ng/mL are highly suggestive of a prolactinoma warranting pituitary imaging. Pituitary MRI could also be considered in young PCOS patients with milder PRL elevation and low LH levels.

Calcium and Vitamin D Supplementation in Boys with Risperidone-Induced Hyperprolactinemia: A Randomized, Placebo-Controlled Pilot Study

BACKGROUND

The chronic use of antipsychotics has been associated with impaired bone mineralization, partially mediated by hyperprolactinemia. We examined if calcium and vitamin D supplementation promote bone mineral accrual in boys with risperidone-induced hyperprolactinemia.

METHODS

Between February 2009 and November 2013, medically healthy, 5- to 17-year-old boys were enrolled in a 36-week double-blind, placebo-controlled study, examining the skeletal effects of supplementation with 1250 mg calcium carbonate and 400 IU of vitamin D3 in risperidone-induced hyperprolactinemia. Anthropometric, dietary, physical activity, and psychiatric assessments were conducted at baseline and week 18 and 36. Plasma prolactin and vitamin D concentrations were measured at baseline and week 36. Total body less head bone mineral content (BMC) and radius trabecular bone mineral density (BMD) were measured at baseline, week 18, and week 36, using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, respectively. Linear mixed-effects regression analysis examined the longitudinal effect of treatment on skeletal outcomes.

RESULTS

Forty-seven boys (mean age: 11.0 ± 2.6 years) were randomized and 38 completed the study. At study entry, the average dietary calcium intake was below the recommended limit, but the average vitamin D concentration was normal. Calcium and vitamin D supplementation failed to significantly increase BMC or trabecular BMD. It also failed to affect several other skeletal and anthropometric outcomes, including plasma vitamin D concentration.

CONCLUSIONS

In this 9-month long pilot study, supplementation with a modest dose of calcium and vitamin D did not increase bone mass accrual in risperidone-treated boys with hyperprolactinemia. Alternative approaches should be investigated to optimize bone health in this population to prevent future morbidity and premature mortality. ClinicalTrials.gov Identifier: NCT00799383.

Extensive phenotypic characterization of a new transgenic mouse reveals pleiotropic perturbations in physiology due to mesenchymal hGH minigene expression

The human growth hormone (hGH) minigene used for transgene stabilization in mice has been recently identified to be locally expressed in the tissues where transgenes are active and associated with phenotypic alterations. Here we extend these findings by analyzing the effect of the hGH minigene in TgC6hp55 transgenic mice which express the human TNFR1 under the control of the mesenchymal cell-specific CollagenVI promoter. These mice displayed a fully penetrant phenotype characterized by growth enhancement accompanied by perturbations in metabolic, skeletal, histological and other physiological parameters. Notably, this phenotype was independent of TNF-TNFR1 signaling since the genetic ablation of either Tnf or Tradd did not rescue the phenotype. Further analyses showed that the hGH minigene was expressed in several tissues, also leading to increased hGH protein levels in the serum. Pharmacological blockade of GH signaling prevented the development of the phenotype. Our results indicate that the unplanned expression of the hGH minigene in CollagenVI expressing mesenchymal cells can lead through local and/or systemic mechanisms to enhanced somatic growth followed by a plethora of primary and/or secondary effects such as hyperphagia, hypermetabolism, disturbed glucose homeostasis, altered hematological parameters, increased bone formation and lipid accumulation in metabolically critical tissues.

Hyperprolactinaemia - a problem in patients from the reproductive period to the menopause

Hyperprolactinaemia especially affects women in reproductive age (90/100,000) but also often is diagnosed in menopause age and leads to disturbances in functioning of LH-RH neurons and, as a consequence, to a decrease of FSH and LH, which causes inhibition of oestradiol production. Prolactin is a peptide hormone, phylogenetically one of the oldest, stimulating cells of various organs, which is produced and secreted mainly by lactotrophic acidophilic cells of the anterior lobe of the pituitary. It influences the increase in the mass of the mammary glands, and stimulation and maintenance of lactation after delivery. There are a number of factors apart of pregnancy, delivery, and lactation than can influence secretion of the hormone in other physiological and pathological circumstances, like high-protein diet, stress, REM sleep, or neoplastic tumours, inflammatory diseases, chronic systematic diseases, thyroid hormonal changes, and drug intake. The purpose of this review is to summarise the current knowledge regarding the proper diagnosis and possible influence of hyperprolactinaemia on fertility and menopause symptoms and current treatment methods.

Prolactin levels are associated with a pro-inflammatory body mass distribution among women with systemic lupus erythematosus

Objectives The objective of this study was to determine whether prolactin levels are associated with a pro-inflammatory body mass distribution in women with systemic lupus erythematosus (SLE). Methods This cross-sectional study was conducted in consecutive female SLE patients seen in our rheumatology department from January 2012 to July 2015. Prolactin was measured in ng/ml. Body mass distribution was measured by dual energy x-ray absorptiometry and it was divided into subtotal (whole body excluding the head), subtotal bone mineral content, lean mass index (appendicular lean mass/height²), subtotal trunk and leg fat percentages and trunk-to-leg fat ratio. The association between prolactin levels and body mass distribution components was evaluated by univariable and multivariable linear regression models adjusting for possible confounders. Results One hundred and eighty-five patients were evaluated; their mean (SD) age at diagnosis was 34.8 (13.8) years; nearly all patients were Mestizo. Patients included in this study were comparable to the rest of the cohort in terms of age, disease duration, SLEDAI, SDI and body mass index. Disease duration was 7.3 (6.6) years. The SLEDAI was 5.2 (4.3) and the SDI 0.9 (1.3). Prolactin levels were 18.9 (16.7) ng/ml. In univariable analyses, prolactin was negatively associated with bone mineral density, bone mineral content, leg fat percentage and lean mass index, and positively associated with trunk-to-leg fat ratio. In the multivariable analyses, prolactin was negatively associated with bone mineral content and positively associated with trunk-to-leg fat ratio. Conclusions Higher prolactin levels are associated with a pro-inflammatory body mass distribution in SLE patients.

SERUM LEVELS OF FIBROBLAST GROWTH FACTOR-23, OSTEOPROTEGERIN, AND RECEPTOR ACTIVATOR OF NUCLEAR FACTOR KAPPA B LIGAND IN PATIENTS WITH PROLACTINOMA

OBJECTIVE

The aim of this study to was to evaluate the effect of fibroblast growth factor-23 (FGF-23), osteoprotegerin (OPG), receptor activator nuclear κB ligand (RANKL), and vitamin D hormones on bone loss in patients with hyperprolactinemia due to pituitary prolactinoma.

METHODS

We recruited 46 premenopausal female patients with prolactinoma and age and sex-matched healthy controls (Group 3, n = 20) for this cross-sectional study. Prolactinoma patients were divided into 2 groups as patients newly diagnosed (Group 1, n = 26) and those under cabergoline treatment (Group 2, n = 20). Anthropometric and metabolic variables; hormonal profiles; and osteocalcin, deoxypyridinoline (DOP), and bone mineral density measurements were performed for all participants. FGF-23, OPG, and RANKL levels were analyzed in all groups.

RESULTS

FGF-23, OPG, calcium, phosphorus, and parathormone levels were similar between all groups despite significantly higher levels in the control group in terms of vitamin D and RANKL levels than in patients. Bone loss was found more in Group 2, particularly observed in Z scores of femur and spinal bone (P<.05). Correlation analysis revealed a negative correlation between FGF-23 and femur neck T score (r = -0.0433, P = .05) in patients with active prolactinoma. A positive correlation was also observed between parameters of DOP and OPG (r = 0.673, P = .02). In patients with remission there were a negative correlation between prolactin and luteinizing hormone (r = -600, P = .08). Additionally, a negative correlation was found between osteocalcin and osteoprotegerin in patients in remission (r = -0.73, P = .01).

CONCLUSION

Our data indicated that FGF-23 and OPG levels do not play a critical role on the development of bone decrease in patients with hyperprolactinemia. However, further prospective studies in larger numbers of participants should be designed to clarify this issue.

ABBREVIATIONS

BFP = body fat percentage BMD = bone mineral density BMI = body mass index CV = coefficient of variation DOP = deoxypyridinoline ELISA = enzyme-linked immunosorbent assay FGF-23 = fibroblast growth factor-23 HOMA-IR = homeostatic model assessment of insulin resistance OPG = osteoprotegerin RANKL = receptor activator nuclear κB ligand.

The role of the prolactin/vasoinhibin axis in rheumatoid arthritis: an integrative overview

Rheumatoid arthritis (RA) is a chronic, autoimmune, inflammatory disease destroying articular cartilage and bone. The female preponderance and the influence of reproductive states in RA have long linked this disease to sexually dimorphic, reproductive hormones such as prolactin (PRL). PRL has immune-enhancing properties and increases in the circulation of some patients with RA. However, PRL also suppresses the immune system, stimulates the formation and survival of joint tissues, acquires antiangiogenic properties upon its cleavage to vasoinhibins, and protects against joint destruction and inflammation in the adjuvant-induced model of RA. This review addresses risk factors for RA linked to PRL, the effects of PRL and vasoinhibins on joint tissues, blood vessels, and immune cells, and the clinical and experimental data associating PRL with RA. This information provides important insights into the pathophysiology of RA and highlights protective actions of the PRL/vasoinhibin axis that could lead to therapeutic benefits.

Obesity impairs lactation performance in mice by inducing prolactin resistance

Obesity reduces breastfeeding success and lactation performance in women. However, the mechanisms involved are not entirely understood. In the present study, female C57BL/6 mice were chronically exposed to a high-fat diet to induce obesity and subsequently exhibited impaired offspring viability (only 15% survival rate), milk production (33% reduction), mammopoiesis (one-third of the glandular area compared to control animals) and postpartum maternal behaviors (higher latency to retrieving and grouping the pups). Reproductive experience attenuated these defects. Diet-induced obese mice exhibited high basal pSTAT5 levels in the mammary tissue and hypothalamus, and an acute prolactin stimulus was unable to further increase pSTAT5 levels above basal levels. In contrast, genetically obese leptin-deficient females showed normal prolactin responsiveness. Additionally, we identified the expression of leptin receptors specifically in basal/myoepithelial cells of the mouse mammary gland. Finally, high-fat diet females exhibited altered mRNA levels of ERBB4 and NRG1, suggesting that obesity may involve disturbances to mammary gland paracrine circuits that are critical in the control of luminal progenitor function and lactation. In summary, our findings indicate that high leptin levels are a possible cause of the peripheral and central prolactin resistance observed in obese mice which leads to impaired lactation performance.

Profile of leptin, adiponectin, and body fat in patients with hyperprolactinemia: Response to treatment with cabergoline

INTRODUCTION

Though hypoadiponectinemia and leptin resistance have been proposed as potential factors for weight gain in patients with hyperprolactinemia (HPL), the effects of HPL and cabergoline on these adipocyte-derived hormones are not clear. Aims of this study were (i) to assess the alterations of body fat, leptin, and adiponectin in patients with HPL (ii) effect of cabergoline treatment on these parameters.

METHODS

Nineteen consecutive patients with prolactinoma (median prolactin [PRL] 118.6 (interquartile range: 105.3) μg/L) and 20 controls were studied in a nonrandomized matched prospective design. The controls were age, gender, and body mass index (BMI) matched. Anthropometric data, metabolic variables, leptin, and adiponectin were studied at baseline and 3 and 6 months after cabergoline treatment.

RESULTS

Patients with prolactinoma had increased level of fasting plasma glucose (P < 0.001) as compared to age-, gender-, and BMI-matched healthy controls. Estradiol concentration of controls was higher than that of patients (P = 0.018). Patients with prolactinoma had higher levels of leptin (P = 0.027) as compared to healthy controls without a significant difference in adiponectin levels. There was a significant decrease of body weight at 3 months (P = 0.029), with a further decline at 6 months (P < 0.001) of cabergoline therapy. Furthermore, there was a significant decrement of BMI (P < 0.001), waist circumference (P = 0.003), waist-hip ratio (P = 0.03), total body fat (P = 0.003), plasma glucose (P < 0.001), leptin levels (P = 0.013), and an increase in estradiol concentration (P = 0.03) at 6 months of cabergoline treatment.

CONCLUSION

Patients with prolactinoma have adverse metabolic profile compared to matched controls. Normalization of PRL with cabergoline corrects all the metabolic abnormalities.

Spanish consensus on the risks and detection of antipsychotic drug-related hyperprolactinaemia

INTRODUCTION

Iatrogenic hyperprolactinaemia (IHPRL) has been more frequently related to some antipsychotic drugs that provoke an intense blockade of dopamine D2 receptors. There is a wide variation in clinical practice, and perhaps some more awareness between clinicians is needed. Due to the high frequency of chronic treatment in severe mental patients, careful attention is recommended on the physical risk. IHPRL symptoms could be underestimated without routine examination.

METHODOLOGY

An intense scientific literature search was performed in order to draw up a multidisciplinary consensus, including different specialists of psychiatry, endocrinology, oncology and internal medicine, and looking for a consensus about clinical risk and detection of IHPRL following evidence-based medicine criteria levels (EBM I- IV).

RESULTS

Short-term symptoms include amenorrhea, galactorrhoea, and sexual dysfunction with decrease of libido and erectile difficulties related to hypogonadism. Medium and long-term symptoms related to oestrogens are observed, including a decrease bone mass density, hypogonadism, early menopause, some types of cancer risk increase (breast and endometrial), cardiovascular risk increase, immune system disorders, lipids, and cognitive dysfunction. Prolactin level, gonadal hormones and vitamin D should be checked in all patients receiving antipsychotics at baseline although early symptoms (amenorrhea-galactorrhoea) may not be observed due to the risk of underestimating other delayed symptoms that may appear in the medium term. Routine examination of sexual dysfunction is recommended due to possible poor patient tolerance and low compliance. Special care is required in children and adolescents, as well as patients with PRL levels >50ng/ml (moderate hyperprolactinaemia). A possible prolactinoma should be investigated in patients with PRL levels >150ng/ml, with special attention to patients with breast/endometrial cancer history. Densitometry should be prescribed for males >50 years old, amenorrhea>6 months, or early menopause to avoid fracture risk.

Serum vaspin and adiponectin levels in patients with prolactinoma

BACKGROUND

Studies investigating serum vaspin and adiponectin levels in patients with prolactinoma are inconclusive. The aim of this study was to evaluate serum vaspin and adiponectin levels in patients with prolactinoma and healthy controls.

METHODS

A total of 42 prolactinoma patients (Group 1, 21 patients; Group 2, 21 patients) and 30 healthy controls were enrolled in the study. Group 1 consisted of newly diagnosed patients who were never treated or had not received a dopamine agonist (DA) within 6 months prior to screening. Group 2 consisted of prolactinoma patients who were on DA treatment for at least 6 months at the time of screening. The control group (group 3) consisted of healthy controls.

RESULTS

Patients with prolactinoma had higher homeostasis model assessment of insulin resistance and lower quantitative insulin sensitivity check index values in comparison to healthy controls (p < 0.001 for both). Serum levels of adiponectin and vaspin were also significantly lower in prolactinoma patients when compared to the control group (p < 0.01 and p < 0.001, respectively). Following adjustment for confounding factors, the respective odds ratios for prolactinoma in patients in the lower subgroup compared with those in the higher subgroup for adiponectin and vaspin were 2.733 (0.621-12.035; p > 0.05) and 5.041 (1.191-21.339; p < 0.05).

CONCLUSION

This is the first study to demonstrate the presence of low vaspin levels in patients with prolactinomas. Further studies are needed to help establish the roles of vaspin and adiponectin in prolactinoma patients.

Longitudinal examination of the skeletal effects of selective serotonin reuptake inhibitors and risperidone in boys

OBJECTIVE

In a previous cross-sectional study, we found lower bone mass during treatment with selective serotonin reuptake inhibitors (SSRIs) and risperidone in youths. Here, we evaluate the skeletal effects of these psychotropics at follow-up.

METHOD

Between April 2005 and July 2011, medically healthy 7- to 17-year-old males treated with risperidone for 6 months or more were enrolled through child psychiatry outpatient clinics and returned for follow-up 1.5 years later. Treatment history was extracted from the medical and pharmacy records. Anthropometric, laboratory, and bone mass measurements were obtained. Multivariable linear regression analyses compared participants who remained on risperidone at follow-up to those who had discontinued risperidone treatment as well as SSRI-treated versus SSRI-unexposed participants.

RESULTS

The sample consisted of 94 boys with a mean age of 11.8 ± 2.7 years at study entry. The majority had an externalizing disorder and had received risperidone and SSRIs for 2.5 ± 1.7 years and 1.6 ± 1.9 years, respectively, at study entry. By follow-up, 26% (n = 24) had discontinued risperidone. Compared to discontinuing risperidone, continuing it was associated with a decline in participants' age-sex-height-race-specific areal bone mineral density (BMD) z score at the lumbar spine (P < .04) and failure to increase radius trabecular volumetric BMD (P < .03), after accounting for significant covariates. In addition, receiving an SSRI was associated with reduced lumbar spine areal BMD z score and radius trabecular volumetric BMD at both study entry (P < .02 and P < .03, respectively) and follow-up (P < .06 and P < .03, respectively), but without further decline between the 2 visits.

CONCLUSIONS

Chronic SSRI treatment in children and adolescents is associated with reduced, albeit stable, bone mass for age, while chronic risperidone treatment is associated with failure to accrue bone mass.

Treatment of hyperprolactinemia in post-menopausal women: pros

The incidence of hyperprolactinemia in women peaks during the 3rd-4th decade and then greatly decreases after the menopause. Apart from the effects on the hypothalamic-pituitary-gonadal axis, prolactin can act directly on bone metabolism. Hyperprolactinemia is a recognized cause of secondary osteoporosis, and treatment with dopamine agonists can lead to improved BMD. Moreover, hyperprolactinemia has been linked to weight gain and insulin resistance, which can be ameliorated following medical treatment. Although relatively rare, prolactinomas can be observed in post-menopausal women and are frequently large and invasive; dopamine agonists appear to be as effective in these patients as in younger women to induce reduction of prolactin levels and tumour shrinkage. Here, we review data potentially favouring medical treatment with dopamine agonists in post-menopausal women diagnosed with hyperprolactinemia.

Metabolic abnormalities in patients with prolactinoma: response to treatment with cabergoline

BACKGROUND

Hyperprolactinemia has been associated with changes in body composition and metabolic abnormalities. Normalization of prolactin (PRL) with dopamine agonists has been found to reverse these abnormalities. This study was designed to assess the anthropometric and metabolic alterations associated with prolactinoma and response of these abnormalities to cabergoline treatment.

METHODS

In a non-randomised matched prospective design, 19 consecutive patients with prolactinoma (median PRL 118.6 (105.3) μg/L) and 20 controls were studied. The controls were age, gender and body mass index (BMI) matched. Anthropometric data and metabolic variables were studied at baseline, 3 and 6 months after cabergoline treatment.

RESULTS

Patients with prolactinoma had increased level of fasting plasma glucose (P < .001), LDL-cholesterol (P = .001) and triglycerides (TG) (P = .009) as compared to age, gender and BMI matched healthy controls. There was a significant decrease of body weight at 3 months (P = .029), with a further decline at 6 months (P < .001) of cabergoline therapy. In addition, there was a significant decrement of BMI (P < .001), waist circumference (P = .003), waist-hip ratio (P = .03) and total body fat (P = .003) at 6 months of cabergoline treatment. A significant decline in plasma glucose (P < .001), total cholesterol (P = .009), LDL-cholesterol (P < .001) and TG (P < .001) was seen after 6 months of cabergoline treatment.

CONCLUSIONS

Patients with prolactinoma have adverse metabolic profile compared with matched controls. Normalization of PRL with cabergoline corrects all the metabolic abnormalities.

Prevalence of obstructive sleep apnea in patients with prolactinoma before and after treatment with dopamine agonists

OBJECTIVES

Obesity is the main risk factor for the development of obstructive sleep apnea (OSA). Hyperprolactinemia has also been related to obesity. To determine the OSA prevalence in patients with prolactinoma before and after dopamine agonist (DA) and to evaluate the correlation between the apnea-hypopnea index (AHI) and prolactin levels, body mass index (BMI), waist circumference (WC), visceral fat volume (VFV), subcutaneous fat volume, and other metabolic parameters.

METHODS

Thirty-five patients with prolactinoma at baseline and twenty-one who completed the 6-month DA treatment were submitted to clinical/laboratorial evaluations, polysomnography and abdominal imaging.

RESULTS

Before treatment, the prevalence of obesity/overweight and OSA were, respectively, 68.5 and 34.2 %. We found a positive correlation between AHI and weight (r = 0.57; p < 0.001), BMI (r = 0.56; p < 0.001), WC (r = 0.61; p < 0.001), VFV (r = 0.55; p = 0.002), insulin levels (r = 0.57; p < 0.001), and HOMA-IR index (r = 0.57; p < 0.001); and a negative correlation between AHI and HDL-cholesterol (r = -0.47; p = 0.005). After multivariate analysis, VFV and insulin levels were the most important predictors for AHI (p = 0.001 and p = 0.02, respectively). After DA, the obesity/overweight and OSA prevalence did not change.

CONCLUSIONS

The OSA prevalence in patients with prolactinoma is similar to the obese subjects and did not change after treatment. Higher BMI and visceral obesity, but not prolactin levels, seem to be the major factor involved in the occurrence of OSA in these patients.

Pesticides in mixture disrupt metabolic regulation: in silico and in vivo analysis of cumulative toxicity of mancozeb and imidacloprid on body weight of mice

Pesticides acting as endocrine disrupting chemicals disrupt the homeostasis of body metabolism. The present study elucidated that the low dose coexposure of thyroid disrupting dithiocarbamate fungicide mancozeb (MCZ) and neonicotinoid insecticide imidacloprid (IMI) during lactation increased the risk of body weight gain in mice later in life. Body weight gain has been linked to pesticide-induced hypothyroidism and hyperprolactinemia and alteration of lipid profiles. In vivo results were substantiated with in silico molecular docking (MD) analysis that predicted the binding affinity of pesticides with thyroid hormone receptors (TRα and TRβ) and peroxisome proliferator activated receptor gamma (PPARγ), the major nuclear receptors of peripheral fat metabolism. Binding potency of MCZ and IMI was compared with that of T3, and its antagonist ethylene thiourea (ETU) as well as PPARγ agonist (rosiglitazone) and antagonist (HL005). MD simulation predicted that both MCZ and IMI may compete with T3 for binding with TRs. Imidazole group of IMI formed hydrogen bonds with TRs like that of ETU. MCZ may compete with rosiglitazone and HL005 for PPARγ, but IMI showed no affinity. Thus while both MCZ and IMI could disrupt the TRs functioning, MCZ alone may affect PPARγ. Coexposure of pesticides decreased the plasma thyroid hormones and increased the cholesterol and triglyceride. Individual pesticide exposure in low dose might not exert the threshold response to affect the receptors signaling further to cause hormonal/metabolic impairment. Thus, cumulative response of the mixture of thyroid disrupting pesticides can disrupt metabolic regulation through several pathways and contribute to gain in body weight.

Concomitant myasthenia gravis and macroprolactinoma: the immunomodulatory role of prolactin and its potential therapeutic use

Considerable evidence attests to the role of the hypothalamic-pituitary endocrine axis (HPA) in the maintenance of normal immunocompetence. The immune and neuroendocrine systems are integrally linked and coordinated with bidirectional communication maintaining immune balance. Any disturbance of the normal function of the HPA may significantly alter native immunocompetence and therefore be associated with the development of disorders which have a clearly established autoimmune basis. Molecular and functional evidence shows prolactin, produced by the anterior pituitary, to be a cytokine, exerting its effect via both paracrine and endocrine mechanisms [1]. Its involvement in the activation of multiple immune responses may adversely upregulate certain autoimmune diseases. Myasthenia gravis (MG) has long been recognized as an autoimmune disorder. In this mini review, we present the coterminous presentation of MG and prolactin-secreting macroadenoma. We review published cases in the world literature, discuss pathological mechanism, and consider future targeted therapies.

Evaluation of body weight, insulin resistance, leptin and adiponectin levels in premenopausal women with hyperprolactinemia

The effects of hyperprolactinemia on metabolic parameters are not clear and a few data evaluating adiponectin levels in prolactinoma and idiopathic hyperprolactinemia exist. The aim of this study was to evaluate the effects of hyperprolactinemia on body weight, insulin resistance, beta cell function, and leptin and adiponectin levels in premenopausal women with hyperprolactinemia. Forty premenopausal women with prolactinoma or idiopathic hyperprolactinemia were compared to 41 age-matched healthy premenopausal women with regard to body weight, body mass index, waist and hip circumferences, waist to hip ratio, fasting plasma glucose, insulin levels, insulin resistance measured by homeostasis model assessment (HOMA)-insulin resistance index, beta cell function measured by HOMA-β index, leptin and adiponectin levels. Plasma insulin levels and HOMA indexes (both insulin resistance and beta indexes) were significantly higher in hyperprolactinemic women. The other parameters were similar between both groups. There was a positive correlation between prolactin levels and fasting plasma glucose in hyperprolactinemic women. The results of this study showed that high prolactin levels may be associated with hyperinsulinemia and insulin resistance in premenopausal women. This effect seems to be independent of body weight, leptin and adiponectin levels. High prolactin levels may directly stimulate insulin secretion from pancreas and directly cause hepatic and whole-body insulin resistance.

Chronic risperidone exposure does not show any evidence of bone mass deterioration in animal model of schizophrenia

BACKGROUND

It has been shown that bone mass is centrally regulated. Thus schizophrenia being a disease of the central nervous system is an interesting model for studying bone. Most second generation antipsychotic drugs including risperidone are used in the treatment of schizophrenia. Weight gain and metabolic disturbances are common side effects.

OBJECTIVE

The aims of this study were to investigate bone mass, body composition and light microscopic pathology examinations of femur in an animal model of schizophrenia (pharmacologically induced by postnatally administered phencyclidine-PCP) and to further examine the effects of chronic treatment with risperidone on these parameters in rats.

METHODS

Four groups of male rats were studied:1) control group-NaCl postnatally administered, n=9; 2) PCP group-postnatal PCP administration to rat pups (on day 2,6,9 and 12), n=6; 3) risperidone group-rats treated with risperidone alone for 9weeks from day 35 (NaCl-RSP group, n=7); 4) PCP rats treated with risperidone for 9weeks from day 35 (PCP-RSP group, n=7). Bone mass and body composition were measured in vivo by dual X ray absorptiometry (areal DXA and fat mass). Light microscopic analysis of the femoral metaphysis was performed in all groups after sacrificing the animals.

RESULTS

Postnatal phencyclidine (PCP) administration to rat pups caused a long lasting reduction of total bone mass versus control animals (aDXA 128±2mg/cm(2) vs 139±5mg/cm(2), p<0.05). Examination of the femoral bone revealed a decrease in the number and thickness of the metaphyseal trabecule and cortical thinning. There was a decrease in total and retroperitoneal fat. Nine weeks of administration of risperidone alone to rats, resulted in significant weight gain and had no effect on bone mass versus control animals (aDXA was 136±7mg/cm(2) vs 139±5mg/cm(2), p>0.05). Furthermore, there were no changes in the light microscopic analysis of femoral metaphysis in comparison with controls. When PCP rats were treated with risperidone, they did not change their body weight nor bone mass versus PCP alone (aDXA 126±2mg/cm(2) vs 128±2mg/cm(2), p>0.05) but intriguingly on examination of the femoral bone an increase in the number and thickness of the metaphyseal trabecule was found (trabecular thickness 0.6±0.1μm vs 0.35±0.1μm, p<0.01).

CONCLUSION

This study shows that in the PCP rat model of schizophrenia bone mass is reduced. When PCP rats were treated with risperidone bone mass remained unchanged but intriguingly and unexpectedly light microscopic examination of femoral metaphysis showed an increase in thickness of metaphyseal trabeculae. The mechanism of risperidone's action on bone remains to be clarified.

Possible mechanisms for the skeletal effects of antipsychotics in children and adolescents

The increasing use of antipsychotics (APs) to treat pediatric psychiatric conditions has led to concerns over the long-term tolerability of these drugs. While the risk of cardiometabolic abnormalities has received most of the attention, preclinical and clinical studies provide preliminary evidence that APs can adversely impact bone metabolism. This would be most concerning in children and adolescents as suboptimal bone accrual during development may lead to increased fracture risk later in life. However, the potential mechanisms of action through which APs may impact bone turnover and, consequently, bone mineral content are not clear. Emerging data suggest that the skeletal effects of APs are complex, with APs directly and indirectly impacting bone cells through modulation of multiple signaling pathways, including those involving dopamine D2, serotonin, adrenergic, and prolactin receptors, as well as by affecting gonadotropins. Determining the action of APs on skeletal development is further complicated by polypharmacy. In children and adolescents, APs are frequently coprescribed with psychostimulants and selective serotonin reuptake inhibitors, which have also been linked to changes in bone metabolism. This review discusses the mechanisms by which APs may influence bone metabolism. Also covered are preclinical and pediatric findings concerning the impact of APs on bone turnover. However, the dearth of clinical information despite the potential public health significance of this issue underscores the need for further studies. The review ends with a call for clinicians to be vigilant about promoting optimal overall health in chronically ill youth with psychopathology, particularly when pharmacotherapy is unavoidable.

Hyperprolactinemia is not associated with hyperestrogenism in noncycling African elephants (Loxodonta africana)

African elephants in US zoos are not reproducing at replacement levels. This is in part due to physiological problems, one of which is abnormal ovarian cyclicity that has been linked to increased prolactin secretion (hyperprolactinemia). A relationship between increased estrogen production (hyperestrogenism) and hyperprolactinemia has been found in other species. Therefore, the objective of this study was to determine if elevated prolactin was associated with increased estrogen concentrations in non-cycling African elephants. In cycling elephants (n=12), prolactin secretion followed a normal cyclic pattern, with higher concentrations observed during the follicular phase; overall mean concentration was ∼18ng/ml and baseline prolactin was ∼6ng/ml. Non-cycling females (n=18) were categorized into three groups: (1) low prolactin (<15ng/ml; n=3); (2) moderate hyperprolactinemia (16-30ng/ml; n=7); and marked hyperprolactinemia (>31ng/ml; n=8). Mean urinary estrogen conjugate concentrations ranged from 5.4 to 41.4ng/mg Crt, and were similar between normal cycling (15.4±1.5ng/mg Crt) and non-cycling, low prolactin elephants (18.4±7.3ng/mg Crt), but were lower in moderate (9.4±1.3ng/mg Crt) and marked hyperprolactinemic (9.8±1.1ng/mg Crt) groups (P<0.05). In conclusion, African elephants appear to be sensitive to alterations in prolactin production, with both low (e.g., a non-cycling pattern) and high prolactin secretion being associated with abnormal ovarian activity. However, hyperestrogenism was not related to hyperprolactinemia in the non-cycling females.

Drug-induced hypo- and hyperprolactinemia: mechanisms, clinical and therapeutic consequences

INTRODUCTION

The altered profiles of prolactin secretion in the anterior hypophysis, generated by pathological, pharmacological or toxicological causes, have special consequences on multiple functions in both genders.

AREAS COVERED

This selective review presents the main mechanisms controlling prolactin secretion, focusing on the interplay of various neurotransmitters or xenobiotics, but also on the role of psychic or posttraumatic stress. A detailed analysis of several pharmacotherapeutic groups with hyperprolactinemic effects emphasize on the relevance of the pharmacokinetic/pharmacodynamic mechanisms and the clinical significance of the long term administration.

EXPERT OPINION

Accurate monitoring and evaluation of the hyperprolactinemia induced by xenobiotics is strongly recommended. The typical antipsychotics and some of the atypical agents (amisulpride, risperidone, paliperidone), as well as some antidepressants, antihypertensives and prokinetics, are the most important groups inducing hyperprolactinemia. The hyperprolactinemic effects are correlated with their affinity for dopamine D2 receptors, their blood-brain barrier penetration and, implicitly, the requested dose for adequate occupancy of cerebral D2 receptors. Consequently, integration of available pharmacokinetic and pharmacodynamic data supports the idea of therapeutic switch to non-hyperprolactinemic agents (especially aripiprazole) or their association, for an optimal management of antipsychotic-induced hyperprolactinemia. Possible alternative strategies for counteracting the xenobiotics-induced hyperprolactinemia are also mentioned.