Prevalence of osteopenia in men with prolactinoma

Effect of Hyperprolactinemia on Bone Metabolism: Focusing on Osteopenia/Osteoporosis

Prolactin is a hormone secreted from lactotroph cells in the anterior pituitary gland to induce lactation after birth. Hyperprolactinemia unrelated to lactation is a common cause of amenorrhea in women of a childbearing age, and a consequent decrease in the gonadotropin-releasing hormone (GnRH) by a high prolactin level can result in decreased bone mineral density. Osteoporosis is a common skeletal disorder characterized by decreased bone mineral density (BMD) and quality, which results in decreased bone strength. In patients with hyperprolactinemia, changes in BMD can be induced indirectly by the inhibition of the GnRH-gonadal axis due to increased prolactin levels or by the direct action of prolactin on osteoblasts and, possibly, osteoclast cells. This review highlights the recent work on bone remodeling and discusses our knowledge of how prolactin modulates these interactions, with a brief literature review on the relationship between prolactin and bone metabolism and suggestions for new possibilities.

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.

Paeoniflorin Ameliorates Hyperprolactinemia-Induced Inhibition of Osteoblastogenesis by Suppressing the NF-κB Signaling Pathway

Hyperprolactinemia is a common endocrine disease in women of reproductive age. Research has shown that patients with hyperprolactinemia often have decreased bone mineral density and an increased risk of fractures. However, there is still a lack of effective treatments. Paeoniflorin, one of the primary bioactive components in peony, is widely used in traditional Chinese medicine. Research has shown that paeoniflorin promotes osteoblast differentiation. However, whether paeoniflorin plays a role in hyperprolactinemia-induced osteoblastogenesis inhibition is not yet clear. In this study, we investigated the effect of paeoniflorin on prolactin (PRL)-mediated inhibition of osteoblast function. Our results showed that prolactin significantly reduced the expression of alkaline phosphatase (ALP), Osterix, and runt-related transcription factor 2 (RUNX2) in MC3T3-E1 cells cultured in an osteoblast differentiation medium, suggesting that prolactin inhibited osteoblast function. After treatment with paeoniflorin (PF), the expression of these osteoblast markers was upregulated. In addition, our findings proved that paeoniflorin increased the absorbance values of ALP-positive cells and the areas of alizarin red S (ARS) deposition compared to those in the prolactin group, suggesting that paeoniflorin reversed the PRL-induced reduction in osteoblast differentiation. The PRL-induced activation of nuclear factor kappa B (NF-κB) was significantly reversed by paeoniflorin, indicating that paeoniflorin promoted osteoblast function by inhibiting the NF-κB signaling pathway. In summary, these results showed that paeoniflorin alleviated the inhibitory effect of prolactin on osteoblastogenesis by suppressing the NF-κB signaling pathway.

Update on vertebral fractures in pituitary diseases: from research to clinical practice

Derangement of pituitary hormone axes can induce changes in bone remodeling and metabolism with possible alterations in bone microarchitectural structure and increased susceptibility to fractures. Vertebral fractures (VFs), which are a hallmark of skeletal fragility, have been described in a very large number of patients with pituitary diseases. These fractures are clinically relevant, since they predispose to further fractures and may negatively impact on patients' quality of life. However, the management of skeletal fragility and VFs in the specific setting of pituitary diseases is a challenge, since the awareness for this disease is still low, prediction of VFs is uncertain, the diagnosis of VFs cannot be solely based on a clinical approach and also needs a radiological and morphometric approach, the risk of fractures may not be decreased via treatment of pituitary hormone disorders, and the effectiveness of bone-active drugs in this setting is not always evidence-based. This review is an update on skeletal fragility in patients with pituitary diseases, with a focus on clinical and therapeutic aspects concerning the management of VFs.

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.

The use of clozapine is protective for low bone mineral density induced by prolactin-raising antipsychotics in inpatients with schizophrenia

Low bone mineral density (BMD) is common among patients with schizophrenia; however, the pathogenesis is still unclear. Different types of antipsychotics may have different effects on BMD in inpatients with schizophrenia.

INTRODUCTION

This retrospective study aimed to evaluate the effects of prolactin-raising (PR) antipsychotics vs. clozapine combined with PR antipsychotics on BMD of patients with schizophrenia and analyzed clinically related factors that may affect BMD.

METHODS

A total of 125 participants (males/females = 62/63) were included. Patients were treated with PR antipsychotics vs. clozapine combined with PR antipsychotics. They were similar in demographic and clinical characteristics. BMD was examined in their lumbar spine and proximal femur by a dual-energy X-ray (DEXA) absorption measurement device. Laboratory variables (including blood levels of prolactin, estradiol, testosterone, and cortisol) were collected.

RESULTS

Among 125 inpatients with schizophrenia, the prevalence of osteoporosis and low BMD (including osteoporosis and osteopenia) was 26.4% and 64%. The average BMD T value in patients receiving clozapine combined with PR antipsychotics was significantly higher than in patients receiving PR antipsychotics (p < 0.05). Patients in the clozapine combined with PR antipsychotic group had higher testosterone levels than the PR antipsychotic group (Z = - 2.77, p = 0.006). Linear logistic regression analysis indicated that clozapine combined with PR antipsychotic treatment (p < 0.05) and higher estradiol level (p < 0.05) may be significantly associated with higher BMD.

CONCLUSIONS

Our results suggest that the use of clozapine may be a protective factor for low BMD induced by PR antipsychotics in inpatients with schizophrenia. The possible mechanism is that clozapine may protect BMD by regulating estrogen and testosterone levels, but the mechanism by which clozapine regulates these two sex hormones needs further investigation.

Hyperprolactinemia and bone

Prolactin (PRL) has direct and indirect effects on bone metabolism. Experimental studies showed that in the presence of high PRL levels bone resorption was increased as well as bone formation was suppressed. Increased PRL levels in humans caused a reduction in sex hormone levels which turn may have detrimental effects on bone. Patients with hyperprolactinemia did have often decreased bone mineral density as well as an increased risk of fractures. Since PRL control may be relevant to bone health it is a clinical open issue the inclusion of skeletal health in future guidelines as indication to proactive screening, prevention and treatment particularly in high risk patients such as hyperprolactinemic women after menopause and patients with drug induced hyperprolactinemia.

Epidemiology of osteoporosis and its determinants in physically active Majorcan elderly

Objective:

To estimate the prevalence and distribution of determinants of osteoporosis (OP) in a population of physically active Majorcans over 60.

Methods:

Health survey in which consecutive women and men above 60 years old visiting sports facilities during a two-month period were recruited. All underwent a densitometry of the lumbar spine (LS) and femoral neck (FN). Osteoporosis was defined according to the World Health Organization densitometric criteria (T-score <2.5 SD in the LS or FN, and osteopenia if the result was between −2.5 and −1 SD). As osteoporosis shows substantial differences between genders, the study of its determinants was conducted independently for men and women.

Results:

The sample included 731 subjects (86% female), with an average age of 70 (SD 5) among men and 65 (8) among women. The overall prevalence of osteoporosis was 35.7% in the LS, 8.9% in the FN and 39.4% in the LS and/or FN. The analysis by gender showed a higher prevalence of osteoporosis in women than in men (43.8 % vs. 11.1%). The presence of osteoporosis increased with age in men and women (7.8% for 61–75 years old vs 22.7% > 75 years old for men and 48.5% for 61–75 years old vs 62.7% > 75 for women).

Conclusions:

Densitometric osteoporosis is frequent among physically active elderly population, and higher than expected in a largely sunlight-exposed area.

Association Between Antipsychotics and Osteoporosis Based on Real-World Data

Background:

Osteoporosis, which is a major public health concern, has been known to reduce health-related quality of life. Some studies have suggested that antipsychotics could perhaps cause osteoporosis by increasing serum prolactin levels. However, the association between antipsychotics and the risk for developing osteoporosis has been controversial.

Objective:

The present study aimed to assess the association between antipsychotic use and onset of osteoporosis in real-world settings.

Methods:

A multimethod data-mining approach using different algorithms and databases was used. First, disproportionality analysis was conducted using the US Food and Drug Administration Adverse Event Reporting System (FAERS) database (2004-2017) with reporting odds ratio (ROR) and information component (IC) being used to indicate a signal. Furthermore, a sequence symmetry analysis using data from a large Japanese administrative claims database (2005-2017; JMDC Inc, Japan) was conducted. Short-term intervals (ie, 12, 24, and 36 months) were set to investigate the association between antipsychotic use and onset of osteoporosis using the adjusted sequence ratio (SR) to indicate a signal.

Results:

No potential association between osteoporosis and all antipsychotics was observed in the FAERS database, except for perphenazine, which exhibited significant signals using both ROR and IC. Moreover, no potential association between osteoporosis and antipsychotics was observed in the JMDC claims database, except for sulpiride and aripiprazole. None of the antipsychotics indicated significant signals using all analyzed items (ROR, IC, and adjusted SR).

Conclusion and Relevance:

Real-world data show no association between antipsychotic use and the onset of osteoporosis. Further pharmacoepidemiological studies are needed for causality assessment.

Prolactinomas in males: any differences?

CONTEXT

Prolactinomas in men are usually large and invasive, presenting with signs and symptoms of hypogonadism and mass effects, including visual damage. Prolactin levels are high, associated with low testosterone, anemia, metabolic syndrome and if long-standing also osteoporosis.

RESULTS

Medical treatment with the dopamine agonist, cabergoline, became the preferred first-line treatment for male prolactinomas as well as for giant tumors, leading to prolactin normalization in ~ 80% of treated men, and tumor shrinkage, improved visual fields and recovery of hypogonadism in most patients. Multi-modal approach including surgery and occasionally radiotherapy together with a high-dose cabergoline is saved for resistant and invasive adenomas. Experimental treatments including temozolomide or pasireotide may improve clinical response in men harboring resistant prolactinomas.

CONCLUSIONS

Compared to other pituitary adenomas, secreting and non-secreting, where pituitary surgery is the recommended first-line treatment, men with prolactinomas will usually respond to medical treatment with no need for any additional treatment.

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.

Pituitary Diseases and Bone

Neuroendocrinology of bone is a new area of research based on the evidence that pituitary hormones may directly modulate bone remodeling and metabolism. Skeletal fragility associated with high risk of fractures is a common complication of several pituitary diseases such as hypopituitarism, Cushing disease, acromegaly, and hyperprolactinemia. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density as measured by dual-energy X-ray absorptiometry, making difficult the prediction of fractures in these clinical settings. Treatment of pituitary hormone excess and deficiency generally improves skeletal health, although some patients remain at high risk of fractures, and treatment with bone-active drugs may become mandatory. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary diseases.

Osteogenic differentiation of adipose tissue-derived mesenchymal stem cells cultured with different concentrations of prolactin

ABSTRACT The objective was to evaluate the in vitro effect of prolactin in osteogenic potential of adipose tissue-derived mesenchymal stem cells (ADSCs) in female rats. ADSCs were cultured in osteogenic medium with and without the addition of prolactin and distributed into three groups: 1) ADSCs (control), 2) ADSCs with addition of 100ng/mL of prolactin and 3) ADSCs with addition of 300ng/mL of prolactin. At 21 days of differentiation, the tests of MTT conversion into formazan crystals, percentage of mineralized nodules and cells per field and quantification of genic transcript for alkaline phosphatase, osteopontin, osteocalcin, bone sialoprotein, BMP-2 and collagen I by real-time RT-PCR were made. The addition of prolactin reduced the conversion of MTT in group 3 and increased the percentage of cells per field in the groups 2 and 3, however without significantly increasing the percentage of mineralized nodules and the expression of alkaline phosphatase, osteopontin, osteocalcin, bone sialoprotein, BMP-2 and collagen I. In conclusion, the addition of prolactin in concentrations of 100ng/mL and 300ng/mL does not change the osteogenic differentiation to the ADSCs of female rats despite increase in the cellularity of the culture.

Prevalence of osteoporosis and related lifestyle and metabolic factors of postmenopausal women and elderly men: A cross-sectional study in Gansu province, Northwestern of China

The aim of this study was to investigate the osteoporosis prevalence and the risks of postmenopausal women and elderly men in Gansu province.This cross-sectional study involved 3359 postmenopausal women and 3205 elderly males who were randomly selected from 7 areas in Gansu province. Areal bone mineral density (BMD) (g/cm) was measured at the distal one-third radius of the nonstressed forearm using dual-energy X-ray absorptiometry (DXA: Osteometer MediTech). Factors related to osteoporosis were analyzed.The prevalence of osteoporosis in the entire study population was 9.65% for postmenopausal women and 8.08% for elderly males by WHO criteria, while the rate of osteopenia were 27.09% for postmenopausal women and 26.68% for elderly males. Risk of osteoporosis was significantly associated with age, menopause age, duration of menopause, body mass index (BMI), educational level, and alcohol consumption in postmenopausal women. In elderly men, age, BMI, current smoking, alcohol consumption, physical activity, and sun exposure were associated with osteoporosis. The bone turnover markers osteocalcin (OC) and C-terminal cross-linked telopeptides of type I collagen (β-CTX) were inversely correlated with BMD in both genders; serum P and 25(OH)D found no significant correlation with BMD. Serum Ca showed a positive effect on BMD in elderly men only.The osteoporosis prevalence of postmenopausal women and the men aged over 60 years in Gansu province is presented. Risk of osteoporosis was significantly associated with age, menopause age, year since menopause, BMI, and educational level in postmenopausal women. In elderly men, age, BMI, and current smoking were associated with osteoporosis. This study also found that higher OC and β-CTX level were associated with lower BMD. Poor 25(OH)D, Ca, P status were not associated with an increased risk of low BMD.

Male Hypogonadism and Osteoporosis: The Effects, Clinical Consequences, and Treatment of Testosterone Deficiency in Bone Health

It is well recognized that bone loss accelerates in hypogonadal states, with female menopause being the classic example of sex hormones affecting the regulation of bone metabolism. Underrepresented is our knowledge of the clinical and metabolic consequences of overt male hypogonadism, as well as the more subtle age-related decline in testosterone on bone quality. While menopause and estrogen deficiency are well-known risk factors for osteoporosis in women, the effects of age-related testosterone decline in men on bone health are less well known. Much of our knowledge comes from observational studies and retrospective analysis on small groups of men with variable causes of primary or secondary hypogonadism and mild to overt testosterone deficiencies. This review aims to present the current knowledge of the consequences of adult male hypogonadism on bone metabolism. The direct and indirect effects of testosterone on bone cells will be explored as well as the important differences in male osteoporosis and assessment as compared to that in females. The clinical consequence of both primary and secondary hypogonadism, as well as testosterone decline in older males, on bone density and fracture risk in men will be summarized. Finally, the therapeutic options and their efficacy in male osteoporosis and hypogonadism will be discussed.

Long-Term Follow-Up of Primary Medical Versus Surgical Treatment of Prolactinomas in Men: Effects on Hyperprolactinemia, Hypogonadism, and Bone Health

OBJECTIVE

In men with prolactinomas, impaired bone density is the principle consequence of hyperprolactinemia-induced hypogonadism. Although dopamine agonists (DAs) are the first-line approach in prolactinomas, surgery can be considered in selected cases. In this study, we aimed to investigate the long-term control of hyperprolactinemia, hypogonadism, and bone health comparing primary medical and surgical therapy in men who had not had prior DA treatment.

METHODS

This is a retrospective case-note study of 44 consecutive men with prolactinomas and no prior DAs managed in a single tertiary referral center. Clinical, biochemical, and radiologic response to the first-line approach were analyzed in the 2 cohorts.

RESULTS

Mean age at diagnosis was 47 years (range, 22-78 years). The prevalence of hypogonadism was 86%, and 27% of patients had pathologic bone density at baseline. The primary therapeutic strategy was surgery for 34% and DAs for 66% of patients. Median long-term follow-up was 63 months (range, 17-238 months). Long-term control of hyperprolactinemia required DAs in 53% of patients with primary surgical therapy, versus 90% of patients with primary medical therapy (P = 0.02). Hypogonadism was controlled in 73% of patients. The prevalence of patients with pathologic bone density was 37% at last follow-up, with no differences between the 2 therapeutic cohorts (P = 0.48).

CONCLUSIONS

Despite control of hyperprolactinemia and hypogonadism in most patients independent of the primary treatment modality, the prevalence of impaired bone health status remains high, and osteodensitometry should be recommended.

Prolactinoma: A Massive Effect on Bone Mineral Density in a Young Patient

This case highlights a prolactinoma in a young male, and its impact on bone health. Osteoporosis has been noted to be an issue in postmenopausal women with prolactinomas. This case shows a similar impact on bone health in a young male resulting in low bone mineral density for age based on Z-score. This case report highlights the possible mechanisms for the bone loss in the setting of prolactinoma and the need for assessing bone health in such patients. Furthermore it highlights the need for a thorough evaluation in such patients.

Relationship between antipsychotic medication, serum prolactin levels and osteoporosis/osteoporotic fractures in patients with schizophrenia: a critical literature review

INTRODUCTION

Using an antipsychotic medication can increase prolactin (PRL) levels, causing hyperprolactinemia (HPRL). Although the occurrence of osteoporosis within the population of patients with schizophrenia has been recognized, the precise nature of the association between antipsychotic treatment, PRL, osteoporosis, and the disease itself seems to be elusive.

AREAS COVERED

The aim of this review is to critically review the literature regarding the association between osteoporosis and PRL and to summarize the available evidence with respect to the impact of PRL-elevating antipsychotics on bone mineral density (BMD) and fractures in non-elderly patients with schizophrenia.

EXPERT OPINION

Although long-standing HPRL can have an impact on the rate of bone metabolism and, when associated with hypogonadism, may lead to decreased bone density in both female and male subjects, the relative contribution of antipsychotic-induced HPRL in bone mineral loss in patients with schizophrenia remains unclear. Methodological shortcomings of existing studies, including the lack of prospective data and the focus on measurements of BMD instead of bone turnover markers, preclude definitive conclusions regarding the relationship between PRL-raising antipsychotics and BMD loss in patients with schizophrenia. Therefore, more well conducted prospective trials of these biomarkers are necessary to establish the precise relationship between antipsychotics, PRL levels and osteoporosis/osteoporotic risk.

Successful Improvement of Metabolic Disorders, Including Osteopenia, by a Dopamine Agonist in a Male Patient with Macro-Prolactinoma

Patient: Male, 43

Final Diagnosis: Prolactinoma

Symptoms: —

Medication: —

Clinical Procedure: Treatments by a dopamine agonist

Specialty: Endocrinology and Metabolic

Osteoporosis in pituitary diseases: lessons for the clinic

Osteoporosis is a systemic disease characterized by bone mass and density loss leading to fragility fractures. Osteoporosis due to endocrine disorders is an example of secondary osteoporosis. The harmful effects on bones are common in patients harboring pituitary tumors (acromegaly, prolactinoma, Cushing's disease) and suffering from hypopituitarism. Increased fracture risk and high healthcare costs of fractured patients are their consequences. The coexistence of some of these disorders and hypogonadism results in severe osteoporosis. The influence of the certain diseases, their activity and therapy and accompanying hypogonadism on bone turnover, bone mineral density and fracture incidence is presented.

Pituitary disorders and osteoporosis

Various hormonal disorders can influence bone metabolism and cause secondary osteoporosis. The consequence of this is a significant increase of fracture risk. Among pituitary disorders such effects are observed in patients with Cushing's disease, hyperprolactinemia, acromegaly, and hypopituitarism. Severe osteoporosis is the result of the coexistence of some of these disorders and hypogonadism at the same time, which is quite often.

Male prolactinomas presenting with normal testosterone levels

In men harboring prolactinoma the most common symptoms are related to hypogonadism, including decreased libido, erectile dysfunction, and gynecomastia. These men characteristically present with elevated serum prolactin (PRL) levels, suppressed gonadotropins, and low testosterone levels. We studied a group of 11 unique men with prolactinomas presenting with testosterone levels within the normal range (≥2.6 ng/ml; cohort A), and compared them to 11 prolactinoma men with borderline baseline testosterone (2.1-2.5 ng/ml; cohort B) and to a cohort of 34 prolactinoma patients with low testosterone levels (≤2 ng/ml; cohort C). Mean testosterone levels at presentation were 3.91 ± 0.9 ng/ml in cohort A (range, 2.6-5.2 ng/ml), 2.44 ± 0.16 ng/ml in cohort B and 0.96 ± 0.6 in cohort C (p < 0.001). Mean baseline PRL levels were >20 times above normal in cohort A compared to >100 times above normal in cohorts B and C. Symptoms of hypogonadism were present in 55, 64 and 76% of men in groups A, B and C, respectively. There was a trend towards a larger tumor size in the low testosterone group (p = 0.06). Visual fields defects at presentation were more prevalent in this cohort (C). With cabergoline, testosterone level increased from 3.91 to 6.42 ng/ml (Δ = 2.51 ng/ml) in cohort A, from 2.44 to 5.63 ng/ml (Δ = 3.19 ng/ml) in cohort B, and from 0.96 to 3.30 ng/ml (Δ = 2.34 ng/ml) in cohort C (p < 0.05 for each group). Symptoms of hypogonadism improved following treatment in 83% of symptomatic men in cohort A. Normal testosterone does not exclude the likelihood of prolactinoma in men. When treated with cabergoline, testosterone levels in these men can increase higher within the normal range together with clinical improvement.

Bone density in chronic schizophrenia with long-term antipsychotic treatment: preliminary study

OBJECTIVE

Decreased bone mineral density has been found in the chronic schizophrenic patients who have been given a long-term administration of antipsychotics. Hyperprolactinemia from the antipsychotics and the negative symptom of schizophrenia were considered as the causes for this finding. In this study, the effect of hyperprolactinemia and the negative symptom of schizophrenia on bone mineral density was investigated on male schizophrenic patients.

METHODS

The cross-sectional study was carried out with the subjects of 45 male schizophrenic patients who have undertaken the monotherapy with risperidone, olanzapine and clozapine for at least one year. The demographic factors, clinical symtoms, bone mineral density and hematological test were examined for all the subjects.

RESULTS

No significant relationship was found between hyperprolactinemia and the decreased bone mineral density in the subjects. The negative schizophrenia symptom of the subjects showed a significant effect on the decreased bone mineral density.

CONCLUSION

The decreased bone mineral density finding in the male schizophrenic patients may be caused by the negative schizophrenia symptom rather than the hyperprolactinemia due to the antipsychotics. Additional studies are further required regarding other factors that may affect the decreased bone mineral density such as activity, calcium intake and exposure to sunlight.

Bone modeling in bromocriptine-treated pregnant and lactating rats: possible osteoregulatory role of prolactin in lactation

The lactogenic hormone prolactin (PRL) directly regulates osteoblast functions in vitro and modulates bone remodeling in nulliparous rats, but its osteoregulatory roles in pregnant and lactating rats with physiological hyperprolactinemia remained unclear. Herein, bone changes were investigated in rats treated with bromocriptine (Bromo), an inhibitor of pituitary PRL release, or Bromo+PRL at different reproductive phases, from mid-pregnancy to late lactation. PRL receptors were strongly expressed in osteoblasts lining bone trabeculae, indicating bone as a target of PRL actions. By using dual energy X-ray absorptiometry, we found a significant increase in bone mineral density in the femora and vertebrae of pregnant rats. Such pregnancy-induced bone gain was, however, PRL independent and may have resulted from the increased cortical thickness. Bone trabeculae were modestly changed during pregnancy as evaluated by bone histomorphometry. On the other hand, lactating rats, especially in late lactation, showed massive bone loss in bone trabeculae but not in cortical shells. Further study in Bromo- and Bromo+PRL-treated rats suggested that PRL contributed to decreases in trabecular bone volume and number and increases in trabecular separation and eroded surface, as well as a paradoxical increase in bone formation rate in late lactation. Uncoupling of trabecular bone formation and resorption was evident in lactating rats, with the latter being predominant. In conclusion, pregnancy mainly induced cortical bone gain, whereas lactation led to trabecular bone loss in both long bones and vertebrae. Although PRL was not responsible for the pregnancy-induced bone gain, it was an important regulator of bone modeling during lactation.

Is prolactin the cardinal calciotropic maternal hormone?

To produce offspring, mothers require a large amount of calcium for fetal growth and milk production. Increased calcium demand leads to enhanced intestinal calcium absorption and stockpiling of bone calcium in pregnancy prior to demineralization in lactation. These coordinated events must be carefully organized by calciotropic hormone(s), but the classical hormones, namely 1,25-dihydroxyvitamin D(3), parathyroid hormone and calcitonin, do not appear to be responsible. Plasma prolactin (PRL) levels are elevated during pregnancy and, in view of the presence of PRL receptors in gut, bone and mammary glands, as well as recent evidence of the stimulatory effects of PRL on intestinal calcium transport, bone resorption and mammary calcium secretion, we postulate that PRL is the cardinal calciotropic hormone during pregnancy and lactation.

Prolactinoma presenting as chronic anaemia with osteoporosis: a case report

Introduction

Unexplained anaemia is a rare mode of presentation for prolactinoma. We describe a case of a man, with chronic anaemia ascribed to old age. Six years later, he was evaluated and diagnosed with a prolactinoma and resultant osteoporosis. Prolactinoma in old people may present insidiously with chronic anaemia and osteoporosis with or without sexual dysfunction.

Case presentation

We describe the case of a 70-year-old Caucasian man who presented with mild anaemia and tiredness. His anaemia was investigated and ascribed to senescence. Endocrine causes were not considered or tested for. Six years later, he was again referred. Reassessment and direct questioning revealed long-standing sexual dysfunction. It was also discovered that our patient had fractured his radius twice, with minor trauma, during the preceding year. His serum prolactin was massively increased and a magnetic resonance imaging (MRI) scan of the head demonstrated a pituitary mass consistent with a prolactinoma. Dual X-ray absorptiometry revealed osteoporosis. Treatment of the prolactinoma led to a reduction in his serum prolactin with a rise in his haemoglobin to normal levels. This suggested that the prolactinoma was present during the initial presentation and was the cause of his anaemia.

Conclusion

This case highlights the importance of fully evaluating and investigating unexplained anaemia in older people and that endocrine causes should be considered. Osteoporosis also requires evaluation with secondary causes considered.

Femoral bone mineral density and bone mineral content in bromocriptine-treated pregnant and lactating rats

Since hyperprolactinemia was found to induce osteopenia in the metaphysis of long bone in non-mated female rats, pregnant and lactating rats with sustainedly high plasma prolactin (PRL) levels might also exhibit some changes in their long bones. We performed a longitudinal study in pregnant, lactating and post-weaning rats, using dual-energy X-ray absorptiometry to demonstrate site-specific changes (i.e., metaphysis vs. diaphysis) in femoral bone mineral density (BMD) and content (BMC). The results showed that femoral metaphyseal BMD and BMC were higher when compared to their age-matched controls during pregnancy, before decreasing in late lactation and post-weaning. On the other hand, femoral diaphyseal BMC increased during pregnancy, early lactating and mid-lactating periods without change during late lactation and post-weaning. After 7 days of bromocriptine administration which inhibited endogenous PRL secretion, the lactation-induced increases in BMC during early and mid-lactating periods were abolished. Moreover, a decrease in metaphyseal BMD during late lactation was restored to the control levels by bromocriptine. However, bromocriptine did not antagonize the pregnancy-induced increases in BMD and BMC. It could be concluded that the effect of PRL on bone was variable during the reproductive periods. While having no effect on femoral BMD and BMC during pregnancy, PRL was responsible for bone gain in early and mid-lactating periods, but induced bone loss during late lactating period.

Skeletal sequelae of cancer and cancer treatment

INTRODUCTION

Survivors of cancer may experience lingering adverse skeletal effects such as osteoporosis and osteomalacia. Skeletal disorders are often associated with advancing age, but these effects can be exacerbated by exposure to cancer and its treatment. This review will explore the cancer and cancer treatment-related causes of skeletal disorders.

METHODS

We performed a comprehensive search, using various Internet-based medical search engines such as PubMed, Medline Plus, Scopus, and Google Scholar, for published articles on the skeletal effects of cancer and cancer therapies.

RESULTS

One-hundred-forty-two publications, including journal articles, books, and book chapters, met the inclusion criteria. They included case reports, literature reviews, systematic analyses, and cohort reports. Skeletal effects resulting from cancer and cancer therapies, including hypogonadism, androgen deprivation therapy, estrogen suppression, glucocorticoids/corticosteroids, methotrexate, megestrol acetate, platinum compounds, cyclophosphamide, doxorubicin, interferon-alpha, valproic acid, cyclosporine, vitamin A, NSAIDS, estramustine, ifosfamide, radiotherapy, and combined chemotherapeutic regimens, were identified and described. Skeletal effects of hyperparathyroidism, vitamin D deficiency, gastrectomy, hypophosphatemia, and hyperprolactinemia resulting from cancer therapies were also described.

DISCUSSION/CONCLUSIONS

The publications researched during this review both highlight and emphasize the association between cancer therapies, including chemotherapy and radiotherapy, and skeletal dysfunction.

IMPLICATIONS FOR CANCER SURVIVORS

These studies confirm that cancer survivors experience a more rapid acceleration of bone loss than their age-matched peers who were never diagnosed with cancer. Further studies are needed to better address the skeletal needs of cancer survivors.

The effects of hyperprolactinemia on bone and fat

Many patients with prolactin secreting pituitary tumors have decreased bone mineral. The bone loss is associated with an increase in bone resorption and is secondary to prolactin-induced hypogonadism. In both sexes trabecular bone in the spine and hip is more affected than cortical bone in the distal radius. Normalization of prolactin and restoration of gonadal function increases bone density but is not associated with normalization of bone mass. It is not known whether the bone loss in hyperprolactinemic subjects represents a failure to achieve peak bone mass or is due to accelerated bone loss. Despite low bone density hyperprolactinemic subjects do not demonstrate increased fractures. The association between prolactin, weight gain and obesity suggests that prolactin may also be a modulator of body composition and body weight. It is not known whether hyperprolactinemia associated weight gain is due to stimulation of lipogenesis or due to disruption of central nervous system dopaminergic tone. Hyperprolactinemia is also associated with insulin resistance and endothelial dysfunction which may improve after normalization of prolactin. The clinical significance of these findings and the precise role of prolactin in regulation of weight and metabolism remain to be elucidated.

Body fat in men with prolactinoma

OBJECTIVE

(a) To evaluate body fat in men with prolactinoma and healthy controls, using whole body dual energy x-ray absorptiometry (DXA), and (b) to correlate DXA results with anthropometry and clinical aspects of male prolactinomas.

MATERIAL AND METHODS

A cross-sectional study was performed in two University referral centers. Eleven newly-diagnosed men with prolactinoma and 9 with normal PRL levels due to dopamine agonist treatment were submitted to DXA and blood analysis (PRL, testosterone, dihydrotestosterone, estradiol, and SHBG) by the time of their clinical evaluation. They were compared with 14 control men of similar age and body mass index distribution.

RESULTS

Newly-diagnosed men with prolactinoma had higher fat percentage in the arms and the total body, when compared with patients treated with dopamine agonists and controls. The former group also presented higher fat percentage in the legs than the controls. Truncal fat percentage of the newly-diagnosed patients was lower than the dopamine agonist treated group. The 3 groups had similar android and gynoid fat contents. Fat percentage of the 6 sites correlated with PRL, testosterone, and dihydrotestosterone levels.

CONCLUSION

Newly-diagnosed men with prolactinomas had higher body fat content. Body fat was linked to disease control, especially to the PRL and androgen levels. Consequently, adequate control of hyperprolactinemia should be pursued in order to reduce the risk of obesity and its metabolic complications in men with prolactinoma.

Prolactin directly enhances bone turnover by raising osteoblast-expressed receptor activator of nuclear factor kappaB ligand/osteoprotegerin ratio

Hyperprolactinemia leads to high bone turnover as a result of enhanced bone formation and resorption. Although its osteopenic effect has long been explained as hyperprolactinemia-induced hypogonadism, identified prolactin (PRL) receptors in osteoblasts suggested a possible direct action of PRL on bone. In the present study, we found that hyperprolactinemia induced by anterior pituitary transplantation (AP), with or without ovariectomy (Ovx), had no detectable effect on bone mineral density and content measured by dual-energy X-ray absorptiometry (DXA). However, histomorphometric studies revealed increases in the osteoblast and osteoclast surfaces in the AP rats, but a decrease in the osteoblast surface in the AP+Ovx rats. The resorptive activity was predominant since bone volume and trabecular number were decreased, and the trabecular separation was increased in both groups. Estrogen supplement (E2) fully reversed the effect of estrogen depletion in the Ovx but not in the AP+Ovx rats. In contrast to the typical Ovx rats, bone formation and resorption became uncoupled in the AP+Ovx rats. Therefore, hyperprolactinemia was likely to have some estrogen-independent and/or direct actions on bone turnover. Osteoblast-expressed PRL receptor transcripts and proteins shown in the present study confirmed our hypothesis. Furthermore, we demonstrated that the osteoblast-like cells, MG-63, directly exposed to PRL exhibited lower expression of alkaline phosphatase and osteocalcin mRNA, and a decrease in alkaline phosphatase activity. The ratios of receptor activator of nuclear factor kappaB ligand (RANKL) and osteoprotegerin (OPG) proteins were increased, indicating an increase in the osteoclastic bone resorption. The present data thus demonstrated that hyperprolactinemia could act directly on bone to stimulate bone turnover, with more influence on bone resorption than formation. PRL enhanced bone resorption in part by increasing RANKL and decreasing OPG expressions by osteoblasts.

Osteoporosis in celiac disease and in endocrine and reproductive disorders

As the increase in lifespan brings to light diseases that were previously not clinically detectable, osteoporosis has become an issue of worldwide significance. The disease is marked by a loss of bone mass; the bones become less dense, fragile and more prone to fracturing. Because it is regulated by endocrine and environmental factors, osteoporosis presents a multifactorial etiopathogenesis, with the genetic component accounting for 70% of an individual variation in bone mass density (BMD), the principal determinant, with age, of fracture risk. Pathological conditions such as celiac disease (CD) exacerbate the process of bone loss, so that the occurrence of osteoporosis in celiac subjects is of particular note: indeed, the screening of osteoporosis patients for this disease is advisable, since it may be the only sign of undiagnosed CD. An increase in interleukin IL-1β, of the IL-1 system, in the relatives of celiac patients confirms the genetic predisposition to osteoporosis and its presence is evidence of an association between the two conditions. The direct effect on the bones of CD is secondary to poor absorption of calcium and vitamin D. In women osteoporosis is indirectly associated with early menopause and amenorrhea, and it may follow prolonged breast-feeding and frequent pregnancies, while in men it is associated with hypogonadism and GH deficit. These endocrine and non-endocrine factors exert their effects on bones by modulating the RANK/RANK-L/OPG system. An appropriate lifestyle from adolescence onwards, together with early diagnosis of and treatment for CD and primary and secondary endocrine pathologies are important for the prevention of damage to the bones.

Quality of life in women with microprolactinoma treated with dopamine agonists

OBJECTIVES

To evaluate QOL in women with microprolactinomas treated with dopamine agonists, comparing the patients with normal versus those with elevated prolactin levels, and to identify clinical and biochemical influences on patients' QOL.

MATERIAL AND METHODS

A cross-sectional evaluation was performed in two University referral centers. Fifty women with microprolactinoma answered the SF-36 questionnaire by the time of their clinical evaluation. Their biochemical analysis included PRL, estradiol, testosterone, and SHBG. Fifty women of similar age distribution served as controls.

RESULTS

Patients had lower scores than controls in all SF-36 categories: physical functioning, physical role, pain, general health, vitality, social functioning, emotional aspect, and mental health. Within the patients' group, the ones with normal PRL levels had higher scores than those with high PRL levels in all categories but the physical role. The physical functioning score correlated with the free androgen index, while the pain, vitality, social functioning, emotional aspect, and mental health scores were associated with the prolactin levels obtained at study entry.

CONCLUSIONS

QOL is impaired in women with microprolactinoma treated with dopamine agonists, and was inversely associated with the PRL levels. This latter finding reinforces the importance of providing adequate disease control for these patients in order to avoid the adverse consequences of hyperprolactinemia on QOL.

Bone density in women with prolactinoma treated with dopamine agonists

OBJECTIVES

(1) to evaluate bone density in women with prolactinoma treated with dopamine agonists and healthy controls, using dual energy x-ray absorptiometry (DXA), (2) to classify the results according to the current International Society for Clinical Densitometry (ISCD) criteria, and (3) to correlate bone density with lean and fat masses, biochemical data and clinical aspects of prolactinomas.

MATERIALS AND METHODS

A cross-sectional study was performed in two University referral centers. Forty-five premenopausal women with prolactinoma were submitted to DXA and blood analysis (prolactin, estradiol, testosterone, SHBG, calcium, phosphorus, PTH, C-telopeptides of type 1 collagen, and osteocalcin) by the time of their clinical evaluation. They were compared with 25 control women of similar age and body mass index distribution.

RESULTS

Women with prolactinoma had lower lumbar spine Z-score than controls. Femoral neck, trochanter, and total proximal femur Z-scores were similar in patients and controls. Twenty-two percent of the patients had Z-scores below the expected age range vs. 4% in the control group. Lumbar spine, femoral neck, and total proximal femur Z-scores were mainly correlated with the amenorrhea duration. The trochanter Z-score was associated with the gynoid lean/fat mass ratio.

CONCLUSIONS

Based on the current ISCD criteria, bone density evaluation in women with prolactinoma reveals bone loss, especially of trabecular type. Bone density in these patients was particularly associated with the duration of amenorrhea, which reinforces the importance of the adequate disease control in women with prolactinoma in order to avoid complications of this disease.

Body fat in nonobese women with prolactinoma treated with dopamine agonists

OBJECTIVES

To evaluate body fat in nonobese women with prolactinoma treated with dopamine agonists, using whole body dual energy X-ray absorptiometry (DXA) and to correlate DXA results with biochemical data and clinical aspects of the prolactinoma.

DESIGN, PATIENTS AND MEASUREMENTS

A cross-sectional study was performed in two University referral centres. Thirty-one nonobese premenopausal women with prolactinoma were subjected to DXA and blood analysis at clinical evaluation. They were compared with 21 control women of similar age and body mass index (BMI).

RESULTS

Women with prolactinoma treated with dopamine agonists and controls had similar body fat percentages in all sites evaluated with DXA (arms, legs, trunk, android, gynoid and total body). Patients with normal PRL levels at study entry had lower body fat percentages in all sites. In the patient group, arm, leg, truncal, android, gynoid and total body fat were positively associated with PRL levels.

CONCLUSION

Body fat percentage is similar in nonobese women with prolactinoma and in controls. The lower body fat content in patients with normal PRL levels is likely to be due to the metabolic effects of adequate dopamine receptor type 2 (DR2) activation as a result of regular dopamine agonist treatment. This finding reinforces the importance of the appropriate treatment with dopamine agonists in women with prolactinoma, which, besides normalizing PRL levels, reduces body fat content and the consequent risk of developing Metabolic Syndrome and its complications.

[Decreased bone mineral density in pre-menopause women with prolactinoma]

Tumoral hyperprolactinemia and consequent hypogonadism have been associated with osteoporosis. Bone mineral density (BMD) was measured by dual-energy RX absorptiometry in 24 patients with prolactinoma (15 macro and 9 micro adenomas; age range = 18 to 49 years). Student unpaired t or Mann-Whitney tests were used to compare groups, and Spearman test studied correlations. Lumbar spine (LS) was the most affected, as LS Z-score was < -2 SD in 20.83% of the patients. No difference was found in densitometric parameters for the comparison between macro and microprolactinoma, or those with normal prolactin versus hyperprolactinemia. LS BMD and LS Z-score were higher in the patients with > 8 menstrual cycles in the preceding year then in those with oligoamenorrhea (p = 0.030). The number of cycles was correlated to LS BMD (r = 0.515, p = 0.017) and body mass index to femoral neck BMD (r = 0.563, p = 0.006) and total femur BMD (r = 0.529, p = 0.011).

CONCLUSIONS

Decreased bone mineral density was detected in 20.83% of our young patients with prolactinoma. The great involvement of trabecular bone skeletal regions, such as vertebrae, suggests the participation of hypogonadism in the pathogenesis of bone disease. Irrespective of prolactin levels, return to normal menses seems the best index of good control.

Prolactin is an important regulator of intestinal calcium transport

Prolactin has been shown to stimulate intestinal calcium absorption, increase bone turnover, and reduce renal calcium excretion. The small intestine, which is the sole organ supplying new calcium to the body, intensely expresses mRNAs and proteins of prolactin receptors, especially in the duodenum and jejunum, indicating the intestine as a target tissue of prolactin. A number of investigations show that prolactin is able to stimulate the intestinal calcium transport both in vitro and in vivo, whereas bromocriptine, which inhibits pituitary prolactin secretion, antagonizes its actions. In female rats, acute and long-term exposure to high prolactin levels significantly enhances the (i) transcellular active, (ii) solvent drag-induced, and (iii) passive calcium transport occurring in the small intestine. These effects are seen not only in pregnant and lactating animals, but are also observed in non-pregnant and non-lactating animals. Interestingly, young animals are more responsive to prolactin than adults. Prolactin-enhanced calcium absorption gradually diminishes with age, thus suggesting it has an age-dependent mode of action. Although prolactin's effects on calcium absorption are not directly vitamin D-dependent; a certain level of circulating vitamin D may be required for the basal expression of genes related to calcium transport. The aforementioned body of evidence supports the hypothesis that prolactin acts as a regulator of calcium homeostasis by controlling the intestinal calcium absorption. Cellular and molecular signal transductions of prolactin in the enterocytes are largely unknown, however, and still require investigation.

Enhanced trabecular-bone calcium deposition in female rats with a high physiological dose of prolactin diminishes after ovariectomy

Although an increase in trabecular-bone calcium deposition has been shown to be regulated by prolactin during lactation, the physiological significance of prolactin in bone calcium metabolism in nonlactating rats remains unclear. This investigation sought to demonstrate the effects of endogenous prolactin and a high physiological dose of exogenous prolactin on bone turnover and bone calcium deposition in normal female rats, using the45Ca-labeling technique. Our results showed that suppression of endogenous prolactin with 6 mg/kg bromocriptine for 15 days significantly enhanced bone formation, but not bone resorption, in primarily trabecular sites, resulting in a significant increase in calcium deposition in the sternum and vertebrae, from –0.20 ± 0.07 to 0.40 ± 0.09 (p < 0.05) and –0.07 ± 0.11 to 0.34 ± 0.06 (p < 0.05) mmol Ca·(g dry mass)–1, respectively. Similarly, 2.5 mg/kg prolactin, a high physiological dose, increased sternal and vertebral calcium deposition, from –0.20 ± 0.07 to 0.24 ± 0.09 (p < 0.05) and –0.07 ± 0.11 to 0.25 ± 0.18 (p < 0.05) mmol Ca·(g dry mass)–1, respectively, by increasing bone formation more than bone resorption. However, as expected, prolactin had no effect on the tibia or femur, which are primarily cortical sites. Because several actions of prolactin have been known to be estradiol-dependent, we further investigated the dependence of prolactin action on 17β-estradiol. We found that 2.5 mg/kg prolactin did not increase sternal calcium deposition in ovariectomized rats. However, 10 µg/kg 17β-estradiol supplementation restored the action of prolactin. Ovariectomized rats given 17β-estradiol plus prolactin also manifested slightly but significantly higher sternal total calcium content than sham-operated rats, (4.58 ± 0.12 vs. 4.36 ± 0.11 mmol Ca·(g dry mass)–1(p < 0.05)). We concluded that a high physiological dose of prolactin promoted calcium deposition in primarily trabecular sites of nonlactating rats. This effect was diminished after ovariectomy. In addition, we showed that basal endogenous prolactin played a role in the maintenance of normal trabecular-bone turnover.

Avaliação plasmática de igf-1 no prolactinoma

Prolactinomas são os tumores hipofisários mais comuns, podendo co-secretar GH (hormônio do crescimento). IGF-1 (fator de crescimento insulina-símile-1) é o principal responsável pelas ações do GH e parâmetro diagnóstico de acromegalia. Objetivando determinar por uma dosagem de IGF-1, na avaliação inicial de pacientes com prolactinoma, ocorrência de tumores mistos [GH e prolactina (PRL)], estudamos 7 homens e 27 mulheres, entre 19 e 72 anos, confrontando-os aos resultados de GH basal e durante teste oral de tolerância à glicose, quando GH basal >0,4 ng/mL ou níveis de IGF-1 alterados. A proporção de pacientes com GH >0,4 ng/mL e IGF-1 elevada foi alta; mas, após administração de 75g de glicose por via oral, nenhum paciente foi diagnosticado como acromegálico. Sugerimos, porém que a dosagem de IGF-1 seja realizada pelo risco de co-secreção de GH nos prolactinomas. Atenção especial para pacientes que apresentem significativa diminuição dos níveis de PRL, sem correspondente regressão do tamanho do adenoma.