Risk Assessment of Diabetes Mellitus during and after Pregnancy in Women with Prolactinomas

CONTEXT

Prolactin (PRL) is a crucial mediator of gluco-insulinemic metabolism.

OBJECTIVE

Dissecting glucose metabolism during and after pregnancy in patients with prolactinomas.

METHODS

52 patients treated with cabergoline (CAB) were evaluated before conception, during pregnancy and up to 10 years after delivery. During pregnancy, CAB was discontinued, while it was restarted in 57.7 % of patients after delivery, due to recurrent hyperprolactinemia (RH). Hormonal (serum PRL) and metabolic (HbA1c, fasting glucose/FG, glucose tolerance) parameters were assessed.

RESULTS

During pregnancy, PRL gradually increased, while FG remained stable. An inverse correlation between PRL and FG was found in the first (p=0.032) and third (p=0.048) trimester. PRL percent increase across pregnancy was inversely correlated with third trimester FG. Serum PRL before conception emerged as predictive biomarker of third trimester FG (τ=2.603; p=0.048). Elderly patients with lower HbA1c at first trimester and lower FG at 3 years postpartum, delivered infants with reduced birth weight. Breastfeeding up to 6 months correlated with lower FG at 4 and 10 years postpartum. A positive correlation between BMI and FG at 10 years after delivery (p=0.03) was observed, particularly in overweight/obese patients requiring higher CAB doses. Patients with RH who had to restart CAB showed shorter breastfeeding duration and higher FG at 2 years postpartum.

CONCLUSIONS

Low PRL levels before pregnancy may be detrimental to FG during pregnancy. CAB duration and dose may influence long-term glucose tolerance, besides family history and BMI. Pre-conceptional metabolic management should be recommended to reduce the risk of gestational and type 2 diabetes mellitus.

Investigational drugs for the treatment of acromegaly: new agents to transform therapy

INTRODUCTION

Disease control is essential to decrease morbidity burden and mortality in acromegaly patients. In the last decades, the availability of new drugs increased the rate of disease control. However, up to 55% of patients remain uncontrolled despite available treatment strategies in real-world data. The reasons for this finding may include poor adherence, inadequate tolerability, therapeutic inertia, and high costs. Since acromegaly is a chronic disease and medical therapy is usually life-long, patient's adherence to treatment is fundamental in both achieving and maintaining disease control. Less invasive routes of administration could improve adherence and concur to increase disease control rate.

AREAS COVERED

The aim of current review is to provide a detailed update about investigational drugs for acromegaly treatment currently under investigation as paltusotine, ONO-5788, AP102, GT-02037, ISIS 766720, CAM2024, Lanreotide PRF, DP1038, MTD201, solid dose injection of octreotide.

EXPERT OPINION

Medical therapy of acromegaly is an evolving field. Current studies are addressing patient's need for both new molecules and less invasive routes of administration for already existing drugs. It cannot be ruled out that drugs currently used for other diseases such as cancer could be considered in the future for the treatment of acromegaly.

Long-term pasireotide therapy in acromegaly: extensive real-life experience of a referral center

PURPOSE

Pasireotide is a novel therapeutic option for patients with acromegaly resistant to first-generation somatostatin receptor ligands. To date, real-life data are still scant, therefore, the aim of the current study is to evaluate the impact of long-term pasireotide therapy on disease control, pituitary tumor size, gluco-insulinemic and lipid profile in a real-life setting.

METHODS

Retrospective study of data prospectively collected, evaluating hormonal, tumoral, and metabolic data of 28 patients with acromegaly administered with pasireotide in a pituitary tertiary referral center.

RESULTS

Within the first 12 months of treatment, 70.4% of patients achieved normal IGF-I levels, which was maintained at 36-month evaluation in these responders patients. Patients who started with pasireotide 60 mg monthly exhibited significantly lower IGF-I levels after 36 months (p = 0.05) as compared to patients administered first with pasireotide 20 or 40 mg monthly. The maximal tumoral diameter was significantly decreased after 12 months of pasireotide (p < 0.001) and a further reduction was registered throughout the following months, with 41.2% of patients achieving a significant reduction (> 25% of baseline measurement) after 36 months of treatment. Fasting glucose significantly increased during the first 6 months (p < 0.001) with a gradual rise in diabetes prevalence during the following months, resulting diabetes prevalence after 36 months of pasireotide significantly increased compared to baseline (p = 0.003), although with glycated hemoglobin levels within the normal range. Diabetes was managed using oral glucose-lowering drugs or glucagon-like peptide 1 agonists, with no patient requiring insulin therapy. Pasireotide improved lipid profile, mainly during the first 12 months of treatment, by increasing HDL and decreasing triglycerides levels.

CONCLUSION

Pasireotide is effective and safe in the long-term. Hyperglycemia is a common event and is manageable even without insulin treatment.

Circulating myomiRNAs as biomarkers in patients with Cushing's syndrome

PURPOSE

Impairment of skeletal muscle mass and strength affects 40-70% of patients with active Cushing's syndrome (CS). Glucocorticoid excess sustains muscle atrophy and weakness, while muscle-specific microRNAs (myomiRs) level changes were associated with muscle organization and function perturbation. The aim of the current study is to explore changes in circulating myomiRs in CS patients compared to healthy controls and their involvement in IGFI/PI3K/Akt/mTOR pathway regulation in skeletal muscle.

METHODS

C2C12, mouse myocytes, were exposed to hydrocortisone (HC), and atrophy-related gene expression was investigated by RT-qPCR, WB and IF to assess HC-mediated atrophic signalling. miRNAs were evaluated in HC-treated C2C12 by PCR Arrays. MyomiRs significantly overexpressed in C2C12 were investigated in 37 CS patients and 24 healthy controls serum by RT-qPCR. The anti-anabolic role of circulating miRNAs significantly upregulated in CS patients was explored in C2C12 by investigating the IGFI/PI3K/Akt/mTOR pathway regulation.

RESULTS

HC induced higher expression of atrophy-related genes, miR-133a-3p, miR-122-5p and miR-200b-3p in C2C12 compared to untreated cells. Conversely, the anabolic IGFI/PI3K/Akt/mTOR signalling was reduced and this effect was mediated by miR-133a-3p. In CS patients miR-133a-3p and miR-200b-3p revealed higher circulating levels (p < 0.0001, respectively) compared to controls. ROC curves for miR-133a-3p (AUC 0.823, p < 0.0001) and miR-200b-3p (AUC 0.850, p < 0.0001) demonstrated that both myomiRs represent potential biomarkers to discriminate between CS and healthy subjects. Pearson's correlation analysis revealed that circulating levels of miR-133a-3p are directly correlated with 24 h urinary-free cortisol level (r = 0.468, p = 0.004) in CS patients.

CONCLUSIONS

HC induces atrophic signals by miR-133a-3p overexpression in mouse myocytes and humans. Circulating miR-133a-3p is promising biomarkers of hypercortisolism.

Pasireotide effects on biochemical control and glycometabolic profile in acromegaly patients switched from combination therapies or unconventional dosages of somatostatin analogs

PURPOSE

To evaluate the impact of pasireotide (PAS) therapy on hormonal and glycometabolic outcome in patients with acromegaly previously treated with combination medical therapies or unconventional dosages of first-generation somatostatin receptor ligands (fg-SRLs).

METHODS

Retrospective study carried out in two referral centers for pituitary diseases. Twenty-one acromegalic patients were switched to PAS (12 had biochemical control, 9 were uncontrolled). Data were collected after 3- and 6-months PAS treatment, and at the last available visit (median 35 months).

RESULTS

After switching to PAS therapy, a significant reduction in IGF-1 values was observed [median 39%; 0.79 xULN (IQR 0.5-1.01) vs 1.29 xULN (IQR 1.06-1.83); p = 0.009]. IGF-1 reduction was statistically significant in the 9 patients previously uncontrolled (61%, p = 0.016), and in the 12 controlled subjects (33%, p = 0.037). At last follow-up, the number of patients reaching an acceptable biochemical control (IGF-1 < 1.3 xULN) raised from 57 to 90% (p = 0.032). Mean HbA1c levels increased from 5.7% (5.5-5.9) to 6.0% (5.9-7) (p = 0.002), and the percentage of diabetic patients raised from 14% (3/21) to 67% (14/21) (p = 0.004). At the last evaluation HbA1c was ≥ 7.0% in 5 patients (24%). Antidiabetic drugs were initiated in 9 new patients, and in 7 out of 9 metformin alone was effective. Younger age and male sex were predictors for the maintenance of glucose homeostasis.

CONCLUSION

PAS monotherapy can be effective in acromegalic patients previously treated with combination medical therapies or unconventional dosages of fg-SRLs. Glucose imbalance can be managed in the vast majority of cases by use of lifestyle interventions and metformin.

Low prolactin level identifies hypoactive sexual desire disorder women with a reduced inhibition profile

PURPOSE

Data on the role of prolactin (PRL) in the physiologic range in the female sexual response are scanty. We aimed at investigating the association between PRL and sexual function as assessed by the Female Sexual Function Index (FSFI). We explored the presence of a cut-off level of PRL able to identify Hypoactive Sexual Desire Disorder (HSDD).

METHODS

277 pre- and post-menopausal women consulting for Female Sexual Dysfunction (FSD) and sexually active were enrolled in an observational, retrospective study. 42 women were used as no-FSD controls. A clinical, biochemical and psychosexual evaluation was performed. The main outcome measures were: FSFI, Female Sexual Distress Scale-Revised, Middlesex Hospital Questionnaire and Sexual excitation/sexual inhibition scale (SIS/SES).

RESULTS

Normo-PRL FSD women (n = 264) showed lower FSFI Desire score than controls (n = 42), and higher than hyper-PRL FSD women (n = 13). These differences emerged both in pre-menopausal and post-menopausal subjects. In the normo-PRL FSD group, those with PRL in the higher quintile reported higher FSFI Desire scores than those with PRL in the lowest quintile. Women with HSDD presented a lower PRL level than those without (p = 0.032). A ROC curve analysis for PRL showed an accuracy of 0.610 ± 0.044 (p = 0.014) in predicting HSDD. With a threshold of < 9.83 μg/L, sensitivity and specificity for HSDD were 63% and 56%, respectively. Subjects with PRL < 9.83 μg/L also reported lower sexual inhibition (p = 0.006) and lower cortisol levels (p = 0.003) than those with PRL >  = 9.83 μg/L.

CONCLUSIONS

Hyper-PRL is associated with low desire; however, among normo-PRL FSD women, those with the lowest levels demonstrated a poorer desire than those with the highest levels. PRL < 9.83 μg/L predicted HSDD and a lower sexual inhibitory trait.

Approach to the Patient With Prolactinoma

Prolactinomas are the most common pituitary tumor histotype, with microprolactinomas being prevalent in women and macroprolactinomas in men. Hyperprolactinemia is among the most common causes of hypogonadotropic hypogonadism in both sexes, prompting medical advice for hypogonadism (infertility, oligo-amenorrhea, impotence, osteoporosis/osteopenia) in both sexes, and for signs and symptoms of mass effects (hypopituitarism, visual loss, optic chiasm compression, cranial nerve deficits, headaches) predominantly in men. Diagnostic workup involves a single prolactin measurement and pituitary imaging, but some laboratory artifacts (ie, the "hook effect" and macroprolactin) can complicate or delay the diagnosis. The treatment of choice for prolactinomas is represented by dopamine agonists, mainly cabergoline, which are able to induce disease control, restore fertility in both sexes, and definitively cure one-third of patients, thus permitting treatment discontinuation. Pregnancy and menopause may promote spontaneous prolactin decline and anticipate cabergoline discontinuation in women. Surgery and/or radiotherapy are indicated in case of resistance to cabergoline not overcome by the increase in drug dose up to the maximally tolerated or the patient's personal choice of surgery. The evidence of resistance to cabergoline in invasive and proliferative tumors may indicate biological aggressiveness, thus requiring alternative therapeutic approaches mainly based on temozolomide use as monotherapy or combined with radiotherapy. In uncontrolled patients, new medical approaches (alternative hormonal treatments, cytotoxic drugs, peptide receptor radionuclide therapy, mTOR/Akt inhibitors, tyrosine kinase inhibitors, or immunotherapy) may be offered but the experience collected to date is still very scant. This article reviews different facets of prolactinomas and discusses approaches to the condition in more common clinical situations.

Control of acromegaly in more than 90% of patients after 10 years of pegvisomant therapy: an European referral centre real-life experience

PURPOSE

Pegvisomant (PEG) efficaciously controls IGF-I excess in acromegaly and possesses a positive impact on glucose metabolism. Data on very prolonged PEG treatment are still limited, therefore, we investigated the effects of 10-years PEG on disease control, maximal tumour diameter (MTD), and metabolic profile in consecutive patients resistant to somatostatin analogues (SRLs) followed in an European referral centre for acromegaly.

METHODS

Since the 2000s, we collected data on anthropometric, hormonal and metabolic parameters, and MTD of patients receiving PEG. In the current study, we included 45 patients (19 men, 26 women, 46.8 ± 11 years) treated for at least 5 years with PEG mono or combined therapy, analyzing data before, after 5- and 10-years PEG.

RESULTS

After10 years, 91% of patients showed full disease control and in 37% a significant decrease in MTD was found. Diabetes prevalence was slightly increased, whereas HbA1c remained stable over the decade. Transaminases remained stable and no case of cutaneous lipohypertrophy was recorded. A different metabolic impact between mono- or combined therapy was found. Patients in monotherapy showed significantly lower fasting glucose (p = 0.01), fasting insulin (p = 0.008), HbA1c (p = 0.007), HOMA-IR (p = 0.001), and significantly higher ISI₀ (p = 0.002), whereas patients under combined therapy showed significantly lower total (p = 0.03), and LDL cholesterol (p = 0.007). Acromegaly duration before PEG was inversely related to ΔFG (r = - 0.46, p = 0.03) and ΔFI (r = - 0.54, p = 0.05).

CONCLUSIONS

PEG is effective and safe in long term. In patients resistant to SRLs, early beginning of PEG allows a wider gluco-insulinemic improvement.

Fertility in Acromegaly: a single center experience on female patients during active disease and after disease remission

CONTEXT

Fertility represents a major concern in patients with acromegaly.

OBJECTIVE

Investigation of gonadal function and fertility rate in acromegalic women.

DESIGN

Retrospective study. Anthropometric, metabolic, hormonal parameters, and gynaecological ultrasound were evaluated at diagnosis and after disease control. Data about menstrual disturbances, pregnancy, and PCO-morphology (PCOM) were investigated at disease onset, diagnosis and after disease control.

SETTING

Referral center.

PATIENTS

50 acromegalic women with disease onset within the reproductive age.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Prevalence of gonadal dysfunction and infertility.

RESULTS

At presumed disease onset, menstrual disturbances were reported in 32% of patients. Uterine leiomyoma, ovarian cysts and PCOM were diagnosed in 18%, 12% and 8%, respectively; 36.8% of patients were infertile. At diagnosis, menstrual disturbances were found in 58.1% (p = 0.02), being significantly more prevalent in patients with higher IGF-I quartiles (Q) (p = 0.03, Q1 vs Q4). Gynaecological ultrasound revealed uterine leiomyoma, ovarian cysts and PCOM in 39.1% (p = 0.04), 28.2% (p = 0.09), and 13% (p = 0.55), respectively. The infertility rate was 100% (p = 0.02). At disease control, menstrual disturbances (p = 0.05), particularly amenorrhea (p = 0.03), significantly persisted in patients with disease duration above than in those with disease duration below 5 years (median). Among patients with pregnancy desire, 73.3% conceived at least once, resulting infertility significantly decreased compared to diagnosis (26.7%, p = 0.01). At-term, pre-term deliveries and spontaneous abortions were recorded in 86.7%, 3.3% and 10%, respectively. No neonatal malformations and/or abnormalities were recorded.

CONCLUSIONS

Gonadal dysfunction and infertility are common in acromegalic women within the reproductive age, being directly influenced by the disease status and/or duration.

Metabolic effects of prolactin

Over the last years, the metabolic role of PRL has emerged. PRL excess is known to promote weight gain, obesity, metabolic syndrome, and impairment in gluco-insulinemic and lipid profiles, likely due to the suppression of physiologic dopaminergic tone. Prolactin receptors and dopamine receptors type 2 have been demonstrated to be expressed on both human pancreatic β- cell and adipocytes, supporting a key role of prolactin and dopamine in peripheral metabolic regulation. Medical treatment with the dopamine agonists bromocriptine and cabergoline has been demonstrated to decrease the prevalence of metabolic syndrome and obesity, and significantly improve gluco-insulinemic and lipid profiles. In hyperprolactinemic men with concomitant hypogonadism, correction of hyperprolactinaemia and testosterone replacement has been proven to restore metabolic impairment. In turn, low prolactin levels have also been demonstrated to exert a detrimental effect on weight gain, glucose and lipid metabolism, thus leading to an increased prevalence of metabolic syndrome. Therefore, PRL values ranging from 25 to 100 mg/L, in absence of other recognizable pathological causes, have been proposed to represent a physiological response to the request for an increase in metabolic activity, and nowadays classify the so-called HomeoFIT- PRL as a promoter of metabolic homeostasis. The current review focuses mainly on the effects of hyperprolactinemia and its control by medical treatment with DAs on the modulation of food intake, body weight, gluco-insulinemic and lipid profile. Furthermore, it provides the latest knowledge about the metabolic impact of hypoprolactinemia.

Metabolic syndrome in the era of COVID-19 outbreak: impact of lockdown on cardiometabolic health

PURPOSE

COVID-19 pandemics and cardiometabolic health are mutually interconnected. Chronic metabolic diseases are known risk factors for increased mortality after SARS-CoV-2 infection. In turn, COVID pandemics imposed sudden changes in lifestyle and social isolation with consequent potential cardiometabolic sequelae. The present study aimed at investigating the impact of changes in lifestyle and social life on metabolic profile in hyperprolactinemic or osteoporotic patients without pre-existing cardiometabolic diseases at the time of COVID-19.

METHODS

The primary study outcome measurement was the prevalence of obesity, arterial hypertension, impaired glucose tolerance (IGT) or diabetes mellitus (DM), dyslipidemia and metabolic syndrome after COVID-19 outbreak. Seventy-four patients (21 men and 53 women, aged 51.8 ± 17.8 years) were admitted to the outpatient clinic of the Neuroendocrine Disease Unit at University "Federico II" of Naples, Italy, as per their routine clinical practice because of tumoral and non-tumoral hyperprolactinemia in 52 patients (70.3%), and osteoporosis/osteopenia in 22 (29.7%). Among female patients, 25 (47.2%) were at menopausal age.

RESULTS

At the end of lockdown, prevalence of obesity (from 37.8% to 51.3%, p < 0.0001), dyslipidemia (from 28.4 to 48.6%, p = 0.003) and metabolic syndrome (from 14.9 to 27%, p < 0.0001) significantly increased compared to pre-COVID evaluation. No significant change was found in the prevalence of arterial hypertension and IGT/DM.

CONCLUSION

SARS-CoV-2 outbreak has led to a rapid increase in the prevalence of metabolic syndrome, potentially contributing to the increased COVID-19 related mortality.

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.

The Vaginal Microbiome: A Long Urogenital Colonization Throughout Woman Life

Vaginal microbial niche is a dynamic ecosystem, composed by more than 200 bacterial species which are influenced by genes, ethnic background and environmental-behavioral factors. Several lines of evidence have well documented that vaginal microbiome constantly changes over the course of woman’s life, so to exert an important impact on woman quality of life, from newborn to post-menopausal ages. This review aims at analyzing the role of vaginal microbiome in the maintenance of woman’s homeostasis and at tracking critical changes that commonly occur across woman’s lifetime. The role of hormone replacement therapy in the modulation of vaginal microbiome composition and in the improvement of vaginal wellness in postmenopausal women with decreasing levels of circulating estrogen is discussed.

Effects of Pituitary Surgery and High-Dose Cabergoline Therapy on Metabolic Profile in Patients With Prolactinoma Resistant to Conventional Cabergoline Treatment

OBJECTIVE

Control of prolactin excess is associated with the improvement in gluco-insulinemic and lipid profile. The current study aimed at investigating the effects of pituitary surgery and medical therapy with high dose cabergoline (≥2mg/week) on metabolic profile in patients with prolactinoma resistant to cabergoline conventional doses (<2mg/week).

DESIGN

Thirty-four patients (22 men, 12 women, aged 33.9 ± 12.5 years) with prolactinoma (4 microadenomas and 30 macroadenomas) were included in the present study. Among them 17 (50%) received pituitary surgery (PS, Group1) and 17 (50%) medical therapy with high dose cabergoline (Group 2).

METHODS

In the whole patient cohort, anthropometric (weight, BMI) and biochemical (fasting glucose and insulin, triglycerides, total, HDL and LDL-cholesterol, HOMA-IR, HOMA-β and ISI0) parameters were evaluated before and within 12 months after treatment.

RESULTS

In Group 1, prolactin (p=0.002), total cholesterol (p=0.012), and triglycerides (p=0.030) significantly decreased after pituitary surgery compared to the baseline. Prolactin significantly correlated with fasting glucose (r=0.056, p=0.025). In Group 2, fasting insulin (p=0.033), HOMA-β (p=0.011) and ISI0 (p=0.011) significantly improved compared to baseline. Postoperative cabergoline dose significantly correlated with Δfasting glucose (r=-0.556, p=0.039) and ΔLDL cholesterol (r=- 0.521, p=0.046), and was the best predictor of ΔLDL cholesterol (r^{2 =} 0.59, p=0.002) in Group 1.

CONCLUSIONS

The rapid decrease in PRL levels induced by PS might improve lipid metabolism, whereas HD-CAB might exert a beneficial impact on both insulin secretion and peripheral sensitivity, thus inducing a global metabolic improvement.

Sex Disparities in COVID-19 Severity and Outcome: Are Men Weaker or Women Stronger?

The coronavirus disease 2019 (COVID-19) outbreak, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global public health issue which has profound effects on most aspects of societal well-being, including physical and mental health. A plethora of studies globally have suggested the existence of a sex disparity in the severity and outcome of COVID-19 patients, mainly due to mechanisms of virus infection, immune response to the virus, development of systemic inflammation, and consequent systemic complications, particularly thromboembolism. Epidemiological data report a sex difference in the severity of COVID-19, with a more favorable course of the disease in women compared to men regardless of age, although the rate of SARS-CoV-2 infection seems to be similar in both sexes. Sex hormones, including androgens and estrogens, may not only impact virus entry and load, but also shape the clinical manifestations, complications, and ultimately the outcome of the disease. The current review comprehensively summarizes the current literature on sex disparities in susceptibility and outcome of COVID-19 as well as the literature underpinning the pathophysiological and molecular mechanisms, which may provide a rationale to a sex disparity. These mechanisms include sex hormone influence on factors that facilitate virus entry and priming, immune and inflammatory response, as well as coagulation and thrombosis diathesis. Based on present evidence, women appear to be relatively protected from COVID-19 because of a more effective immune response and a less pronounced systemic inflammation, with consequent moderate clinical manifestations of the disease, together with a lesser predisposition to thromboembolism. Conversely, men appear to be particularly susceptible to COVID-19 because of a less effective immune response with consequent severe clinical manifestations of the disease, together with a greater predisposition to thromboembolism. In the elderly, generally characterized by the phenomenon of inflammaging, sex disparities in overall mortality following SARS-CoV-2 infection are even more palpable as elderly men appear to be more prone to severe COVID-19 because of a greater predisposition to infections, a weaker immune defense, and an enhanced thrombotic state compared to women. The information revealed from the review highlights potential novel therapeutic approaches employing the administration of hormonal or antihormonal therapy in combination with antiviral drugs in COVID-19 patients.

The Interplay Between Prolactin and Reproductive System: Focus on Uterine Pathophysiology

Over the last years, increasing evidence has focused on crucial pathogenetic role of PRL on malignant, premalignant and benign uterine diseases. Studies in animals and humans have documented that PRL receptors (PRL-Rs) are widely expressed on uterine cells and that PRL is directly synthesized by the endometrium under the stimulatory action of progesterone. Uterine PRL secretion is finely modulated by autocrine/paracrine mechanisms which do not depend on the same control factors implied in the regulation of PRL secretion from pituitary. On the other hand, PRL is synthesized also in the myometrium and directly promotes uterine smooth muscle cell growth and proliferation. Therefore, PRL and PRL-Rs appear to play an important role for the activation of signaling pathways involved in uterine cancers and preneoplastic lesions. Circulating PRL levels are reportedly increased in patients with cervical or endometrial cancers, as well as uterine premalignant lesions, and might be used as discriminative biomarker in patients with uterine cancers. Similarly, increased PRL levels have been implicated in the endometriosis-induced infertility, albeit a clear a causative role for PRL in the pathogenesis of endometriosis is yet to be demonstrated. This evidence has suggested the potential application of dopamine agonists in the therapeutic algorithm of women with malignant, premalignant and benign uterine lesions. This review focuses on the role of PRL as tumorigenic factor for uterus and the outcome of medical treatment with dopamine agonists in patients with malignant and benign uterine disease.

Glucose Abnormalities Associated to Prolactin Secreting Pituitary Adenomas

The pathogenesis of obesity and alterations in glucose profile have been linked to PRL excess, as it is reportedly associated with metabolic syndrome in thereabout one third of patients. In vitro exposure of pancreatic islet to PRL is known to stimulate insulin secretion and β-cell proliferation, and in turn overexpression of PRL in β-cells increases insulin release and β-cell replication. PRL excess has been found to worsen glucose profile because it reduces glucose tolerance and induces insulin resistance either in obese and non-obese patients. To note, pancreatic β-cells and adipocytes widely express dopamine receptors type 2, and dopamine has been hypothesized to play a key role as modulator of insulin and adipose functions. The dopamine agonists bromocriptine and cabergoline significantly improve abnormalities in glucose profile and reduce the prevalence of metabolic syndrome in a remarkable proportion of patients, regardless of whether body weight and PRL status may change. However, in men with hyperprolactinemia complicated by hypogonadism, testosterone replacement can ameliorate insulin resistance and abnormalities in glucose metabolism. Therefore, in patients with PRL-secreting pituitary adenomas control of PRL excess by dopamine agonists is mandatory to improve glucose and insulin abnormalities.

Dopamine Agonists: From the 1970s to Today

The discovery of dopamine inhibitory effects on prolactin secretion has led to an era of successful dopaminergic therapy for prolactinomas. Herein we provide an overview of the evolution of dopamine agonists and their use in patients with PRL-secreting pituitary tumors, starting from the 1970s up to today, highlighting that normalization of PRL levels, restoration of eugonadism, and reduction of tumor mass can be achieved in the majority of patients by treatment with dopamine agonists.

Effect of combined treatment with a pan-PI3K inhibitor or an isoform-specific PI3K inhibitor and everolimus on cell proliferation in GH-secreting pituitary tumour in an experimental setting

PURPOSE

PI3K/Akt/mTOR pathway activation is common in GH-secreting pituitary tumours, and a target for treatment with mTOR inhibitors, including everolimus (EVE). The current study aimed to evaluate the efficacy of two PI3K inhibitors (PI3Ki), NVP-BKM120 and NVP-BYL719, alone and in combination with EVE in rat GH-secreting pituitary tumour cell line (GH3) and human GH-secreting pituitary tumour cell cultures.

METHODS

In GH3 cell line and in six GH-secreting tumour cell cultures, the effects of PI3Ki and EVE, as single agents and in combination, were tested on cell viability and colony survival, by MTT and clonogenic assay, respectively, whereas western blot was performed to evaluate the underlying intracellular signalling pathways.

RESULTS

PI3Ki and EVE showed a dose-dependent inhibition of cell viability in GH3 cell line, with PI3Ki displaying a synergistic effect when combined with EVE. PI3Ki and EVE inhibited colony survival in GH3 cell line with no further improvement in combination. In GH-secreting pituitary tumour cell cultures PI3Ki are effective in inhibiting cell viability increasing the slight and non significant inhibition induced by EVE as single agent, generally showing a synergistic effect. Despite in both GH3 cell line and GH-secreting pituitary tumour cell cultures combination of PI3Ki enhanced EVE effect, the study of intracellular signalling pathways revealed a different regulation of PI3K/Akt/mTOR and MAPK between the two models.

CONCLUSIONS

The results of the current study demonstrated that PI3Ki, especially in combination with EVE, are effective in inhibiting cell proliferation, therefore representing a promising therapeutic tool for the treatment of aggressive GH-secreting pituitary tumours, not responsive to standard medical therapies.

The effects of hyperprolactinemia and its control on metabolic diseases

INTRODUCTION

Hyperprolactinaemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with impaired metabolic profile and metabolic syndrome in approximately one third of patients.

AREAS COVERED

Suppression of dopaminergic tone has been proposed as a potential mechanism responsible for weight gain and metabolic abnormalities in such patients. Dopamine receptor type 2 (D₂R) is abundantly expressed on human pancreatic β-cell and adipocytes, suggesting a regulatory role for peripheral dopamine in insulin and adipose functions. Medical treatment with the dopamine-agonists bromocriptine and cabergoline has been shown to significantly improve gluco-insulinemic and lipid profile, also reducing the prevalence of metabolic syndrome. In patients with concomitant hypogonadism, simultaneous correction of both PRL excess and testosterone deficiency is mandatory to improve insulin resistance and metabolic abnormalities.

EXPERT COMMENTARY

Hyperprolactinemia promotes metabolic alterations. Control of PRL excess by dopamine agonists is mandatory to induce weight loss and to improve metabolic profile, and replacement treatment for concomitant hypogonadism effectively ameliorates insulin resistance and metabolic syndrome.

Effects of long-term combined treatment with somatostatin analogues and pegvisomant on cardiac structure and performance in acromegaly

To date, no data are available on the effects of long-term combined treatment with somatostatin analogues (SA) and pegvisomant (PEG) on cardiovascular complications in acromegaly. The current study aimed at investigating the effects of long-term SA + PEG on cardiac structure and performance. Thirty-six patients (14 M, 22 F, aged 52.3 ± 10.2 years) entered this study. Weight, BMI, systolic (SBP) and diastolic (DBP) blood pressure, IGF-I, fasting glucose (FG), fasting insulin (FI), HOMA-IR, HbA_1c, and lipids were evaluated at baseline (T0), after long-term (median 36 months) SA (T1), after 12 (T12) and 60 (T60) months of SA + PEG, and at last follow-up (LFU, median 78 months). At each time point, all patients underwent echocardiography. At T1, induced a slight but not significant decrease in IGF-I (p = 0.077), whereas FI (p = 0.004), HOMA-IR (p = 0.013), ejection fraction (EF, p = 0.013), early (E) to late (A) ventricular filling velocities (E/A, p = 0.001), and isovolumetric relaxation time (IVRT, p = 0.000) significantly improved. At T12, IGF-I (p = 0.000) significantly reduced compared to T0, and FI (p = 0.001), HOMA-IR (p = 0.000), LVMI (p = 0.000), and E/A (p = 0.006) further improved compared to T1. At T60, FI (p = 0.027), HOMA-IR (p = 0.049), and E/A (p = 0.005) significantly improved as compared to T1. At LFU IGF-I normalized in 83.3 %, FI (p = 0.000), HOMA-IR (p = 0.000), LVMi (p = 0.000), and E/A (p = 0.005) further improved as compared to T1. PEG dose significantly correlated with LVMi at T12 (r = 0.575, p = 0.000) and T60 (r = 0.403, p = 0.037). Long-term PEG addition to SA improves cardiac structure and performance, particularly diastolic dysfunction, in acromegalic patients resistant to SA.

Complications of acromegaly: cardiovascular, respiratory and metabolic comorbidities

Acromegaly is associated with an enhanced mortality, with cardiovascular and respiratory complications representing not only the most frequent comorbidities but also two of the main causes of deaths, whereas a minor role is played by metabolic complications, and particularly diabetes mellitus. The most prevalent cardiovascular complications of acromegaly include a cardiomyopathy, characterized by cardiac hypertrophy and diastolic and systolic dysfunction together with arterial hypertension, cardiac rhythm disorders and valve diseases, as well as vascular endothelial dysfunction. Biochemical control of acromegaly significantly improves cardiovascular disease, albeit completely recovering to normal mainly in young patients with short disease duration. Respiratory complications, represented mainly by sleep-breathing disorders, particularly sleep apnea, and respiratory insufficiency, frequently occur at the early stage of the disease and, although their severity decreases with disease control, this improvement does not often change the indication for a specific therapy directed to improve respiratory function. Metabolic complications, including glucose and lipid disorders, are variably reported in acromegaly. Treatments of acromegaly may influence glucose metabolism, and the presence of diabetes mellitus in acromegaly may affect the choice of treatments, so that glucose homeostasis is worth being monitored during the entire course of the disease. Early diagnosis and prompt treatment of acromegaly, aimed at obtaining a strict control of hormone excess, are the best strategy to limit the development or reverse the complications and prevent the premature mortality.

Somatostatin analogs, cabergoline and pegvisomant: comparing the efficacy of medical treatment for acromegaly

Therapies for acromegaly aim at normalizing hormonal excess and controlling tumor growth . Therapeutic approaches are surgery, pharmacotherapy and radiotherapy. Area covered: This review focuses on the role of medical therapy of acromegaly, comparing the efficacy of somatostatin analogues (SSA), dopamine-agonists (DA) and pegvisomant (PEG), the three available drug classes for treating acromegaly. To clarify the difference in response rates reported in the literature for these therapies, we performed a search for original articles published in PubMed. SSA represent the first-line approach to medical treatment. This therapy is effective in controlling acromegaly in about 40% of patients, however there are great differences in the reported hormonal efficacy of SSA in the different series. In patients partially resistant to SSA, cabergoline can be added when hormonal levels are close to normalization, resulting effective in control IGF-I levels in 43% of patients. In patients with higher hormonal levels PEG is indicated, normalizing IGF-I levels in 79.8% and 80.6% of cases when used in monotherapy or in combination with SSA. Pasireotide, the newly developed SSA multi-ligand receptor, represents a new option in SSA resistant patients. Expert commentary: Medical therapy represents an important therapeutic option resulting safe and effective in controlling acromegaly in a high percentage of patients. The best treatment should be individually tailored for each patient, taking into account sex, age, comorbidities, tumor characteristics and hormonal levels.

Interpreting biochemical control response rates with first-generation somatostatin analogues in acromegaly

CONTEXT

The somatostatin analogues octreotide LAR and lanreotide Autogel have been evaluated for the treatment of acromegaly in numerous clinical trials, with considerable heterogeneity in reported biochemical response rates. This review examines and attempts to account for these differences in response rates reported in the literature.

EVIDENCE ACQUISITION

PubMed was searched for English-language studies of a minimum duration of 24 weeks that evaluated ≥10 patients with acromegaly treated with octreotide LAR or lanreotide Autogel from 1990 to March 2015 and reported GH and/or IGF-1 data as the primary objective of the study.

EVIDENCE SYNTHESIS

Of the 190 clinical trials found, 18 octreotide LAR and 15 lanreotide Autogel studies fulfilled the criteria for analysis. It is evident from the protocols of these studies that multiple factors are capable of impacting on reported response rates. Prospective studies reporting an intention-to-treat analysis that evaluated medically naïve patients and used the composite endpoint of both GH and IGF-1 control were associated with lower response rates. The use of non-composite biochemical control endpoints, heterogeneous patient populations, analyses that exclude treatment non-responders, assay variability and prior responsiveness to medical therapy are just a few of the factors identified that likely contribute to higher success rates.

CONCLUSIONS

The wide range of reported response rates with somatostatin analogues may be confusing and could lead to misinterpretation by both the patient and the physician in certain situations. Understanding the factors that potentially drive the variation in response rates should allow clinicians to better gauge treatment expectations in specific patients.

The effects of somatostatin analogue therapy on pituitary tumor volume in patients with acromegaly

INTRODUCTION

In nearly all cases, acromegaly is caused by excess GH from a pituitary adenoma, resulting in elevated circulating levels of GH and, subsequently, IGF-1. Treatment goals are to eliminate morbidity and restore the increased mortality to normal rates. Therapeutic strategies aim to minimize tumor mass and normalize GH and IGF-1 levels. Somatostatin analogues are the medical treatment of choice in acromegaly, as first-line or post-surgical therapy, and have proven efficacy in pituitary tumor volume reduction (TVR).

METHODS

Here we review the effects of somatostatin analogue therapy on pituitary tumor volume in patients with acromegaly.

RESULTS

TVR with somatostatin analogues may be mediated by direct anti-proliferative effects via activation of somatostatin receptors, or by indirect effects, such as angiogenesis inhibition, and is more pronounced when they are administered as first-line therapy. Various studies of first-line treatment with octreotide LAR have shown significant TVR in ≥73% of patients. First-line treatment with lanreotide Autogel has shown evidence of TVR, although more studies are needed. In a recent randomized, double-blind, 12-month trial in 358 medical-treatment-naïve acromegaly patients, significant TVR was achieved by 81% of patients administered pasireotide LAR and 77% administered octreotide LAR. Pre-operative somatostatin analogue therapy may also induce TVR and improve post-operative disease control compared with surgery alone. TVR is progressive with prolonged treatment, and decreased IGF-1 levels may be its best predictor, followed by age and degree of GH decrease. However, TVR does not always correlate with degree of biochemical control.

CONCLUSION

Somatostatin analogues (first- or second-line treatment) are the mainstay of medical therapy and, as first-line medical therapy, are associated with significant pituitary TVR in most patients.

Cabergoline use for pituitary tumors and valvular disorders

Cabergoline (CAB) is widely used for the medical treatment of pituitary tumors, particularly those associated with hormone hypersecretion. Whether treatment with CAB is associated with an increased risk of clinically relevant cardiac valve disease in patients with pituitary tumors is still debated. In most studies, CAB has been found not associated with an increased risk of significant valvulopathy, and no correlation has been shown between valvular abnormalities and CAB duration or cumulative dose. This review provides an overview of the studies reporting on the outcome of CAB in terms of cardiac valve disease in patients with pituitary tumors.

Effect of chronic cabergoline treatment and testosterone replacement on metabolism in male patients with prolactinomas

INTRODUCTION

Hyperprolactinemia and hypogonadism are reportedly associated with an impaired metabolic profile. The current study aimed at investigating the effects of testosterone replacement and cabergoline (CAB) treatment on the metabolic profile in male hyperprolactinemic patients.

PATIENTS AND METHODS

Thirty-two men with prolactinomas, including 22 with total testosterone (TT) <8 nmol/l (HG, 69%) and 10 with TT >8 nmol/l (non-HG, 31%), were entered in the study. In all patients, metabolic parameters were assessed at diagnosis and after 12- and 24-month treatment.

RESULTS

Compared to non-HG patients, at baseline the HG patients had higher waist circumference (WC). TT significantly correlated with body mass index (BMI). Twelve-month CAB induced PRL normalization in 84%. HG prevalence significantly decreased (28%) and non-HG prevalence significantly increased (72%). Anthropometric and lipid parameters, fasting insulin (FI), insulin sensitivity index (ISI0), homeostatic model assessment of insulin secretion (HOMA-β) and homeostatic model assessment of insulin resistance (HOMA-IR) significantly improved compared to baseline. TT was the best predictor for FI. Percent change (Δ) of TT significantly correlated with ΔCholesterol, ΔWeight and ΔBMI. Compared to non-HG patients, the HG patients had a higher weight, BMI, WC and HOMA-β. In HG, testosterone replacement was started. After 24 months, PRL normalized in 97%. HG prevalence significantly decreased (6%) and non-HG prevalence significantly increased (94%). Anthropometric and lipid parameters, FI, ISI0, HOMA-β and HOMA-IR significantly improved compared to baseline, with FI, ISI0, HOMA-β and HOMA-IR further ameliorating compared to the 12-month evaluation. Compared to non-HG patients, the HG patients still had a higher weight, BMI and WC.

CONCLUSIONS

In hyperprolactinemic hypogonal men, proper testosterone replacement induces a significant improvement in the metabolic profile, even though the amelioration in the lipid profile might reflect the direct action of CAB.

Increased risk of osteoporosis in postmenopausal women with type 2 diabetes mellitus: a three-year longitudinal study with phalangeal QUS measurements

Type 2 diabetes mellitus (T2DM) is associated with a higher risk of fractures even in presence of normal or increased bone mineral density. The purpose of this three-year longitudinal study was to evaluate the risk of osteoporotic fractures by assessing the changes of Quantitative Ultrasound (QUS) parameters in a group of postmenopausal women with type 2 diabetes mellitus (T2DM) compared with non-diabetic controls. The measurements were taken on a group of 18 postmenopausal women affected by T2DM and 18 healthy age-matched controls, aged 55-70 years, referring to the Osteolab laboratory at the ISBEM Research Institute (Brindisi, Italy) between 2009 and 2013. Subjects had baseline and 3-year follow-up measurements with phalangeal QUS carried out by a DBM Sonic Bone Profiler 1200 (Igea®); medical history, current drug therapies and risk factors for fractures were recorded for each patient. The analyzed phalangeal QUS parameters were Amplitude-Dependent Speed of Sound (AD-SoS), Bone Transmission Time (BTT), Fast Wave Amplitude (FWA) and Signal Dynamic (SDy). At the baseline visit we found no statistically significant difference between T2DM and non-diabetic patients when looking at phalangeal QUS parameters. At the three-year follow-up visit, a significantly higher decrease of both BTT (P<0.001) and AD-SoS (P<0.001) parameters was found in the T2DM group. On the contrary, the decrease of FWA was significantly higher in non-diabetic controls (P<0.001). Our data confirm the ability of phalangeal QUS to detect differences in the risk of osteoporotic fractures in T2DM postmenopausal women compared to non-diabetic controls. The study suggests that T2DM women present a higher cortical porosity and increased trabecular bone density compared to non-diabetic controls, respectively shown by the higher decrease of both AD-SoS and BTT and the lower decrease of FWA.

Could different treatment approaches in acromegaly influence life expectancy? A comparative study between Bulgaria and Campania (Italy)

BACKGROUND

Mortality in acromegaly strictly depends on optimal control of GH and IGF1 levels. Modern medical therapy with somatostatin analogs (SSAs) and GH receptor antagonists (GHRAs) is not available in many countries due to funding restrictions. This retrospective, comparative, cohort study investigated the impact of different treatment modalities on disease control (GH and IGF1) and mortality in acromegaly patients.

METHODS

Two cohorts of patients with acromegaly from Bulgaria (n=407) and Campania, Italy (n=220), were compared, and mortality rates were evaluated during a 10-year period (1999-2008).

RESULTS

The major difference in treatment approach between cohorts was the higher utilization of SSAs and GHRAs in Italy, leading to a decreased requirement for radiotherapy. Significantly more Italian than Bulgarian patients had achieved disease control (50.1 vs 39.1%, P=0.005) at the last follow-up. Compared with the general population, the Bulgarian cohort had a decreased life expectancy with a standardized mortality ratio (SMR) of 2.0 (95% CI 1.54-2.47) that was restored to normal in patients with disease control - SMR 1.25 (95% CI 0.68-1.81). Irradiated patients had a higher cerebrovascular mortality - SMR 7.15 (95% CI 2.92-11.37). Internal analysis revealed an independent role of age at diagnosis and last GH value on all-cause mortality and radiotherapy on cerebrovascular mortality. Normal survival rates were observed in the Italian cohort: SMR 0.66 (95% CI 0.27-1.36).

CONCLUSIONS

Suboptimal biochemical control was associated with a higher mortality in the Bulgarian cohort. Modern treatment options that induce a strict biochemical control and reduce the necessity of radiotherapy might influence the life expectancy. Other factors, possibly management of comorbidities, could contribute to survival rates.

Cushing, acromegaly, GH deficiency and tendons

Cushing's syndrome, induced by an endogenous or exogenous cortisol excess, and acromegaly, the clinical syndrome caused by growth hormone (GH) excess in adulthood, as well as the disease induced by GH deficiency (GHD), represent perfect models for the evaluation of the effects induced by chronic exposure in vivo, respectively, to cortisol and GH/IGF-1 excess or deficiency on the complex structure of the tendons as well as on the related post-traumatic repair mechanism. Although the literature is still scant, here in main scientific evidence on this topic is summarized in order to provide suggestions about the management of the above mentioned illnesses, to translate such information in the field of sports medicine and/or traumatology, and to increase and to disseminate knowledge on this misunderstood theme.

Pituitary tumors and pregnancy: the interplay between a pathologic condition and a physiologic status

Pregnancy is becoming a relatively common event in patients with pituitary tumors (PT), due to the increasing availability of medical treatments, which control pituitary diseases associated with the development of PT. However, the presence of PT and its treatment may be a disturbing factor for pregnancy, and pregnancy significantly influences the course and the management of PT. This review summarizes the knowledge about the management of PT during pregnancy and the occurrence of pregnancy in patients with pre-existent PT, focusing on secreting PT characterized by hormonal excess and on clinically non-functioning PT often associated to hormone deficiency, which configure the hypopituitaric syndrome.

Safety of long-term treatment with cabergoline on cardiac valve disease in patients with prolactinomas

OBJECTIVE

Cabergoline (CAB) has been found to be associated with increased risk of cardiac valve regurgitation in Parkinson's disease, whereas several retrospective analyses failed to detect a similar relation in hyperprolactinemic patients. The current study aimed at investigating cardiac valve disease before and after 24 and 60 months of continuous treatment with CAB only in patients with hyperprolactinemia.

SUBJECTS AND METHODS

Forty patients (11 men and 29 women, aged 38.7 ± 12.5 years) newly diagnosed with hyperprolactinemia entered the study. Cumulative CAB dose ranged from 12 to 588 mg (median 48 mg) at 24 months and 48-1260 mg (median 149 mg) at 60 months. All patients underwent a complete trans-thoracic echocardiographic examination. Valve regurgitation was assessed according to the American Society of Echocardiography.

RESULTS

At baseline, the prevalence of trace mitral, aortic, pulmonic, and tricuspid regurgitations was 20, 2.5, 10, and 40% respectively, with no patient showing clinically relevant valvulopathy. After 24 months, no change in the prevalence of trace mitral (P=0.78) and pulmonic (P=0.89) regurgitations and of mild aortic (P=0.89) and tricuspid (P=0.89) regurgitations was found when compared with baseline. After 60 months, the prevalence of trace tricuspid regurgitation was only slightly increased when compared with that after 24 months (37.5%; P=0.82), but none of the patients developed significant valvulopathy. No correlation was found between cumulative dose and prevalence or grade of valve regurgitation at both evaluations. Prolactin levels normalized in all patients but one.

CONCLUSION

CAB does not increase the risk of significant cardiac valve regurgitation in prolactinomas after the first 5 years of treatment.

Treatment with GH receptor antagonist in acromegaly: effect on cardiac arrhythmias

OBJECTIVE

To evaluate the effects of short- and long-term treatment with pegvisomant (PEG) on arrhythmias in acromegalic patients resistant to long-term, high-dose therapy with somatostatin analogs (SA).

MATERIALS AND METHODS

Thirteen patients entered the study. all patients started peg at initial dose of 10MG daily and then titrated to 5MG every 6 weeks on the basis of IGF1. A standard 24-H electrocardiography registration was performed in all patients at baseline and after 6 AND 18 months of PEG to evaluate: mean (HR), maximum (MHR), and minimum (mHR) heart rate; pauses number (P) and duration (PD); supraventricular episodes (SEs) number and duration (SED); and ventricular ectopic beats (EB) number and duration (EBD). Left ventricular mass (LVM) was also evaluated by standard echocardiography.

RESULTS

A slight but not significant decrease in HR, MHR, and mHR was observed after 6-month PEG, whereas a significant decrease in HR (P=0.03), MHR (P=0.05), and mHR (P=0.05) was found after 18-month PEG compared with baseline. LVM significantly (P=0.05) correlated with MRH (r=-0.50) after short-term treatment, and with HR (r=-0.54) and mHR (r=-0.55) after long-term treatment. Long-term PEG induced the complete recovery of arrhythmias recorded at baseline in one patient and the improvement of rhythm disorders developed after 6-month therapy in another patient. The prevalence of conduction disturbances passed from 15 to 7.7% after long-term PEG.

CONCLUSIONS

Long-term treatment with PEG reduces HR, MHR, and mHR and improves rhythm abnormalities in acromegaly.

Effect of cabergoline on metabolism in prolactinomas

INTRODUCTION

Hyperprolactinemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with an impaired metabolic profile. The current study aimed at investigating the effects of 12- and 60-month treatment with cabergoline (CAB) on metabolic syndrome (MetS) in patients with prolactinomas.

PATIENTS AND METHODS

61 patients with prolactinomas (13 men, 48 women, 41 with microadenoma, 20 with macroadenoma), aged 34.4 ± 10.3 years, entered the study. In all patients, prolactin (PRL) and metabolic parameters were assessed at diagnosis and after 12 and 60 months of continuous CAB treatment. MetS was diagnosed according to NCEP-ATP III criteria.

RESULTS

Compared to baseline, CAB induced a significant decrease in PRL with complete normalization in 93% of patients after the 60-month treatment. At baseline, MetS prevalence was significantly higher in patients with PRL above (34.5%) than in those with PRL lower (12.5%) than the median (129 μg/l, p = 0.03). MetS prevalence significantly decreased after 12 (11.5%, p = 0.039) and 60 (5.0%, p = 0.001) months compared to baseline (28.0%). At both evaluations the lipid profile significantly improved compared to baseline. Fasting insulin and homeostatic model assessment of insulin resistance significantly decreased after 1 year of CAB (p = 0.012 and p = 0.002, respectively) and further improved after 60 months (p = 0.000). The visceral adiposity index significantly decreased after the 60-month treatment (p = 0.000) compared to baseline. At the 5-year evaluation CAB dose was the best predictor of percent decrease in fasting insulin (t = 2.35, p = 0.022).

CONCLUSIONS

CAB significantly reduces MetS prevalence and improves the adipose tissue dysfunction index. The improvement in PRL, insulin sensitivity and other metabolic parameters might reflect the direct effect of CAB.

Results of a single-center observational 10-year survey study on recurrence of hyperprolactinemia after pregnancy and lactation

CONTEXT

The current survey study investigated the recurrence rate of hyperprolactinemia after cabergoline (CAB)-induced pregnancy and after lactation as well as safety of CAB exposure during early gestation.

PATIENTS AND METHODS

From 1997-2008, 143 pregnancies were recorded in 91 patients with hyperprolactinemia (age 30.4 ± 4.7 yr, 76 microadenomas, 10 macroadenomas, and five nontumoral hyperprolactinemia). CAB therapy was discontinued within wk 6 of gestation in all. Pregnancies were monitored until delivery or termination, during and after lactation, twice yearly up to 60 months. The incidence of abortions, premature delivery, and fetal malformations was also analyzed.

RESULTS

Pregnancies resulted in 13 (9.1%) spontaneous abortions and 126 (88.1%) live births. No neonatal malformations and/or abnormalities were recorded. In 29 of 91 patients (three with macroadenomas), treatment with CAB had to be restarted within 6 months after lactation because of hyperprolactinemia recurrence, whereas in 68% of cases, no additional therapy was required up to 60 months. No tumor mass enlargement was observed. All patients but three were breastfeeding, 35 (38.5%) for less than 2 months and 56 (61.5%) for 2-6 months. Three months after cessation of lactation and 60 months after pregnancy, no difference in prolactin levels was found between patients nursing for less than 2 months and 2-6 months.

CONCLUSIONS

Fetal exposure to CAB at conception does not induce any increased risk of miscarriage or malformations. Pregnancy is associated with normalization of prolactin levels in 68% of patients. Breastfeeding does not increase the recurrence rate of hyperprolactinemia.

Glycometabolic control in acromegalic patients with diabetes: a study of the effects of different treatments for growth hormone excess and for hyperglycemia

BACKGROUND

Diabetes mellitus is frequently observed in patients with acromegaly. Current therapies for acromegaly may impact glucose regulation, influencing insulin sensitivity and secretion. The question whether these therapies modify control and progression of diabetes once present is still open.

AIM

Aim of our study is to analyze glucose control in acromegalic patients with diabetes, evaluating the relation with treatments for GH excess and for diabetes.

METHODS

Seventy patients with acromegaly and diabetes were studied. Duration and treatments of acromegaly and diabetes were recorded, together with clinical and metabolic parameters.

RESULTS

Most patients (92.8%) were treated with somatostatin analogs (SSA), either alone or in combination with dopamine-agonists (20%) or pegvisomant (15.7%); 7.1% of patients had been treated by surgery alone. Metformin (65.7%), alone or in combination with other hypoglycemic drugs, was the most frequent treatment for diabetes, followed by insulin (21.5%). Only 15.7% were treated with diet alone. The whole cohort showed a very good control of diabetes and acromegaly. Median glycated hemoglobin was 6.4% (5.9-7). IGF-I was within normal range for age in most patients. No relation was observed between duration of acromegaly or diabetes and metabolic control. SSA had a negative effect on insulin secretion, but these effects did not influence glucose control. Finally, we observed a low prevalence of nephropathy (6%) and retinopathy (20%).

CONCLUSIONS

Our study shows that a good control of hyperglycemia can be obtained with success in the majority of acromegalic patients with diabetes, independently of the type of treatment for GH excess.

Mutations of calcium-sensing receptor gene: two novel mutations and overview of impact on calcium homeostasis

OBJECTIVE

Genetic disorders of calcium metabolism arise in a familial or sporadic setting. The calcium-sensing receptor (CASR) plays a key role in maintaining calcium homeostasis and study of the CASR gene can be clinically useful in determining etiology and appropriate therapeutic approaches. We report two cases of novel CASR gene mutations that illustrate the varying clinical presentations and discuss these in terms of the current understanding of CASR function.

PATIENTS AND METHODS

A 16-year-old patient had mild hypercalcemia associated with low-normal urinary calcium excretion and normal-to-high parathyroid hormone (PTH) levels. Because of negative family history, familial hypocalciuric hypercalcemia was originally excluded. The second patient was a 54-year-old man with symptomatic hypocalcemia, hyperphosphatemia, low PTH, and mild hypercalciuria. Familial investigation revealed the same phenotype in the patient's sister. The coding region of the CASR gene was sequenced in both probands and their available first-degree relatives.

RESULTS

The first patient had a novel heterozygous inactivating CASR mutation in exon 4, which predicted a p.A423K change; genetic analysis was negative in the parents. The second patient had a novel heterozygous activating CASR mutation in exon 6, which predicted a p.E556K change; the affected sister of the proband was also positive.

CONCLUSIONS

We reported two novel heterozygous mutations of the CASR gene, an inactivating mutation in exon 4 and the first activating mutation reported to date in exon 6. These cases illustrate the importance of genetic testing of CASR gene to aid correct diagnosis and to assist in clinical management.

Resistance to somatostatin analogs in acromegaly

Somatostatin analogs (SA) are widely used in acromegaly, either as first-line or adjuvant treatment after surgery. First-line treatment with these drugs is generally used in the patients with macroadenomas or in those with clinical conditions so severe as to prevent unsafe reactions during anesthesia. Generally, the response to SA takes into account both control of GH and IGF-I excess, with consequent improvement of clinical symptoms directly related to GH and IGF-I excess, and tumor shrinkage. This latter effect is more prominent in the patients treated first-line and bearing large macroadenomas, but it is also observed in patients with microadenomas, even with little clinical implication. Predictors of response are patients' gender, age, initial GH and IGF-I levels, and tumor mass, as well as adequate expression of somatostatin receptor types 2 and 5, those with the highest affinity for octreotide and lanreotide. Only sporadic cases of somatostatin receptor gene mutation or impaired signaling pathways have been described in GH-secreting tumors so far. The response to SA also depends on treatment duration and dosage of the drug used, so that a definition of resistance based on short-term treatments using low doses of long-acting SA is limited. Current data suggest that response to these drugs is better analyzed taking together biochemical and tumoral effects because only the absence of both responses might be considered as a poor response or resistance. This latter evidence seems to occur in 25% of treated patients after 12 months of currently available long-acting SA.

Growth hormone nadir during oral glucose load depends on waist circumference, gender and age: normative data in 231 healthy subjects

OBJECTIVE

  (i) To analyse the predictors of GH suppression after standard glucose load (oGTT) in the healthy population and (ii) to establish the 97th percentile of GH nadir post-oGTT according to these variables. Design  Analytical, retrospective.

MEASUREMENTS

GH nadir after oGTT.

SUBJECTS

Two hundred and thirty-one healthy subjects (113 women, 118 men 15-80years) were studied.

RESULTS

The GH nadir after glucose load ranged from 0·01 (<assay detection limit) to 0·65 μg/l was higher in women and was inversely correlated with age, BMI, waist circumference, waist/hip, total cholesterol, triglycerides, basal and maximal glucose and basal insulin levels and directly correlated with basal GH levels, IGF-I SDS and HDL-cholesterol (P values ranging 0·004-<0·0001). On multistep regression analysis, the best predictors of nadir GH levels were waist circumference (t = -9·64, P < 0·0001), gender (t = -3·86, P = 0·0001) and age (t = -3·63, P = 0·0003). The results of comparative analysis among subjects grouped according to these variable showed different results in GH nadir in premenopausal women with waist circumference ≤88 cm (97th percentile 0·65 μg/l), in premenopausal women with waist circumference ≤88 cm and in men of any age with waist circumference ≤102 cm (97th percentile 0·33 μg/l) and in subjects of either gender and any age with waist circumference >88 cm in women and 102 cm in men (97th percentile 0·16 μg/l). CONCLUSIONS The results of this study show that GH nadir after oGTT should be analysed according to gender, menopausal status and waist circumference. The GH cut-off should be limited to the assay used.

The treatment with growth hormone receptor antagonist in acromegaly: effect on vascular structure and function in patients resistant to somatostatin analogues

BACKGROUND

Acromegaly is known to be associated to vascular damage characterized by an increase of vascular wall thickness and an impairment of vascular function.

AIM

The aim of this study was to evaluate the effect of medical treatment with the GH receptor antagonist pegvisomant on vascular structure and function in acromegalic patients resistant to somatostatin analogues.

PATIENTS

Ten patients (4 males and 6 females, 28-58 yr) and 20 sex-, age-, and body mass index-matched healthy controls entered the study. All patients were treated for 18 months with pegvisomant at doses ranging from 10 to 40 mg/day.

OUTCOME MEASURES

Primary outcome measures were measurement of carotid arteries intima-media thickness (IMT), and brachial arteries flow mediated dilation (FMD); secondary outcome measures were blood pressure, blood glucose and lipids levels.

RESULTS

Carotid arteries maximal IMT was significantly higher in patients than in controls at baseline (1.18±0.59 vs 0.69±0.13, p=0.001) and slightly, but not significantly, decreased after treatment (0.97±0.17). Brachial arteries FMD was significantly lower in patients than controls at baseline (7.5±2.5 vs 13.1±1.4, p<0.001) and significantly increased after treatment (8.8±3.7, p=0.016). Systolic (SBP) and diastolic (DBP) blood pressure values, serum glucose and insulin levels and homeostasis model assessment (HOMA) index were higher, whereas HDL-cholesterol levels were lower in patients than controls at baseline. After treatment, SBP and DBP, as well as serum glucose and insulin levels and HOMA index significantly decreased whereas no significant change was found in serum lipid profile.

CONCLUSIONS

The results of the current study suggested that long-term treatment with pegvisomant induced a slight reduction of carotid arteries wall thickness and a significant improvement of brachial arteries vascular function in patients with acromegaly resistant to somatostatin analogues.

The kidney in acromegaly: renal structure and function in patients with acromegaly during active disease and 1 year after disease remission

BACKGROUND

The GH/insulin-like growth factor 1 axis is physiologically involved in the regulation of electrolytes and water homeostasis by kidneys, and influences glomerular filtration and tubular re-absorption processes. The aim of the study was to investigate renal structure and function in acromegalic patients during active disease and disease remission.

PATIENTS

Thirty acromegalic patients (15 males and 15 females), aged 32-70 years, were enrolled for the study. Ten de novo patients had active disease, whereas 20 patients showed disease remission 1 year after medical treatment with somatostatin analogs (SA) (ten patients) or surgery (ten patients). Thirty healthy subjects matched for age, gender, and body surface area were enrolled as controls.

RESULTS

In both active (A) and controlled (C) patients, creatinine clearance (P<0.001) and citrate (P<0.05) and oxalate levels (P<0.001) were higher, whereas filtered Na (P<0.001) and K (P<0.001) fractional excretions were lower than those in the controls. Urinary Ca (P<0.001) and Ph (P<0.05) levels were significantly increased compared with the controls, and in patients with disease control, urinary Ca (P<0.001) levels were significantly reduced compared with active patients. Microalbuminuria was significantly increased in active patients (P<0.05) compared with controlled patients and healthy control subjects. The longitudinal (P<0.05) and transverse (P<0.05) diameters of kidneys were significantly higher than those in the controls. In all patients, the prevalence of micronephrolithiasis was higher than that in the controls (P<0.001), and was significantly correlated to disease duration (r=0.871, P<0.001) and hydroxyproline values (r=0.639, P<0.001).

CONCLUSIONS

The results of the current study demonstrated that acromegaly affects both renal structure and function. The observed changes are not completely reversible after disease remission.

Complete disappearance of a GH-secreting pituitary macroadenoma in a patient with acromegaly: effect of treatment with lanreotide Autogel and consequence of treatment withdrawal

BACKGROUND

Somatostatin analogs (SA) are the cornerstone in the medical treatment of acromegaly, used as either primary or adjunctive therapy. In particular, SA are effective in inducing the biochemical remission of the disease and tumor shrinkage, although only few cases of complete disappearance of the pituitary tumor in patients treated with SA as long-acting formulations have been reported. SA withdrawal has been demonstrated to keep safe levels of GH and IGF1 at least in a small subset of patients well responsive to SA, although it is generally followed by disease recurrence after several months.

CASE REPORT

A 61-year-old female patient bearing a very large GH-secreting pituitary macroadenoma was treated with 12-month lanreotide Autogel (ATG), at the initial dose of 120 mg/28 days. After 3 months, GH and IGF1 levels were fully normalized, to prolong the administration interval from 28 to 56 days. After 6 months of treatment, a significant tumor shrinkage (90% of baseline size) was observed, whereas GH and IGF1 excess was still well controlled. After 12-month therapy, a complete disappearance of the pituitary tumor was observed, and the hormonal evaluation confirmed the complete biochemical remission of acromegaly. Lanreotide ATG treatment was withdrawn. The clinical, biochemical, and radiological remission of acromegaly was maintained 24 months after lanreotide ATG treatment discontinuation, without evidence of disease recurrence.

CONCLUSIONS

This report represents an exemplary case of the potentiality of treatment with lanreotide ATG in inducing a complete remission of acromegalic disease, persistent after a long period of time from treatment withdrawal.

Cardiovascular disease in Cushing's syndrome: heart versus vasculature

Cushing's syndrome (CS) causes metabolic abnormalities that determine an increased cardiovascular risk not only during the active phase of the disease but also for a long time after cure. Cardiovascular complications, such as premature atherosclerosis, coronary artery disease, heart failure, and stroke, in patients with CS cause a mortality rate higher than that observed in a normal population. The increased cardiovascular risk is mainly due to metabolic complications, such as metabolic syndrome, but also to vascular and cardiac alterations such as atherosclerosis and cardiac structural and functional changes. In the clinical management of patients with CS the focus should be on identifying the global cardiovascular risk and the aim should be to control not only hypertension but also other correlated risk factors, such as obesity, glucose intolerance, insulin resistance, dyslipidemia, endothelial dysfunction and the prothrombotic state. Considering that remission from hypercortisolism is often difficult to achieve and that the cardiovascular risk can persist even during disease remission, care and control of all cardiovascular risk factors should be one of the primary goals during the follow-up of these patients.

Effects of initial therapy for five years with somatostatin analogs for acromegaly on growth hormone and insulin-like growth factor-I levels, tumor shrinkage, and cardiovascular disease: a prospective study

OBJECTIVE

The objective of the study was to evaluate the efficacy of 5 yr of depot somatostatin analogs (SSAs) as first-line therapy in acromegaly.

OUTCOME MEASURES

Primary measures were fasting GH 2.5 microg/liter or less and IGF-I normalized for age and tumor shrinkage. Secondary measures were control of hypertension, arrhythmias, left ventricular hypertrophy, diastolic and systolic dysfunction, and change in lipid and glucose profile.

PATIENTS

Patients included 45 de novo patients (18 women and 27 men, aged 20-82 yr); 28 were treated with octreotide-long-acting release and 17 with lanreotide.

RESULTS

GH was controlled in 100% and IGF-I levels in 97.8%, tumor shrinkage was 74.9 +/- 22.1 and 78.2+/-14.5%, in the octreotide-long-acting release and lanreotide groups, respectively. There was a significant improvement in the prevalence of hypertension (from 46.7 to 22.2%, P = 0.027), arrhythmias (from 17.8% to zero, P = 0.01), left ventricular hypertrophy (from 82.2 to 42.2%, P < 0.0001), diastolic dysfunction (from 60.0 to 15.6%, P < 0.0001), systolic dysfunction (from 40.0 to 4.4%, P < 0.0001), and hypertriglyceridemia (from 40.0 to 4.4%, P < 0.0001). The prevalence of impaired glucose tolerance (IGT; from 28.9 to 20.0%. P = 0.46) and diabetes mellitus (from 22.4 to 31.1%, P = 0.64) did not change.

CONCLUSIONS

In patients with severe comorbidities and those who refuse surgery, 5 yr of exclusive SSA therapy induce successful control of GH and IGF-I; tumor shrinkage (by median 80%), and improvement of hypertension, cardiac performance; and dyslipidemia. No patient was withdrawn from treatment because of side effects, and glucose tolerance was stable. We suggest that first-line SSA treatment may be safely continued in patients with acromegaly, according to an individual patient's indications and preferences.

Glucose tolerance and somatostatin analog treatment in acromegaly: a 12-month study

OBJECTIVE

The objective of the study was to investigate the impact of first-line somatostatin analogs (SSAs) on glucose tolerance (GT) in acromegaly.

DESIGN

The design was open and prospective.

PATIENTS

One hundred twelve patients [63 with normal GT (56.2%), 24 with impaired GT (21.4%), and 25 with diabetes (22.3%)] were treated with depot SSAs for 12 months: 54 patients (48.2%) achieved mean fasting GH levels less than 2.5 microg/liter in presence of normal IGF-I levels (controlled) during SSA.

PRIMARY OUTCOME MEASURES

Fasting glucose and glycosylated hemoglobin levels were measured.

RESULTS

At study end, 57 patients had normal GT (50.1% vs. baseline; P = 0.55), 30 had impaired fasting glucose or impaired GT (26.8%, P =0.43) and 25 had diabetes (22.3%; P = 1.0). Twenty-eight patients (25.0%), modified their GT [11 improved (9.8%), 17 worsened (15.2%)]: 90% of the patients with GT improvement achieved control of acromegaly and 89% of those having GT worsening did not (P < 0.0001). The major predictors of GT changing were disease control (t = -4.99; P < 0.0001), baseline GT (t = -2.84; P = 0.0054), and GH levels (t = 2.70; P = 0.008). Fasting glucose levels were predicted by patients' age (t = 2.74; P = 0.0071) and IGF-I levels (t = 2.14; P = 0.035). Glycosylated hemoglobin levels were predicted by disease duration (t = 3.53; P = 0.0006), GH levels (t = 2.70; P = 0.0071), and IGF-I levels (t = 2.11; P = 0.037).

CONCLUSIONS

This study showed a similar prevalence of deterioration and improvement of GT 12 months after first-line SSA treatment. Uncontrolled acromegaly during SSA treatment and abnormal GT at baseline were associated with GT worsening.