Excess mortality in patients with non-functioning pituitary adenoma: a systematic review and meta-analysis

BACKGROUND

Patients with non-functioning pituitary adenoma (NFPA) often present with a variety of clinical manifestations and comorbidities, mainly determined by the local mass effect of the tumor and by hypopituitarism. Whether this has an impact on overall mortality, however, is still unclear.

METHODS

PubMed/Medline, EMBASE, and Cochrane Library databases were systematically searched until May 2023 for studies reporting data either about standardized mortality ratios (SMRs) or about predictors of mortality in patients with NFPA. Effect sizes were pooled through a random-effect model. This systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO, #CRD42023417782).

RESULTS

Eleven studies were eligible for inclusion in the systematic review; among these, five studies reported data on SMRs, with a total follow-up time of approximately 130,000 person-years. Patients with NFPA showed an increased mortality risk compared to the general population (SMR = 1.57 [95%CI: 1.20-1.99], p < 0.01). Age and sex appeared to act as effect modifiers, with a trend towards higher SMRs in females (SMR = 1.57 [95%CI: 0.91-2.41], p = 0.10) than in males (SMR = 1.00 [95%CI: 0.89-1.11], p = 0.97), and in patients diagnosed at age 40 years or younger (SMR = 3.19 [95%CI: 2.50-3.97], p < 0.01) compared to those with later onset of the disease (SMR = 1.26 [95%CI: 0.93-1.65], p = 0.13). The trend towards excess mortality was similar in patients with normal (SMR = 1.22 [95%CI: 0.94-1.53], p = 0.13) or deficient (SMR = 1.26 [95%CI: 0.82-1.79], p = 0.27) pituitary function.

CONCLUSIONS

Excess mortality is observed in patients with NFPA, regardless of pituitary function, especially in women and in patients with a younger age at diagnosis.

Once upon a time: the glucagon stimulation test in diagnosing adult GH deficiency

PURPOSE

The clinical features of adult GH deficiency (GHD) are nonspecific, and its diagnosis is established through GH stimulation testing, which is often complex, expensive, time-consuming and may be associated with adverse side effects. Moreover, diagnosing adult GHD can be challenging due to the influence of age, gender, and body mass index on GH peak at each test. The insulin tolerance test (ITT), GHRH + arginine test, glucagon stimulation test (GST), and, more recently, testing with macimorelin are all recognized as useful in diagnosing adult GHD. To date GST is still little used, but due to the unavailability of the GHRH all over the world and the high cost of macimorelin, in the next future it will probably become the most widely used test when ITT is contraindicated. The aim of the present review is to describe the current knowledge on GST.

METHODS

Narrative review.

RESULTS

In the last years several studies have suggested some changes in the original GST protocol and have questioned its diagnostic accuracy when the classic GH cut-point of 3 μg/L is used, suggesting to use a lower GH cut-point to improve its sensitivity and specificity in overweight/obese patients and in those with lower pretest GHD probability.

CONCLUSION

This document provides an update on the utility of GST, summarizes how to perform the test, shows which cut-points should be used in interpreting the results, and discusses its drawbacks and caveats referring to the most recent studies.

Neuroendocrine response to diclofenac in healthy subjects: a pilot study

PURPOSE

The precise effects of non-steroidal anti-inflammatory drugs on the neuroendocrine hydro-electrolytic regulation are not precisely understood. The aim of this pilot study was to evaluate, in healthy subjects, the neuroendocrine response of the antidiuretic system to intravenous diclofenac infusion.

METHODS

For this single-blinded, cross-over study, we recruited 12 healthy subjects (50% women). Test sessions were divided into three observation times (pre-test; test; 48 h post-test), which were repeated equally on two different occasions, with the administration of diclofenac (75 mg in saline solution 0.9% 100 cc) on 1 day, or placebo (saline solution 0.9% 100 cc) on another day. The night before the test the subjects were asked to collect a salivary cortisol and cortisone sample, which was repeated on the night of the procedure session. Serial urine and blood samples were collected on the test day (for osmolality, electrolytes, ACTH, cortisol, copeptin, MR-proADM, MR-proANP; the last three represent more stable and analytically reliable molecules than their respective active peptides). Moreover, the subjects were evaluated with the bioimpedance vector analysis (BIVA) before and after the test. Forty-eight hours after the end of the procedure urine sodium, urine potassium, urine osmolality, serum sodium and copeptin were revaluated together with BIVA.

RESULTS

No significant changes in circulating hormone levels were observed; anyway, 48 h after diclofenac, BIVA showed a significant water retention (p < 0.00001), especially in extracellular fluid (ECF) (16.47 ± 1.65 vs 15.67 ± 1.84, p < 0.001). Salivary cortisol and cortisone tended to increase only the night after placebo administration (p = 0.054 cortisol; p = 0.021 cortisone).

CONCLUSION

Diclofenac resulted in an increased ECF at 48 h, but this phenomenon seems to be associated with a greater renal sensibility to the action of vasopressin rather than with an increase in its secretion. Moreover, a partial inhibitory effect on cortisol secretion can be hypothesized.

GHRH + arginine test and body mass index: do we need to review diagnostic criteria for GH deficiency?

INTRODUCTION

The proportion of patients with low GH response to provocative tests increases with the number of other pituitary hormone deficiencies, reason why in panhypopituitary patients GH stimulation tests may be unnecessary to diagnose GH deficiency (GHD) PURPOSE: To re-evaluate the diagnostic cut-offs of GH response to GHRH + arginine (ARG) test related to BMI, considering the patients' pituitary function as the gold standard for the diagnosis of GHD.

METHODS

The GH responses to GHRH + ARG were studied in 358 patients with history of hypothalamic-pituitary disease. GHD was defined by the presence of at least 3 other pituitary deficits (n = 223), while a preserved somatotropic function was defined by the lack of other pituitary deficits and an IGF-I SDS ≥ 0 (n = 135). The cut-off with the best sensitivity (SE) and specificity (SP), was identified for each BMI category using the ROC curve analysis. To avoid over-diagnosis of GHD we subsequently searched for the cut-offs with a SP ≥ 95%.

RESULTS

The best GH cut-off was 8.0 μg/l (SE 95%, SP 100%) in lean, 7.0 μg/l (SE 97.3%, SP 82.8%) in overweight, and 2.8 μg/l (SE 84.3%, SP 91.7%) in obese subjects. The cut-off with a SP ≥ 95% was 2.6 μg/l (SE 68.5%, SP 96.6%) in overweight and 1.75 μg/l (SE 70.0%, SP 97.2%) in obese subjects.

CONCLUSIONS

This is the first study that evaluates the diagnostic cut-offs of GH response to GHRH + ARG related to BMI using a clinical definition of GHD as gold standard. Our results suggest that with this new approach, the GHRH + ARG cut-offs should be revised to avoid GHD over-diagnosis.

Benefits of dual-release hydrocortisone treatment on central adiposity and health-related quality of life in secondary adrenal insufficiency

PURPOSE

Patients with secondary adrenal insufficiency (SAI) have an increased morbidity and an impaired health-related quality of life (HRQoL), which seems to primarily depend on the sub-optimal replacement of hypoadrenalism with standard glucocorticoid (GC) therapy, and on the inadequate correction of other associated pituitary deficiencies. A dual-release hydrocortisone (DR-HC) formulation has shown to exert positive effects on morbidity and HRQoL, mainly in patients with primary adrenal insufficiency. We assessed the variations of anthropometric and metabolic parameters and HRQoL in patients with SAI after switching from cortisone acetate (CA) or hydrocortisone (HC) to DR-HC.

METHODS

Twenty-one patients (17 M, 4 F) treated with CA (n = 16; 25 mg/day twice a day) or HC (n = 5; 20 mg/day three times a day), were evaluated for waist circumference, BMI, fasting glucose, HbA1c, insulin, HOMA-IR index, serum lipids, electrolytes, blood pressure and HRQoL at baseline, at 3, 6 and 12 months after switching from CA/HC to DR-HC.

RESULTS

The study showed a significant reduction of waist circumference and BMI (p = 0.04, for both), after 3 and 6months of DR-HC treatment, respectively. No significant changes were observed for fasting glucose, insulin, HOMA-IR index, HbA1c, total cholesterol, triglycerides, LDL cholesterol, electrolytes, and blood pressure. However, HDL cholesterol significantly decreased (p = 0.003). An improvement of AddiQoL total score was observed during DR-HC treatment (p = 0.01), mainly for the category "emotions". No predictors resulted for these changes.

CONCLUSION

DR-HC treatment provides some benefits in patients with SAI, reducing central adiposity and improving HRQoL; however, worsening of HDL cholesterol is observed during treatment with DR-HC.

Development and internal validation of a predictive score for the diagnosis of central adrenal insufficiency when morning cortisol is in the grey zone

BACKGROUND

When evaluating a patient for central adrenal insufficiency (CAI), there is a wide range of morning cortisol values for which no definite conclusion on hypothalamus-pituitary-adrenal (HPA) axis function can be drawn; in these cases, a stimulation test is required. Aim of this study was to develop an integrated model for CAI prediction when morning cortisol is in the grey zone, here defined as 40.0-160.0 μg/L.

METHODS

Overall, 119 patients with history of sellar tumour which underwent insulin tolerance test (ITT) for the evaluation of HPA axis were enrolled. Supervised regression techniques were used for model development.

RESULTS

An integrated predictive model was developed and internally validated, and showed a significantly better diagnostic performance than morning cortisol alone (AUC 0.811 vs 0.699, p = 0.003). A novel predictive score (CAI-score) was retrieved, on a 5.5-point scale, by considering morning cortisol (0 points if 130.1-160.0 μg/L, 1 point if 100.1-130.0 μg/L, 1.5 points if 70.1-100.0 μg/L, 2.5 points if 40.0-70.0 μg/L), other pituitary deficits (2 points if ≥ 3 deficits), and sex (1 point if male). A diagnostic algorithm integrating CAI-score and ITT was finally proposed, with an overall accuracy of 99%, and the possibility to avoid the execution of stimulation tests in 25% of patients.

CONCLUSIONS

This was the first study that proposed an integrated score for the prediction of CAI when morning cortisol is in the grey zone. This score might be helpful to reduce the number of patients who need a stimulation test for the assessment of HPA axis function.

Mean GH profile is more accurate than single fasting GH in the evaluation of acromegaly disease control during somatostatin receptor ligands therapy

PURPOSE

This study aims to compare the accuracy of mean GH profile (GHP) < 2.5 ng/ml and single fasting GH (SGH) < 1 ng/ml in the evaluation of disease control in acromegaly patients during somatostatin receptor ligands (SRLs) therapy.

METHODS

We retrospectively enrolled 100 acromegaly patients, 68 responder, and 32 partial responder to SRLs. Controlled disease has been defined as IGF-I levels within age-related normal limits, while partial response as pathological IGF-I values despite a reduction ≥ 50%. In all patients, GHP, SGH, IGF-I, and IGFBP-3 were evaluated.

RESULTS

Median GHP levels (1.2 ng/ml, IQR 0.5-2.3 ng/ml) were lower (p = 0.001) than SGH (1.9 ng/ml, IQR 1.0-3.6 ng/ml). Accuracy of GHP was 81%, whereas that of SGH was 55%, with a Kappa index of 0.520 and 0.237, respectively. In multivariable analysis GHP (p = 0.002) and IGFBP-3 (p = 0.004), but not SGH, were independently associated with normal IGF-I levels. At receiver-operator characteristic curve (ROC) analysis GHP cut-off sensitivity and specificity were 94.1% and 50.0%, respectively, while SGH sensitivity and specificity were 35.3% and 93.7%, respectively. Finally, in obese patients the GH cut-off level (both as SGH and GHP) associated to good disease control was significantly different with respect to not obese ones.

CONCLUSIONS

GHP associates with IGF-I (and therefore with appropriate control of disease) with higher accuracy than SGH. When GH evaluation is needed, the measurement of mean GHP should be preferred and use of BMI-related cut-offs is suggested.

Optimal timing of blood samplings to detect GH inhibition during oral glucose tolerance test

BACKGROUND

In patients with suspected acromegaly, evaluation of IGF-I is recommended as first-line test, while the assessment of GH-nadir during oral glucose tolerance test (OGTT) is advised as confirmatory test. The procedure of this test generally involves GH measurement every 30 min (30') from baseline to +120' or +180'. However, the optimal timing of samplings for the distinction between patients with or without active acromegaly is still a matter of debate.

METHODS

Sixty-seven healthy subjects and 46 acromegalic patients who achieved documented and persistent long-term cure were enrolled. A greedy algorithm was used to identify the minimal subset of time-points that sufficed to correctly detect GH suppression.

RESULTS

The sampling at 90' was the one in which a GH level < 1 μg/L was most frequently achieved (i.e., in 91.3% of cured acromegalic patients and in 91.0% of healthy subjects). Considering the whole cohort, the best combination of 2 time-points was +90' and +150' and achieved 95.6% accuracy; the best combination of 3 time-points was +60', +90' and +150' and achieved 99.1% accuracy. The minimal subset of GH determinations that demonstrated perfect accuracy (100%) needed the inclusion of 4 time-points, namely +60', +90', +120' and +150'.

CONCLUSION

A subset of 4 time-points (60' - 90' - 120' - 150') was identified as the most relevant to detect GH suppression at OGTT, with a perfect classification of 100% of subjects. This supports the possibility to restrict the blood samplings to these time-points when assessing disease cure, with possible advantages in terms of saving time and lowering costs.

First but not second postoperative day growth hormone assessments as early predictive tests for long-term acromegaly persistence

PURPOSE

Postoperative assessment of acromegaly activity is typically performed at least 3 months after neurosurgery (NS). Few studies have evaluated the use of early postoperative growth hormone (GH) levels as a test to predict short- and long-term remission of acromegaly. Our objective was to evaluate the diagnostic performance of serum random GH on a postoperative day one (D1-rGH) and two (D2-rGH), particularly in predicting long-term disease persistence.

MATERIALS AND METHODS

Forty-one subjects with acromegaly who were undergoing NS were enrolled (mean age ± SD 47.4 ± 13.1 years at diagnosis; women 54%; macroadenomas 71%). The final assessment of disease activity was performed one year after NS. ROC curves were used to evaluate the diagnostic performance of D1-rGH and D2-rGH.

RESULTS

After a 1-year follow-up, the overall remission rate was 55%. ROC analysis identified an optimal D1-rGH cut-off value of 2.1 ng/mL for diagnosing long-term disease persistence (55.6% SE; 90.9% SP). The cut-off point became 2.5 ng/mL after maximizing specificity for disease persistence (yielding a 100% positive predictive value) and 0.3 ng/mL after maximizing sensitivity for disease remission. The optimal D2-rGH cut-off value was 0.6 ng/mL (81.8% SE; 50% SP); the cut-off point became 2.9 ng/mL after maximizing specificity and 0.1 ng/mL after maximizing sensitivity, with no clinical utility.

CONCLUSIONS

D1-rGH could be a highly specific test for the early diagnosis of long-term acromegaly persistence, which is predicted by a value > 2.5 ng/mL with a great degree of certainty. The diagnostic performance of D2-rGH was insufficient. Further research is required to validate these preliminary results prior to modifying the postoperative management of acromegaly.

Biliary adverse events in acromegaly during somatostatin receptor ligands: predictors of onset and response to ursodeoxycholic acid treatment

PURPOSE

Somatostatin receptor ligands (SRL) are the first-line medical treatment for acromegaly. Gallbladder alterations are one of most important SRL side effect, but according to some authors growth hormone hypersecretion itself is a risk factor for gallstones. This single center, longitudinal retrospective study evaluated the incidence and the predictors of biliary adverse events (BAE) in acromegaly during SRL therapy and their response to ursodeoxycholic acid (UDCA).

METHODS

91 acromegaly patients with indication to SRL were enrolled. Evaluations of acromegaly activity (GH, IGF-I, IGF-I/ULN) and metabolic profile were collected before starting treatment, yearly during follow-up and at BAE onset. In patients developing BAE we searched for predictors of UDCA effectiveness.

RESULTS

61.5% of patients developed BAE (58.9% cholelithiasis; 41.1% only sludge). IGF-I and IGF-I/ULN proved to be positive predictor of BAE, which occur about 5 years after SRL starting. None of metabolic markers proved to be associated with BAE. Only five patients (5.5%) underwent cholecystectomy for symptomatic cholelithiasis. 71% of patients started UDCA treatment, achieving regression of BAE in 60% of cases (88% in patients developing only sludge and 30% in patients affected by cholelithiasis, p < 0.001). BMI and obesity were negative predictors of UDCA efficacy. In 50% of the subjects BAE resolved after 36 months of therapy with a lower rate if cholelithiasis was present.

CONCLUSION

Biliary stone disease is a frequent SRL adverse event, although it is often symptomless. Ultrasound follow-up mainly in the first 5 years of therapy, early UDCA starting and proper lifestyle represent a valid strategy in their detection and management.

Safety and effectiveness of Omnitrope® in patients with growth hormone deficiency: snapshot analysis of PATRO Adults study in the Italian population

PURPOSE

PATRO adults is an ongoing, multicenter, observational, post-marketing surveillance study aimed at investigating the long-term safety (primary endpoint) and effectiveness (secondary endpoint) of the recombinant human growth hormone (rhGH) Omnitrope® during routine clinical practice. This report describes data from Italian participants in PATRO Adults with growth hormone deficiency (GHD), up to August 2017.

METHODS

Participants were adults (aged > 18 years) with GHD requiring rhGH therapy and were prescribed Omnitrope®, including those who had previously received another rhGH product. Adverse events (AEs) were evaluated in all study participants. Data were collected on insulin-like growth factor (IGF)-I levels and cardiovascular risk factors, including blood pressure, lipids, and anthropometric parameters.

RESULTS

From September 2007 to August 2017, 88 patients (mean age 48.9 years, 58.0% male) were enrolled at 8 sites in Italy. The mean treatment duration with Omnitrope® was 51.5 ± 37 months. AEs occurred in 54 patients; the most common were asthenia (20.5%), headache (14.8%), and arthralgia (13.6%). Serious AEs occurred in 22 patients (25%), including pneumonia (n = 2) and renal failure (n = 2). Neoplasms (2 benign and 1 malignant) developed in three patients, but none were considered to be drug-related. There were no significant changes in fasting glucose or glycosylated hemoglobin (HbA1c) during the study period. Long-term Omnitrope® therapy showed slight positive effects on lipid profile, while no significant changes were observed in body weight and BMI during the study.

CONCLUSION

This snapshot analysis of Italian participants in PATRO Adults confirmed the long-term safety and effectiveness of Omnitrope® in adults with GHD.

Acromegaly and joint pain: is there something more? A cross-sectional study to evaluate rheumatic disorders in growth hormone secreting tumor patients

PURPOSE

The aim of the present study was to evaluate the rheumatic profile in acromegalic patients to better characterize joint pain.

METHODS

The immunological pattern (rheumatoid factor; antinuclear antibodies-ANA, extractable nuclear antigens-ENA-Ab; anti-citrullinated protein antibodies; erythrocyte sedimentation rate) was evaluated in 20 acromegaly subjects (AS) and 20 control subjects (CS). Bilateral joint ultrasound of hands/wrists and nail capillaroscopy were also performed.

RESULTS

Articular pain was more frequent in AS than in CS (p = 0.027). No difference was detected in immunological parameters. ANA and ENA-Ab were positive in only 10% of AS and in 5% of CS, while no difference was found in anti-citrullinated protein antibodies. No difference was detected between rheumatoid factor positivity, but threefold higher IgG were detected in AS compared to CS. The erythrocyte sedimentation rate was significantly higher in AS than CS (p = 0.040), while in AS, there was a trend in increased Power Doppler (PWD) articular uptake. The capillaroscopic evaluation showed a significant difference in almost each parameter (presence and number of tortuous capillaries, capillary enlargements, and hemorrhages), showing a moderate-to-severe microangiopathy in AS.

CONCLUSION

The results of our study suggest that joint damage in acromegaly has not an autoimmune etiology. Increased erythrocyte sedimentation rate levels and PWD alteration in acromegalic population reflect a possible inflammatory nature, while the capillaroscopic findings suggest a moderate-to-severe microangiopathy that could help to identify patients with a greater macroangiopathic risk.

Untreated adult GH deficiency is not associated with the development of metabolic risk factors: a long-term observational study

PURPOSE

Uncertainties exist about the predictors of the severity of the clinical picture of GH deficiency (GHD) syndrome. Aim of the study was to evaluate, in adult patients with GHD, the predictors of the development of hypercholesterolemia, hypertension, diabetes mellitus, and osteoporosis.

METHODS

We retrospectively studied 327 adult patients (age 47.1 ± 17.1 years) with untreated severe GHD (mean follow-up 110.9 ± 56.8 months). GHD was defined by GHRH + arginine test using BMI cut-offs. The possible development of hypercholesterolemia, hypertension, diabetes mellitus, and osteoporosis was investigated by Kaplan-Meier survival analysis. For each clinical outcome, either a univariate or multivariate analysis according to the Cox proportional-hazards model was performed to identify those factors that were associated with the development of the event.

RESULTS

GH secretion parameters were not associated with the outcomes. Hypercholesterolemia was positively and negatively predicted by a BMI ≥ 30 kg/m² (HR 2.50, p 0.00) and the dose of l-thyroxine possibly in place (HR 0.98, p 0.02), respectively. Hypertension was positively predicted by a BMI ≥ 30 kg/m² (HR 2.64, p 0.00) and IGF-I SDS values (HR 2.26, p 0.00). Diabetes mellitus was positively predicted by hypertension (HR 11.76, p 0.01). Osteoporosis was positively and negatively predicted by hypercholesterolemia (HR 3.25, p 0.01) and hypertension (HR 0.21, p 0.00), respectively.

CONCLUSIONS

The severity of the impairment of GH secretion does not predict the development of the clinical picture of GHD syndrome: untreated adult GHD does not increase the development of metabolic risk factors in hypopituitaric patients.

Long-term safety and efficacy of Omnitrope® in adults with growth hormone deficiency: Italian interim analysis of the PATRO Adults study

PURPOSE

To report the long-term effectiveness and safety of the recombinant human growth hormone Omnitrope^®, a somatropin biosimilar to Genotropin^®, in Italian patients with growth hormone deficiency (GHD) enrolled in the PATRO Adults study.

METHODS

The PATRO Adults study is an ongoing observational, longitudinal, non-interventional global post-marketing surveillance study, conducted in several European countries. The primary endpoint is long-term safety; secondary endpoints include the effectiveness of Omnitrope^®, which was assessed using serum insulin-like growth factor-1 levels, body composition, bone mineral density and lipid levels. Here we report the data from the Italian patients enrolled in the study.

RESULTS

Sixty-seven patients (mean age 50.4 years, 61.2% male) have been enrolled and have received a mean 45.4 ± 24.3 months of Omnitrope^®. A total of 55.2% of patients were reported to have experienced adverse events (AEs), including arthralgia, myalgia, abdominal distension and hypoaesthesia, and 4.5% had adverse drug reactions. Fourteen serious AEs have been recorded; none of these are considered related to the study drug. The effectiveness of Omnitrope^® was similar to other available somatropin preparations.

CONCLUSIONS

This study confirms the effectiveness and safety of Omnitrope^® in adult patients with GHD in Italy. However, due to the limited size of the study population, these results need to be further confirmed by the global PATRO Adults study.

Usefulness of an ad hoc questionnaire (Acro-CQ) for the systematic assessment of acromegaly comorbidities at diagnosis and their management at follow-up

PURPOSE

To determine the validity of a self-administered questionnaire (Acro-CQ) developed to systematically assess the presence, type and time of onset of acromegaly comorbidities.

METHODS

This is a cross-sectional study; 105 acromegaly patients and 147 controls with other types of pituitary adenoma, referred to a specialized Italian Center, autonomously compiled Acro-CQ in an outpatient clinical setting. To test its reliability in a different setting, Acro-CQ was administered via mail to 78 patients with acromegaly and 100 with other pituitary adenomas, referred to a specialized US Center. Data obtained from questionnaires in both settings were compared with medical records (gold standard).

RESULTS

Demographics of patients and controls from both countries were similar. In both settings, >95 % of the questionnaires were completely filled; only one item was missed in the others. Concordance with medical record was excellent (k > 0.85) for most of the items, independently from the way of administration, patient age, gender and nationality, pituitary adenoma type and disease activity.

CONCLUSIONS

Acro-CQ is an inexpensive, highly accepted from patients and reliable tool recommended to expedite systematic collection of relevant clinical data in acromegaly at diagnosis, to be replicated at follow-ups. This tool may guide a targeted, cost-effective management of complications. Moreover, it could be applied to retrieve data for survey studies in both acromegaly and other pituitary adenomas, as information is easily and rapidly accessible for statistical analysis.

Retrospective observational analysis of non-irradiated non-functioning pituitary adenomas

PURPOSE

The management of choice of non-functioning pituitary adenomas (NFPAs) remains debulking surgery when symptomatic. However, patient series systematically reporting the NFPAs outcome that were not treated either surgically, medically or with radiotherapy during long follow-up thereby giving an indication of their natural history are limited. Aim of the present study was to evaluate the natural course of presumed NFPAs, the outcome of confirmed NFPAs during a long follow-up period.

METHODS

Between 1993 and 2013, 84 patients with presumed NFPA were studied retrospectively. Patients were enrolled based on the following criteria: imaging suggestive of pituitary adenoma, absence of any biochemical/clinical evidence of hormonal excess, exclusion of prolactinomas and at least one sequential imaging during the follow-up. Repeated assessment of the pituitary function, visual fields and imaging was performed at regular intervals. The follow-up duration was evaluated from the first and last imaging dates.

RESULTS

In group F (follow-up without surgery, 33 patients), the macroadenomas showed a 15% probability of tumor growth and reduction. Similar tumor size alterations were observed also for the microadenomas. In group S (surgery, 51 patients), both residual tumors (>1 and <1 cm) following initial surgical resection remain mainly stable until the last imaging.

CONCLUSIONS

Based on the given lack of approved medical treatment and the possible risks of surgical intervention in presence of significant comorbidities, our study proposes a conservative approach with a careful follow-up in patients with NFPAs without visual or neurological abnormalities.

Role of UGT1A1 and ADH gene polymorphisms in pegvisomant-induced liver toxicity in acromegalic patients

CONTEXT

Hepatotoxicity is one of the most serious adverse effects in acromegalic patients treated with pegvisomant (PEG-V). Recent studies have found an association between this adverse event and the UGT1A1 allele 28 polymorphism associated with Gilbert's syndrome.

OBJECTIVE

To determine whether UGT1A1*28 and alcohol dehydrogenase (ADH) polymorphisms influence liver toxicity during PEG-V treatment.

DESIGN AND SETTING

Multicenter observational retrospective study conducted in 13 tertiary care endocrinology units in Italy.

PATIENTS

A total of 112 patients with active disease resistant to somatostatin analogs (SSTa) and 108 controls were enrolled.

INTERVENTIONS

Clinical and biochemical data were recorded by electronic clinical reporting forms. Blood or DNA samples were sent to the coordinating center for genotyping.

RESULTS

No differences in genotypes between patients and controls were found. During PEG-V therapy liver function tests (LFT), abnormalities and overt hepatotoxicity developed in 17 and 4.5% of patients respectively. Logistic and linear regression analyses showed an association between LFT abnormalities during the follow-up visit and prior events of LFT abnormalities in medical history (odds ratio=1.25; P=0.04) and the number of concomitant medications, other than SSTa (B=3.9; P=0.03). No correlation between LFT alterations and UGT1A1 allele 28 as well as ADH1C and B polymorphisms was found.

CONCLUSIONS

UGT1A1 allele 28 and ADH1C and B polymorphisms do not predict increased risk of hepatotoxicity during PEG-V therapy. Conversely, patients with multi-therapies and with previous episodes of liver disease should be carefully managed, due to the observed association between these conditions and LFT abnormalities during PEG-V therapy.

Measurement of height velocity is an useful marker for monitoring pituitary function in patients who had traumatic brain injury

To assess the incidence of abnormal neuroendocrine function post-traumatic brain injuriy (TBI) in a large group of paediatric patients and its correlations with clinical parameters (Glasgow coma scale-GCS, Glasgow outcome scale-GOS, TC marshall scale, height velocity). We evaluated 70 patients [58 M, 12 F; age at the time of TBI (mean ± SEM) 8.12 ± 4.23 years] previously hospitalized for TBI at the "Regina Margherita" Hospital, in Turin and "Maggiore della Carità Hospital" in Novara, Italy, between 1998 and 2008. All patients included underwent: auxological, clinical, hormonal and biochemical assessments at recall (after at least 1 year from TBI to T0); auxological visit after 6 months (T6) and hormonal assessments at 12 months (T12) in patients with height velocity (HV) below the 25th centile. At T0, 4 cases of hypothalamus-pituitary dysfunction had been diagnosed; At T6 20/70 patients had an HV <25th centile, but no one had HV < the 3rd centile limit. At T12, among the 20 patients with HV <25th centile, in 13 patients the HV was below the 25th centile and GHRH + Arginine test has been performed. Four subjects demonstrated an impaired GH peak and were classified as GH deficiency (GHD). Of these 4 subjects, 3 subjects showed isolated GHD, while one patient showed multiple hypopituitarism presenting also secondary hypocortisolism and hypothyroidism. The GCS at admission and GOS do not correlate with the onset of hypopituitarism. A simple measurement of the height velocity at least 1 year after the TBI, is enough to recognize patients with a pituitary impairment related to GH deficiency. We suggest to follow-up paediatric population who had TBI with auxological evaluations every 6 months, limiting hormonal evaluation in patients with a reduction of height velocity below the 25th centile limit.

Metabolic alterations in patients who develop traumatic brain injury (TBI)-induced hypopituitarism

OBJECTIVE

Hypopituitarism is associated with metabolic alterations but in TBI-induced hypopituitarism data are scanty. The aim of our study was to evaluate the prevalence of naïve hypertension, dyslipidemia, and altered glucose metabolism in TBI-induced hypopituitarism patients.

DESIGN

Cross-sectional retrospective study in a tertiary care endocrinology center. 54 adult patients encountering a moderate or severe TBI were evaluated in the chronic phase (at least 12 months after injury) after-trauma. Presence of hypopituitarism, BMI, hypertension, fasting blood glucose and insulin levels, oral glucose tolerance test (if available) and a lipid profile were evaluated.

RESULTS

The 27.8% of patients showed various degrees of hypopituitarism. In particular, 9.3% had total, 7.4% multiple and 11.1% isolated hypopituitarism. GHD was present in 22.2% of patients. BMI was similar between the two groups. Hypopituitaric patients presented a higher prevalence of dyslipidemia (p<0.01) and altered glucose metabolism (p<0.005) with respect to non hypopituitaric patients. In particular, triglycerides (p<0.05) and HOMA-IR (p<0.02) were higher in hypopituitaric TBI patients.

CONCLUSIONS

We showed that long-lasting TBI patients who develop hypopituitarism frequently present metabolic alterations, in particular altered glucose levels, insulin resistance and hypertriglyceridemia. In view of the risk of premature cardiovascular death in hypopituitaric patients, major attention has to been paid in those who encountered a TBI, because they suffer from the same comorbidities and may present other deterioration factors due to complex pharmacological treatments and restriction in participation in life activities and healthy lifestyle.

Involvement of hypothalamus autoimmunity in patients with autoimmune hypopituitarism: role of antibodies to hypothalamic cells

CONTEXT

Antipituitary antibodies (APA) but not antihypothalamus antibodies (AHA) are usually searched for in autoimmune hypopituitarism.

OBJECTIVE

Our objective was to search for AHA and characterize their hypothalamic target in patients with autoimmune hypopituitarism to clarify, on the basis of the cells stained by these antibodies, the occurrence of autoimmune subclinical/clinical central diabetes insipidus (CDI) and/or possible joint hypothalamic contribution to their hypopituitarism.

DESIGN

We conducted a cross-sectional cohort study.

PATIENTS

Ninety-five APA-positive patients with autoimmune hypopituitarism, 60 without (group 1) and 35 with (group 2) lymphocytic hypophysitis, were studied in comparison with 20 patients with postsurgical hypopituitarism and 50 normal subjects.

MAIN OUTCOME MEASURES

AHA by immunofluorescence and posterior pituitary function were evaluated; then AHA-positive sera were retested by double immunofluorescence to identify the hypothalamic cells targeted by AHA.

RESULTS

AHA were detected at high titer in 12 patients in group 1 and in eight patients in group 2. They immunostained arginine vasopressin (AVP)-secreting cells in nine of 12 in group 1 and in four of eight in group 2. All AVP cell antibody-positive patients presented with subclinical/clinical CDI; in contrast, four patients with GH/ACTH deficiency but with APA staining only GH-secreting cells showed AHA targeting CRH- secreting cells.

CONCLUSION

The occurrence of CDI in patients with lymphocytic hypophysitis seems due to an autoimmune hypothalamic involvement rather than an expansion of the pituitary inflammatory process. To search for AVP antibody in these patients may help to identify those of them prone to develop an autoimmune CDI. The detection of AHA targeting CRH-secreting cells in some patients with GH/ACTH deficiency but with APA targeting only GH-secreting cells indicates that an autoimmune aggression to hypothalamus is jointly responsible for their hypopituitarism.

Effects of chronic slow release-lanreotide treatment on insulin-like growth factor system and metabolic parameters in acromegalic patients

Insulin and IGF binding protein (IGFBP)-1 are linked by negative association. Somatostatin (SS) reduces insulin secretion by acting on pancreatic β-cell and also by decreasing GH secretion. SS analogues in acromegaly reduce total IGF-I levels inhibiting GH hypersecretion, but they also reduce free IGF-I bioactivity increasing IGFBP-1 levels by inducing insulin decrease. In 13 acromegalic patients we studied GH, IGF system, insulin, and glucagon levels at baseline and at 7 days, 1 and 6 months under treatment with slow release (SR)-lanreotide (LAN) (60 mg im monthly). The hormonal and metabolic response to arginine (ARG) (0.5 g/kg iv in 30 min) was also studied at each time point. LAN decreased GH, total IGF-I, and IGFBP-3 levels at each time point. Insulin and glucagon levels were reduced, while IGFBP-1 and free IGF-I levels were increased by LAN at day 7 and after 1 month only. LAN did not modify the GH, insulin, glucagon, glucose, and IGFBP-1 responses to ARG. At each time point ARG-induced insulin increase was coupled to increase in glucagon and IGFBP-1 levels. This study shows that acromegalic patients under chronic treatment with LAN display: a) inhibition of GH and total IGF-I levels, not coupled to persistent decrease in free IGF-I levels; b) persistent decrease in IGFBP- 3 but transient decrease and increase in insulin and IGFBP- 1, respectively; c) unchanged hormonal and metabolic response to ARG. Our findings also show that ARG stimulates IGFBP-1 despite marked increase in insulin secretion; this escape from the negative relationship linking insulin and IGFBP- 1 would likely reflect the ARG-induced glucagon increase.

Growth hormone receptor variants and response to pegvisomant in monotherapy or in combination with somatostatin analogs in acromegalic patients: a multicenter study

CONTEXT

The influence of full-length GH receptor (GHR) and exon 3-deleted GHR (d3GHR) on responsiveness to pegvisomant (PEG-V) in acromegalic patients is uncertain.

OBJECTIVE

The aim of the study was to assess the distribution of GHR genotypes in a large series of patients on PEG-V therapy and their influence on treatment efficacy and adverse effects.

DESIGN AND SETTING

A cross-sectional multicenter pharmacogenetic study was conducted in 16 Italian endocrinology centers of major universities and tertiary care hospitals.

PATIENTS

The study included 127 acromegalic patients enrolled from 2009 to 2010 not cured by previous surgery, radiotherapy, and long-acting somatostatin (SST) analogs, treated with PEG-V.

INTERVENTION AND MAIN OUTCOME MEASURE

Sixty-three of 127 patients received combined PEG-V + SST analog therapy. Clinical and hormonal data at diagnosis and before and during PEG-V therapy were inserted in a database. GHR exon 3 deletion and other polymorphisms were genotyped by the coordinator center. Differences in PEG-V dosage required for IGF-I normalization and occurrence of adverse effects between carriers and noncarriers of GHR variants were evaluated.

RESULTS

d3GHR variants were not in Hardy-Weinberg equilibrium (P = 0.008). No association of these variants with PEG-V dose required for IGF-I normalization, adverse effects occurrence, and tumor regrowth was found in patients on PEG-V and on PEG-V + SST analog treatment. Similar data were obtained considering the GHR variant rs6180.

CONCLUSIONS

This study did not confirm a better response of d3GHR to PEG-V treatment in acromegaly. Other studies are needed to determine whether deviation from Hardy-Weinberg equilibrium may indicate an association of d3GHR genotype with poor response to usual treatments.

Retesting the childhood-onset GH-deficient patient

GH deficiency (GHD) in adults has to be shown by a single provocative test, provided that it is validated. Insulin tolerance test (ITT) has been indicated as the test of choice; now also glucagon test is validated and represents an alternative. The GHRH plus arginine (ARG) test and testing with GHRH plus a GH secretagogue are equally reliable diagnostic tools, and are now considered as 'golden' standards as ITT. Childhood-onset (CO) GHD needs retesting in late adolescence or young adulthood; this is a major clinical challenge and raises questions about the most appropriate method and cut-off value. Appropriate re-evaluation of GH status is represented by simple measurement of IGF1 concentration off rhGH treatment. Clearly, low IGF1 levels are evidence of persistent severe GHD in subjects with genetic GHD or panhypopituitarism. However, normal IGF1 levels never rule out severe GHD and CO-GHD with normal IGF1 levels must undergo a provocative test. The appropriate GH cut-off limit is specific for each provocative test. As shown by the ROC curve analysis, in late adolescents and young adults, the lowest normal GH peak response to ITT is 6.1 microg/l while that to GHRH+ARG test is 19.0 microg/l. These cut-off limits, however, are just indicative as being variable as a function of the assay used. No other test is validated for retesting. As GHRH+ARG test mostly explores the GH-releasable pool, normal GH response would be verified by a second ITT in order to rule out subtle hypothalamic defect.

Growth hormone/insulin-like growth factor I axis, glucose metabolism, and lypolisis but not leptin show some degree of refractoriness to short-term fasting in acromegaly

Starvation exerts critical influence on somatotroph and leptin secretion. Fasting enhances GH levels in normal subjects, but not in GH hyposecretory states, while it always inhibits leptin secretion. We aimed to clarify the GH/IGF-I and metabolic response to short-term fasting in a GH hypersecretory state such as acromegaly. To this goal, in 8 active acromegalic (ACRO) and in 7 normal women (NS) we evaluated mean GH (mGHc), leptin (mLEPc), insulin (mINSc), glucose (mGLUc) concentrations as well as IGF-I, IGF binding protein (IGFBP)-3, IGFBP-1, and free fatty acid (FFA) levels before and after 36-h fasting. Before fasting, mGHc, IGF-I, mINSc, mGLUc, and FFA levels in ACRO were higher (p<0.01) than in NS. IGFBP-3, IGFBP-1, and mLEPc were similar in ACRO and in NS. Fasting clearly (p<0.02) increased mGHc in NS only. After 36-h fasting, significant IGF-I reduction was recorded in NS only (p<0.03). IGFBP-3 did not change both in ACRO and NS. IGFBP-1 significantly increased (p<0.05) after fasting in both groups but in ACRO were lower (p<0.03) than in NS. Fasting decreased (p<0.03) mLEPc, mGLUc, and mINSc in ACRO as well as in NS; mINSc and mGLUc after fasting in ACRO persisted higher (p<0.005) than in NS. FFA levels were increased by fasting in NS (p<0.02), but not in ACRO. This study shows that GH/IGF-I axis, glucose metabolism, and lypolisis but not leptin display some degree of refractoriness to short-term fasting in acromegaly. The lack of any GH response to fasting in acromegaly would likely reflect neuroendocrine alterations secondary to the GH hypersecretory state. On the other hand, the lack of somatotropic response and the peculiarly blunted metabolic reaction to short-term fasting would partially reflect the delayed adaptation of insulin resistance to starvation.

Update on epidemiology, etiology, and diagnosis of adult growth hormone deficiency

The most updated guidelines for the diagnosis of adult GH deficiency (GHD) come from the GH Research Society Consensus Workshop held in Sydney, Australia, in 2007. Regarding who to test for GHD, advice should be extended from primitive hypothalamic- pituitary diseases and cranial irradiation to include brain injuries (Traumatic Brain Injury in particular). Regarding how to test for GHD, the insulin tolerance test (ITT) remains a provocative test of reference; among classical provocative test, glucagon test has also been validated. Above all, GHRH + arginine and GHRH + GH-secretagogues are now considered, at least, as reliable as ITT for the diagnosis of adult GHD. Interestingly, it is now accepted that very low IGF-I represents definite evidence of severe GHD in congenital forms of GHD and also in patients with acquired multiple hypopituitarism. These patients would skip provocative test; however, as normal IGFI levels do not rule out severe GHD, patients suspected for hypopituitarism showing normal IGF-I levels must undergo a provocative test of GH secretion. Retesting the GH status in the transition age is of major relevance in order to decide about continuing or not recombinant human GH replacement in adult life.

Normal age-dependent values of serum insulin growth factor-I: results from a healthy Italian population

Serum IGF-I levels were measured in 547 non-hypopituitaric, non-acromegalic healthy subjects of both sexes in Italy to develop reference values in relation to age and sex. Participant subjects were stratified in three age classes (25- 39, 40-59 and >or=60 yr) and IGF-I assay was carried out by double-antibody radio immunoassay. Pearson's correlation coefficient between age and IGF-I values was calculated by sex and predefined age ranges. IGF-I levels significantly decreased with age (p<0.001, Kruskal-Wallis test) while sex was not a significant factor. The median IGF-I levels were 206 ng/ml in the 25-39 yr range, 147 ng/ml in the 40-59 yr range and 103 ng/ml in the >or=60 yr range. Pearson's correlation coefficient confirmed the negative correlation between age and IGF-I levels in the total sample of subjects (r=-0.529). The r coefficient between age and IGF-I levels did not differ between sexes (r=-0.570 in males and r=-0.529 in females), thus reflecting no sex-effect on IGF-I levels decline over years. No correlations were found in the 25-39 yr range (r=-0.036) or in the 40-59 yr range (r=-0.080) either, while in subjects aged >60 yr, IGF-I levels tended to further decrease with increased age (r=0.389). Ranges of normal values set at the 2.5th-97.5th percentile in the three age ranges were 95.6-366.7 ng/ml between 25 and 39 yr, 60.8-297.7 ng/ml between 40 and 59 yr and 34.5-219.8 ng/ml in subjects aged >or=60 yr. This study may contribute to the development of age-specific reference ranges for IGF-I determination in serum of normal subjects of both sexes in Italy.

Diagnosis of adult GH deficiency

Based on previous consensus statements, it has been widely accepted that the diagnosis of adult growth hormone deficiency (GHD) must be shown biochemically by provocative tests of GH secretion; in fact, the measurement of IGF-I as well as of other markers was considered unable to distinguish between normal and GHD subjects. The Insulin Tolerance Test (ITT) was indicated as that of choice and severe GHD defined by a GH peak lower than 3 microg/l. It is now recognized that, although normal IGF-I levels do not rule out severe GHD, very low IGF-I levels in patients highly suspected for GHD (i.e. patients with childhood-onset severe GHD or with multiple hypopituitarism acquired in adulthood) can be considered as definite evidence for severe GHD. However, patients suspected for adult GHD with normal IGF-I levels must be investigated by provocative tests. ITT remains a test of reference but it should be recognized that other tests are as reliable as ITT. Glucagon as classical test and, particularly, new maximal tests such as GHRH in combination with arginine or GH secretagogues (GHS) (i.e. GHRP-6) have well defined cut-off limits, are reproducible, able to distinguish between normal and GHD subjects. Overweight and obesity have confounding effect on the interpretation of the GH response to provocative tests. In adults cut-off levels of GH response below which severe GHD is demonstrated must be appropriate to lean, overweight and obese subjects to avoid false positive diagnosis in obese adults and false negative diagnosis in lean GHD patients.

Endocrine dysfunction in patients operated on for non-pituitary intracranial tumors

OBJECTIVE

Hypopituitarism frequently follows pituitary neurosurgery (NS) and/or irradiation. However, the frequency of hypothalamic-pituitary dysfunction after NS of non-pituitary intracranial tumors is unclear. The aim of this study was to assess the presence of endocrine alterations in patients operated on for intracranial tumors.

DESIGN

This is a retrospective study.

METHODS

We studied 68 consecutive adult patients (28 female, 40 male, age 45.0 +/- 1.8 years; body mass index (BMI): 26.5 +/- 0.6) with intracranial tumors who underwent NS only (n = 17) or in combination with radiotherapy (RT) and/or chemotherapy (CT) (n = 51). In all subjects, basal endocrine parameters and the GH response to GHRH + arginine test (using BMI-dependent cut offs) were evaluated.

RESULTS

In 20.6% of the patients, peripheral endocrinopathy related to CT and/or RT was present. Hypopituitarism was found in 38.2% of the patients. Total pituitary hormone, multiple pituitary hormone, and isolated pituitary hormone deficits were present in 16.2, 5.8, and 16.2% respectively. The most common pituitary deficits were, in decreasing order: LH/FSH 29.4%, GH 27.9%, ACTH 19.1%, TSH 17.7%, and diabetes insipidus 4.4%. Hyperprolactinemia was present in 13.2%. The prevalence of hypopituitarism was higher in patients who underwent NS only and with tumors located closely to the sella turcica, but a substantial proportion of patients with tumors not directly neighboring the sella also showed hypopituitarism.

CONCLUSIONS

Hypopituitarism frequently occurs after NS for intracranial tumors. Also, exposure of these patients to CT and/or RT is frequently associated with peripheral endocrinopathies. Thus, endocrine evaluation and follow-up of patients treated for intracranial tumors should be performed on a regular basis.

Cortistatin-17 and somatostatin-14 display the same effects on growth hormone, prolactin, and insulin secretion in patients with acromegaly or prolactinoma

CONTEXT

Cortistatin binds all somatostatin receptor subtypes but also has particular central actions; moreover, a specific cortistatin receptor has also been discovered.

OBJECTIVE

We compared the endocrine effects of cortistatin-17 with those of somatostatin-14 in patients with acromegaly (ACRO) or prolactinoma (PRLOMA). Normal subjects (NS) were studied as control group.

DESIGN

All subjects underwent the following tests: 1) saline, 2) somatostatin-14 (2.0 microg/kg.h iv, 0-120 min) and 3) cortistatin-17 (2.0 microg/kg.h iv, 0-120 min) infusion.

RESULTS

Cortistatin-17 and somatostatin-14 inhibited GH secretion to the same extent in ACRO (P < 0.05) and NS (P < 0.01). Cortistatin-17 and somatostatin-14 inhibited PRL secretion in PRLOMA (P < 0.05), to some extent in ACRO (P value not significant), but not in NS. Insulin secretion was inhibited by both cortistatin-17 and somatostatin-14 to the same extent in all groups (P < 0.05).

CONCLUSIONS

Cortistatin-17 and somatostatin-14 display the same effects on GH, PRL, and insulin secretion in patients with ACRO or PRLOMA.

Efficacy and safety of 48 weeks of treatment with octreotide LAR in newly diagnosed acromegalic patients with macroadenomas: an open-label, multicenter, non-comparative study

The aim of the present multicentric, open-label, non-comparative study was to evaluate the role of octreotide long-acting repeatable (LAR) as primary therapy for the treatment of GH-secreting pituitary macroadenomas. The patients received octreotide LAR 20 mg every 4 weeks for 12 weeks; afterwards the dose was confirmed or adjusted at 30 mg every 4 weeks, for the remaining 12 weeks, for responder or non-responder patients, respectively. Responder patients continued the study until 48 weeks. Twenty-one naive active acromegalic patients were enrolled. In all patients, GH profile, IGF-I levels and magnetic resonance imaging (MRI) were evaluated at baseline and during treatment. The ability of octreotide LAR to decrease mean GH < 2.5 microg/I and/or normalize IGF-I levels, adjusted for age and gender, was defined respectively as total or partial success. Total success was achieved in 5/21 (23.8%), 6/20 (30%) and 4/14 (28.6%) patients after 12, 24 and 48 weeks; partial success in 7/21 (33.3%), 9/20 (45%) and 9/14 (64%) patients at 12, 24 and 48 weeks according to GH levels, while according to IGF-I levels in 7/21 (33.3%), 7/20 (35%) and 5/14 (35.7%) patients at 12, 24 and 48 week. Tumor size was notably decreased after treatment with octreotide LAR: in 16 macroadenoma patients completing the study, the tumor sizes were 1609 +/- 1288, 818 +/- 616 (49.1 +/- 23.7%) and 688 +/- 567 mm3 (54.6 +/- 24.4%) at baseline, 24 and 48 weeks. This study shows that octreotide LAR is effective in suppressing GH/IGF-I secretion and inducing tumor shrinkage in GH-secreting macroadenomas in a 48-week treatment. Octreotide LAR could be used as primary therapy in patients harbouring large pituitary tumors, who are less likely to be cured by neurosurgery.

Different degrees of GH deficiency evidenced by GHRH+arginine test and IGF-I levels in adults with pituritary disease

To verify if the entity of the peak GH responses to the GHRH+arginine (ARG) test is able to show different degree forms of GH deficiency (GHD), we linked these responses with the number of other anterior pituitary deficits. These anterior pituitary deficits were also related with IGF-I levels. To this purpose, we studied a large cohort of lean patients with pituitary disease of different etiologies [86 males and 68 females; age: mean +/- SEM 41.5 +/- 1.2 yr, body mass index (BMI) <25 kg/m2]. The patients were subdivided into 4 groups according to the increasing number of hormone deficiencies: isolated GHD (HYPO1, no.=28) or GHD plus one, two or three additional hormones (gonadotrophin, ACTH, and TSH) deficiencies (HYPO2, no.=20; HYPO3, no.=15; HYPO4, no.=91). Peak GH responses to the GHRH+ARG test and IGF-I levels showed a clear difference among the groups (p < 0.01 and p < 0.001, respectively). A significant difference was found between HYPO1 and HYPO4 for IGF-I levels (p < 0.05), and between HYPO1 and HYPO4 and between HYPO2 and HYPO4 for the GHRH+ARG test (p < 0.005). Considering only the patients who underwent both GHRH+ARG test and insulin tolerance test (ITT) (no.=70), the pattern of the peak GH responses to the GHRH+ARG test was the same of the whole group of patients, while no statistical difference was found with ITT. Our data show that the peak GH responses to the GHRH+ARG test and the IGF-I levels are linked to the severity of hypopituitarism, expressed by the number of increasing anterior pituitary deficits. This association is lost if the evaluation of the GH status is performed by the ITT. In all, the GHRH+ARG test and measurement of IGF-I are able to evidence different degrees of GHD in adult patients with pituitary disease.

Treatment of acromegaly with SS analogues: should GH and IGF-I target levels be lowered to assert a tight control of the disease?

BACKGROUND

in acromegaly, the criteria for the cure of the disease after neurosurgery have become tighter and tighter. In contrast, the evaluation of control of disease activity during medical treatment is based upon the normalisation of IGF-I levels and epidemiological criteria, i.e. lessening GH (assessed by RIA) to levels reported to normalise increased mortality. The aim of this study was to evaluate GH and IGF-I suppression during prolonged SS analogues (SA) treatment. The concordance between "safe" GH and normalised IGF-I levels during SA was also assessed, according to gender and gonadal status.

DESIGN

multicentre, retrospective. Patients. GH/IGF-I levels were evaluated in 207 acromegalic patients (132 females, aged 20-85 yr) during a prolonged treatment (longer than 12 months) with individually tailored doses of depot SA( lanreotide or octreotide-LAR in 97 and 110 patients, respectively). Final IGF-I levels were transformed in z-scores using data collected in a large cohort of normal subjects of 3 different age groups (20-40 yr old, 41-60 yr old, 61-80 yr old, n=160, 148, 115, respectively), that allowed to set up quartiles of normality (I = 3rd-25th percentile, II = 26th-50th, III = 51th-75th, IV = 76th-97th).

RESULTS

fifty-nine and 19.3% of patients achieved GH levels <2.5 and <1 microg/l, respectively. IGF-I were normalised (z-score between 2 and -2) in 58.4% of patients. The distribution of normal IGF-I values among quartiles was uneven: 7%, 19%, 25%, and 49% of values were distributed in the I, II, III, and IV quartile, respectively. The concordance between GH and IGF-I values was poor: 28.4% of patients attaining GH values <2.5 microg/l had still pathological IGF-I (even 12.5% of those with GH <1 microg/l), and 39.3% of those with GH levels still above the "safe" limit had "nor IGF-I. Although proportions of IGF-I normalisation were not different between males and females, the regression line obtained between GH and IGF-I z-score showed the same slope but with a significantly lower intercept in regularly cycling women than in males and in postmenopausal females. Thus for any GH value, cycling females had lower IGF-I than menopausal women and males, and their IGF-I normalisation could be achieved by higher GH values. By ROC analysis, the achievement of normal IGF-I was predicted by the GH value of 1.8 microg/l in males and 2.4 microg/l in females.

CONCLUSIONS

in acromegalic patients on SA treatment, GH and IGF-I levels are often not concordant. In addition to age, sex is to be taken into account in the evaluation of hormonal targets. A better refinement of GH and IGF-I targets to be reached while on treatment with SA is warranted.

Cost-of-illness study in acromegalic patients in Italy

INTRODUCTION

acromegalic therapeutic goals are directed at removing the tumor, preventing tumor re-growth and reducing long-term morbidity and mortality. In this scenario, the acromegalic patient needs a variety of health resources (diagnostic tests, surgery, radiotherapy, specialist visits and drugs) for his/her cure, in order to decrease/stop the progression of the disease and to cure the co-morbid diseases. Lack of epidemiological data has suggested performing an Italian retrospective study aiming to assess the health resource consumption that is caused by acromegalic cure and the relative co-morbidities, in order to estimate the amount of the direct costs of acromegalic patients.

METHOD

a retrospective study was performed on a total of 134 patients (142 patients selected, 76 in Genoa and 66 in Turin) for a period of about 7 yr preceding the enrolment date. Only direct costs were evaluated by performing an analysis on the perspective of Italian Healthcare Service (SSN).

RESULTS

the mean total direct costs for acromegaly cure ranged from 7,968.41 to 12,533.02 Euros/yr (p < 0.01; Mann Whitney Test), respectively, for Responders and Non-Responders. The cost driver was drug (SS analogs) for acromegalic cure. The co-morbidity conditions associated to acromegalic Non-Responder patients are clearly higher than those with well-controlled disease.

CONCLUSION

the study supports the hypothesis that controlled patients drove a saving for SSN in comparison to poor control patients that use more health resources.

Hypopituitarism and growth hormone deficiency (GHD) after traumatic brain injury (TBI)

In adults, hypopituitarism and growth hormone deficiency (GHD) should be suspected and diagnosed within an appropriate clinical context. It has been demonstrated that all patients with primary hypothalamic-pituitary diseases before and after any medical intervention (defined as neurosurgery, radiotherapy and medical therapy) are at obvious risk - more than just at high risk - for hypopituitarism (greater than 80% had severe GHD). The same obvious risk applies to patients diagnosed as having congenital or acquired GHD in childhood (between 30% and 50% of patients with severe GHD after retesting). Taking into account the fragility of the infundibular-hypothalamic structure, patients with other common pathological conditions of the central nervous system (CNS), such as traumatic brain injury (TBI), subarachnoid haemorrhage (SAH) or primary brain tumours (BT) with related medical intervention could be at risk for developing hypopituitarism, including GHD. GHD is the first and most common sign of pituitary impairment. Despite the risk of pituitary dysfunction and the results of some studies that these risks are greater than previously believed, neuroendocrine evaluations are still not routinely included as part of the clinical management plan for patients with TBI and SAH. Preliminary results of a multicenter study performed under the auspices of the Italian Society of Endocrinology underscore the high risk of hypopituitarism and GHD under these clinical conditions. Thus, careful screening of pituitary function should always be performed in patients following TBI and SAH.

Diagnostic reliability of a single IGF-I measurement in 237 adults with total anterior hypopituitarism and severe GH deficiency

OBJECTIVE

Within an appropriate clinical context, GH deficiency (GHD) in adults must be demonstrated biochemically by a single provocative test. Insulin-induced hypoglycaemia (ITT) and GH-releasing hormone (GHRH) + arginine (ARG) are indicated as the tests of choice, provided that appropriate cut-off limits are defined. Although IGF-I is the best marker of GH secretory status, its measurement is not considered a reliable diagnostic tool. In fact, considerable overlap between GHD and normal subjects is present, at least when patients with suspected GHD are considered independently of the existence of other anterior pituitary defects. Considering the time and cost associated with provocative testing procedures, we aimed to re-evaluate the diagnostic power of IGF-I measurement.

DESIGN

To this goal, in a large population [n = 237, 139 men, 98 women, age range 20-80 years, body mass index (BMI) range 26.4 +/- 4.3 kg/m2] of well-nourished adults with total anterior pituitary deficit including severe GHD (as shown by a GH peak below the 1st centile limit of normal response to GHRH + ARG tests and/or ITT) we evaluated the diagnostic value of a single total IGF-I measurement. IGF-I levels in hypopituitary patients were evaluated based on age-related normative values in a large population of normal subjects (423 ns, 144 men and 279 women, age range 20-80 years, BMI range 18.2-24.9 kg/m2).

RESULTS

Mean IGF-I levels in GHD were lower than those in normal subjects in each decade, but not the oldest one (74.4 +/- 48.9 vs. 243.9 +/- 86.7 micro g/l for 20-30 years; 81.8 +/- 46.5 vs. 217.2 +/- 56.9 micro g/l for 31-40 years; 85.8 +/- 42.1 vs. 168.5 +/- 69.9 micro g/l for 41-50 years; 82.3 +/- 39.3 vs. 164.3 +/- 60.3 micro g/l for 51-60 years; 67.5 +/- 31.8 vs. 123.9 +/- 50.0 micro g/l for 61-70 years; P < 0.0001; 54.3 +/- 33.6 vs. 91.6 +/- 53.5 micro g/l for 71-80 years, P = ns). Individual IGF-I levels in GHD were below the age-related 3rd and 25th centile limits in 70.6% and 97.63% of patients below 40 years and in 34.9% and 77.8% of the remaining patients up to the 8th decade, respectively.

CONCLUSIONS

Total IGF-I levels are often normal even in patients with total anterior hypopituitarism but this does not rule out severe GHD that therefore ought to be verified by provocative testing of GH secretion. However, despite the low diagnostic sensitivity of this parameter, very low levels of total IGF-I can be considered definitive evidence of severe GHD in a remarkable percentage of total anterior hypopituitary patients who could therefore skip provocative testing of GH secretion.

Occurrence of GH deficiency in adult patients who underwent neurosurgery in the hypothalamus-pituitary area for non-functioning tumour masses

Hypothalamus-pituitary tumours and their treatments (neurosurgery and/or radiotherapy) are major causes of acquired hypopituitarism. Scientific and clinical evidences show the positive effect of GH replacement therapy in severe adult GH deficiency (GHD) pointed toward the need of diagnostic screening of conditions at high risk for GHD. We screened 152 adults (82 males, 70 females; age: 52.3+/-1.2 years, age-range: 20-80 years, BMI: 26.4+/-0.8 kg/m(2)) in order to disclose the presence of GHD after neurosurgery for hypothalamus-pituitary tumours. The whole group (studied at least 3 months after neurosurgery) included: 111 non-functioning pituitary adenomas and 41 peri-pituitary tumours (24 craniopharyngiomas, 7 meningiomas, 5 cysts, 2 chondrosarcomas, 1 colesteatoma, 1 germinoma and 1 hemangiopericitoma). In 14 patients who underwent both neurosurgery and radiotherapy due to a tumour remnant, the somatotroph function was evaluated again 6 months after the end of radiotherapy. GHD was assumed to be shown by GH peak <5 microg/L (severe <3 microg/L) after Insulin Tolerance Test (ITT) or <16.5 microg/L (severe <9 microg/L) after GH-releasing hormone+arginine test (GHRH+ARG) (3rd and 1st centile limits of normality, respectively), two widely accepted provocative tests. Before neurosurgery GHD was present in 97/152 (63.8%) and resulted severe in 66/152 (43.4%) patients. After neurosurgery GHD was present in 122/152 (80.2%) and severe in 106/152 (69.7%). While 26 patients developed severe GHD (GHD) as consequence of neurosurgery, only one patient who had been classified as GHD before neurosurgery showed normal GH response after surgery. After neurosurgery, 91.0% (81/89) of the pan-hypopituitaric patients showed severe GHD. Considering the 14 patients who underwent also radiotherapy after neurosurgery, 7/14 had GHD before neurosurgery while 12/14 became severe GHD after radiotherapy in a context of pan-hypopituitarism. IGF-I levels below the 3rd age-related normal limits were present in 39.0% of patients in whom severe GHD was showed by provocative tests. In conclusion, this study shows that the occurrence of acquired severe GHD is extremely common in adult patients bearing non-functioning tumour masses in the hypothalamus-pituitary area and further increases after neurosurgery. All patients bearing non-functioning hypothalamus-pituitary tumours should undergo evaluation of their somatotroph function before and after neurosurgery that represents a condition at obvious more than high risk for hypopituitarism.

Three-hour spontaneous GH secretion profile is as reliable as oral glucose tolerance test for the diagnosis of acromegaly

The diagnosis of acromegaly, in an appropriate clinical context, usually relies on lack of GH suppression below 1 microg/l during OGTT coupled with elevated IGF-I levels. On the other hand, in normal subjects glucose-induced inhibition of GH secretory bursts without any further decrease of interpulse GH levels had already been shown. Based on the foregoing, we aimed to compare the diagnostic reliability of OGTT-induced GH nadir with that recorded during 3-h spontaneous GH secretion. In 59 acromegalic patients (17 male and 42 female, age, mean +/- SE 51.5 +/- 1.9, range 21-76 yr) and in 82 normal subjects (43 male and 39 female, age, mean +/- SE 35.7 +/- 1.5, range 15-72 yr) GH secretion was evaluated every 30 min from 0 to 180 min during slow saline infusion or OGTT (75 g at 0 min). A nadir GH concentration below 1 microg/l was recorded in all normal subjects either during OGTT or saline infusion if GH secretion was evaluated over 180 min. In contrast in acromegalic patients a nadir GH concentration below 1 microg/l never occurred in both conditions. This study shows that a 3-h spontaneous GH profile is as reliable as OGTT in the diagnosis of active acromegaly.

Hormonal diagnosis of GH hypersecretory states

GH hypersecretory states include organic and functional causes. Among functional GH hypersecretory states, enhanced somatotroph secretion physiologically occurs at birth associated with reduced IGF-I levels reflecting the still immature sensitivity of liver to circulating GH levels; this may also occur in women exposed to oral extrogens. Pathophysiological conditions of GH hypersecretion are generally associated with congenital or acquired/functional conditions of peripheral GH insensitivity. Genetic alterations of the GH receptor lead to the so called Laron's syndrome. On the other hand, a relevant number of clinical conditions (malnutrition, malabsorption, anorexia nervosa, liver cirrhosis, renal failure, Type 1 diabetes mellitus) are associated with acquired GH insensitivity and a more or less pronounced GH hypersecretion. Both organic and acquired conditions of GH insensitivity show low IGF-I synthesis and release and therefore lack the negative IGF-I feedback action on somatotroph function. GH hypersecretion may be associated with renal failure; however, in this case, the alteration in the metabolic clearance rate of GH would also have a role; moreover, IGF-I levels are generally normal in this condition. Hyperthyroidism is another condition connoted by elevated GH levels that reflects a true GH hypersecretory state and is, in fact, associated with high-normal IGF-I levels; this peculiar condition is likely to be reflecting the stimulatory effect of thyroid hormones on both GH and IGF-I secretion and is promptly reversed by treatment-induced euthyroidism. Apart from these "functional" hypersecretory state, the classic organic GH hypersecretory state is represented by acromegaly or giantism. In these conditions GH hypersecretion is generally sustained by a pituitary adenoma hypersecreting GH alone or together with another pituitary hormone, mostly PRL; less frequently GH hypersecretion may be due to ectopic GHRH hypersection. Exaggerated GH secretion elicits exaggerated IGF-I synthesis and secretion that is, in turn, responsible for the large majority of endocrine signs and symptoms. In the appropriate clinical context of acromegalic features, evidence of concomitant marked GH and IGF-I hypersecretion at baseline demonstrates active acromegaly or giantism and indicates the need for magnetic resonance imaging in order to verify the presence of a pituitary tumor. However, as random measurement of basal GH levels is not reliable for definite diagnosis of acromegaly, it is considered mandatory to rely on the lack of GH suppression below 1 microg/l during oral glucose tolerance test (OGTT) coupled with elevated IGF-I levels. The same criteria are assumed, at present, to define true cure of the disease after (or under) treatment. There is consensus about the assumption that concomitant normalization or persistent abnormality of both OGTT-induced GH nadir and IGF-I levels define a successfully or a poorly controlled disease status, respectively. On the other hand, acromegalic patients with GH nadir above 1 microg/l or IGF-I levels persistently elevated are inadequately controlled and their disease should not be considered inactive. It has been clearly demonstrated that an extended exposure to GH and IGF-I excess level, even if slight, has a very harmful effect on patients; therefore early diagnosis of acromegaly and appropriate definition of its cure are of fundamental extreme in order to plan a prompt and appropriate therapeutic intervention(s) guaranteed also by the continuous improvement in the therapeutic tools available to treat this systemic disease.

Hypopituitaric patients with corticotropin insufficiency show marked impairment of the cortisol response to ACTH (1-24) independently of the duration of the disease

It is widely accepted that the classical dose of 250.0 microg ACTH (1-24) (tetracosactin) is clearly supra-maximal while 1.0 and 0.03 microg have been shown as the maximal and the lowest stimulatory ACTH doses for cortisol (F) secretion in normal young subjects. Testing with low ACTH dose would better evaluate adrenal sensitivity to corticotropin. The aims of the present study were: a) to clarify the adrenal sensitivity to ACTH in patients with different duration of corticotroph insufficiency by testing with low and very low tetracosactin doses; and b) to evaluate diagnostic implication regarding the ability of ACTH tests to distinguish patients with corticotroph insufficiency from normal subjects. In 24 hypopituitaric patients (HYPOPIT, 15 male and 9 female, age 22-50 yr, BMI: 22-26 kg/m2) with corticotrophin deficiency we studied the F, DHEA and aldosterone (A) responses to challenges with low ACTH doses (0.06 or 0.5 microg iv at 0 min) followed by 250 microg iv (at +60 min). The results in HYPOPIT were compared with those recorded in 12 normal controls (NS, 6 male and 6 female, age 22-34 yr, BMI: 20-25 kg/m2). Basal F and DHEA levels in HYPOPIT were lower than in NS, while A levels were similar in both groups. The F responses to ACTH in HYPOPIT were dose-independent and markedly lower (p < 0.0001) than in NS. After the 0.06 and 0.5 microg ACTH dose, 16% of HYPOPIT patients showed AF peak within the range of normal response. No HYPOPIT showed AF peak within the normal range after 250 microg ACTH. The DHEA responses to ACTH in HYPOPIT were dose-independent and markedly lower than in NS (p < 0.0001). Overlap between individual DHEA responses in HYPOPIT and NS was present after 0.06 microg and 0.5 microg but not after 250 microg tetracosactin. The A responses in HYPOPIT were dose-dependent and overlapped with those in NS. The adrenal responses to ACTH in HYPOPIT were not associated with the duration of the disease. In conclusion, the present study shows that the mean F and DHEA but not the A responses to ACTH (1-24) are markedly impaired in hypopituitaric patients with corticotroph insufficiency independently of the duration of the disease. The impaired F and DHEA response to ACTH is also independent of the dose, suggesting the existence of relatively enhanced sensitivity of the fasciculata and reticularis adrenal zone to ACTH but meantime remarkable impairment of the adrenal function due to corticotrophin deficiency. In the present study, testing with submaximal ACTH doses did not distinguish patients with secondary adrenal insufficiency from normal subjects.

Gender- and age-related differences in the endocrine parameters of acromegaly

Acromegaly is a severe slow-developing disease associated with a poor prognosis for cardiovascular disease. To evaluate the impact of age and gender on the severity of the disease, 151 de novo patients with acromegaly (79 women, 72 men, age range 19-77 yr) were included in this open retrospective multi-center cohort study. Basal GH and IGF-I levels, GH response after glucose load and maximal tumor diameter at MRI were measured in all patients at diagnosis. Fasting GH levels and maximal tumor diameter were similar in women and men, while serum IGF-I levels were lower (664.9+/-24.9 vs 755.9+/-32 microg/l; p=0.02) and GH nadir after glucose load was higher (27.5+/-3.7 vs 18.5+/-2.2 microg/l; p=0.04) in women than in men. In both sexes, patients' age was negatively correlated with basal and nadir GH, IGF-I levels and tumor size; fasting GH levels were positively correlated with IGF-I levels and nadir GH after glucose. No interaction between age and gender was found on biochemical and morphological parameters. At diagnosis, elderly patients with acromegaly have lower GH and IGF-I levels, lower GH nadir after glucose load and smaller adenomas than young patients. Women have lower IGF-I levels but higher GH nadir after glucose load than men. These age and gender differences should be considered to appropriately evaluate the activity of acromegaly throughout a life-span.