Management of Osteoporosis in Men: A Narrative Review

Male osteoporosis is a still largely underdiagnosed pathological condition. As a consequence, bone fragility in men remains undertreated mainly due to the low screening frequency and to controversies in the bone mineral density (BMD) testing standards. Up to the 40% of overall osteoporotic fractures affect men, in spite of the fact that women have a significant higher prevalence of osteoporosis. In addition, in males, hip fractures are associated with increased morbidity and mortality as compared to women. Importantly, male fractures occur about 10 years later in life than women, and, therefore, due to the advanced age, men may have more comorbidities and, consequently, their mortality is about twice the rate in women. Gender differences, which begin during puberty, lead to wider bones in males as compared with females. In men, follicle-stimulating hormones, testosterone, estrogens, and sex hormone-binding levels, together with genetic factors, interact in determining the peak of bone mass, BMD maintenance, and lifetime decrease. As compared with women, men are more frequently affected by secondary osteoporosis. Therefore, in all osteoporotic men, a complete clinical history should be collected and a careful physical examination should be done, in order to find clues of a possible underlying diseases and, ultimately, to guide laboratory testing. Currently, the pharmacological therapy of male osteoporosis includes aminobisphosphonates, denosumab, and teriparatide. Hypogonadal patients may be treated with testosterone replacement therapy. Given that the fractures related to mortality are higher in men than in women, treating male subjects with osteoporosis is of the utmost importance in clinical practice, as it may impact on mortality even more than in women.

Mortality in an Italian nursing home during COVID-19 pandemic: correlation with gender, age, ADL, vitamin D supplementation, and limitations of the diagnostic tests

INTRODUCTION

The COVID-19 pandemic caused an increased mortality in nursing homes due to its quick spread and the age-related high lethality.

RESULTS

We observed a two-month mortality of 40%, compared to 6.4% in the previous year. This increase was seen in both COVID-19 positive (43%) and negative (24%) residents, but 8 patients among those testing negative on the swab, tested positive on serological tests. Increased mortality was associated with male gender, older age, no previous vitamin D supplementation and worse "activities of daily living (ADL)" scores, such as Barthel index, Tinetti scale and S.OS.I.A.

CLASSIFICATION

CONCLUSION

Our data confirms a higher geriatric mortality due to COVID-19. Negative residents also had higher mortality, which we suspect is secondary to preanalytical error and a low sensitivity of the swab test in poorly compliant subjects. Male gender, older age and low scores on ADL scales (probably due to immobility) are risk factors for COVID-19 related mortality. Finally, mortality was inversely associated with vitamin D supplementation.

DESIGN

In this observational study, we described the two-month mortality among the 157 residents (age 60-100) of a nursing home after Sars-CoV-2 spreading, reporting the factors associated with the outcome. We also compared the diagnostic tests for Sars-CoV-2.

Italian association of clinical endocrinologists (AME) position statement: drug therapy of osteoporosis

Treatment of osteoporosis is aimed to prevent fragility fractures and to stabilize or increase bone mineral density. Several drugs with different efficacy and safety profiles are available. The long-term therapeutic strategy should be planned, and the initial treatment should be selected according to the individual site-specific fracture risk and the need to give the maximal protection when the fracture risk is highest (i.e. in the late life). The present consensus focused on the strategies for the treatment of postmenopausal osteoporosis taking into consideration all the drugs available for this purpose. A short revision of the literature about treatment of secondary osteoporosis due both to androgen deprivation therapy for prostate cancer and to aromatase inhibitors for breast cancer was also performed. Also premenopausal females and males with osteoporosis are frequently seen in endocrine settings. Finally particular attention was paid to the tailoring of treatment as well as to its duration.

High-dose intramuscular octreotide in patients with acromegaly inadequately controlled on conventional somatostatin analogue therapy: a randomised controlled trial

OBJECTIVE

In acromegaly, 25-50% of patients respond inadequately to conventional long-acting somatostatin analogue (SSA) therapy. Response may be improved by increasing SSA frequency or dose. This study evaluated the biochemical efficacy and safety of high-dose octreotide in patients with acromegaly.

DESIGN

A 24-week prospective, multicentre, randomised, open-label trial conducted from 12 December 2005 to 23 October 2007 in patients with persistently uncontrolled acromegaly despite > or =6 month conventional SSA therapy.

METHODS

Patients with > or =50% reduction in GH levels during previous SSA treatment were randomised to high-dose (60 mg/28 days) or high-frequency (30 mg/21 days) octreotide i.m. injection. Primary end-points were week 12 and 24 reduction in serum IGF1 and GH from baseline. Secondary end points included IGF1 normalisation and tumour shrinkage rates, and safety/tolerability evaluations.

RESULTS

Significantly, more patients (10 out of 11) achieved week 24 IGF1 reduction in the high-dose than the high-frequency group (8 out of 15; P<0.05). In the high-dose group only, week-24 IGF1 values were significantly reduced (P=0.02) versus baseline. Normalisation of IGF1 occurred only with the high-dose regimen (4/11; P=0.02). Out of 14 patients experiencing adverse events, 5 reported drug-related gastrointestinal effects. No dose-response relationship was seen. Safety parameters were similar between treatment groups, apart from a slight decrease in HbA1c in the high-dose group only.

CONCLUSION

High-dose octreotide treatment is safe and effective (normalisation of IGF1 levels) in a subset of patients with active acromegaly inadequately controlled with long-term SSA. Individualised octreotide doses up to 60 mg/28 days may improve outcomes of SSA therapy.

Effects of somatostatin analogs on glucose homeostasis: a metaanalysis of acromegaly studies

BACKGROUND

Somatostatin analogs (SSA) may influence glucose metabolism, but the clinical relevance of this effect is uncertain because trials performed so far are limited in terms of number of patients and heterogeneity for length and type of follow-up.

PURPOSE

The purpose of the study was to assess, via the metaanalysis of acromegaly studies, the clinical impact of SSA on glucose metabolism. The outcomes analyzed were fasting plasma glucose, fasting plasma insulin, hemoglobin A(1c), and plasma glucose concentrations during oral glucose tolerance test.

STUDY SELECTION

Eligibility criteria were: 1) duration of SSA treatment of at least 3 wk; 2) available numerical data for at least one of the four biochemical outcomes investigated; 3) measurement of the outcomes before and after SSA treatment; and 4) no selection of acromegalic patients for their responsivity to SSA. After revision, only 31 studies fulfilled eligibility criteria and were therefore selected for data extraction and analysis.

DATA SYNTHESIS

SSA treatment was found to induce statistically significant decrease in fasting plasma insulin [effect size -0.45, 95% confidence interval (CI) from -0.58 to -0.32, P < 0.001], without any significant change of fasting plasma glucose (effect size +0.04, 95% CI from -0.07 to +0.15, P = 0.52) and hemoglobin A(1c) (effect size +0.11, 95% CI from -0.02 to +0.23, P = 0.09). Serum glucose values during the oral glucose tolerance test were shown to significantly change during SSA treatment (effect size +0.31, 95% CI from +0.17 to +0.45, P < 0.001), although with high inconsistency among trials.

CONCLUSIONS

Our data suggest that modifications of glucose homeostasis induced by SSA may have an overall minor clinical impact in acromegaly.

Prevalence of vertebral fractures in men with acromegaly

CONTEXT

Data on osteoporotic fractures in acromegaly are limited. An increased prevalence of radiological vertebral fractures was already observed in postmenopausal women with active acromegaly. It is unknown whether this observation may reflect a more general increased risk of fractures in acromegaly.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at referral centers.

PATIENTS AND CONTROL SUBJECTS

Subjects included 40 males with acromegaly (25 patients with controlled disease and 15 patients with active disease) and 31 control males, with age and gonadal status comparable with the patients.

INTERVENTIONS

Evaluation of vertebral fractures (quantitative morphometric analysis) and bone mineral density (BMD) at lumbar spine and total hip (dual energy X-ray absorptiometry) was done.

MAIN OUTCOME MEASURE

Vertebral fractures were assessed.

RESULTS

Although BMD was not significantly different between acromegalic patients and control subjects, the prevalence of vertebral fractures was higher in acromegalic patients as compared with the control subjects (57.5 vs. 22.6%; chi(2): 8.7; P = 0.003). Fractured and nonfractured acromegalic patients showed no significant difference in age and BMD Z-score. However, acromegalic patients with fractures had serum IGF-I values significantly higher and duration of active disease significantly longer with respect to patients without fractures. Moreover, patients with fractures showed significantly longer untreated hypogonadism as compared with patients without fractures. In a multivariate logistic regression analysis, the duration of active acromegaly was the only risk factor significantly correlated with the occurrence of fractures (odds ratio 1.1, confidence interval 1.04-1.6).

CONCLUSIONS

This study reports for the first time a high prevalence of osteoporotic vertebral fractures in an unselected acromegalic male population generally considered at low risk of osteoporosis, suggesting that complicated osteoporosis is an important comorbidity of acromegaly.

Prevention and treatment of glucocorticoid-induced osteoporosis

Glucocorticoid-induced osteoporosis (GIO) is the most common form of secondary osteoporosis with fractures occurring in as many as 30-50% of patients receiving chronic glucocorticoid therapy. Calcium and vitamin D are important measures in the primary prevention of GIO. However, vitamin D and calcium alone do not allow to prevent fractures. Estrogens and androgens should be used in patients with documented hypogonadism. Bisphosphonates are the most effective of the various therapies that have been assessed for the management of GIO. These drugs need to be started early in order to correct the increase in bone resorption occurring in the first weeks of glucocorticoid treatment. Anabolic therapeutic strategies are under investigation. Teriparatide seems to be also efficacious for the treatment of patients with GIO.

Biochemical evaluation of patients with active acromegaly and type 2 diabetes mellitus: efficacy and safety of the galanin test

The oral glucose tolerance test, which is considered the gold standard for the diagnosis of active acromegaly, should not be performed in the presence of basal hyperglycemia. Moreover, false-positive responses may occur in patients with diabetes mellitus. Galanin has previously been demonstrated to induce paradoxical inhibition of growth hormone (GH) secretion in most patients with active acromegaly. In this study, we assessed GH response to galanin infusion in a series of 17 consecutive patients with active acromegaly, 7 of whom had coexistent type 2 diabetes mellitus and 10 were without either diabetes mellitus or impaired tolerance to glucose. 6 acromegalic patients with diabetes mellitus (85.7%) and 7 without diabetes (70.0%) showed a decrease in serum GH values during galanin infusion (chi2 0.9; p = 0.6). The GH nadir occurred at a comparable time in the two groups of acromegalic patients. Moreover, the two groups showed no significant difference (p = 0.45) in DeltaGH during galanin infusion. Galanin infusion did not induce any significant change in plasma glucose levels in both diabetic and non-diabetic patients with acromegaly. The results of our study provide evidence that the galanin test may be of value for the diagnosis of acromegaly in patients with type 2 diabetes mellitus.

Effect of gonadal status on bone mineral density and radiological spinal deformities in adult patients with growth hormone deficiency

Growth hormone deficiency (GHD) in adult patients is associated with marked decrease in bone turnover, low bone mass and high risk of clinical and subclinical fractures. We investigated whether the prevalence of spinal deformities in adults with GHD was related to the gonadal status of patients. A total of 89 adult hypopituitary patients with severe GHD were evaluated for bone mineral density (BMD) and vertebral deformities (quantitative morphometric analysis). At the study entry, 54 patients were eugonadic whereas 35 patients were hypogonadic without replacement treatment. Radiological spinal deformities were found in 55 patients (61.8%) with higher prevalence in untreated (56 cases) versus treated (33 cases) GHD patients. Eugonadic and hypogonadic patients showed no significant difference in spinal deformities although T-score was significantly lower in hypogonadic as compared with eugonadic patients. Gonadal function was not correlated with the occurrence of spinal deformities which was instead inversely correlated with rhGH treatment. In conclusion, gonadal status may influence BMD in adult patients with GHD without affecting the risk to develop vertebral deformities. Conversely, rhGH replacement treatment seems to be the only factor influencing the risk to develop vertebral deformities in adult GHD patients.

Functional effects of nitric oxide-releasing aspirin on vein conduits of diabetic patients undergoing CABG

BACKGROUND

Type 2 diabetes mellitus (DM) is known to negatively affect biological properties of venous vasculature, and, particularly, to reduce endothelium-derived nitric oxide release. This condition might influence venous graft function following coronary artery bypass surgery (CABG). The aim of this study was to evaluate the functional effects of a NO-releasing aspirin (NORA) on vein grafts (VG) of diabetics and control patients undergoing elective CABG.

METHODS

In 40 consecutive ischemic heart disease patients, the effects of NORA were tested on segments of saphenous vein conduits harvested during elective CABG. Twenty patients had type-2 DM (mean age 69+/-2), whereas 20 patients had no DM (NDM) and represented the control group (mean age 67+/-4). Functional responses were tested by exposing VGs to NORA and to standard vasoactive agents in an organ-bath preparation. Histological features of VGs were also assessed by light and electronic microscopy.

RESULTS

Significant impairment of endothelial-dependent vasodilation (acetylcholine induced) was documented in VGs of DM subjects. NORA induced a significant and comparable vascular relaxation in all venous segments of NDM and DM patients (56+/-12% of maximal relaxation vs 61+/-11% in the control group, respectively). Histology showed variable extent of vascular layer and cellular abnormalities in VGs of diabetics (intimal hyperplasia, calcific deposition, endothelial cell degeneration) likely responsible of the endothelial functional impairment, whereas control group VG showed preserved structures.

CONCLUSIONS

This preliminary study confirms the impairment of endothelium-dependent vasodilative property of VGs in DM patients. It also indicates that NORA effectively induces vasodilation of VGs which was effective also in DM patients thereby representing a promising therapy for diabetics undergoing CABG with the use of VGs, although further studies are mandatory to conclusively assess the safety and benefits of this pharmacological agent.

Active acromegaly enhances spontaneous parathyroid hormone pulsatility

In healthy subjects, parathyroid hormone (PTH) is secreted in a dual fashion, with low-amplitude and high-frequency pulses superimposed on tonic secretion. These 2 components of PTH secretion seem to have different effects on target organs. The aim of our study was to evaluate whether growth hormone excess in acromegaly may modify the spontaneous pulsatility of PTH. Five male patients with newly diagnosed active acromegaly and 8 healthy subjects were evaluated by 3-minute blood sampling for 6 hours. Plasma PTH concentrations were evaluated by multiparameter deconvolution analysis. Plasma PTH release profiles were also subjected to an approximate entropy (ApEn) estimate, which provides an ensemble measure of the serial regularity or orderliness of the release process. In acromegalic patients, baseline serum PTH values were not significantly different from those measured in the healthy subjects, as well as tonic PTH secretion rate, number of bursts, fractional pulsatile PTH secretion, and ApEn ratio. Conversely, PTH pulse half-duration was significantly longer in acromegalic patients vs healthy subjects (11.8+/-0.95 vs 6.9+/-1.6 minutes; P=.05), whereas PTH pulse mass showed a tendency (P=.06) to be significantly greater in acromegalic patients. These preliminary data suggest that growth hormone excess may affect PTH secretory dynamics in patients with acromegaly. Potentially negative bone effects of the modifications of PTH secretory pattern in acromegaly should be investigated.

Increased prevalence of radiological spinal deformities in adult patients with GH deficiency: influence of GH replacement therapy

This cross-sectional study shows that a high number of untreated adult patients with GHD develop radiological vertebral deformities. Patients undergoing GH replacement treatment showed a significantly lower prevalence of vertebral deformities versus treated patients in the presence of similar BMD, as assessed by DXA.

INTRODUCTION

In this cross-sectional study, we investigated whether the prevalence and degree of spinal deformities in adults with growth hormone deficiency (GHD) were related to the age of patients, degree of bone turnover, BMD, and recombinant human GH (rhGH) replacement therapy.

MATERIALS AND METHODS

One hundred seven adult hypopituitary patients (67 males and 40 females; mean age, 47 years; range: 16-81 years) with severe GHD and 130 control subjects (39 males, 91 females; mean age: 58.9 years; range: 26-82 years) were evaluated for BMD (DXA) and vertebral deformities (quantitative morphometric analysis). At study entry, 65 patients were on replacement therapy with rhGH, whereas 42 patients had never undergone rhGH.

RESULTS

Vertebral fractures were significantly more frequent in GHD patients versus control subjects (63.6% versus 37.7%; chi2 15.7; p < 0.001). The fracture prevalence, as well as the fracture number, was significantly higher in untreated versus treated patients (78.6% versus 53.8%; chi2: 6.7; p = 0.009), although the two groups of patients did not show any significant difference in median T score. In untreated GHD patients, the prevalence of vertebral deformities was correlated with T score (p = 0.002) and duration of disease (p = 0.003). In treated GHD patients, the prevalence of spinal deformities was correlated only with the timing of the beginning of rhGH replacement.

CONCLUSIONS

This cross-sectional study reports high prevalence of vertebral radiological deformities in adult patients with untreated GHD. The replacement treatment of GHD leads to a significant decrease in fracture rate.

Neuroendocrine tumors secreting growth hormone-releasing hormone: Pathophysiological and clinical aspects

Hypothalamic GHRH is secreted into the portal system, binds to specific surface receptors of the somatotroph cell and elicits intracellular signals that modulate pituitary GH synthesis and/or secretion. Moreover, GHRH is synthesized and expressed in multiple extrapituitary tissues. Excessive peripheral production of GHRH by a tumor source would therefore be expected to cause somatotroph cell hyperstimulation, increased GH secretion and eventually pituitary acromegaly. Immunoreactive GHRH is present in several tumors, including carcinoid tumors, pancreatic cell tumors, small cell lung cancers, endometrial tumors, adrenal adenomas, and pheochromocytomas which have been reported to secrete GHRH. Acromegaly in these patients, however, is uncommon. The distinction of pituitary vs. extrapituitary acromegaly is extremely important in planning effective management. Regardless of the cause, GH and IGF-1 are invariably elevated and GH levels fail to suppress (<1 microg/l) after an oral glucose load in all forms of acromegaly. Dynamic pituitary tests are not helpful in distinguishing acromegalic patients with pituitary tumors from those harbouring extrapituitary tumors. Plasma GHRH levels are usually elevated in patients with peripheral GHRH-secreting tumors, and are normal or low in patients with pituitary acromegaly. Unique and unexpected clinical features in an acromegalic patient, including respiratory wheezing or dyspnea, facial flushing, peptic ulcers, or renal stones sometimes are helpful in alerting the physician to diagnosing non pituitary endocrine tumors. If no facility to measure plasma GHRH is available, and in the absence of MRI evidence of pituitary adenoma, a CT scan of the thorax and abdominal ultrasound could be performed to exclude with good approximation the possibility of an ectopic GHRH syndrome. Surgical resection of the tumor secreting ectopic GHRH should be the logical approach to a patient with ectopic GHRH syndrome. Standard chemotherapy directed at GHRH-producing carcinoid tumors is generally unsuccessful in controlling the activated GH axis. Somatostatin analogs provide an effective option for medical management of carcinoid patients, especially those with recurrent disease. In fact, long-acting somatostatin analogs may be able to control not only the ectopic hormonal secretion syndrome, but also, in some instances, tumor growth. Therefore, although cytotoxic chemotherapy, pituitary surgery, or irradiation still remain available therapeutic options, long-acting somatostatin analogs are now preferred as a second-line therapy in patients with carcinoid tumors and ectopic GHRH-syndrome.

Growth hormone deficiency in the adult

Growth hormone deficiency (GHD) in adults may be of either adult or childhood onset and may occur as isolated GHD or as multiple hormone deficiencies. Adult-onset GHD (AoGHD) usually results from damage to the pituitary gland or hypothalamus. GH is frequently undetectable in normal subjects and thus GHD cannot be distinguished from the normal state using a single random GH measurement. In general, a stimulation test is required to recognize GHD. Insulin tolerance test (ITT) has been considered the gold standard by the most important scientific societies, although alternative tests, in particular GHRH plus arginine have been proposed as valuable alternative to ITT. The clinical syndrome associated with AoGHD is characterized by a wide array of symptoms and important chronic complications, such as cardiovascular complications, which may be responsible for an increased mortality. The rationale for GH replacement in adults GHD patients is justified by the beneficial effects on some clinical end-points, such as quality of life (QoL) and cardiovascular risk factors, whereas the effects on mortality risk are still controversial. Over the recent years, guidelines on the use of rhGH as a substitution treatment in adult hypopituitarism have been issued by international (Growth hormone research society-GRS, Endocrine Society) and relevant national (National Institute of Clinical Excellence-UK, NICE) institutions. The aim of the paper is to review and discuss these guidelines.

Resistance to somatostatin analogs in acromegaly: an evolving concept?

The aim of acromegaly treatment is to control the disease by suppressing GH hyperactivity and reducing the size or impeding the growth of the pituitary GH secreting mass. Over recent years, many studies have emphasized the role of SS analogs in the treatment of acromegaly. In fact, SS analogs have been demonstrated to be an effective tool not only in the control of GH hypersecretion but also more recently in the control of tumor growth, in a relevant number of acromegalic patients both as primary or adjunctive treatment. In this context, the therapeutic failure of medical treatment with SS analogs needs to be accurately defined particularly when they are used as primary treatment but also when they are given to patients previously operated upon, since other effective therapeutic options are nowadays available. Current definition of resistance to SS analogs is based on their efficacy to control GH and IGF-I. However, due to the emerging significance of the shrinkage effect of SS analogs on pituitary adenomas as well as to the apparent dissociation between this effect and the biochemical effects of treatment with these analogs, an evolution in the concept of SS resistance is likely to be occurring. In this review, we will discuss the biological basis of the discordance between biochemical and volumetric effects of SS analogs, and we will address the intriguing clinical and therapeutic aspects related to a possible redefinition of the resistance to SS analogs.

Increased prevalence of radiological spinal deformities in active acromegaly: a cross-sectional study in postmenopausal women

This cross-sectional study shows that high numbers of postmenopausal women with acromegaly develop vertebral fractures in relation to the activity of disease. In patients with active acromegaly, vertebral fractures occur even in presence of normal BMD, whereas in patients with controlled acromegaly, vertebral fractures are always accompanied by a pathological BMD.

INTRODUCTION

We studied the frequency of radiological vertebral fractures in a cohort of postmenopausal women with active or controlled acromegaly.

MATERIALS AND METHODS

Thirty-six postmenopausal acromegalic patients (15 with active and 21 with controlled disease) were evaluated for BMD, bone metabolism (serum 25-hydroxyvitamin D, PTH, bone-specific alkaline phosphatase [BSALP], and urinary deoxypyridinoline [Dpd]), and vertebral quantitative morphometry. Thirty-six nonacromegalic postmenopausal women, matched for age, were selected among the patients consulting the Bone Center as a control group for BMD evaluation and vertebral quantitative morphometry.

RESULTS

Vertebral fractures were shown in 19 patients (52.8%) and 11 controls (30.6%; chi2: 3.7; p=0.06). Fractured acromegalic women were older and had higher serum IGF-1, Dpd, and BSALP and lower T score and serum vitamin D values compared with nonfractured patients. Moreover, the fractured women had a longer diagnosis and were in the postmenopausal period for a longer period than the nonfractured women. The fracture rate was significantly higher in active than in controlled acromegaly (80% versus 33.3%; chi2: 7.6; p=0.008). The patients with active acromegaly who fractured (12 cases) had significantly higher serum IGF-1 values (356 ng/ml; range: 212-950 versus 120 ng/ml; range: 84-217; p<0.001) and T scores (-1.3 SD, range: -2.9 to +1.3 versus -2.7 SD, range: -3.4 to -1.5, p=0.04) compared with the fractured women whose disease was controlled (7 cases). All fractured women with controlled acromegaly had T scores<-1.0 SD (57.1% of them had osteoporosis, and 42.9% were osteopenic). In contrast, 41.7% of women whose fractures were associated with active disease had a normal T score (>-1.0 SD), whereas osteopenia and osteoporosis were found only in 33.3% and 25.0% of them, respectively.

CONCLUSIONS

This cross-sectional study shows that high numbers of postmenopausal women with acromegaly develop vertebral fractures in relation to the activity of disease. Furthermore, our study shows that, in patients with active acromegaly, vertebral fractures occur even in the presence of normal BMD, whereas in patients with controlled acromegaly, vertebral fractures are always accompanied by a pathological BMD.

Cardiac and metabolic effects of chronic growth hormone and insulin-like growth factor I excess in young adults with pituitary gigantism

Chronic growth hormone (GH)/insulin-like growth factor I (IGF-I) excess is associated with considerable mortality in acromegaly, but no data are available in pituitary gigantism. The aim of the study was to evaluate the long-term effects of early exposure to GH and IGF-I excess on cardiovascular and metabolic parameters in adult patients with pituitary gigantism. Six adult male patients with newly diagnosed gigantism due to GH secreting pituitary adenoma were studied and compared with 6 age- and sex-matched patients with acromegaly and 10 healthy subjects. Morphologic and functional cardiac parameters were evaluated by Doppler echocardiography. Glucose metabolism was assessed by evaluating glucose tolerance and homeostasis model assessment index. Disease duration was significantly longer (P<.05) in patients with gigantism than in patients with acromegaly, whereas GH and IGF-I concentrations were comparable. Left ventricular mass was increased both in patients with gigantism and in patients with acromegaly, as compared with controls. Left ventricular hypertrophy was detected in 2 of 6 of both patients with gigantism and patients with acromegaly, and isolated intraventricular septum thickening in 1 patient with gigantism. Inadequate diastolic filling (ratio between early and late transmitral flow velocity<1) was detected in 2 of 6 patients with gigantism and 1 of 6 patients with acromegaly. Impaired glucose metabolism occurrence was higher in patients with acromegaly (66%) compared with patients with gigantism (16%). Concentrations of IGF-I were significantly (P<.05) higher in patients with gigantism who have cardiac abnormalities than in those without cardiac abnormalities. In conclusion, our data suggest that GH/IGF-I excess in young adult patients is associated with morphologic and functional cardiac abnormalities that are similar in patients with gigantism and in patients with acromegaly, whereas occurrence of impaired glucose metabolism appears to be higher in patients with acromegaly, although patients with gigantism are exposed to GH excess for a longer period.

Cardiovascular risk in aging and obesity: is there a role for GH

GH has significant impact in adults. In fact, patients with the GH deficiency (GHD) syndrome are now recognized as having an increased cardiovascular risk. The effects of human aging on GH secretion have been evaluated by a number of researchers. Studies of 24 h secretion of GH have shown variable reductions in most 24-h GH secretory parameters in middle-aged and in older men and women, resulting in a decrease in plasma levels of its anabolic mediator IGF-I. Obesity is also associated with several endocrine and metabolic abnormalities. These include decreased serum GH concentrations, reduced GH half-life, frequency of GH secretory episodes and daily GH production rate. The mechanism of the low GH in obesity is not completely understood nor is it clear whether its relationship with visceral adiposity is causal. The aim of this article will be to review the available clinical data concerning the potential involvement of "subclinical" or perhaps better "functional" GHD, which is observed in aging and obesity, in the increase in cardiovascular risk which characterizes these two conditions.

Primary empty sella

CONTEXT

The term primary empty sella (PES) refers to a number of endocrine and/or neurological disturbances that may be caused by the herniation of subarachnoid space within the sella.

SETTING

The records of all patients with a diagnosis of empty sella between 1985 and 2002 seen at the Catholic University of Rome and University of Brescia were examined retrospectively.

PATIENTS

We have observed 171 female and 42 male patients affected by PES (over 4:1 sex ratio). The mean age at diagnosis in our subjects was 51.8 +/- 2.1 yr. Mean body mass index was 27.3 +/- 3.5 kg/m2.

MAIN OUTCOME MEASURE

All the patients have been analyzed first either with sellar computed tomography scan or magnetic resonance imaging. All patients underwent neurological, ophthalmological, and baseline endocrine evaluation (appropriate stimulation tests were performed when hypopituitarism was suspected).

RESULTS

In the overall population, 40 of 213 patients had documented endocrine abnormalities, specifically 31 females and nine males. Twenty-two patients (10.3% of total patients; 18 women, 10.5% of all women, with a mean age of 38.6 +/- 1.1 yr and four males, with a mean age 46.5 +/- 3.52 yr) presented with hyperprolactinemia. Global anterior hypopituitarism was confirmed in nine patients. Eight patients presented an isolated GH deficiency. One hundred thirty-eight of our patients presented a so-called partial empty sella at computed tomography scan/magnetic resonance imaging, and 75 had total PES.

CONCLUSIONS

PES may be associated with variable clinical conditions ranging from mild endocrine disturbances to severe intracranial hypertension and rhinorrhea. The need for treatment of hyperprolactinemia as well as for replacement hormone therapy must be assessed in PES. Symptomatic intracranial hypertension makes cerebrospinal fluid shunting procedures necessary.

The somatostatin subtype-2 receptor antagonist, BIM-23627, improves the catabolic effects induced by long-term glucocorticoid treatment in the rat

BIM-23627 is a synthetic peptide with "in vitro" and "in vivo" properties consistent with a pure sst2 antagonist. The aim of the present study was to evaluate the effects of long-term administration of BIM-23627 and the combined effects of BIM-23627 and dexamethasone (DEX) on the somatotropic axis, including growth, epididymal fat accumulation, glucose homeostasis and insulin activity, in young male rats. Beginning on day 23 of age, 16 animals were treated daily with saline or DEX (40 microg/kg/daily). Each group was subdivided into two paired groups and treated with either vehicle or BIM-23627 (0.5 mg/kg, t.i.d.). The treatment period lasted 31 days. The animals were killed by decapitation; trunk blood and pituitaries were collected for the determination of hormone concentrations and GH mRNA expression, respectively. Based on plasma GH and IGF-I concentrations and GH mRNA expression in the pituitary, BIM-23627 was able to counteract the inhibitory effects of DEX on the somatotropic axis; however, only a partial reversal of somatic growth inhibition was observed. DEX-treated rats remained euglycemic, but their insulin levels were significantly increased, indicating an incipient insulin resistance. Although BIM-23627 itself tended to increase insulin concentration in saline-treated rats, its administration to DEX-treated rats reduced insulin levels (saline: 25+/-3; DEX: 55+/-16*; DEX+BIM-23627: 34+/-5; BIM-23627: 38+/-7 microIU/ml; *P<0.05 vs. saline), apparently improving the degree of insulin sensitivity. DEX administration significantly reduced circulating ghrelin, whereas the sst2 antagonist had no significant effect. An inverse correlation was found between ghrelin concentrations and plasma insulin levels. Both rats receiving DEX and rats receiving BIM-23627 had decreased plasma concentration of total testosterone (P<0.05); however, the effects of DEX and BIM-23627 were not additive. In conclusion, BIM-23627 may represent a new pharmacological agent to reduce the suppression of the GH-IGF-I axis in long-term GC treated patients and enhance insulin sensitivity. Further studies are required in order to fully optimize the SSTR-2 antagonist-induced reversal of DEX-induced somatic growth inhibition.

Growth hormone response to growth hormone-releasing hormone is reduced in adult asthmatic patients receiving long-term inhaled corticosteroid treatment

BACKGROUND

Some studies have demonstrated that the function of the growth hormone (GH)-insulin-like growth factor (IGF)-1 axis is significantly impaired in patients with oral corticosteroid (CS)-induced osteoporosis. The aim of study was to investigate the effects of long-term therapy with inhaled CSs (ICSs) on the hypothalamic-pituitary-GH axis by the GH response to GH-releasing hormone (GHRH), as well as bone turnover, in adult asthmatic patients.

DESIGN

Cross-sectional study.

PATIENTS

Twenty-seven adult subjects with mild-to-moderate persistent asthma (long-term ICS therapy [ie, > 1 year], 20 patients; naive to ICS treatment, 7 patients) and 10 control subjects.

MEASUREMENTS

Each subject underwent testing with an IV bolus (1 mug/kg) injection of human GHRH, and samples of GH were taken 15 min before the GHRH injection, at 0 min (ie, at the time of GHRH injection), and at 15, 30, 45, 60, and 90 min after injection to obtain values for peak GH and DeltaGH. At baseline, samples of serum IGF-1 and blood-urine were collected for bone turnover markers.

RESULTS

The GH response to GHRH was significantly reduced in asthmatic patients receiving ICSs (peak GH, p < 0.05; and DeltaGH, p < 0.01) in comparison with control subjects and asthmatic patients who were naive to ICS therapy (peak GH and DeltaGH, p < 0.01). Baseline IGF-1 levels were similar in the three groups. Serum osteocalcin, a marker of bone formation, was significantly reduced (p < 0.01) and correlated with GH peak (r(2) = 0.34; p = 0.007) in asthmatic patients who were treated with ICSs.

CONCLUSIONS

We conclude that GH secretion in response to GHRH is significantly reduced in adult asthmatic patients receiving therapy with ICS and that such inhibition could play a negative role in bone metabolism.

Clinical review: Growth hormone and cardiovascular risk factors

The aim of this article is to review the lessons on the relationship between GH and the principal metabolic cardiovascular risk factors that we learned from studies of GH deficiency (GHD) in the adult. The lesson that "organic" GHD has taught us is that primary impairment in the GH/IGF-I axis may lead to a high-risk cardiovascular profile that is partially reversible during GH replacement. Waiting for the definitive demonstration that GH substitution may reduce cardiovascular mortality in these patients, we find that data so far reported are encouraging and indicate in the beneficial cardiovascular effects of GH one of the major factors supporting this type of treatment in hypopituitary GHD adults. Moreover, enough evidence from GHD studies has been produced to suggest a physiological role for the GH/IGF-I axis in the control and regulation of several metabolic cardiovascular risk factors.

Chronic glucocorticoid treatment alters spontaneous pulsatile parathyroid hormone secretory dynamics in human subjects

OBJECTIVE

Spontaneous parathyroid hormone (PTH) secretory dynamics include tonic and pulsatile components. It is not known how glucocorticoids might alter these secretory dynamics.

DESIGN

The aim of our study was to evaluate spontaneous fluctuations in serum PTH levels in six adult male patients (aged 31-64 years) receiving chronic (>6 months) therapy with glucocorticoids (daily dosage >7.5 mg of prednisone or dose equivalent of other corticosteroid) as compared with a control group of 10 age- and sex-matched normal subjects.

METHODS

Peripheral venous blood sampling was performed every 3 min for 6 h from 0900 to 1500 h. Plasma PTH release profiles were subjected to deconvolution analysis, a method that resolves measured hormone concentrations into secretion and clearance components, and to an approximate entropy (ApEn) estimate, that in turn provides an integrated measure of the serial regularity or orderliness of the release process.

RESULTS

In the glucocorticoid-treated group, the PTH tonic secretory rate was reduced (4.3+/-0.74 vs 8.8+/-1.4 pg/ml per min in controls, P = 0.017). There was, however, an increase in the fractional pulsatile PTH secretion (42+/-8.2 vs 18.3+/-3.9 pg/ml per min, P = 0.006) in glucocorticoid-treated vs normal subjects. Mean overall PTH concentration, as well as mean integrated area, was similar among normal and glucocorticoid-treated subjects.

CONCLUSIONS

These results demonstrate, for the first time, that chronic glucocorticoid treatment induces a redistribution of spontaneous PTH secretory dynamics by reducing the amount released in tonic fashion and increasing the amount released as pulses.

Diagnosis and treatment of acromegaly and its complications: consensus guidelines

In February 1999, May 2000 and April 2002, three workshops were held in Cortina, Montecarlo and Versailles, respectively, to develop a consensus defining the diagnosis and treatment of acromegaly and its complications. The workshops were sponsored by the Pituitary Society and European Neuroendocrine Association. Invited international participants included endocrinologists, neurosurgeons and radiotherapists skilled in the management of acromegaly. This review paper summarizes the main points of the three consensus statements published following these three workshops.

Diagnostic and therapeutic consensus on acromegaly

In February 1999 and May 2000, two workshops were held in Cortina, Italy and Montecarlo, respectively, to develop a consensus defining the diagnosis and treatment of acromegaly. The workshops were sponsored by the Italian Society of Endocrinology, the Pituitary Society and European Neuroendocrine Association. Partecipants from all over the world included endocrinologists, neurosurgeons and radiotherapists skilled in the management of acromegaly. This review paper summarizes the main points of the two consensus statements published following these two workshops.

GH deficiency in the adult and bone

GH acts on various tissues and organs, like liver, kidney, bone and muscle. There are no conclusive data on adult onset GH deficiency (GHD) effects on bone remodeling. In fact reduced, increased or unchanged values of serum markers of bone formation and resorption have been described. However, a direct link between GHD and reduced bone mass in hypopituitarism is supported by reports that GH replacement therapy can improve bone mineral density (BMD) in these patients. Recently, many studies have shown an increased prevalence of osteoporosis in adult-onset GHD patients, and the fracture rate in these subjects seems to be twice that in the non-GH-deficient population. Long-term studies in these years have described a BMD increase in GHD patients during treatment with GH alone or in combination with biphosphonates. To understand if these BMD changes may result in a reduction of fracture risk, it is necessary to carry out a longitudinal follow-up of large cohorts of GHD adults on GH replacement therapy.

Acromegalic patients show the presence of hypertrophic remodeling of subcutaneous small resistance arteries

Structural alterations of small resistance arteries in patients with essential hypertension (EH) are mostly characterized by inward eutrophic remodeling. However, we have observed the presence of hypertrophic remodeling in patients with renovascular hypertension, as well as in patients with noninsulin-dependent diabetes mellitus, suggesting a relevant effect of humoral growth factors on vascular structure. Growth hormone may stimulate in vitro proliferation of vascular smooth muscle cells. However, no data are presently available about small artery structure in acromegalic patients. Therefore, we have investigated the structure of subcutaneous small arteries in 12 normotensive (NT) subjects, in 12 EH subjects, and in 9 acromegalic patients (APs). All subjects underwent biopsy of the subcutaneous fat; then, small resistance arteries were dissected and mounted on a micromyograph. The normalized internal diameter, media thickness, media-to-lumen ratio, the media cross-sectional area together with remodeling, and growth indices were calculated. Demographic variables were similar in the three groups, except for blood pressure. The media-to-lumen ratio was significantly greater in EH and AP, compared with NT. No difference was observed between EH and AP. The media cross-sectional area was significantly greater in AP compared with EH and with NT. The calculation of remodeling and growth index suggests the presence of eutrophic remodeling in EH (growth index 0%) and of hypertrophic remodeling in AP (growth index 40%). In conclusion, our data suggest the presence of hypertrophic remodeling of subcutaneous small resistance arteries of AP, probably as a consequence of growth-stimulator properties of IGF-1.

Acromegalic Patients Show the Presence of Hypertrophic Remodeling of Subcutaneous Small Resistance Arteries

Structural alterations of small resistance arteries in patients with essential hypertension (EH) are mostly characterized by inward eutrophic remodeling. However, we have observed the presence of hypertrophic remodeling in patients with renovascular hypertension, as well as in patients with noninsulin-dependent diabetes mellitus, suggesting a relevant effect of humoral growth factors on vascular structure. Growth hormone may stimulate in vitro proliferation of vascular smooth muscle cells. However, no data are presently available about small artery structure in acromegalic patients. Therefore, we have investigated the structure of subcutaneous small arteries in 12 normotensive (NT) subjects, in 12 EH subjects, and in 9 acromegalic patients (APs). All subjects underwent biopsy of the subcutaneous fat; then, small resistance arteries were dissected and mounted on a micromyograph. The normalized internal diameter, media thickness, media-to-lumen ratio, the media cross-sectional area together with remodeling, and growth indices were calculated. Demographic variables were similar in the three groups, except for blood pressure. The media-to-lumen ratio was significantly greater in EH and AP, compared with NT. No difference was observed between EH and AP. The media cross-sectional area was significantly greater in AP compared with EH and with NT. The calculation of remodeling and growth index suggests the presence of eutrophic remodeling in EH (growth index 0%) and of hypertrophic remodeling in AP (growth index 40%). In conclusion, our data suggest the presence of hypertrophic remodeling of subcutaneous small resistance arteries of AP, probably as a consequence of growth-stimulator properties of IGF-1.

Transformation of a MGUS to overt multiple myeloma: the possible role of a pituitary macroadenoma secreting high levels of insulin-like growth factor 1 (IGF-1)

We present a female patient with monoclonal gammopathy of undetermined significance who has remained stable for five years but evolved to overt myeloma in strict temporal relationship with the diagnosis of GH-secreting pituitary macroadenoma. IGF-I serum levels correlated with serum and urine M component. Since the in vitro role of IGF-I on proliferation and survival of normal and neoplastic plasma cells has been recently emphasized, the pathogenetic link between acromegaly and transformation of gammopathy to overt myeloma in this case is discussed.

[Growth hormone secretion in heart failure]

Growth hormone is a pituitary polypeptide hormone regulating growth in paediatric age as well as inducing anabolic actions directly or IGF-I mediated in adult age. Particularly, in many animals GH and IGF-I receptors were observed in cardiac myocyte membrane. GH modifies left ventricle structure and function. As concerns spontaneous GH secretion, some data suggest that pituitary gland can have a compensatory role on endocrine response to heart failure. Heart failure stage was directly correlated to nocturnal GH levels. All GH spontaneous night secretion parameters as well as IGF-I levels showed a range between normal people and very high spontaneous secretion. Therefore in these patients there are either a GH peripheric resistance or a reduction of the activity of GH/IGF-I axis. Anyhow in our patients, GH 24 hour infusion was inducing a 5 fold increase in GH concentration and a 50% increase in basal IGF-I levels. Anker et al. suggested to evaluate nutritional state in heart failure patients, observing no differences in non-cachectic patients vs controls, while cachectic patients presented a typical GH resistance syndrome. Interestingly, cardiovascular effects of GH administration seem to be only marginally correlated to hemodynamic basal state. On the other hand basal hormonal setting of the patient seems to correlate to the GH-induced cardiovascular response. In fact, low basal IGF-I but high basal GH patients presented the worst endocrine and cardiovascular response to GH infusion. In literature there are controversial data about GH treatment in patients with chronic heart failure. The heterogeneity of the population could be the reason for this discrepancy. Besides very different IGF-I responses to GH have been reported. Therefore, as there is good clinical evidence that GH acute infusion can improve heart failure, it seems to be necessary firstly to evaluate the basal endocrine status of the patients. Particularly attention should be given to those patients that present a peripheric GH resistance. On the other hand, those patients with a reduced pituitary GH reserve are supposed to have very beneficial effects from GH treatment.

Ectopic secretion of growth hormone-releasing hormone (GHRH) in neuroendocrine tumors: relevant clinical aspects

The aim of this article is to briefly review the physiology of growth hormone-releasing hormone (GHRH) and the diagnosis and treatment of GHRH-mediated acromegaly. Moreover, the role of GHRH and its antagonists in the pathogenesis and treatment of cancer will be reviewed. Hypothalamic GHRH is secreted into the portal system, binds to specific surface receptors of the somatotroph cell and elicits intracellular signals that modulate pituitary GH synthesis and/or secretion. GHRH-producing neurons have been well characterized in the hypothalamus by immunostaining techniques. Hypothalamic tumors, including hamartomas. choristomas, gliomas. and gangliocitomas. may produce excessive GHRH with subsequent GH hypersecretion and resultant acromegaly. GHRH is synthesized and expressed in multiple extrapituitary tissues. Excessive peripheral production of GHRH by a tumor source would therefore be expected to cause somatotroph cell hyperstimulation and increased GH secretion. The structure of hypothalamic GHRH was infact elucidated from material extracted from pancreatic GHRH-secreting tumors in two patients with acromegaly. Immunoreactive GHRH is present in several tumors, including carcinoid tumors, pancreatic cell tumors, small-cell lung cancers, adrenal adenomas, and pheochromocitomas which have been reported to secrete GHRH. Acromegaly in these patients. however, is uncommon. In a retrospective survey of 177 acromegalic patients only a single patient was identified with elevated plasma GHRH levels. Measuring GHRH plasma levels therefore provides a precise and cost-effective test for the diagnosis of ectopic acromegaly. Peripheral GHRH levels are not elevated in patients with hypothalamic GHRH- secreting tumors, supporting the notion that excess eutopic hypothalamic GHRH secretion into the hypophyseal portal system does not appreciably enter the systemic circulation. Elevated circulating GHRH levels, a normal or small-size pituitary gland, or clinical and biochemical features of other tumors known to be associated with extrapituitary acromegaly, are all indications for extrapituitary imaging. An enlarged pituitary is, however, often found on MRI of patients with peripheral GHRH-secreting tumors, and the radiologic diagnosis of a pituitary adenoma may be difficult to exclude. Surgical resection of the tumor secreting ectopic GHRH should reverse the hypersecretion of GH, and pituitary surgery should not be necessary in these patients. Nonresectable, disseminated or reccurrent carcinoid syndrome with ectopic GHRH secretion can also be managed medically with long-acting somatostatin analogs (octreotide and lanreotide). The presence of GHRH and its receptors in several extrahypothalamic tissues, including ovary, testis and the digestive tract, suggests that GHRH may have a regulatory role in these tissues. As previously mentioned, biologically or immunologically active GHRH and mRNA encoding GHRH have been found in several human malignant tumors. including cancers of the breast, endometrium and ovary and their cell lines. The synthesis and evaluation of analogs with various modifications revealed that certain hydrophobic and helix-stabilizing amino acid substitutions can produce antagonists with increased GH releasing inhibitory potencies and GHRH receptor-binding affinities in vitro. The review of experimental results of these substances are promising altrough no clinical data are yet available. Finally, the advent of these antagonists has allowed significant progress in the understanding of the role of the central and tissue GHRH-GH-IGFs system in the pathogenesis of tumors.

Hyperinsulinemia in the physiologic range is not superior to short-term fasting in suppressing insulin secretion in obese men

The negative-feedback control exerted by plasma insulin on beta-cell insulin release in normal-weight and obese subjects is still a matter of debate. Subjects submitted to a euglycemic insulin clamp undergo a suppression of insulin secretion that is due to both the infused insulin and the 2- to 3-hour fast during the procedure. We elected to elucidate the role of physiologic hyperinsulinemia per se in the insulin negative autofeedback in obese men. Ten men with massive uncomplicated obesity (age, 18 to 37 years; body mass index [BMI], 41 +/- 1.15 kg/m2) and 6 normal-weight healthy men (age, 22 to 30 years; BMI, 22 +/- 0.28 kg/m2) underwent 2 studies in random order: (1) a euglycemic-hyperinsulinemic glucose clamp with an insulin infusion rate of 1 mU/kg/min and (2) a control study with saline infusion. Serum C-peptide concentrations were significantly higher in obese versus control subjects at baseline (2.54 +/- 0.178 v 1.63 +/- 0.256 ng/mL, P < .05). Exogenous insulin infusion significantly suppressed serum C-peptide at steady state ([SS] last 30 minutes of insulin or saline infusion) in controls (mean of the last 4 measurements from 120 minutes to 150 minutes, 0.86 +/- 0.306 ng/mL, P < .05 vbaseline) but not in obese patients (2.03 +/- 0.26 ng/mL, nonsignificant [NS] v baseline). During the saline infusion studies, C-peptide levels slightly and similarly declined over time in both groups (2.71 +/- 0.350 at baseline v 2.31 +/- 0.300 ng/mL at SS in obese patients, NS, and 1.96 +/- 0.189 v 1.62 +/- 0.150 ng/mL in controls, NS). This study shows that in obese men hyperinsulinemia within the postprandial range is not superior to a 2.5-hour fast for the suppression of beta-cell activity, suggesting an impairment of the insulin negative autofeedback in this clinical condition.