Awareness and management of hyponatraemia: the Italian Hyponatraemia Survey

BACKGROUND

Hyponatraemia is the most frequent electrolyte disorder in hospitalized patients and has been associated with increased morbidity, mortality and length of hospital stay. There is evidence that also mild chronic hyponatraemia may have clinical consequences, such as gait disturbances, attention deficits, falls, increased risk of fractures and reduced bone mineral density. Nevertheless, this condition appears to be rather often not taken into consideration, or inappropriately managed and treated, thus negatively affecting patients' outcome.

AIM

The aim of this study was to investigate the awareness and management of hyponatraemia secondary to SIAD, a common cause of hyponatraemia, among Italian physicians (endocrinologists, nephrologists, internists) commonly involved as consultants.

METHODS

A questionnaire, covering definition, diagnosis, management, treatment and prognosis of hyponatraemia secondary to SIAD, was developed with the support of the Italian Society of Endocrinology.

RESULTS

Among the respondents (n=275), the majority was aware of the negative implications of hyponatraemia or of an inappropriate treatment. Nevertheless, the answers indicated that SIAD is still underdiagnosed and incorrectly managed in clinical practice. In particular, only 47% of respondents used the validated biochemical parameters to diagnose hyponatraemia secondary to SIAD. The survey also indicated a rather satisfactory knowledge of the therapeutic options, including the currently available vasopressin receptor antagonists.

CONCLUSIONS

One of the main findings of the survey was that the diagnostic work-up of hyponatraemia still represents a critical issue. Therefore, there is urgent need of educational programs in order to improve the management of this condition and reduce morbidity, mortality and costs.

The hyponatremias

Introduction: Plasma sodium concentrations are commonly measured in hospitalized patients. In our department, hypernatremia (defined as a serum sodium < 135 mmol/L) is usually an incidental finding. More rarely, however, clinical manifestations of hypernatremia occur. Symptoms depend on the magnitude and rapidity of onset of the hypernatremia. When acute, severe hyponatremia develops, brain edema may occur. Considerable morbidity and mortality can be associated with hyponatremic encephalopathy per se. Moreover, rapid correction of hyponatremia also carries a risk of neurological damage related to the osmotic demyelination syndromes. This review focuses on the epidemiology, pathophysiology, and therapy of hyponatremia. Materials and methods: We carried out a search of the literature in Medline, the Cochrane Library and Clinical Evidence using the search terms hypernatremia and sodium. Conclusions: Hyponatremia is the most common electrolyte disorder encountered in clinical practice, occurring in approximately 15% to 30% of hospitalized patients, and it is not uncommon in outpatients. When faced with a hyponatremic patient, the physician has to identify the cause, treat the defect, and take care of the patient, bearing in mind that hypernatremia and its correction are associated with significant morbidity and mortality. Hyponatremic encephalopathy following acute hypernatremia is well known to be a potentially life-threatening condition, especially in patients with concomitant diseases. In contrast, chronic hypernatremia is more common, and it is often considered to be a laboratory abnormality devoid of clinical consequences. Paradoxically, however, this is just the setting in which rapid correction of plasma sodium levels can cause severe neurologic defects and death. Despite substantial progress in understanding the pathophysiology of brain damage related to hyponatremia and its treatment, optimal, safe therapies have not been well defined yet. The imminent availability of aquaretic nonpeptide arginine vasopressin receptor antagonists could provide new insights into this field. However, because of their unique effects, i.e., selective increase of solute-free water excretion by the kidney, this new class of drugs cannot be used in patients with hypovolemic hyponatremia.

Screening of Cushing's syndrome in outpatients with type 2 diabetes: results of a prospective multicentric study in Italy

CONTEXT

Cushing's syndrome may remain unrecognized among patients referred for metabolic syndrome; thus, a proactive screening has been suggested in certain patient populations with features of the disorder. However, conflicting data have been reported on the prevalence of Cushing's syndrome in patients with type 2 diabetes.

OBJECTIVE

Our aim was to evaluate the prevalence of unsuspected Cushing's syndrome among outpatients with type 2 diabetes.

DESIGN AND SETTING

This was a cross-sectional prospective study in 24 diabetes clinics across Italy.

PATIENTS

Between June 2006 and April 2008, 813 patients with known type 2 diabetes without clinically overt hypercortisolism were evaluated. Follow-up of the study was closed in September 2010. Patients were not selected for characteristics conferring a higher pretest probability of hypercortisolism. Patients underwent a first screening step with the 1-mg overnight dexamethasone suppression test.

RESULTS

Forty patients failed to suppress serum cortisol less than 5.0 μg/dl (138 nmol/liter) and underwent a standard 2-d, 2-mg dexamethasone suppression test, after which six patients (0.6% of the overall series) failed to suppress cortisol less than 1.8 μg/dl (50 nmol/liter), receiving a definitive diagnosis of Cushing's syndrome that was adrenal dependent in five patients. Four patients were cured, being able to discontinue, or reduce, the glucose-lowering agents.

CONCLUSIONS

The present data do not support widespread screening of patients with type 2 diabetes for Cushing's syndrome; however, the disorder is less rare than previously thought when considering epidemiology of type 2 diabetes. Our results support a case-finding approach in patients with uncontrolled diabetes and hypertension despite appropriate treatment.

Predictors of morbidity and mortality in acromegaly: an Italian survey

OBJECTIVE

To describe demographic and hormonal characteristics, comorbidities (diabetes mellitus and hypertension), therapeutic procedures and their effectiveness, as well as predictors of morbidity and mortality in a nationwide survey of Italian acromegalic patients.

DESIGN

Retrospective multicenter epidemiological study endorsed by the Italian Society of Endocrinology and performed in 24 tertiary referral Italian centers. The mean follow-up time was 120 months.

RESULTS

A total of 1512 patients, 41% male, mean age: 45±13 years, mean GH: 31±37 μg/l, IGF1: 744±318 ng/ml, were included. Diabetes mellitus was reported in 16% of cases and hypertension in 33%. Older age and higher IGF1 levels at diagnosis were significant predictors of diabetes and hypertension. At the last follow-up, 65% of patients had a controlled disease, of whom 55% were off medical therapy. Observed deaths were 61, with a standardized mortality ratio of 1.13 95% (confidence interval (CI): 0.87-1.46). Mortality was significantly higher in the patients with persistently active disease (1.93; 95% CI: 1.34-2.70). Main causes of death were vascular diseases and malignancies with similar prevalence. A multivariate analysis showed that older age, higher GH at the last follow-up, higher IGF1 levels at diagnosis, malignancy, and radiotherapy were independent predictors of mortality.

CONCLUSIONS

Pretreatment IGF1 levels are important predictors of morbidity and mortality in acromegaly. The full hormonal control of the disease, nowadays reached in the majority of patients with modern management, reduces greatly the disease-related mortality.

Erratum a: Le iponatremie [Italian Journal of Medicine 2011;5(3):156-68.]

Not available

Thyrotropin-secreting pituitary tumours: significance of “atypical adenomas” in a series of 10 patients and association with Hashimoto thyroiditis as a cause of delay in diagnosis

Background:

Thyrotropin-secreting adenomas (TSH-As) are rare and, according to the World Health Organization criteria (WHO 2004), a significant proportion of them present features of atypical adenomas at the time of diagnosis.

Aims:

To determine the frequency of “atypical adenomas” and the significance of this definition as regards follow-up. To investigate their possible association with Hashimoto thyroiditis, leading to a delay in diagnosis.

Methods:

Case notes for patients who underwent trans-sphenoidal surgery between 1992 and 2006 were retrieved. Follow-up ranged from 6 to 180 months.

Results:

Ten cases of TSH-As out of 908 pituitary adenomas were selected. Before surgery, eight patients had hyperthyroidism, one was euthyroid and another one showed hypothyroidism associated with Hashimoto thyroiditis. All cases were macroadenomas; six of them were invasive. Three cases met the criteria for classification as atypical. In none of the cases, including the three “atypical adenomas”, were clinical or radiological signs of recurrence observed.

Conclusions:

The three cases with features of atypical adenoma did not recur or metastasise, suggesting that, at least in the present series, a strict relationship between the morphological criteria for diagnosing atypical adenomas and biological behaviour may be sometimes lacking. Furthermore, the casual association of TSH-As with Hashimoto thyroiditis may led to an adjunctive delay in diagnosis, because of low thyroid hormone levels.

Non-functioning pituitary adenoma database: a useful resource to improve the clinical management of pituitary tumors

OBJECTIVE

The long-term outcome of non-functioning pituitary adenoma (NFPA) patients is not clearly established, probably due to the low annual incidence and prolonged natural history of these rare tumors. The aim of this study was to evaluate clinical data at presentation and long-term post-surgery and radiotherapy outcome in a cohort of patients with NFPA.

DESIGN AND METHODS

A computerized database was developed using Access 2000 software (Microsoft Corporation, 1999). Retrospective registration of 295 NFPA patients was performed in seven Endocrinological Centers of North West Italy. Data were analyzed by STATA software.

RESULTS

The main presenting symptoms were visual defects (67.8%) and headache (41.4%) and the most frequent pituitary deficit was hypogonadism (43.3%), since almost all tumors were macroadenomas (96.5%). Surgery was the first choice treatment (98% of patients) and total debulking was achieved in 35.5%. Radiotherapy was performed as adjuvant therapy after surgery in 41% of patients. At the follow-up, recurrence occurred in 19.2% of patients without post-surgical residual tumor after 7.5 +/- 2.6 years, regrowth in 58.4% of patients with post-surgical remnant after 5.3 +/- 4.0 years and residue enlargement in 18.4% of patients post-surgically treated with radiotherapy after 8.1 +/- 7.3 years.

CONCLUSIONS

Our database indicates that the goal of a definitive surgical cure has been achieved during the last decade in a low percentage of patients with NFPA. This tumor database may help to reduce the delay between symptom onset and diagnosis, to assess prognostic parameters for the follow-up of patients with different risk of recurrence and to define the efficacy and safety of different treatments and their association with mortality/morbidity.

Residual pituitary function after brain injury-induced hypopituitarism: a prospective 12-month study

CONTEXT

Traumatic brain injury (TBI) and subarachnoid hemorrhage (SAH) are conditions at high risk for the development of hypopituitarism.

OBJECTIVE

The objective of the study was to clarify whether pituitary deficiencies and normal pituitary function recorded at 3 months would improve or worsen at 12 months after the brain injury.

DESIGN AND PATIENTS

Pituitary function was tested at 3 and 12 months in patients who had TBI (n = 70) or SAH (n = 32).

RESULTS

In TBI, the 3-month evaluation had shown hypopituitarism (H) in 32.8%. Panhypopituitarism (PH), multiple (MH), and isolated (IH) hypopituitarism had been demonstrated in 5.7, 5.7, and 21.4%, respectively. The retesting demonstrated some degree of H in 22.7%. PH, MH, and IH were present in 5.7, 4.2, and 12.8%, respectively. PH was always confirmed at 12 months, whereas MH and IH were confirmed in 25% only. In 5.5% of TBI with no deficit at 3 months, IH was recorded at retesting. In 13.3% of TBI with IH at 3 months, MH was demonstrated at 12-month retesting. In SAH, the 3-month evaluation had shown H in 46.8%. MH and IH had been demonstrated in 6.2 and 40.6%, respectively. The retesting demonstrated H in 37.5%. MH and IH were present in 6.2 and 31.3%, respectively. Although no MH was confirmed at 12 months, two patients with IH at 3 months showed MH at retesting; 30.7% of SAH with IH at 3 months displayed normal pituitary function at retesting. In SAH, normal pituitary function was always confirmed. In TBI and SAH, the most common deficit was always severe GH deficiency.

CONCLUSION

There is high risk for H in TBI and SAH patients. Early diagnosis of PH is always confirmed in the long term. Pituitary function in brain-injured patients may improve over time but, although rarely, may also worsen. Thus, brain-injured patients must undergo neuroendocrine follow-up over time.

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.

Silent corticotroph carcinoma of the adenohypophysis: a report of five cases

We report five silent corticotroph carcinomas of the pituitary gland. They represent 0.05% of adenohypophyseal tumors surgically treated at Mayo Clinic during a 20-year period and about 5% of all reported pituitary carcinomas. The patients (three females and two males), ranging in age from 26 to 58 years (mean 39 years, median 35 years) presented with symptoms of mass effect; none had Cushing's disease. All tumors were initially invasive macroadenomas, recurred locally, and metastasized, three outside the central nervous system. The follow-up period ranged from 2 to 23 years (mean 10.6 years). All patients died, four of disseminated tumor and one of myocardial infarction. Histologically, three of the primary lesions were indistinguishable from an ordinary benign adenoma. Two were initially diagnosed as atypical adenomas as they featured nuclear pleomorphism, prominent nucleoli, mitotic activity, high MIB-1 labeling indices, and p53 overexpression. For the purpose of comparison, 17 silent corticotroph adenomas were also investigated. In addition, the clinicopathologic features of the silent carcinomas were compared with those of a meta-analysis of published Cushing's disease-associated pituitary carcinomas. The silent adrenocorticotropin carcinomas showed a propensity for extraneural dissemination and an outcome similar to those of the Cushing's disease-associated carcinomas. The two patients with initial atypical tumors died with metastases outside the central nervous system at 2 and 4 years, whereas the three patients with tumors lacking atypia died 16, 18, and 23 years after initial sellar surgery.

Ectopic TSH-secreting pituitary adenoma of the vomerosphenoidal junction

OBJECTIVE

We describe an unusual case of ectopic TSH-secreting pituitary adenoma arising from the vomerosphenoidal junction.

CLINICAL PRESENTATION

A 52-Year-old man with a long-standing history of hyperthyroidism was referred to the University Hospital in September 2001 because of increasingly disabling symptoms of nasal obstruction. For the past 18 Years the patient had complained of palpitations, hypertension, weight loss, and nervousness. A presumptive diagnosis of Graves' disease was made. Treatment with methimazole was begun, but the patient was lost to follow-up. On admission, physical examination revealed signs of hyperthyroidism and a large diffuse goiter. Tests of thyroid function showed inappropriate secretion of TSH with hyperthyroidism. Both a TSH-secreting pituitary adenoma and resistance to thyroid hormone could be taken into account. There was no evidence of pituitary tumour by magnetic resonance imaging (MRI), but a large space-occupying lesion involving the nasal cavity and the nasopharynx was incidentally discovered. INTERVENTATION AND TECHNIQUE: Using an endoscopic endonasal approach, the tumour was removed en bloc together with the sphenoid floor, sphenoid rostrum, bony septum, and part of the soft palate mucosa. Histological features and immunophenotype were those of a TSH-secreting tumour.

CONCLUSION

Although exceedingly rare, ectopic TSH-secreting pituitary tumour should be borne in mind in cases of inappropriate secretion of TSH with hyperthyroidism and no evidence of pituitary tumour by computed tomography and/or MRI when a mass located along the migration path of the Rathke's pouch is demonstrated by radiological examination. To our knowledge, this is only the second reported case in the literature.

Pituitary function in a man with congenital aromatase deficiency: effect of different doses of transdermal E2 on basal and stimulated pituitary hormones

To clarify the role of estrogen on male pituitary function, the effects of different doses of transdermal E2 on pituitary secretion were evaluated in a man with aromatase deficiency. The study protocol was divided into the following three phases: no E2 treatment (phase 1); 25 microg transdermal E2 twice weekly for 9 months (phase 2);12.5 microg transdermal E2 twice weekly for 9 months (phase 3). Pituitary function was studied in detail during each phase of the study protocol by measuring hormone levels in basal conditions and after dynamic testing (GnRH, insulin tolerance test, GHRH plus arginine, TRH, and corticotropin-releasing factor; tests). Basal and GnRH-stimulated gonadotropin levels resulted inversely related to E2 serum levels, according to the dosage of estrogen administered. Basal and stimulated GH, PRL, and TSH serum levels did not change during the protocol study. The secretory pituitary reserve of GH was clearly impaired. Basal and stimulated ACTH and cortisol serum levels were not modified by estrogen administration. This study demonstrated that in the human male E2 is required at pituitary level for normal functioning of gonadotropin feedback both in basal and stimulated conditions. In this patient GH deficiency seems to be an adult-onset event since he reached a tall stature. However, the finding of a severe impairment in GH response to potent provocative stimuli together with the insensitivity of GH/IGF-I axis to circulating estrogens strongly suggest a possible involvement of estrogens on both the development and maturation of the somatotrophic axis. Finally, the congenital lack of estrogen activity seems to be associated with a slightly impaired secretion of PRL and TSH, suggesting a possible role of estrogens on the pituitary secretion of these hormones in the human male.