Nocturnal breathing abnormalities in acromegaly after adenomectomy

Prevalence and outcome of comorbidities associated with acromegaly

BACKGROUND

Acromegaly is associated with various comorbidities, such as arterial hypertension (aHT), type 2 diabetes mellitus (DM2), obstructive sleep apnoea syndrome (OSAS), carpal tunnel syndrome (CTS) and polyposis coli. For therapeutic decisions, it is essential to know if, and to what extent, these associated morbidities are reversible or preventable. The aim of this study is to assess the prevalence and course of aHT, obesity, OSAS, CTS, DM2 and polyposis coli in acromegalic patients.

METHODS

The following criteria for inclusion in this database study were used: treatment for acromegaly at the authors' institutions; full endocrinological and radiological work- and follow-up; screening for aHT, DM2, CTS, OSAS, obesity and polyposis coli. All patients were followed-up for > 3 months, and treatments were indicated with the intent of biochemical remission (normal IGF-1 and random growth hormone level).

RESULTS

Sixty-three patients were included. Twelve (19%), 45 (71%) and 6 (10%) patients harboured micro-, macro- and giant adenomas, respectively. Nineteen tumours (30%) invaded the cavernous sinus. Mean tumour volume was 5.4 cm³. Mean follow-up time was 42 months. Sixty-one (97%) patients had transsphenoidal surgery; two patients only had drug therapy. Surgery led to remission in 31 (51%) patients. Intracavernous growth and larger tumour volume were negative predictors for cure. Drug therapy lead to remission in 22 (73%) patients within a mean follow-up of 54 months. The pretherapeutic prevalence of associated morbidities was as follows: aHT, 56%; DM2, 25%; OSAS, 29%; CTS, 29%; polyposis coli, 5%. There were neither age nor gender preferences for the respective prevalences. Surgery leads to remission of aHT and DM2 in 6% and 25%, respectively. Additional drug therapy resulted in remission of aHT, DM2 and CTS in 17%, 14% and 14%, respectively. Other associated morbidities persisted regardless of therapeutic efforts. Even if criteria for remission were not met, no new comorbidities of acromegaly developed during follow-up.

CONCLUSIONS

Treating acromegaly may relieve threatening associated morbidities such as aHT and DM2; nevertheless, only few comorbidities are reversible, which highlights the importance of treating acromegaly as early as possible.

Obstructive sleep apnea caused by acromegaly: Case report

BACKGROUND

Acromegaly is an uncommon syndrome caused by growth hormone-producing pituitary adenoma or pituitary gland hypertrophy. Acromegaly is known to be characterized by progressive somatic disfigurement and a wide range of systematic manifestations. This case study describes a rare case of severe obstructive sleep apnea (OSA) caused by acromegaly.

CLINICAL PRESENTATION

A female patient presented to the consultant clinic with the chief complaint of progressively worsening sleep and was diagnosed with severe OSA. Because of a peculiar facial appearance of the patient, acromegaly was suspected and confirmed by the findings of hormonal analysis and magnetic resonance imaging (MRI). After transsphenoidal resection of the pituitary adenoma, her OSA was almost cured, with residual AHI of 5.5.

CONCLUSION

This case highlights the importance of a comprehensive clinical examination of OSA patients. In every sleep-related breathing disorder case, sleep clinicians should be aware of alternate problems that could cause upper airway obstruction.

Sleep quality in acromegaly and changes after transsphenoidal surgery: a prospective longitudinal study

OBJECTIVE

To elucidate the sleep quality characteristics and factors related to either good or poor sleep quality in acromegaly patients before surgery and to explore sleep quality changes after transsphenoidal surgery and the factors related to these changes.

METHODS

We prospectively enrolled 39 acromegaly patients and 78 patients with nonfunctioning pituitary adenomas. Scales for anxiety, depression, disease stigma and nasal condition were evaluated. The Pittsburgh Sleep Quality Index (PSQI) questionnaire was administered before surgery as well as one month and three months after surgery.

RESULTS

A higher percentage of acromegaly patients had poor sleep quality compared to controls (35.9% vs. 5.1%, p < 0.001). In addition, acromegaly patients experienced worse subjective sleep quality, extended sleep latency, increased sleep disturbance and decreased daytime functioning. Higher scores for anxiety, disease stigma and sinonasal outcomes were correlated with worse sleep quality in acromegaly patients. At one month after transsphenoidal surgery, we found worse subjective sleep quality, extended sleep latency, shortened sleep duration, impaired sleep efficiency and increased sleep disturbance in acromegaly patients. At three months postoperatively, most impaired PSQI domains in acromegaly patients recovered to preoperative levels. The use of soluble gauze was related to decreased sleep quality at one month after surgery and severe anxiety and depression were related to improved sleep quality at three months after surgery.

CONCLUSIONS

Sleep quality was reduced in acromegaly patients. Moreover, sleep quality initially worsened after surgery but later recovered. Emotional problems and the use of soluble gauze were related factors.

CLINICAL TRIAL REGISTRATION

None.

The posterior pharyngeal wall thickness is associated with OSAHS in patients with acromegaly and correlates with IGF-1 levels

PURPOSE

To evaluate the incidence of obstructive sleep apnea-hypopnea syndrome (OSAHS), explore the structural changes in pharyngeal soft tissue underlying OSAHS development and analyze the correlation between hormone levels and pharyngeal soft tissue changes in patients with untreated acromegaly.

METHODS

Twenty-five patients with untreated acromegaly were prospectively enrolled. Pituitary hormones were tested, sellar magnetic resonance imaging was confirmed, overnight polysomnography was conducted, and upper airway computed tomography was performed on these patients.

RESULTS

Patients with untreated acromegaly had a high incidence of OSAHS (52.0%, 13/25). The average age of the patients with OSAHS was 12 years older than that of patients without OSAHS (47.0 ± 8.5 years vs. 35.1 ± 9.5 years, p = 0.003). The posterior pharyngeal soft tissues were thicker in four different planes, including the planes of the soft palate, uvula, tongue and epiglottis (p = 0.003, 0.008, 0.027, and 0.003, respectively), and the soft palate (p = 0.024) was more hypertrophic in patients with acromegaly presenting with OSAHS than patients without OSAHS. The posterior pharyngeal wall thickness (cm) positively correlated with the serum insulin-like growth factor 1 (IGF-1) level (ng/ml) in the planes of the soft palate (slope = 0.001, p = 0.006) and epiglottis (slope = 0.002, p = 0.039).

CONCLUSIONS

OSAHS is a common complication in patients with untreated acromegaly, and advanced age is a risk factor. Posterior pharyngeal soft tissue thickening and soft palate hypertrophy are structural changes underlying OSAHS development in patients with acromegaly. Higher IGF-1 levels predict an increase in the posterior pharyngeal soft tissue thickness in patients with acromegaly.

Complications of acromegaly: cardiovascular, respiratory and metabolic comorbidities

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

Definition, discrimination, diagnosis and treatment of central breathing disturbances during sleep

The complexity of central breathing disturbances during sleep has become increasingly obvious. They present as central sleep apnoeas (CSAs) and hypopnoeas, periodic breathing with apnoeas, or irregular breathing in patients with cardiovascular, other internal or neurological disorders, and can emerge under positive airway pressure treatment or opioid use, or at high altitude. As yet, there is insufficient knowledge on the clinical features, pathophysiological background and consecutive algorithms for stepped-care treatment. Most recently, it has been discussed intensively if CSA in heart failure is a “marker” of disease severity or a “mediator” of disease progression, and if and which type of positive airway pressure therapy is indicated. In addition, disturbances of respiratory drive or the translation of central impulses may result in hypoventilation, associated with cerebral or neuromuscular diseases, or severe diseases of lung or thorax. These statements report the results of an European Respiratory Society Task Force addressing actual diagnostic and therapeutic standards. The statements are based on a systematic review of the literature and a systematic two-step decision process. Although the Task Force does not make recommendations, it describes its current practice of treatment of CSA in heart failure and hypoventilation.

Sleep and the Endocrine System

In this article, the effect of sleep and sleep disorders on endocrine function and the influence of endocrine abnormalities on sleep are discussed. Sleep disruption and its associated endocrine consequences in the critically ill patient are also reviewed.

Sleep and the endocrine system

In this article, the effect of sleep and sleep disorders on endocrine function and the influence of endocrine abnormalities on sleep are discussed. Sleep disruption and its associated endocrine consequences in the critically ill patient are also reviewed.

Outcome of complications in acromegaly patients after long-term disease remission

Acromegaly patients suffer from pathologically high growth hormone (GH) and IGF-1 levels that in 99% of cases is due to a GH-producing pituitary adenoma. During active disease, GH excess is associated with a number of pathological conditions, such as hypertension, hypertrophic cardiomyopathy, sleep apnea, arthropathy, vertebral fractures and insulin resistance. After adequate treatment in the form of transsphenoidal surgery, radiotherapy, medical treatment or by a combination of these treatment modalities, several comorbid conditions improve considerably. However, despite long-term biochemical disease control, the prevalence of late manifestations of GH excess is high and significantly impair quality of life. In addition, there is evidence that adequate treatment is not able to normalize mortality risk in these patients. In this review, we critically evaluate the long-term consequences of acromegaly after treatment, focusing on comorbid conditions, quality of life and mortality. We also discuss ongoing challenges in the management of acromegaly patients.

Craniofacial and pharyngeal airway morphology in patients with acromegaly

OBJECTIVE

The aim of this study was to assess differences in craniofacial characteristics, upper spine and pharyngeal airway morphology in patients with acromegaly compared with healthy individuals.

MATERIALS AND METHODS

Twenty-one patients with acromegaly were compared with 22 controls by linear and angular measurements on cephalograms. The differences between the mean values of cephalometric parameters were analyzed with Mann-Whitney U-test.

RESULTS

With respect to controls, anterior (p<0.05), middle (p<0.01) and posterior (p<0.05) cranial base lengths were increased, sella turcica was enlarged (p<0.001) and upper spine morphology demonstrated differences in the height of atlas (p<0.01) and axis (p<0.05) in patients with acromegaly. Craniofacial changes were predominantly found in the frontal bone (p<0.01) and the mandible (p<0.05). As for the airway, patients with acromegaly exhibited diminished dimensions at nasal (p<0.001), uvular (p<0.01), mandibular (p<0.01) pharyngeal levels and at the narrowest point of the pharyngeal airway space (p<0.001) compared to healthy controls. Soft palate width was significantly higher (p<0.001) and the hyoid bone was more vertically positioned (p<0.01) in patients with acromegaly.

CONCLUSIONS

Current results point to the importance of the reduced airway dimensions and that dentists and/or orthodontists should be aware of the cranial or dental abnormalities in patients with acromegaly.

Prader-Willi syndrome and sleep-disordered breathing

Prader-Willi Syndrome is a complex neurogenetic disorder characterized by appetite dysregulation, obesity with decreased muscle mass and increased fat mass, behavioral problems, various endocrinopathies, and sleep and respiratory abnormalities. Respiratory issues include both central and obstructive sleep apnea, excessive daytime sleepiness, narcolepsy, and impaired ventilatory control. There is some controversy as to whether growth hormone treatment, which is the standard of care for patients with Prader-Willi Syndrome, exacerbates or ameliorates the sleep-disordered breathing issues associated with this syndrome. The natural history of sleep and breathing issues and the issues surrounding growth hormone treatment on sleep-disordered breathing are discussed.

The impact of sleep apnea treatment on carbohydrate metabolism in patients with acromegaly

Sleep Apnea is highly prevalent and may contribute to insulin resistance in patients with acromegaly. The primary aim of this study was to assess the impact of sleep apnea treatment with a continuous positive air pressure (CPAP) device on insulin resistance evaluated by hyperinsulinemic euglycemic clamp (HEC). A prospective, randomized, open label, placebo-controlled, crossover study was performed at a tertiary outpatient pituitary center. Twelve acromegalic subjects on somatostatin analogs (SA) with a recent diagnosis of moderate to severe sleep apnea were randomized to CPAP therapy or to nasal dilator adhesive (NDA) with placebo effect for 3 months and then crossed over for another 3 months period without washout. Assessment of HEC, mathematical insulin resistance indexes (HOMA, HOMA2 and QUICKI), GH, IGF-1, HbA1c and free fat acids were performed. A significant reduction on insulin resistance was demonstrated by HEC at the end of the study in patients on CPAP (HEC, pre- and post-CPAP: 4.27 vs. 6.10 mg/Kg/min, P = 0.032). This reduction was not observed in NDA group (HEC, pre- and post-adhesive: 5.53 vs. 5.19 mg/Kg/min, P = 0.455). There was no significant difference on HbA1c or on peripheral insulin resistance indexes in both treatments. CPAP promoted a significant increase on peripheral insulin sensitivity in acromegalic patients with moderate to severe sleep apnea on SA use. Our results support the concept that sleep apnea plays an important role on glucose metabolism. Insulin resistance indexes were unable to detect this finding.

Improvement of cardiac parameters in patients with acromegaly treated with medical therapies

In acromegaly, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) excess results in a specific cardiomyopathy characterized by concentric cardiac hypertrophy primarily associated with diastolic dysfunction that can lead to impaired systolic function and eventually heart failure. This review of the literature evaluates the effect of therapeutic intervention on cardiac parameters. Clinical studies investigating the impact of treatments for acromegaly on cardiac function published between January 1980 and January 2009 were identified through electronic searches of Medline. Suppression of GH and IGF-1 following surgery or medical treatment with somatostatin analogue therapy is effective in decreasing left ventricular (LV) hypertrophy, with subsequent improvement in cardiac function. First-line treatment with somatostatin analogues resulted in improved cardiac outcome compared with first-line surgery, possibly due to somatostatin analogues acting directly through somatostatin receptors on cardiac cells. Additional cardiac improvement has been reported when somatostatin analogue treatment was combined with surgery. In patients where complete biochemical control was not achieved, an improved cardiac performance following treatment with somatostatin analogues has been reported. Treatment with pegvisomant has been demonstrated to reduce LV hypertrophy and improve diastolic and systolic performance. In contrast, reports have suggested that treatment with the dopamine agonist cabergoline increased the incidence of valvular heart disease. Although surgery and somatostatin analogues are effective in improving cardiomyopathy, a greater beneficial effect is observed with somatostatin analogue treatment. Selected patients with acromegaly should consider first-line therapy or pre-treatment with somatostatin analogues prior to surgery to achieve biochemical control and improve cardiac dysfunction.

Characteristics of sleep-disordered breathing in Japanese patients with acromegaly

Sleep-disordered breathing (SDB), especially sleep apnea-hypopnea syndrome (SAS), is often observed in patients with active acromegaly. This complication is a risk factor for cardiovascular disease and associated with increased morbidity and mortality in acromegaly. However there is little information on SDB in Japanese patients with acromegaly. We investigated the prevalence of SDB and association between the severity of SDB and various features and biomarkers in Japanese patients with acromegaly. Twenty-four Japanese patients with active acromegaly underwent overnight cardiorespiratory monitoring, hormonal assays and cephalometric measurements on X-ray. A high prevalence of SDB was detected in acromegaly (87.5%). Log apnea-hypopnea index (AHI) correlated positively with soft palate length / body height (X-ray) (r=0.44, p=0.043), but not with log growth hormone levels and insulin-like growth factor type-1 standard deviation scores, size of pituitary adenoma, disease duration, body mass index, waist circumference, estimated visceral fat area, heel pad thickness / height, tongue thickness/ height, or oropharyngeal dimension/ height. In conclusion, our study demonstrated a high prevalence of SDB in Japanese patients with acromegaly, and its severity correlated with soft palate length. Based on the high incidence of SDB identified in the present study, we recommend that all patients with acromegaly are routinely screened for SDB for early diagnosis and treatment.

Sleep apnea in acromegaly: a review on prevalence, pathogenetic aspects and treatment

Sleep apnea syndrome is a common complication of acromegaly with a negative impact on quality of life and survival. Obstructive sleep apnea is the prevailing form and is characterized by recurrent episodes of apnea and hypopnea owing to the total or partial collapse of the upper airways during sleep. The craniofacial deformations and the hypertrophy of upper airway soft tissue are responsible for its occurrence. Successful treatment of acromegaly can improve the severity of this complication, but can only seldom reverse it, particularly after a long time of active acromegaly. Thus, it is advisable to evaluate patients for sleep apnea syndrome at diagnosis and during treatment, and also when acromegaly is biochemically controlled. In selected cases, continuous positive airway pressure should be implemented to improve patient outcome.

Assessment of the awareness and management of sleep apnea syndrome in acromegaly. The COM.E.TA (Comorbidities Evaluation and Treatment in Acromegaly) Italian Study Group

In 2007 the Italian COM.E.T.A. (COMorbidities Evaluation and Treatment in Acromegaly) study group started to assess the application in a clinical setting of the Versailles criteria for management of acromegaly complications by a first questionnaire focusing on cardiovascular co-morbidities. A further questionnaire on sleep apnea syndrome (SAS) was delivered by the COM.E.T.A. study group to 107 endocrine centers in Italy. The results of our survey suggest that SAS is a well-known comorbidity even if its estimated prevalence is lower than in the literature. Polysomnography is the preferred tool for diagnosis. Control of SAS is considered relevant both for quality of life and co-morbidities. Continuous positive airway pressure is the cornerstone of therapy, but patients' acceptance may be critical. Control of GH/IGF-I secretion is important to improve SAS. Management of SAS requires cooperation between specialists.

Sleep-related problems in common medical conditions

Common medical problems are often associated with abnormalities of sleep. Patients with chronic medical disorders often have fewer hours of sleep and less restorative sleep compared to healthy individuals, and this poor sleep may worsen the subjective symptoms of the disorder. Individuals with lung disease often have disturbed sleep related to oxygen desaturations, coughing, or dyspnea. Both obstructive lung disease and restrictive lung diseases are associated with poor quality sleep. Awakenings from sleep are common in untreated or undertreated asthma, and cause sleep disruption. Gastroesophageal reflux is a major cause of disrupted sleep due to awakenings from heartburn, dyspepsia, acid brash, coughing, or choking. Patients with chronic renal disease commonly have sleep complaints often due to insomnia, insufficient sleep, sleep apnea, or restless legs syndrome. Complaints related to sleep are very common in patients with fibromyalgia and other causes of chronic pain. Sleep disruption increases the sensation of pain and decreases quality of life. Patients with infectious diseases, including acute viral illnesses, HIV-related disease, and Lyme disease, may have significant problems with insomnia and hypersomnolence. Women with menopause have from insomnia, sleep-disordered breathing, restless legs syndrome, or fibromyalgia. Patients with cancer or receiving cancer therapy are often bothered by insomnia or other sleep disturbances that affect quality of life and daytime energy. The objective of this article is to review frequently encountered medical conditions and examine their impact on sleep, and to review frequent sleep-related problems associated with these common medical conditions.

Medical treatment of acromegaly: comorbidities and their reversibility by somatostatin analogs

Relief of symptoms can be achieved following surgery for growth hormone (GH)-secreting adenomas, as well as after pharmacological therapy with somatostatin analogs. Recently, long-acting somatostatin analog depot formulations, octreotide LAR and lanreotide SR have become available. Somatostatin analogs control GH/insulin-like growth factor (IGF)-1 excess, induce tumor shrinkage in a high proportion of patients, improve symptoms of acromegaly with relatively limited side effects and are successfully administered in patients not suitable for surgery. Furthermore, preoperative somatostatin analogs have been suggested to improve outcome for tumors with limited invasiveness, while surgical tumor debulking in cases that are, at least partially, somatostatin resistant, increases the achievement of normal IGF-1 levels by postoperative somatostatin analog treatment. Effective control of hypertension, as well as diabetes, is mandatory in order to reduce the increased vascular morbidity/mortality. Control of GH/IGF-1 excess generally improves glucose metabolism. Somatostatin analogs improve insulin sensitivity, exerting, however, a concomitant direct inhibitory effect on insulin secretion, with a net balance leaning towards a deterioration in glucose homeostasis. As a result, oral insulin secretagogues (and/or insulin) should probably be preferred to insulin sensitizers in acromegalic patients developing diabetes while on somatostatin analogs. Nevertheless, glucose tolerance remains normal in most of the nondiabetic acromegalic patients, while diabetic acromegalic patients on insulin are at risk for hypoglycemia during initiation of somatostatin analog therapy. Although successful management of acromegaly has been associated with improvement in morphological and functional parameters of cardiomyopathy, limited and conflicting information is available regarding the effect on blood pressure control. Contradictory results have also been reported regarding sleep hypopnea or apnea in treated acromegalic patients. As acromegalic skeletal abnormalities are rather irreversible, apneic episodes may persist after normalization of hormonal levels. Aggressive therapy, including surgery, pharmacological treatment and, in some cases, pituitary irradiation, aiming at normalization of IGF-1 levels, is required for arthropathy management. Some improvement in pain, crepitus and range of motion has been observed after treatment with somatostatin analogs. Information on the impact of disease control, either by surgery or somatostatin analog treatment, on gonadal function is limited. Finally, the link between the hormonal/biochemical and the psychiatric/psychological features of acromegaly, as well as a potential basis for positive effects of somatostatin analog therapy remain unclear.

Perioperative management of patients undergoing transsphenoidal pituitary surgery

Pituitary adenomas often present with the symptoms of hormonal hypersecretion, and although medical therapy is available for most hyperfunctioning states, it is not curative. As a result, transsphenoidal pituitary surgery has become a commonly performed neurosurgical procedure with unique challenges for the anesthesiologist due to the distinct medical comorbidities associated with various adenomas. Any type of pituitary tumor may also produce hypopituitarism and local mass effects secondary to the expanding intrasellar mass. Here we review the perioperative concerns surrounding surgery to remove adenomas and decompress the sellar space. Special attention is given to Cushing's disease (hypercortisolism secondary to an adrenocorticotropic hormone-secreting adenoma), acromegaly (secondary to a growth hormone-secreting adenoma), and hyperthyroidism in the setting of thyrotropic adenomas. Operative risks, including bleeding, diabetes insipidus, the syndrome of inappropriate antidiuretic hormone secretion, and hypopituitarism, are addressed in detail. Understanding preoperative assessment, intraoperative management, potential complications, their management, and strategies for avoidance are fundamental to successful perioperative patient care and avoidance of morbidity and mortality.

Etiologic aspects and management of acromegaly

Acromegaly is a systemic disease with various etiologies. It can occur as a sporadic or, more rarely, as a familial disease. Numerous complications such as endocrine, cardiovascular, respiratory, metabolic, osteoarticular and neoplastic disturbances occur and must be taken into account when establishing a therapeutic strategy. For this reason, the decision as to a treatment modality of acromegaly must be followed by a thorough evaluation of the patient and once the diagnosis of complications is settled, adequate treatment should be instituted. Follow up of the patients requires periodical re-assessment of complications’ status.

Systemic complications of acromegaly: epidemiology, pathogenesis, and management

This review focuses on the systemic complications of acromegaly. Mortality in this disease is increased mostly because of cardiovascular and respiratory diseases, although currently neoplastic complications have been questioned as a relevant cause of increased risk of death. Biventricular hypertrophy, occurring independently of hypertension and metabolic complications, is the most frequent cardiac complication. Diastolic and systolic dysfunction develops along with disease duration; and other cardiac disorders, such as arrhythmias, valve disease, hypertension, atherosclerosis, and endothelial dysfunction, are also common in acromegaly. Control of acromegaly by surgery or pharmacotherapy, especially somatostatin analogs, improves cardiovascular morbidity. Respiratory disorders, sleep apnea, and ventilatory dysfunction are also important contributors in increasing mortality and are advantageously benefitted by controlling GH and IGF-I hypersecretion. An increased risk of colonic polyps, which more frequently recur in patients not controlled after treatment, has been reported by several independent investigations, although malignancies in other organs have also been described, but less convincingly than at the gastrointestinal level. Finally, the most important cause of morbidity and functional disability of the disease is arthropathy, which can be reversed at an initial stage, but not if the disease is left untreated for several years.

Cephalometric assessment of cranial abnormalities in patients with acromegaly

OBJECTIVE AND PATIENTS

Patients with acromegaly (12 women, 26 men) and a control group (36 women, 50 men) were chosen for cephalometry to assess the size, shape and positional characteristics of the craniofacial bones and the upper airways.

RESULTS

When compared with the controls, patients of both sexes with acromegaly were found to have significant anomalies in the orofacial skeleton: increased facial height, elongated ascending ramus mandibulae and greater basion-supramentale distance, a negative difference between maxillary and mandibular protrusions, enlarged lower part of the gonion angle and of the angle of inclination of the maxilla, as well as alterations in the neurocranium: enlargement of sella turcica and of sinus frontalis and protrusion of the supraorbital ridges. As for the soft tissues, patients with acromegaly exhibited an elongated soft palate and a diminished angle between the uvular axis and the palatal plane. A comparison between the cephalometric parameters of patients with active acromegaly and those without active disease revealed no significant differences in either sex.

CONCLUSION

Patients with acromegaly exhibited an enlargement of all parts of the neurocranium and orofacial bones except the maxilla. The greatest anomaly was seen in the mandible, with greater enlargement of the ascending ramus than of the body of the mandible. The shape of this bone was also altered.

Hormones and breathing

A number of hormones, including hypothalamic neuropeptides acting as neurotransmitters and neuromodulators in the CNS, are involved in the physiologic regulation of breathing and participate in adjustment of breathing in disease. In addition to central effects, some hormones also control breathing at peripheral chemoreceptors or have local effects on the lungs and airways. Estrogen and progesterone seem to protect from sleep-disordered breathing, whereas testosterone may predispose to it. Progesterone and thyroxine have long been known to stimulate respiration. More recently, several hormones such as corticotropin-releasing hormone and leptin have been suggested to act as respiratory stimulants. Somatostatin, dopamine, and neuropeptide Y have a depressing effect on breathing. Animal models and experimental human studies suggest that also many other hormones may be involved in respiratory control.

Effect of Sandostatin LAR on sleep apnoea in acromegaly: correlation with computerized tomographic cephalometry and hormonal activity

OBJECTIVES

Sleep apnoea has been reported to occur in subjects with acromegaly. This study evaluates the relationship among biochemical activity, sleep apnoeic activity and upper airway anatomic profile in acromegaly, and the effect of Sandostatin LAR, a long-acting somatostatin analogue, on these parameters.

PATIENTS

Fourteen subjects with acromegaly were recruited.

MEASUREMENTS

Subjects were assessed at baseline and those with apnoea-hypopnoea index (AHI) > or = 5 were reassessed after 6 months of treatment with Sandostatin LAR 20-30 mg IMI 4-weekly. Biochemical activity was assessed with levels of GH and IGF-1. Sleep disordered breathing was assessed with overnight polysomnography. Upper airway anatomic profile was defined with computerized tomographic cephalometry.

RESULTS

Of 14 subjects (age 42.0 +/- 8.1 years, mean +/- SD; 11 men) at baseline, there was a positive correlation between GH and tongue length (VT; P = 0.004), and between AHI and cephalometric indices: length of soft palate (PMU; P = 0.002); mandibular plane-hyoid bone distance (MPH; P = 0.017), maximum thickness of soft palate (Max-SP; P = 0.018) and VT (P = 0.027). Eight patients had sleep disordered breathing (AHI > or = 5) which was predominantly obstructive in nature (AHI = 29.4 +/- 22.6). After treatment, there were significant improvements in hormonal profile: GH, mU/l (before, 51.5 +/- 27.8; after, 8.0 +/- 7.4; P = 0.017) and IGF-1, nmol/l (before, 95.5 +/- 23.4; after, 35.0 +/- 12.4; P = 0.012); sleep-disordered breathing: AHI (before, 29.4 +/- 22.6; after, 13.4 +/- 11.12; P = 0.025), snoring episodes (before, 486 +/- 240; after, 165 +/- 170; P = 0.05); cephalometric indices, mm: MPH (before, 18.8 +/- 12.1; after, 14.8 +/- 8.4; P = 0.018), VT (before, 72.3 +/- 4.4; after, 69.7 +/- 4.3; P = 0.05). There was a positive correlation between the reduction in GH and AHI (r = 0.738, P = 0.037).

CONCLUSIONS

The findings demonstrated that there was correlation between sleep apnoea severity and soft tissue overgrowth at the upper airway region in acromegaly. They also suggest that Sandostatin LAR improved obstructive sleep apnoea in acromegaly, and the effect might be partly mediated via a reduction in upper airway soft tissue, in particular that of the tongue, concomitant with a reduction in GH levels.

Prevalence and pathogenesis of sleep apnea and lung disease in acromegaly

Respiratory disorders are common and important complications in acromegaly. Patients suffering from acromegaly display a 1.6-3.3 fold increase in mortality rate, which is due to respiratory disorders in 25% of cases. In these patients, mortality for lung disease is 2-3 fold higher than in the general population. Every portion of the respiratory system may be involved. Deformities of facial bones, edema and hypertrophy of the mucosae and pharyngeal and laryngeal cartilages, enlargement of the tongue and inspiratory collapse of the hypopharinx, all may contribute to respiratory alterations. Nasal polyps, "hormonal rhinitis", changes of the voice and snoring are common occurrences. Though rarely, a laryngocele may ensue. Pneumomegaly is frequently observed and, as suggested by functional studies, might be due to an increased number rather than volume of the alveoli. An obstructive respiratory syndrome caused by mucosal thickening of the upper airways and bronchi is observed in 25% of female and 70% of male patients. The sleep apnea syndrome (SAS) affects 60-70% of acromegalic patients. SAS may be of obstructive, central or mixed type. Obstructive SAS is the prevailing form in acromegaly. It is due to intermittent obstruction of upper airways with preserved activity of the respiratory center, as testified by the remarkable thoracic and abdominal respiratory efforts. The pathogenesis of the central type of SAS is more complex. Narrowing of the upper airways may induce reflex inhibition of the respiratory center. Moreover, increased GH levels and, possibly, defects in the somatostatinergic pathways, may increase the ventilatory response of the respiratory center to carbon dioxide, thereby leading to respiratory arrest. In the mixed type of SAS, the phenomena underlying the other two forms coexist. Oxygen desaturation concomitant with the apneic episodes accounts for the frequent nocturnal wakening and diurnal drowsiness. Among the clinical correlates of SAS, arterial hypertension is of particular interest due to the close correlation existing between the two disorders. Sleep deprivation related to SAS seems per se to favor the appearance of hypertension. Moreover, short lasting hypoxemia may induce prolonged elevations of blood pressure, mediated by decreased endothelial generation of nitric oxide. Thus, since cardiovascular events are the main cause of mortality in patients with acromegaly, it is reasonable to hypothesize that SAS is involved in the reduced life span of these patients.

Prevalence of the sleep apnea syndrome in acromegaly population

The prevalence of sleep apnea syndrome (SAS) in acromegaly is high. Consequences of SAS are serious and are associated with increased morbidity and mortality. The aim of this study was to assess the relative frequency and predictive factors for SAS in a group of patients with acromegaly (n=55). The presence of SAS was evaluated using the Polymesam device. Hormonal and clinical examination consisted of assessment of growth hormone, insulin-like growth factor I plasma levels, body mass index (BMI), neck circumference, age, sex, treatment modes of acromegaly and ear, nose and throat (ENT) examination. The relative frequency of SAS in our group of patients with acromegaly was 75%. Independent predictors of SAS were: increased activity of acromegaly, higher age and neck circumference. No association between SAS and BMI and ENT findings was observed. The role of gender was controversial.

Collapsibility of passive pharynx in patients with acromegaly

Sleep-disordered breathing (SDB), either central or obstructive in nature, is common in patients with acromegaly. However, no study has systematically examined the collapsibility of the pharynx in acromegaly to date. We evaluated intrinsic mechanical properties of passive pharynx in 10 anesthetized and paralyzed patients with active acromegaly before transsphenoidal adenomectomy for their pituitary adenoma. Static pressure-area relationships of the velopharynx and oropharynx were obtained by step changes in airway pressure during endoscopic cross-sectional area measurement of each segment. Moreover, curve fitting analysis by an exponential function estimated the closing pressure (P'close) of each segment. Preoperative nocturnal oximetry identified five acromegalic patients with an oxygen desaturation index (ODI) greater than 10 h-1 and clinical symptoms suggesting presence of SDB. The pharyngeal airway of all five acromegalic patients with SDB was highly collapsible at both velopharynx and oropharynx with positive P'close. Compared with age-, body mass index (BMI)-, and ODI-matched SDB patients without acromegaly, SDB patients with acromegaly had a higher P'close of the oropharynx, indicating that the etiology of SDB in acromegaly appears to differ from that of ordinary sleep apnea. Our results suggest that anatomic abnormality, especially at the base of the tongue, appears to play a significant role in development of SDB in acromegaly.