Rapid improvement in sleep apnoea of acromegaly after short-term treatment with somatostatin analogue SMS 201-995

Updates in rare and not-so-rare complications of acromegaly: focus on respiratory function and quality of life in acromegaly

Acromegaly is a complex disease with excessive growth hormone and insulin-like growth factor 1 (IGF-1) causing multisystem effects, particularly cardiovascular, respiratory, and metabolic. Psychological concerns and poor quality of life (QoL) are also major disease consequences. This review is intended for clinicians and focuses on the latest developments related to respiratory and QoL effects of long-term growth hormone excess. Along with biochemical disease control, patient treatment satisfaction and outcomes have become major treatment objectives; current knowledge and tools to evaluate and manage this aspect of the disease are described. Sleep apnea syndrome and other derangements of lung function and apparatus, from pathophysiology to treatment, and evaluation tools and determinants of QoL in patients with acromegaly are discussed.

Obstructive Sleep Apnea in Acromegaly and the Effect of Treatment: A Systematic Review and Meta-Analysis

BACKGROUND

Obstructive sleep apnea (OSA) is a common disorder characterized by upper airway collapse requiring nocturnal ventilatory assistance. Multiple studies have investigated the relationship between acromegaly and OSA, reporting discordant results.

AIM

To conduct a meta-analysis on the risk for OSA in acromegaly, and in particular to assess the role of disease activity and the effect of treatments.

METHODS AND STUDY SELECTION

A search through literature databases retrieved 21 articles for a total of 24 studies (n = 734). Selected outcomes were OSA prevalence and apnea-hypopnea index (AHI) in studies comparing acromegalic patients with active (ACT) vs inactive (INACT) disease and pretreatment and posttreatment measures. Factors used for moderator and meta-regression analysis included the percentage of patients with severe OSA, patient sex, age, body mass index, levels of insulin-like growth factor 1, disease duration and follow-up, and therapy.

RESULTS

OSA prevalence was similar in patients with acromegaly who had ACT and INACT disease (ES = -0.16; 95% CI, -0.47 to 0.15; number of studies [k] = 10; P = 0.32). In addition, AHI was similar in ACT and INACT acromegaly patients (ES = -0.03; 95% CI, -0.49 to 0.43; k = 6; P = 0.89). When AHI was compared before and after treatment in patients with acromegaly (median follow-up of 6 months), a significant improvement was observed after treatment (ES = -0.36; 95% CI, -0.49 to -0.23; k = 10; P < 0.0001). In moderator analysis, the percentage of patients with severe OSA in the populations significantly influenced the difference in OSA prevalence (P = 0.038) and AHI (P = 0.04) in ACT vs INACT patients.

CONCLUSION

Prevalence of OSA and AHI is similar in ACT and INACT patients in cross-sectional studies. However, when AHI was measured longitudinally before and after treatment, a significant improvement was observed after treatment.

Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update

Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.

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.

Therapeutic options for obstructive sleep apnea

Obstructive sleep apnea is a common, chronic disorder characterized by the cessation or reduction in airflow due to periodic mechanical obstruction of the upper airway passage during sleep. Symptoms and signs of sleep apnea include daytime sleepiness, fatigue, poor concentration, snoring, resuscitative snorts, and related occupational accidents. Sleep apnea is classified into 3 types based on its severity and management varies accordingly. The first step in treatment is to identify correctible causes and educate patients on lifestyle modifications. Positive airway pressure is the preferred treatment modality and can be delivered via 3 different modes. Oral appliances are of 3 types and are generally indicated in mild to moderate obstructive sleep apnea. Surgery is a final therapeutic option that focuses on the removal of excessive tissue from different sites of the pharyngeal airway.

Impact of successful treatment of acromegaly on overnight heart rate variability and sleep apnea

BACKGROUND

Successful treatment of acromegaly improves disease-related cardiovascular mortality and morbidity, but its effects on autonomic modulation of the heart rate are unknown.

OBJECTIVES

We documented treatment-induced changes in time-domain heart rate variability, taking into account the confounding effects of obstructive sleep apnea.

PATIENTS AND METHODS

Sixteen consecutive patients (12 males, aged 43 ± 12 y) with newly diagnosed acromegaly underwent overnight (12:00-7:00 am) cardiac Holter recordings coupled with polysomnography. Data were obtained before and 10 ± 6 months after successful treatment of acromegaly.

RESULTS

IGF-1 levels fell from 807 ± 333 to 207 ± 69 μg/L and normalized in all patients. Seven patients (44%) had obstructive sleep apnea (apnea-hypopnea index 33 ± 21/h) at baseline. Treatment had no significant effect on polysomnographic indices. After treatment, increases were noted in the normal-to-normal heart period (NN), SD-NN, the percentage of NN differing from the previous NN by greater than 50 msec, and the root mean square of successive differences in NN (each P < .05). These heart rate variability results were not influenced by the type of treatment, and there was no relationship between changes in NN and changes in the apnea-hypopnea index (P = .58).

CONCLUSION

Early after successful treatment of acromegaly, we observed increased parasympathetic modulation/decreased sympathetic modulation of the nighttime heart rate, an effect that seems unrelated to changes in sleep apnea status. Treatments aimed at normalizing IGF-1 may improve cardiovascular homeostasis through improved cardiac autonomic nervous system modulation.

Octreotide for acromegaly treatment: a reappraisal

INTRODUCTION

Acromegaly is a rare disorder characterized by excess secretion of growth hormone (GH) generally caused by a pituitary macroadenoma and associated with reduced life expectancy if the disease is untreated. This article covers the recent available evidences published on octreotide , the first somatostatin analog introduced into clinical practice for the medical treatment of acromegaly.

AREAS COVERED

This article discusses i) pharmacology of somatostatin and octreotide; ii) biochemical effects of regular octreotide and long-acting repeatable formulation; iii) tumor shrinkage effects of octreotide in acromegaly; iv) impact of octreotide on acromegalic clinical manifestations and chronic complications; v) safety of octreotide and vi) place of octreotide in the guidelines for acromegaly treatment. Full-text articles in the English language were selected from a PubMed search spanning 1984 - 2013, for keywords including 'octreotide,' 'acromegaly,' 'GH,' 'IGF-I,' and 'tumor shrinkage.' Reference lists in selected papers were also used to broaden the search.

EXPERT OPINION

Octreotide is a mature drug with a consolidated favorable benefit versus risks profile in the treatment of acromegaly.

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.

Endocrine aspects of obstructive sleep apnea

CONTEXT

Some endocrine and metabolic disorders are associated with a high frequency of obstructive sleep apnea (OSA), and treatment of the underlying endocrine disorder can improve and occasionally cure OSA. On the other hand, epidemiological and interventional studies suggest that OSA increases the cardiovascular risk, and a link between OSA and glucose metabolism has been suggested, via reduced sleep duration and/or quality.

EVIDENCE ACQUISITION

We reviewed the medical literature for key articles through June 2009.

EVIDENCE SYNTHESIS

Some endocrine and metabolic conditions (obesity, acromegaly, hypothyroidism, polycystic ovary disease, etc.) can be associated with OSA. The pathophysiological mechanisms of OSA in these cases are reviewed. In rare instances, OSA may be improved or even cured by treatment of underlying endocrine disorders: this is the case of hypothyroidism and acromegaly, situations in which OSA is mainly related to upper airways narrowing due to reversible thickening of the pharyngeal walls. However, when irreversible skeletal defects and/or obesity are present, OSA may persist despite treatment of endocrine disorders and may thus require complementary therapy. This is also frequently the case in patients with obesity, even after substantial weight reduction.

CONCLUSIONS

Given the potential neurocognitive consequences and increased cardiovascular risk associated with OSA, specific therapy such as continuous positive airway pressure is recommended if OSA persists despite effective treatment of its potential endocrine and metabolic causes. "Apropos of sleep, that sinister adventure of all our nights, we might say that men go to bed daily with an audacity that would be incomprehensible if we did not know that it is the result of ignorance of the danger." Charles Baudelaire, in "Fusées, IX"

Prevalence of sleep apnea and metabolic abnormalities in patients with acromegaly and analysis of cephalometric parameters by magnetic resonance imaging

OBJECTIVES

To determine the prevalence of sleep apnea (SA) and SA syndrome (SAS) in patients with acromegaly and correlate SA with clinical, laboratory, and cephalometric parameters.

DESIGN AND METHODS

Prospective and cross-sectional study of 24 patients with active acromegaly evaluated by clinical and laboratory (GH, IGF-I) parameters, polysomnography and magnetic resonance imaging (MRI) of the pharynx.

RESULTS

Out of 24 patients, 21 had SA (87.5%), of which 20 (95.3%) had the predominant obstructive type. Median age of these 21 patients was 54 years (range 23-75) and median estimated disease duration was 60 months (range 24-300). The frequency in SA patients of impaired glucose tolerance, diabetes mellitus (DM), and hypertension was 19, 33.3, and 71.4% respectively. Goiter was found in 10 patients (47.6%) and obesity in 18 (90%). Median GH level was 14 mug/l (1.4-198) and median %IGF-I (percentage above the upper limit of normal range of IGF-I) was 181% (-31.6 to 571.2). The prevalence of SAS was 52.4%. Apnea-hypopnea index (AHI) correlated significantly with age, waist circumference, body mass index, and hypopharynx area. The AHI was significantly higher in patients with hypertension and DM.

CONCLUSIONS

The prevalence of SA and SAS in acromegaly was similar to the one previously described in other series. Age was a significant risk factor, and hypertension and DM were significantly associated complications of SA. Obesity was also significantly related to SA, as a risk factor, a complication or both. Overall, cephalometric parameters by MRI did not correlate with SA.

Medical consequences of acromegaly: what are the effects of biochemical control?

This chapter discusses the effects of biochemical control of acromegaly on cardiovascular diseases, metabolic complications, respiratory abnormalities, malignancies and bone alterations. Acromegaly is associated with increased morbidity and mortality for cardiovascular and respiratory complications, whereas neoplasms seem to be a minor cause of increased risk of death. Other associated diseases are osteoarthritis, carpal tunnel syndrome, fatigue, visual abnormalities and reproductive disorders. Acromegaly results in premature death because of prolonged elevation of GH an IGF-I levels, and a strong biochemical control improves well-being and restores life expectancy to normal. The main goals of medical treatment of acromegaly include normalization of biochemical markers of disease activity, improvement in signs and symptoms of the disease, removal or reduction of tumor mass and preservation of pituitary function.

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.

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.

Polysomnographic findings in five adult patients with pituitary insufficiency before and after cessation of human growth hormone replacement therapy

OBJECTIVE

We observed the new onset of severe obstructive sleep apnoea syndrome (OSAS) in an adult male patient during human growth hormone (hGH) replacement therapy. This prompted us to evaluate the potential influence of hGH substitution therapy on sleep in middle-aged men.

DESIGN

A longitudinal study.

SUBJECTS

Five male patients (aged 44-56 years, median age 54 years) with postoperative pituitary insufficiency given hGH replacement therapy for 1-2 years (median dose 2.0 U/day; median IGF-I serum concentration 351 microg/l) and 6 months after cessation of hGH treatment (median IGF-I level 77 microg/l - 1 microg/l = 0.131 nmol/l).

MEASUREMENTS

Polysomnographic studies were performed, and the following parameters were determined: time in bed (TIB), sleep period time (SPT), total sleep time (TST), sleep efficiency (SE = TST/TIB), sleep stage 1 onset latency (SL), different sleep stages [W (wake), S1, S2, SWS (slow wave sleep = S3 + S4) and REM; % of SPT], stage shifts per hour of SPT (SS/h), stage shifts to W/h of SPT [A/h (awakening)], index of apnoea and hypopnoea events per hour of TST (AH/h), arousals from apnoea and hypopnoea per hour of TST (Ar/h), index of obstructive (OAH/h), central (CAH/h) and mixed (MAH/h) events of apnoea and hypopnoea per hour of TST and minimal desaturation (MD).

RESULTS

Median baseline results were: TIB, 479 min; SPT, 465 min; TST, 405 min; SE, 77%; SL, 8.5 min; W, 18.9%; S1, 8.2%; S2, 52.7%; REM, 13.5%; SS/h, 17.7; A/h, 2.8; AH/h, 11.9; Ar/h, 4.4; MD, 80%. These parameters did not change significantly after cessation of hGH treatment. In contrast, median SWS decreased significantly from 33 min (7.1%) to 7.5 min (1.8%; P = 0.03). Median OAH/h decreased significantly from 4.4 to 0.1 (P = 0.03) whereas CAH/h increased from 6.3 to 14.6 (P = 0.03) after cessation of hGH. Correspondingly, one patient with OSAS improved markedly whereas another patient developed new and asymptomatic central SAS after cessation of hGH.

CONCLUSION

This study showed that hGH replacement therapy influenced sleep reaction in a complex way in middle-aged men; cessation of treatment was associated with a significant decrease in slow wave sleep and a shift from obstructive to central apnoea and hypopnoea.

Treatment of obstructive sleep apnea. A review

Treatment of obstructive sleep apnea (OSA) has developed over the last 25 years from tracheostomy to a variety of options, including weight loss, nasal continuous positive airway pressure (N-CPAP), pharyngeal surgery, and medications. None of these options is definitive or curative, except possibly weight loss. The most widely prescribed treatment is N-CPAP, but recently published studies using objective measurement of patient compliance show less than ideal compliance. Attempts have been made to design pharyngeal surgery according to the site of upper airway collapse or narrowing, as identified by various techniques in wakefulness. How representative these studies are of upper airway physiology in sleep is questionable. Recent studies have shown improved surgical success in correcting OSA. However, disturbing data are available in a limited number of patients that demonstrate worsening of the OSA months after a favorable response to surgery. More studies assessing the long-term outcome of pharyngeal surgery are needed. Several pharmacologic agents have been used to treat OSA. Results with any particular agent are not better than with N-CPAP or surgery. However, studies of subgroups of patients with OSA in which a particular pharmacologic agent may be specifically indicated, such as thyroxine in hypothyroidism, have not been conducted (to our knowledge). An algorithm for the approach to treatment recommendations is presented. Basic to this algorithm is an objective presentation of therapeutic options to the patient with OSA and a respect for the patient's preferences.

Clinical features and differential diagnosis of pituitary tumours with emphasis on acromegaly

Pituitary adenomas are frequently encountered, benign intracranial tumours. Clinically classified according to their capacity to produce and secrete hormones, pituitary tumours are diagnosed from the clinical manifestations and biochemical findings of specific pituitary hormone overproduction or of impaired pituitary function due to pressure on normal pituitary cells, the pituitary stalk or the hypothalamus. Additionally, the tumour may result in neurological manifestations due to its effect as an intracranial space-occupying lesion. Pituitary adenomas may present acutely with pituitary apoplexy after intrapituitary haemorrhage or infarction. The subsequent hypofunction of the pituitary with concomitant neurological sequelae of an expanding intracranial mass are often associated with excruciating headache, diplopia and visual field defects. Gradually developing neurological deficits or secondary endocrine failure over several years may precede the recognition of non-secretory tumours (30-40% of pituitary adenomas) as well as some of the hormone-producing adenomas, especially when they expand beyond the confines of the sella turcica. Asymptomatic masses occur in the pituitary in 5-27% of unselected autopsy series. About 10-20% of pituitaries imaged as part of a brain study contain lesions 'consistent with a pituitary adenoma', with about half being pituitary adenomas ('incidentalomas'). Many advocate screening such cases for a wide spectrum of pituitary function abnormalities. Clinical judgement should be utilized to determine the extent of the work-up and the frequency of follow-up. Acromegaly, a clinical syndrome caused by excess growth hormone secretion, accounts for one-sixth of resected pituitary tumours. This disorder leads to chronic progressive disability and a shortened life span, with approximately 50% of untreated acromegalic patients experiencing premature death. The prevalence of acromegaly has been estimated to range from 50 to 70 per million, with the age of diagnosis usually between the third and fifth decades. Conditions associated with acromegaly include glucose intolerance, diabetes mellitus, lipid abnormalities, cholelithiasis, goitre, and hyperthyroidism, respiratory complications, hypertension, cardiovascular disease, and calcium metabolism abnormalities. An association between acromegaly and cancer, especially of the colon, is now recognized. Epidemiological series have indicated that cancer of the colon, breast and other types of malignancy are a cause of death with increased frequency in acromegalics compared with expected rates. Hypopituitary symptoms secondary to the mass effect of macroadenomas in acromegalic patients are common. Among premenopausal women, menstrual irregularities and galactorrhoea have been reported in 40-70%, while more than half of the men complain of impotence and decreased libido.(ABSTRACT TRUNCATED AT 400 WORDS)

Improvement of sleep apnoea due to acromegaly during short-term treatment with octreotide

Two acromegalic patients suffering from severe obstructive sleep apnoea syndrome were treated with the long-acting somatostatin analogue octreotide. Daytime sleepiness and fatigue improved within a few days. Repeat sleep studies performed after octreotide treatment revealed more confluent sleep with a shorter duration of sleep apnoea. Nocturnal hypoxaemia improved in one patient. Octreotide might be an effective noninvasive treatment for sleep apnoea of acromegaly.

Obstructive sleep apnea syndrome and acromegaly

Obstructive sleep apnea syndrome is a complex disorder that has been associated with a variety of abnormalities of the upper airway, including tonsil and adenoid hypertrophy, nasal obstruction, retrognathia, and macroglossia. The cause of the airway obstruction in acromegaly is believed to be related to osseous and soft-tissue changes surrounding the upper airway, which lead to narrowing and subsequent collapse during sleep. We describe the results of treatment in seven patients with both sleep apnea and acromegaly. Four patients were treated by transsphenoidal hypophysectomy alone with a resolution of sleep apnea syndrome. One underwent hypophysectomy followed by postoperative radiation therapy, which reduced his apnea. Three patients underwent unsuccessful uvulopalatopharyngoplasty. Successful treatment of the primary disorder, in this case acromegaly, resulted in improved breathing during sleep in five patients. This series would suggest that acromegalic patients with sleep apnea should be treated for their pituitary tumor to reduce growth hormone before consideration of surgery to enlarge or bypass the upper airway.

The role of Sandostatin in acromegaly

Long-acting somatostatin analogues are extensively used for the treatment of acromegalic patients who have not been cured by surgery or for whom surgery is contraindicated or hazardous. Such an analogue, Sandostatin, has been approved for this indication in various countries and to date an overall review is feasible. From the literature and our experience, clinical response of acromegaly is attained in 60% to 70%, with mainly a reduction in headaches, arthralgias, and acral growth. Hormonal response, evaluated on plasma growth hormone (GH) levels, is observed in more than 80% of the patients. In 36% to 45% of the patients, plasma GH levels are reduced to near-normal values, and in 50% of the patients, the percentage of reduction is greater than 50% of pretreatment values. The major source of concern is the occurrence of gallstones during the treatment; its frequency is evaluated differently. From the largest well-documented series, we retain a percentage of 12.5% of newly occurring cholelithiasis and in most cases they remain asymptomatic. Tumor shrinkage is minor in most cases.

[Long-term effects of treatment with SMS 201-995 on sleep apnea syndrome associated with acromegaly]

A 60-year-old woman with acromegaly associated with sleep apnea was treated with the somatostatin analogue SMS 201-995 (Sandoz) for several months. Growth hormone levels were normalized and a rapid improvement in sleep apnea was controlled with polygraphic nocturnal monitoring. Hypophysectomy seems to have variable effects on sleep apnea in acromegaly. The origin of obstructive apnea in acromegaly is therefore unclear.

Successful reversal of sleep apnoea syndrome following treatment for acromegaly, confirmed by polygraphic studies

A patient with acromegaly was shown to have obstructive sleep apnoea by polygraphic recordings. Following successful hypophysectomy, further recordings demonstrated resolution of obstructive sleep apnoea.

Role of a long-acting somatostatin analogue (SMS 201-995) in the treatment of acromegaly

The beneficial effect of the long-acting analogue of somatostatin SMS 201-995 in the treatment of acromegaly is described in three cases, and current published experience is reviewed. A total of 64 patients from 10 series have received the drug from one to 25 months, usually in doses of 50-150 micrograms every eight hours by subcutaneous injection. Clinical and chemical improvement was observed in the majority of subjects but normal 24-hour serum growth hormone levels were achieved in no more than 35 percent of this group and possibly less. We have found that higher doses, up to 1,500 micrograms per day, which have generally been free of side effects, are sometimes required to normalize growth hormone secretion. A reduction of up to 33 percent in pituitary tumor size has been reported in more than half of the 27 cases studied from four groups. Clinically important side effects are infrequent, but diarrhea, usually transient, occurred in about 13 percent, with frank steatorrhea in 2 to 6 percent of cases. Alteration in carbohydrate metabolism, such as transient glucose intolerance at the start of therapy in non-diabetic acromegalic patients, and increased sensitivity to insulin or oral hypoglycemic agents in diabetic acromegalic patients, is common. Overall, SMS 201-995 appears to be a valuable new agent for the treatment of acromegaly, but long-term safety needs to be established.