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Pituitary Disorders Implications of Somatostatin Analogs in the Treatment of Acromegaly Karim Gariani, MD, 1 Patrick Meyer, MD 2 and Jacques Philippe, MD 3 1. Chief Resident, Internal Medicine Service; 2. Associate Clinician; 3. Professor, Head, Division of Diabetology, Endocrinology and Hypertension and Nutrition, Geneva University Hospital, Switzerland Abstract Octreotide has an important role in the medical management of acromegaly. Its place in the management of acromegaly as an adjuvant therapy after neurosurgery is well established with a well-demonstrated efficacy. It can also be used in certain clinical conditions as a neoadjuvant treatment. Clinicians and patients should be aware of the possible side effects of octreotide treatment. Keywords Acromegaly, somatostatin analogs, octreotide, treatment, side effects Disclosure: The authors have no conflicts of interest to declare. Received: April 15, 2013 Accepted: May 13, 2013 Citation: US Endocrinology, 2013;9(1):62–5 Correspondence: Karim Gariani, MD, Department of Internal Medicine, Division of General Internal Medicine, 4 rue Gabrielle-Perret-Gentil, 1211 Genève 4, Geneva, Switzerland. E: Karim.Gariani@hcuge.ch Acromegaly Epidemiology and Clinical Manifestations Acromegaly is an uncommon disorder characterized by the hypersecretion of growth hormone (GH) resulting in an increase in serum insulin-like growth factor-1 (IGF-1) levels. This condition is most often caused by a pituitary adenoma. The prevalence is estimated around 40–125 per million and the incidence is around three to four new cases per million. 1 Two studies has suggested that the prevalence of acromegaly may be more widespread than previously estimated. In a study including 71,972 subjects, the prevalence of pituitary adenoma was more than 3.5–5 times than previously reported, whereas in an another study the prevalence of biochemical acromegaly by screening for elevated IGF-1 levels was even higher with 1,043 cases per million of subjects. 2,3 The mean age at diagnosis is around 40 years. The clinical manifestations of acromegaly are varied and comprise enlargement of the extremities, soft tissue swelling, coarsening of facial features, prognathism, macroglossia, increase in ring and/or shoe size, arthritis, hyperhidrosis, and diabetes mellitus. Acromegaly Diagnosis Criteria The current international consensus for the diagnosis of acromegaly is based on the inability to suppress serum GH to less than 1  μg/L after glucose administration (75  g is recommended), in conjunction with a clinical suspicion and high IGF-1 levels. 4 The diagnosis is often preceded by around 10 years of active unrecognized disease. 5 The clinical manifestations of acromegaly depend on the level of GH and IGF-1, tumor size, the age of the patient, and the delay in diagnosis. Treatment Options in Acromegaly The aims of therapy in acromegaly are alleviation of symptoms, complete tumor removal, and a decrease in morbidity and mortality. 6 Complications 62 linked to acromegaly are principally premature atherosclerosis, hypertrophic cardiomyopathy, diabetes mellitus, arthritis, sleep apnea syndrome, and polyps of the colon. 7 The cause of death in acromegaly patients is cardiovascular disease in 60  % of patients, 25  % respiratory disease, and 15 % neoplasia. 8 A biochemical complete control is achieved by a serum GH level <1  μg/L with a sensitive immunoassay or <2.5 μg/L with a sensitive enzyme-based immunoassay, normalization of serum IGF-1 levels compared with age- and sex-matched controls, and/or GH level under 0.4 μg/L after an oral glucose tolerance test (OGTT). 4 Management of a patient with acromegaly requires a multidisciplinary collaboration with a general practitioner, endocrinologist, neurosurgeon, and radiotherapist. Primary surgical removal of the tumor is considered as the preferred treatment for acromegaly according to the guidelines of the American Association of Clinical Endocrinologists. 4 Transsphenoidal surgery in particular is considered as the first approach in patients with microadenomas and in patients with macroadenomas that are associated with a mass effect. Surgical excision achieves a normalization of serum IGF-1 in 56–68 % patients with noninvasive macroadenomas and in 75– 95 % patients with microadenomas. 9–11 Medical treatment is considered an adjuvant therapy in patients experiencing residual disease after surgical removal of the tumor. The only situations in which medical treatment with somatostatin analogs (SSAs) have been considered as a first-line therapy is in cases of macroadenomas with no local mass effect and a poor chance of surgical cure because of an extrasellar extension, for example in the cavernous © Touc h M E dica l ME dia 2013