Elevated incidence of sleep apnoea in acromegaly-correlation to disease activity.

PURPOSE: An elevated prevalence of sleep apnoea (SA) in patients with acromegaly has been suggested. METHODS: We performed polysomnographies in 52 patients with acromegaly (25 m, 27 f, age 51 years, range 19-82 years). Patients were defined having SA if they had more than five apnoeas or hypopnoeas per hour (respiratory disturbance index = RDI). The type of SA was divided into obstructive (OSA), central (CSA) or mixed (OSA+CSA). Seventeen patients had newly diagnosed disease, and 18 patients were treated with somatostatin analogues. RESULTS: Twenty-three patients had controlled disease activity (mean GH levels <1 µg/l during a 3-h profile and normalised IGF-1 levels). Twelve had active acromegaly despite medical treatment. Thirty patients (58%) had SA. Twenty-five of those had OSA, three had CSA, and two had mixed. Of the patients with active disease, 66% had SA, compared to 48% in the cured group. Significantly more patients with hypertension (n = 18) than without hypertension (n = 12, p = 0.041) had SA. Basal glucose was not significantly different between patients with (100 mg/dl, range 75-207 mg/dl) and without SA (92 mg/dl, range 74-120 mg/dl), but HbA1c was significantly higher in patients with SA (5.9% (4.9-9.0%) vs. 5.4% (4.3-6.1%), p = 0.001). A positive correlation between RDI and BMI (p = 0.04), RDI and age (p = 0.013) and RDI and disease activity (p = 0.014) was seen. No major correlation could be found between RDI and the duration of disease activity nor between RDI and GH levels. CONCLUSION: RDI correlates positively with disease activity but not with the duration of the disease. The parameters of the metabolic syndrome are positively associated to the degree of SA in acromegalic patients.

The acute effect of a single application of cabergoline on endogenous GH levels in patients with acromegaly on pegvisomant treatment.

OBJECTIVE: Treatment with pegvisomant, an antagonist of growth hormone (GH) receptors, increases GH levels in a dose dependent manner. Cabergoline can suppress GH secretion in approximately 40% of acromegalic patients. However, the acute effects of cabergoline have not been studied in patients treated with pegvisomant. We performed this cross-sectional study to evaluate endogenous GH after an additional single cabergoline administration. DESIGN: 9 acromegalic patients on pegvisomant therapy were included. A 6h GH profile after pegvisomant alone (P) and a 9h profile in combination with oral cabergoline 0.5mg (PC) were performed. After 3 or 6h, all patients received a standardized light mixed meal. Endogenous serum GH and pegvisomant levels were measured by special in-house assays. The GH assay showed no interference with pegvisomant. RESULTS: Endogenous GH levels at baseline did not differ significantly between the profiles (P: 16.5 µg/l (range 3.2-36.6 µg/l), PC: 8.0 µg/l (1.6-48 µg/l), p>0.05). In both profiles, GH fluctuated before meal. GH decreased more pronounced in PC but this decrease was not statistically significant. After meal, a significant decline in endogenous GH levels from 16.4 µg/l (0.4-27.1 µg/l, 100%) to 8.1 µg/l (0.2-24.7 µg/l, 66%) appeared in P at 300 min (p<0.01). Also in PC a decline from 7.8 µg/l (1.1-29.6 µg/l, 100%) to 5.2 µg/l (0.4-23.9 µg/l, 75%) at 300 min was observed but it was not significant. CONCLUSION: Endogenous GH is not significantly decreased after a single oral cabergoline application during pegvisomant treatment in acromegaly.

[A 46-year-old patient with atrial fibrillation, elevated thyroid hormones and normal thyrotropine]. / Vorhofflimmern, erhöhte Schilddrüsenhormone und nicht supprimiertes TSH bei einem 46-jährigen Patienten.

We report on a 46 year old patient with a history of paroxysmal atrial fibrillation who presented to our emergency room. Diagnostic evaluation showed elevated free peripheral thyroid hormone levels and thyrotropine (TSH) hormone within normal limits. Ultrasound of the thyroid was normal, and thyroid autoantibodies were found in the normal range. There was a positive family history for thyroid dysfunction. TSH-producing adenoma (TSHoma) of the pituitary gland - the main differential diagnosis - was excluded by cranial MRI and laboratory tests. Familial thyroid hormone resistance (Refetoff syndrome) was suspected and could be confirmed by detection of a pathogenic mutation within the beta-thyroidhormone receptor gene. After spontaneous conversion to sinusrhythm the patient was treated with a beta(1)-selective betareceptor blocker. Up to now, no specific treatment is available to correct the defective beta-thyroidhormone receptor.

The effect of acute application of pegvisomant alone and in combination with octreotide on endogenous GH levels during a 6-h test in patients with acromegaly on constant pegvisomant treatment.

OBJECTIVE: Co-treatment with somatostatin analogues and growth hormone receptor antagonists in acromegaly might be a new treatment option abolishing the negative effects of monotherapy. Nevertheless, little is known about the acute effect of the combined treatment on endogenous GH and pegvisomant levels. DESIGN: Ten acromegalic patients on constant pegvisomant therapy were included. Two 6-h GH secretion profiles were performed once after pegvisomant alone (P), the other after an additional 100 microg octreotide sc injection (PO). After 180 min, all patients received a standardized light mixed meal. Endogenous serum GH and pegvisomant levels were measured by special in-house assays. In addition, insulin and glucose were measured. RESULTS: In the combined profile PO, a significant decrease of median endogenous GH was seen (p<0.01, median percentage decline 75.2%, range 23.7-88.2), which was not seen in profile P. Seven of 10 patients had a decline >70% and might be seen as responders. After meal, endogenous GH significantly decreased only in profile P (p<0.01). Pegvisomant levels did not differ significantly between profiles and did not change significantly during the tests. After meal, glucose levels rose higher and later and insulin levels lower and later in profile PO than in profile P. CONCLUSION: During pegvisomant treatment, endogenous GH can be reduced significantly by acute application of a somatostatin analogue. Therefore, in acromegalic patients on pegvisomant therapy GH regulation due to somatostatin analogues seems to be preserved.

Impaired glucose tolerance in pancreas grafted diabetic patients is due to insulin secretory defects.

INTRODUCTION: Pancreas transplantation in diabetic patients can sustain insulin independence for years. The aim of the study was to measure the incidence of an impaired or diabetic glucose tolerance in patients after successful transplantation and analyse insulin resistance and insulin secretion. METHODS: 174 Type 1 diabetic recipients of simultaneous pancreas/kidney (SPK) transplants were investigated early (three months) and 95 patients late (five years) after transplantation using an oral glucose tolerance test combined with an iv arginine load. RESULTS: Although mean fasting blood glucose and HbA1c levels were within the normal range, only 65% of the patients displayed a normal glucose tolerance (NGT), whereas 25% had an impaired (IGT) and 10% showed a diabetic glucose tolerance (DGT). Fasting blood glucose and HbA1c values were significantly lower in patients with NGT compared to graft recipients with IGT or DGT, either three months or five years after SPK. Indicators of insulin resistance (fasting insulin, HOMA-IR, Matsuda/de Fronzo Index) were elevated in all graft recipients, but no differences were found between groups. In contrast insulin secretion was significantly reduced in patients with IGT and DGT early and late after transplantation. SUMMARY: Insulin resistance is a common feature after pancreas transplantation. However, either three months or five years after SPK abnormal glucose tolerance was mainly due to a reduced glucose- and arginine-induced secretory response of insulin.

Effects of the long-acting somatostatin analogue Lanreotide Autogel on glucose tolerance and insulin resistance in acromegaly.

OBJECT: Treatment with somatostatin analogues (SA) not only inhibits GH secretion but may also impair insulin secretion. In order to evaluate the influence of SA on glucose metabolism, we investigated insulin resistance (IR) and beta-cell function, using the recommended combination of homeostatic model assessment of IR (HOMA-IR) and beta-cell function (HOMA-beta). DESIGN AND METHODS: This is a prospective, cross-sectional study. We measured fasting insulin, blood glucose and IGF-I. Insulin and blood glucose measurements were taken 120 min after an oral glucose tolerance test with 75 g glucose. We studied 51 patients (27 female/24 male, age 54 years (20-75)). Eighteen patients were on Lanreotide Autogel (LA) treatment, 33 had no medical treatment. GH-levels of more than 2.5 ng/ml was reached by 59% of the patients, 74.5% had normal IGF-I levels. RESULTS: We found no significant influence of disease activity on HOMA-IR and HOMA-beta. In the 33 of 51 subjects without any drug treatment, median HOMA-beta was 170.4% (36.0-624.0%). In contrast, in the 18 patients on LA treatment, median HOMA-beta was found to be significantly lower (84.2% (36.5-346.2%); P = 0.001). Despite this, there was no difference in HOMA-IR in both groups (2.4 (0.7-8.4) vs 2.3 (0.7-6.1); P < 0.001) despite similar insulin values. CONCLUSION: In conclusion, we found that LA decreases beta-cell function significantly without affecting IR. Therefore, we think that insulin secretagogues are probably more effective in the treatment of diabetes mellitus in acromegalic patients on LA therapy than insulin sensitizers.

[Pharmacotherapy of pituitary diseases]. / Medikamentöse Therapie von Hypophysenerkrankungen.

Successful pharmacotherapy of pituitary hormonal excess is established only in the treatment of acromegaly (dopamine agonists, somatostatin analogues, GH-receptor-antagonists) and of prolactinomas (dopamine agonists). Gold standard in the treatment of acromegaly is transsphenoidal pituitary surgery, while in prolactinomas, surgery is indicated only in exceptional cases. Substitution of pituitary insufficiency offers the patients a normal quality of life. Substitution of the cortico- and thyrotrope axis with hydrocortisone and levothyroxine is vital. In women, substitution of the gonadotrope axis should be performed up to menopause (estrogen/gestagen). In men, substitution should be performed lifelong (trans-dermal testosterone body patches, testosterone gel, testosterone undecanoate/enanthate). To achieve fertility, gonadotropins or pulsatile GnRH therapy has very good results. Especially in younger patients, substitution of growth hormone may be useful (somatropin).

Gamma-knife surgery is effective in normalising plasma insulin-like growth factor I in patients with acromegaly.

OBJECTIVE: For patients in whom acromegaly persists despite pituitary surgery or drug treatment, gamma-knife surgery represents an additional treatment option. Considering carefully the different reported biochemical outcomes, the central point is whether gamma-knife radiosurgery has advantages compared to conventional radiotherapy or, furthermore, to newer medical therapies, such as long-acting somatostatin analogues or growth hormone receptor antagonists. DESIGN AND METHODS: We report the outcome of 44 patients with acromegaly, who received gamma-knife surgery with the Leksell gamma knife. The median follow-up time was 1.9 years (0.5-4.3 years) post-radiosurgery. 43 of 44 patients had previously undergone pituitary surgery. RESULTS: Immediately prior to gamma-knife surgery, median xULN of patients' serum IGF-I was 1.9 times above upper limit of normal (range: 0.5-8.9 xULN [multiple of upper limit of normal range]). There was a significant decline of serum IGF-I at patients' final follow-up. We found a normal age-adjusted IGF-I in 21/44 patients (xULN of IGF-I<1). Furthermore, as the number of treated patients increased, we found an improvement in remission rate, which let us assume that there was a learning effect for the gamma-knife performing team over time. In addition, the median adenoma size decreased from 1.5 ml (0.1-6.9 ml) prior to gamma-knife therapy to 0.3 ml (no rest vol. detectable-2.4 ml) at patients' last visit. CONCLUSION: We have shown that pituitary gamma-knife surgery is effective in lowering serum IGF-I levels. At the end of the follow-up period, 48 % of our cohort had normal age-adjusted IGF-I levels.

Four-year follow-up of acromegalic patients treated with the new long-acting formulation of Lanreotide (Lanreotide Autogel).

Lanreotide Autogel (Ipsen) is a long-acting somatostatin analogue (SA) in a new galenic formulation suitable for subcutaneous (s.c.) injection. In our department, 11 patients with therapy-resistant acromegaly were treated with Lanreotide Autogel for 48 months. 10/11 patients had previously undergone transsphenoidal surgery. For a median duration of 1.4 years prior to Lanreotide Autogel, the patients received Lanreotide PR 30 mg every 7, 10, or 14 days. 60, 90, or 120 mg of Lanreotide Autogel was administered by deep s.c. injection every 28 days, with the higher dosage being given to those with the previously shortest injection interval under Lanreotide PR. Dose was adjusted on the basis of Growth Hormone (GH) level after 4, 8, and 12 months with a minimum dose of 60 mg and a maximum dose of 120 mg. The efficacy of Lanreotide Autogel treatment was evaluated by measuring GH concentrations (4 hour profiles) and IGF-I levels. Before switching to Lanreotide Autogel, the multiple of the upper limit of normal (xULN) of IGF-I levels was 1.2 (median) and the median GH level was 1.3 microg/l. 3 out of 11 patients had an IGF-I within the age- and sex-adjusted normal range. After 48 months of treatment with Lanreotide Autogel, six patients had an IGF-I within the normal range. Median GH levels were at 1.3 microg/l and xULN of IGF-I was at 1.0 compared to Lanreotide PR 30 mg treatment (p < 0.001). At the end of the study, 8 patients received 120 mg Lanreotide Autogel, 2 patients 90 mg and 1 patient 60 mg, respectively. There was slight but significant deterioration of glucose metabolism with an increase of HbA1c. In conclusion, the new galenic formulation of Lanreotide improves not only the control of biochemical markers of acromegaly compared to the conventional PR formulation, but is also easier to administer given its deep s.c. method of administration. Glucose metabolism has to be followed carefully in patients on high-dose Lanreotide Autogel.

Efficacy of the new long-acting formulation of lanreotide (lanreotide Autogel) in the management of acromegaly.

Lanreotide Autogel is a new long-acting aqueous preparation of lanreotide for the treatment of acromegaly and is administered by deep sc injection from a small volume, prefilled syringe. The aim of this study was to evaluate the efficacy and safety of this new long-acting formulation in a large population of acromegalic patients previously responsive to lanreotide 30 mg, im (sustained release microparticle formulation). Lanreotide Autogel was administered by deep sc injection every 28 d to 107 patients (54 males and 53 females; mean age, 54 +/- 1.2 yr). All patients had been treated with lanreotide (30 mg) for at least 3 months before study entry and had a mean GH level less than 10 ng/ml after at least 4 subsequent im injections every 14 d (48%), 10 d (32%), or 7 d (20%). Treatment was switched from lanreotide 30 mg injected every 14, 10, or 7 d to 60, 90, or 120 mg lanreotide Autogel, respectively, every 28 d. After three fixed dose injections of lanreotide Autogel, mean lanreotide levels were similar to those obtained at steady state with lanreotide 30 mg. During lanreotide Autogel treatment, the control of acromegalic symptoms was comparable with that previously achieved during lanreotide 30 mg treatment. After 3 injections of lanreotide Autogel, mean GH (2.87 +/- 0.22 ng/ml) and IGF-I (317 +/- 15 ng/ml) values were comparable with those recorded at the end of lanreotide 30 mg treatment (GH, 2.82 +/- 0.19 ng/ml; IGF-I, 323 +/- 16 ng/ml). GH levels below 2.5 ng/ml and age-/sex-normalized IGF-I were achieved in 33% and 39% of patients during lanreotide 30 mg and lanreotide Autogel treatment, respectively. Diarrhea, abdominal pain, and nausea were reported by 38%, 22%, and 18% of patients during lanreotide 30 mg treatment and by 29%, 17%, and 9% of patients, respectively, during lanreotide Autogel treatment. In conclusion, this clinical study shows that lanreotide Autogel is at least as efficacious and well tolerated as lanreotide 30 mg. This new long-acting lanreotide formulation, lanreotide Autogel, which is administered from a small volume, prefilled syringe by deep sc injection, is therefore likely to improve the acceptability of medical treatment for patients requiring long-term somatostatin analog therapy.

[Therapy of pituitary diseases. What can be achieved with medication and hormones?]. / Therapie hypophysärer Erkrankungen. Was Sie mit Medikamenten und Hormonen erreichen können.

Pharmacotherapy is available only for pituitary adenomas producing growth hormone and prolactin (acromegaly, hyperprolactinemia). While dopamine agonists and somatostatin analogues are usually administered to acromegaly patients only after unsuccessful surgery, dopamine agonists are the treatment of choice in patients with prolactinomas. Replacement treatment in patients with insufficiency of the anterior lobe of the hypophysis is oriented to the extent of the deficits. Theoretically, replacement treatment can be applied for any functional loss. Of essential importance is the replacement of lost adrenal cortical function by the regular administration of physiological doses of hydrocortisone, and of lost thyroid function by the administration of L-thyroxine. In high-stress situations, for example, due to severe illness, the hydrocortisone dose must be increased significantly, and if necessary given parenterally. Gonadal function is replaced either with gonadal steroid hormones or gonadotropin or GnRH in patients wishing to have children. In adults, replacement of growth hormone is also indicated to decrease cardiovascular risk. This, however is very expensive and requires s.c. injections.

Conventional pituitary irradiation is effective in normalising plasma IGF-I in patients with acromegaly.

OBJECTIVE: For patients in whom acromegaly persists despite pituitary surgery, conventional pituitary irradiation represents an additional treatment option. A 30-60% cure rate is described in the literature, but these studies did not utilise strict rules of remission, such as "safe" GH levels <2.5 microg/l, and age-adjusted normal IGF-I levels. DESIGN AND METHODS: We report the outcome of 41 patients with acromegaly who received pituitary conventional external irradiation. The median follow-up time was 12.8 years (3.7-43.4 years) post-radiotherapy. RESULTS: The median pre-irradiation GH level was 31.0 microg/l (7.0-210 microg/l). Information on IGF-I levels was only available for 6 patients prior to therapy. Utilising strict rules of remission, one-third (14/41) of our patients had normal biochemical parameters, i.e. "safe" GH (0.5 microg/l (range 0.2-1.6 microg/l)) and normal age-adjusted IGF-I levels (multiple of upper limit of normal range (xULN); 0.45 (0.2-1.0)) at the end of the follow-up period. An additional 9 patients achieved normal levels with adjunctive drug therapy. Furthermore, disease activity was reduced in a considerable proportion of the 18 patients who did not achieve normal biochemical levels (GH: 3.6 microg/l (1.9-15.7 microg/l); xULN of IGF-I: 1.6 (0.9-2.6)). In retrospect, remission is unlikely in patients who had a GH level greater than 52 microg/l (mean+2 s.d. of cured patients) prior to radiotherapy. In addition to the 12 patients with pre-irradiation pituitary functional deficiency, another 11 patients developed symptoms of panhypopituitarism during the 3-year period following irradiation. Within a 6-year period, partial pituitary insufficiency was observed in a further 7 patients, thus necessitating hormone substitution treatment. CONCLUSION: Using strict rules of remission, in our cohort we found both a normalisation of IGF-I and safe GH levels in 34% of patients treated for acromegaly with conventional irradiation therapy.