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G M Besser

Publications and source records attributed to G M Besser.

At least 55 records · Page 3Linked to original sources
PubMed2001

Colonic transit influences deoxycholic acid kinetics.

BACKGROUND & AIMS: Prolonged large bowel transit, and an increase in the proportion of deoxycholic acid (DCA), have been implicated in the pathogenesis of cholesterol gallstones-including those developing in acromegalics treated with octreotide. However, there are few data on the effects of intestinal transit on bile acid kinetics. METHODS: We therefore measured the kinetics of DCA and cholic acid (CA) using stable isotopes, serum sampling, and mass spectrometry. The results were related to mouth-to-caecum (MCTT) and large bowel transit times (LBTTs) in 4 groups of 8 individuals: (1) non-acromegalic controls, (2) acromegalics untreated with octreotide, (3) acromegalics on long-term octreotide, and (4) patients with constipation. Paired, before and during octreotide, studies were performed in 5 acromegalics. RESULTS: In the unpaired and paired studies, octreotide significantly prolonged MCTT and LBTT. In the paired studies, the octreotide-induced prolongation of LBTT caused an increase in the DCA input rate (6.4 +/- 2.8 to 12 +/- 2.6 micromol. kg. d, P < 0.05) and pool size (18 +/- 12 to 40 +/- 13 micromol/kg, P < 0.05), and a decrease in CA pool size (45 +/- 15 to 25 +/- 11 micromol/kg, P < 0.05). Furthermore, during octreotide treatment, the mean conversion of 13C-CA to 13C-DCA (micromoles) was greater (P < 0.05) on study days 3, 4, and 5. There were also positive linear relationships between LBTT and DCA input rate (r = 0.78), pool size (r = 0.82, P < 0.001), and a weak (r = -0.49) negative linear relationship between LBTT and CA pool size (P < 0.01). CONCLUSIONS: These data support the hypothesis that, by increasing DCA formation and absorption, prolongation of large bowel transit is a pathogenic factor in the formation of octreotide-induced gallstones.

Acromegaly↗
PubMed2001

Effects of cisapride on gall bladder emptying, intestinal transit, and serum deoxycholate: a prospective, randomised, double blind, placebo controlled trial.

BACKGROUND: Octreotide inhibits gall bladder emptying and prolongs intestinal transit. This leads to increases in the proportion of deoxycholic acid in, and cholesterol saturation of, gall bladder bile, factors that contribute to the pathogenesis of octreotide induced gall stones. AIMS: To see if an intestinal prokinetic, cisapride, could overcome these adverse effects of octreotide and if so, be considered as a candidate prophylactic drug for preventing iatrogenic gall bladder stones. METHODS: A randomised, double blind, placebo controlled, crossover design was used to examine the effects of cisapride (10 mg four times daily) on gall bladder emptying, mouth to caecum and large bowel transit times, and the proportions of deoxycholic acid and other bile acids, in fasting serum from: (i) control subjects (n=6), (ii) acromegalic patients not treated with octreotide (n=6), (iii) acromegalics on long term octreotide (n=8), and (iv) patients with constipation (n=8). RESULTS: Cisapride had no prokinetic effect on the gall bladder. In fact, it significantly increased both fasting and postprandial gall bladder volumes. However, it shortened mouth to caecum (from 176 (13) to 113 (11) minutes; p<0.001) and large bowel (from 50 (3.0) to 31 (3.4) h; p<0.001) transit times. It also reduced the proportion of deoxycholic acid in serum from 26 (2.3) to 15 (1.8)% (p<0.001), with a reciprocal increase in the proportion of cholic acid from 40 (3.5) to 51 (3.8)% (p<0.01). There were significant linear relationships between large bowel transit time and the proportions of deoxycholic acid (r=0.81; p<0.001) and cholic acid (r=-0.53; p<0.001) in fasting serum. INTERPRETATION/SUMMARY: Cisapride failed to overcome the adverse effects of octreotide on gall bladder emptying but it countered octreotide induced prolongation of small and large bowel transit. Therefore, if changes in intestinal transit contribute to the development of octreotide induced gall bladder stones, enterokinetics such as cisapride may prevent their formation.

Acromegaly↗
PubMed2001

Cushing's disease in childhood: presentation, investigation, treatment and long-term outcome.

Seventeen patients with Cushing's disease (CD) were treated from 1978 to 2000. There were 11 males and 6 females aged 6.8-18.8 years (mean age 13.0 +/- 5.9 years). Presenting features were: weight gain (100%); growth failure (71%); hirsutism (53%); striae (53%); hypertension (47%). Mean age of patients with striae was 15.2 +/- 2.3 years, without striae 10.3 +/- 3.3 years. Median height SDS was -1.81 (range -0.28 to -4.17), 53% having height SDS < -1.8. The height velocity in 6 subjects was subnormal (0.9-3.8 cm/year). Median BMI SDS was 2.29 (range 1.72-5.06). Cushing's disease was confirmed by detectable serum ACTH, median 28 ng/l (range 12-99, NR <10-50) (n = 15); loss of cortisol circadian rhythm values at midnight ranging from 216 to 1,080 nmol/l (NR <50) (n = 15); lack of cortisol suppression (NV < 50 nmol/l) during low-dose dexamethasone suppression test (LDDST) (0.5 mg 6-hourly x 8) (n = 14); and >50% suppression of cortisol compared with the basal value during high-dose dexamethasone suppression test (HDDST) (2 mg 6-hourly x 8) (n = 14). A CRH test (1 microg/kg i.v.) showed an increase of cortisol from 12 to 217% (median 73.5%) (n = 16). Pituitary imaging (CT/MRI) showed an image consistent with microadenoma in 6/17 patients, but there was concordance between pituitary imaging and surgical findings in 1/11 patients (9%). Inferior petrosal sinus sampling (IPSS) for ACTH after CRH was performed in 11 subjects (age 10.7-18.8 years). Central to peripheral ACTH ratios were >2 (2.5-157.2) in 10/11 patients. The inter-petrosal sinus ACTH gradient was >1.4 in 10 patients (2.1-20.8), indicating lateralization of ACTH secretion. In 10 patients (91%), the side of the tumour on IPSS was predictive of findings at surgery. Therapy consisted of transsphenoidal microadenomectomy (TSS) in 16 patients and bilateral adrenalectomy (1978) in 1. Following TSS alone, 7 patients were cured (cortisol <50 nmol/l) and 2 were in remission (cortisol <300 nmol/l), i.e. 56%. Seven had persisting hypercortisolaemia and underwent pituitary irradiation (4,500 cGy). Therapeutic outcome for a median of 8 years (0.5-24 years) resulted in cure of CD in 14/17 patients (82%) and remission in 1. Linear growth after TSS +/- pituitary irradiation in 10 subjects showed no short-term catch-up growth, with peak growth hormone (GH) 0.5-20.9 mU/l to insulin tolerance test (ITT)/glucagon. Eight patients were treated with human growth hormone (hGH) (14 U/m(2)/week) combined in 3 with GnRH analogue. The mean final (n = 6) or latest (n = 4) height SDS was -1.36. The difference between final/latest height SDS and target height SDS was 0.93 +/- 1.13, i.e. less (p = 0.005) than the difference between height SDS and target height SDS at presentation, i.e. 1.72 +/- 1.26, indicating long-term catch-up growth.

Adolescent↗
PubMed2001

Hypothalamo-pituitary surveillance imaging in hypopituitary patients receiving long-term GH replacement therapy.

Most cases of adult-onset (AO) GH deficiency (GHD) result from the presence of hypothalamo-pituitary tumors or their treatment. GH replacement is now widely used in adults with hypopituitarism, but its effect on hypothalamo-pituitary tumor growth or recurrence is unknown. Anecdotal evidence from early experience of GH replacement in adults documented occasional tumor recurrence, but any relationship of this to the use of GH was unclear. We have now prospectively imaged the pituitary glands of 100 consecutive patients (60 females, 40 males; mean age, 46 yr; range, 18-69 yr) who had AO-GHD after appropriate treatment for a pituitary or peripituitary tumor. External radiotherapy had been given to 91 patients. All patients were treated with a dose titration regimen to maintain serum IGF-I between the median and upper end of the age-related reference range. Pituitary imaging was performed before the commencement of GH and after 6 and 12 months of treatment in all patients, again at 2 yr in 92 patients, at 3 yr in 63 patients, and after 4 yr in 23 patients. In only one patient was there evidence of slight intrasellar tissue enlargement at 6 months; GH replacement was continued, and there was no further change between 6 and 12 months. In all other patients, either the appearances were unchanged or the amount of tissue was reduced during long-term follow-up on GH. We have shown that hypothalamo-pituitary tumor recurrence was thus very rare over this time period in this group of GH-treated patients, and this is reassuring. Similar prospective longitudinal observation of patients who have not received postoperative irradiation and comparison with rates of tumor recurrence in control series are desirable.

Adenoma↗
PubMed2001

Relative contributions of inferior petrosal sinus sampling and pituitary imaging in the investigation of children and adolescents with ACTH-dependent Cushing's syndrome.

Selective transsphenoidal microadenomectomy is the first line treatment of childhood Cushing's disease, with accurate preoperative localization of the corticotroph adenoma an important step in its investigation. Inferior petrosal sinus sampling (IPSS) for ACTH after CRH stimulation is a recognized investigation in adults, but there are few data in the pediatric age range. We report the relative contributions of IPSS and pituitary imaging in 11 patients, aged 10.7-18.8 yr, presenting with Cushing's disease. All underwent transsphenoidal surgery (TSS). IPSS was performed without complication. Sampling was from the inferior petrosal sinuses in 7 patients and the high jugular veins in 4 (patients 2, 4, 5, and 10). The central to peripheral ACTH (IPS/P) ratios were more than 2 (2.5-157.2) in 10 of 11 patients, confirming central ACTH secretion. In 3 patients with high jugular sampling, IPS/P ratio ranged from 2.5-21.1. In the fourth patient with high jugular sampling (IPS/P ratio, 0.95), a central adenoma was identified surgically, and the patient was cured after TSS. The interpetrosal sinus ACTH gradient (IPSG) was more than 1.4 (2.1-20.8) in 10 patients, indicating lateralization of ACTH secretion to the right side in 6 patients and to the left in 4. IPSG ratios were 2.1-8.5 in 3 patients with high jugular sampling. Pituitary imaging (computed tomography and or magnetic resonance imaging) was reported to identify an adenoma in 5 of 11 patients. At operation a tumor was visualized by the same surgeon in all 11 cases. In 9 patients with lateralization on IPSS, the correct side of the tumor was confirmed at surgery. In a 10th patient with a negative IPSG, a central tumor was present. Thus, IPSS gave a 91% prediction of correct tumor localization. In only 1 of 5 patients with an adenoma reported on pituitary imaging was this localization confirmed at surgery, a prediction rate of only 9%. After TSS, 8 patients were cured, 1 was in remission, and 2 required pituitary irradiation. In 73% of patients undergoing IPSS, localization of the adenoma was followed by surgical cure or remission. Pituitary scanning was therefore relatively unhelpful in localizing the adenoma. In experienced hands, however, IPSS was feasible in this age group, safe, and strongly predictive of the site of the adenoma, leading to a high rate of successful surgical outcome.

Adenoma↗
PubMed2001

Comparison of somatostatin analog and meta-iodobenzylguanidine radionuclides in the diagnosis and localization of advanced neuroendocrine tumors.

A comparison has been made of [(123)I]meta-iodobenzylguanidine ([(123)I]MIBG) and [(111)In]pentetreotide scintigraphy in 54 patients with a variety of neuroendocrine tumors of whom 46 patients had metastatic disease. [(111)In]Pentetreotide scintigraphy was more sensitive in detecting metastatic lesions, as demonstrated on computed tomography and/or magnetic resonance scanning, than [(123)I]MIBG: 67% vs. 50% for carcinoid tumors (n = 24), 91% vs. 9% for pancreatic islet cell tumors (n = 12), 100% vs. 60% for medullary thyroid carcinomas (n = 5), and 75% vs. 100% for pheochromocytomas/paragangliomas (n = 4). In only 2 patients were lesions seen with [(123)I]MIBG scanning that were not apparent with [(111)In]pentetreotide. With the exception of pancreatic islet cell tumors, both radionuclides exhibited a similar sensitivity in detecting hepatic metastases, whereas in three patients the two radionuclides exerted a complementary role as different deposits exhibited uptake to only 1 or the other radionuclide. Hepatic metastases were the most important clinical predictor of a positive scan for both radionuclides. Neither elevated 5-hydroxyindoleacetic acid levels nor any other hormonal marker was predictive of a positive scan. In 8 patients with clinical and/or hormonal evidence of a neuroendocrine tumor but negative conventional radiology, [(111)In]pentetreotide scintigraphy was more sensitive than [(123)I]MIBG (37.5% vs. 12.5%) in detecting lesions. In conclusion, scintigraphy with [(111)In]pentetreotide detects more metastatic lesions than [(123)I]MIBG in patients with carcinoid and pancreatic islet cell tumors and medullary thyroid carcinomas; [(123)I]MIBG scintigraphy may be more sensitive for sympathoadrenomedullary tumors. The radionuclides may exert a complementary role in the detection and treatment of neuroendocrine tumors in occasional patients, as areas of different pattern of uptake were identified within the same patient. These data have implications not only for staging such tumors, but also for identifying patients who might benefit from treatment using either [(131)I]MIBG or radioactive somatostatin analogs.

3-Iodobenzylguanidine↗
PubMed2001

Predictors of the outcome of surgical treatment in acromegaly and the value of the mean growth hormone day curve in assessing postoperative disease activity.

Acromegaly is associated with increased morbidity and mortality unless serum GH levels are persistently less than 5 mU/L ( approximately 2 ng/mL) after treatment. Transsphenoidal surgical resection is the best available treatment for restoring GH to such "safe" levels; however, criteria for the assessment of the response to treatment are not uniform. To determine the clinically most useful method of assessing disease activity postoperatively and identify predictors of a favorable response to surgical treatment, we have analyzed 67 patients with acromegaly who underwent transsphenoidal surgery between 1993 and 1998. We used three different definitions of a satisfactory or safe response: 1) a postoperative mean GH less than 5 mU/L obtained from averaging five serum GH values obtained throughout one day; 2) a random single GH less than 5 mU/L; or 3) a serum insulin-like growth factor I (IGF-I) level within the normal range. Relying on a single GH measurement alone, 9 of the 23 patients with a single postoperative mean GH level less than 5 mU/L obtained at least one GH value of more than 5 mU/L (false positive rate, 28%) and 8 of the patients with a postoperative mean GH value of more than 5 mU/L obtained a single GH value of less than 5 mU/L (false negative rate, 15%). Postoperatively, a significant increase in the fluctuation of random GH values around the mean was observed in patients who were rendered safe (coefficient of variation, from 26 +/- 2% to 53 +/- 6%; P < 0.001) compared with patients with persistence of inadequately controlled disease. However, 13% (3 of 23) of patients with mean postoperative GH levels of less than 5 mU/L had elevated serum IGF-I levels postoperatively, and 17% (8 of 44) of patients with mean serum GH levels more than 5 mU/L had postoperative IGF-I levels within the normal range. There was no difference in the rate of agreement between mean GH less than 5 mU/L and normalization of IGF-I in relation to the interval since operation when IGF-I levels were measured. Preoperative tumor size and pretreatment mean GH levels were the major determinants of the outcome of surgery, as patients who were rendered safe had significantly lower preoperative mean GH levels than patients who were not cured (median, 31 mU/L vs. 78.5 mU/L, P < 0.01). IGF-I levels were weakly correlated with tumor size and could not be used to predict the patients who would be rendered safe. Preoperative PRL levels were higher in patients who failed to achieve a surgical satisfactory outcome [498 mU/L (187-857) vs. 196 mU/L (136-315), P < 0.01]. In summary, although single random GH values and IGF-I values are both significantly correlated with mean GH levels, they should not be used as an alternative to averaging several GH values to assess disease activity, because of the pulsatile nature of GH secretion and the multiple factors that may influence serum IGF-I. Because significant discrepancies occur, particularly postoperatively, mean GH levels remain the more reliable indicator of surgical outcome and disease activity. As there is considerably more evidence relating long-term prognosis to serum GH levels than to IGF-I and discrepancies occur between GH levels and IGF-I, we suggest that mean serum GH levels and single IGF-I levels, measured early in the postoperative period, are currently the best biochemical guide to the adequacy of surgery and, hence, the need for further treatment.

Acromegaly↗
PubMed2001

The relationship between steroidogenic factor 1 and DAX-1 expression and in vitro gonadotropin secretion in human pituitary adenomas.

The orphan nuclear receptors, steroidogenic factor 1 (SF-1) and DAX-1, are involved in gonadotroph differentiation, and SF-1 has been shown to activate the LH-beta and glycoprotein hormone alpha-subunit (alpha GSU) gene promoters. Pituitary adenomas from 34 patients [13 somatotroph tumors, 4 prolactinomas, and 17 clinically nonfunctioning pituitary adenomas (NFPAs)] were enzymatically dispersed and cultured in vitro for 48 h. Tissue culture medium was collected and assayed for LH, FSH, and alpha GSU; messenger RNA was extracted from adherent cells, and expression of SF-1 and DAX-1 messenger RNA was determined by RT-PCR and verified by direct DNA sequencing. The presence of DAX-1 protein in tumor tissue was confirmed by immunocytochemistry. DAX-1 was demonstrated in all NFPAs, 7 of 13 somatotroph tumors and 0 of 4 prolactinomas. SF-1 expression occurred in 8 of 16 NFPAs, 4 of 12 somatotroph tumors, and 1 of 4 prolactinomas. LH secretion in vitro was greater in NFPAs that were SF-1 positive (P < 0.05). Neither FSH secretion nor alpha GSU secretion in vitro were significantly related to the expression of SF-1 or DAX-1. SF-1-positive somatotroph tumors immunostained positively for LH-beta and/or FSH-beta and secreted gonadotropins in vitro. SF-1 expression is associated with the in vitro secretion of LH by NFPAs. A proportion of somatotroph tumors also express SF-1 and DAX-1 and secrete gonadotropin hormones in vitro.

Adenoma↗
PubMed2001

Modulation of cortisol metabolism by the growth hormone receptor antagonist pegvisomant in patients with acromegaly.

Pegvisomant is a GH receptor antagonist and highly efficacious new treatment for acromegaly. The two isoenzymes of 11beta-hydroxysteroid dehydrogenase are responsible for the interconversion of cortisol and its inactive metabolite cortisone. We demonstrated previously that the type I isoform, which is principally responsible for conversion of cortisone to cortisol, is partially inhibited by GH. The net activity of the enzyme can be measured by analysis of the urinary ratio of 11-hydroxy/11-oxo cortisol metabolites or of the urinary ratio of tetrahydrocortisol/tetrahydrocortisone [(tetrahydrocortisol + 5alpha-tetrahydrocortisol)/tetrahydrocortisone]. We studied the influence of pegvisomant on cortisol metabolism in patients with active acromegaly. Seven patients (four women and three men; median age, 58 yr; range, 39-72) were studied at baseline and again after a mean of 46 weeks of treatment. The mean insulin-like growth factor I (IGF-I) level at baseline fell from 939.7 +/- 271.1 to 346.9 +/- 379.0 ng/mL on 20 mg/day pegvisomant. The 11-hydroxy/11-oxo ratio increased from a pretreatment mean value of 0.61 +/- 0.18 to 0.88 +/- 0.20 (P < 0.02) and when the six patients in whom serum IGF-I normalized were considered separately, the change was from 0.62 +/- 0.19 to 0.90 +/- 0.21 (P < 0.04). The tetrahydrocortisols/tetrahydrocortisone ratio increased from a pretreatment mean value of 0.64 +/- 0.21 to 0.98 +/- 0.26 (P < 0.02) and in the six patients in whom serum IGF-I normalized, the ratio rose from 0.66 +/- 0.23 to 1.01 +/- 0.26 (P < 0.04). These data 1) indicate that blockade of GH action with pegvisomant in patients with acromegaly is associated with reversal of the inhibition of 11beta-hydroxysteroid dehydrogenase and correction of cortisol metabolism, and 2) suggest that in active acromegaly, cortisol clearance is accelerated and that this is reversed by successful treatment. This is further evidence of the efficacy of pegvisomant in the management of acromegaly and has important implications for determining optimum glucocorticoid replacement.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed2001

MRI of pancreatic neuroendocrine tumours.

Neuroendocrine tumours of the pancreas are rare and are frequently difficult to demonstrate. Several imaging modalities have been used to demonstrate these tumours, but recent reports have suggested that MRI may have an important role in their localization. We review the spectrum of MRI appearances of pancreatic neuroendocrine tumours.

Adenoma, Islet Cell↗
PubMed2001

Successful treatment of resistant acromegaly with a growth hormone receptor antagonist.

BACKGROUND/OBJECTIVE: Pegvisomant is a pegylated analogue of human GH and functions as a potent GH receptor antagonist. This novel mode of action gives it the potential to achieve biochemical control in patients with acromegaly whose disease activity cannot be satisfactorily controlled by conventional therapy. We have documented the clinical details of seven patients with residual active acromegaly after surgery and/or radiation therapy successfully treated with pegvisomant. PATIENTS/METHODS: Seven patients (four male, mean age 47 years, range 34-67 years) who participated in two separate clinical trials of pegvisomant have completed 2 years (four patients) or 1 year (three patients) of treatment. All had active acromegaly (mean serum GH level >5 mU/l; serum IGF-I elevated for age) that could not be controlled with standard medical therapy (dopamine agonist and/or a somatostatin analogue) following appropriate primary treatment with surgery and/or radiotherapy. RESULTS: On a median dose of 20 mg/day (range 15-40) pegvisomant, serum IGF-I fell from a mean of 920+/-351 ng/ml (s.d.) to 258+/-91 ng/ml and was normalised in all seven patients. These changes were associated with improvements in soft tissue enlargement and general well being. Treatment was well tolerated and no change in pituitary tumour size was evident on MRI scans performed every 6 months. CONCLUSIONS: Treatment with pegvisomant is safe and efficacy is maintained after 2 years. Serum IGF-I may be normalised in patients who are refractory to conventional therapy.

Acromegaly↗
PubMed2000

The pathology of median neuropathy in acromegaly.

BACKGROUND: Median neuropathy is commonly associated with acromegaly, although its pathology is uncertain. OBJECTIVE: To study the pathology of median neuropathy in acromegaly by using magnetic resonance imaging (MRI). DESIGN: Case series. SETTINGS: Outpatient clinic and MRI unit. PATIENTS: Nine patients with acromegaly, four of whom had clinical symptoms of neuropathy. MEASUREMENTS: At presentation and 6 months after treatment, median nerve size, its signal intensity, and the volume of the carpal tunnel contents were measured. RESULTS: At presentation, patients with symptoms of neuropathy had increased nerve size and signal intensity compared with asymptomatic patients, but the two groups did not differ in volume of carpal tunnel contents. These measures improved with treatment of acromegaly in symptomatic patients; asymptomatic patients experienced no change or worsening. CONCLUSION: The predominant pathology of median neuropathy in acromegaly seems to be increased edema of the median nerve within the carpal tunnel rather than extrinsic compression from increased volume of the carpal tunnel contents.

Acromegaly↗
PubMed2000

Treatment of acromegaly with the growth hormone-receptor antagonist pegvisomant.

BACKGROUND: Patients with acromegaly are currently treated with surgery, radiation therapy, and drugs to reduce hypersecretion of growth hormone, but the treatments may be ineffective and have adverse effects. Pegvisomant is a genetically engineered growth hormone-receptor antagonist that blocks the action of growth hormone. METHODS: We conducted a 12-week, randomized, double-blind study of three daily doses of pegvisomant (10 mg, 15 mg, and 20 mg) and placebo, given subcutaneously, in 112 patients with acromegaly. RESULTS: The mean (+/-SD) serum concentration of insulin-like growth factor I (IGF-I) decreased from base line by 4.0+/-16.8 percent in the placebo group, 26.7+/-27.9 percent in the group that received 10 mg of pegvisomant per day, 50.1+/-26.7 percent in the group that received 15 mg of pegvisomant per day, and 62.5+/-21.3 percent in the group that received 20 mg of pegvisomant per day (P<0.001 for the comparison of each pegvisomant group with placebo), and the concentrations became normal in 10 percent, 54 percent, 81 percent, and 89 percent of patients, respectively (P<0.001 for each comparison with placebo). Among patients treated with 15 mg or 20 mg of pegvisomant per day, there were significant decreases in ring size, soft-tissue swelling, the degree of excessive perspiration, and fatigue. The score fortotal symptoms and signs of acromegaly decreased significantly in all groups receiving pegvisomant (P< or =0.05). The incidence of adverse effects was similar in all groups. CONCLUSIONS: On the basis of these preliminary results, treatment of patients who have acromegaly with a growth hormone-receptor antagonist results in a reduction in serum IGF-I concentrations and in clinical improvement.

Acromegaly↗
PubMed2000

Sustained reduction in circulating cholesterol in adult hypopituitary patients given low dose titrated growth hormone replacement therapy: a two year study.

OBJECTIVE: To study the effects of short (6 months) and longer-term (up to 24 months) growth hormone (GH) replacement therapy using a dose titration regimen, on lipid and glucose metabolism in GH-deficient, hypopituitary adults. DESIGN: On-going open study of GH treatment up to 24 months. Measurements were performed at baseline and at 6, 12, 18 months and 2 years during therapy (data shown at 6 months and 2 years only). Using a dose titration regimen the median GH dose used to achieve and maintain IGF-I levels above the median, but below the upper limit of the age-related reference range (median IGF-I 202.5 microg/l, range 76-397 microg/l), was 1.2 IU daily (range 0.4-3 IU) [0.8 IU/day, males; 1.6 IU/day, females]. PATIENTS: Ninety GH-deficient hypopituitary adults (54 female, median age 48 years, range 19-79 years) entered the study and 24 (14 female, median age 45 years, range 32-79 years) have concluded the 2 year period of assessment. MEASUREMENTS: Body mass index (BMI), waist and hip circumference ratio (WHR), fasting lipids, glucose and glycated haemoglobin (HbA1c) levels were measured at 6 month intervals during GH therapy. RESULTS: Using the dose titration regimen, compared to pretreatment values, total and low density lipoprotein (LDL)-cholesterol levels were significantly lower at 6 months (mean +/- SEM, 5.61+/-0.1 vs. 5.25+/-0.1, and 3.85+/-0.19 vs. 3.43+/-0.26, respectively, P<0.05), and were maintained throughout the study. Male patients had significantly lower pretreatment total and LDL cholesterol levels than females (mean +/- SEM, 5.33+/-0.16 mmol/l vs. 5.7+/-0.12 mmol/l and 3.8+/-0.23 mmol/l vs. 3.92+/-0.29 mmol/l, respectively, P< 0.05). A decrease in total cholesterol was confined to patients with pretreatment total cholesterol levels above 5.8 mmol/l; patients with the highest pretreatment cholesterol levels (> 6.4 mmol/l) obtained the greatest cholesterol reduction (mean +/- SEM, 7.13 +/- 0.14 mmol/l vs. 5.76+/-0.31 mmol/l, P<0.05). A cholesterol-lowering effect of GH therapy was evident in patients who had elevated pre-GH total cholesterol levels even if they were already receiving and continuing lipid lowering medication (mean +/- SEM, 5.62+/-0.22 vs. 5.03+/-0.285, P<0.05). A modest increment in high density lipoprotein (HDL)-cholesterol was evident at 18 months but there was no significant change in triglycerides at any time point. Fasting plasma glucose increased significantly at 6 months but remained within the reference range. Glycated haemoglobin increased significantly at 6 months and was maintained throughout the study; one patient developed frank diabetes mellitus while receiving treatment. There was a weak but significant correlation between the increment in glycated haemoglobin and pretreatment BMI (r = + 0.215, P<0.05). CONCLUSION: The effect of GH on lowering total and low density lipoprotein-cholesterol is more prominent in patients with higher pretreatment cholesterol levels and is evident even in patients receiving other lipid-lowering medication. A modest increment in mean fasting glucose (within the reference range) and mean glycated haemoglobin persisted throughout the study. One patient developed diabetes mellitus. A GH replacement regimen using low dose and careful titration to avoid elevated IGF-I levels and adverse effects is associated with sustained beneficial effects on circulating lipids.

Adult↗
PubMed2000

How common are polycystic ovaries and the polycystic ovarian syndrome in women with Cushing's syndrome?

OBJECTIVE: Women with Cushing's syndrome (CS) may present with menstrual irregularity and symptoms/signs of hyperandrogenism, a phenotype similar to that of the polycystic ovarian syndrome (PCOS); however, currently there are no data on the prevalence of either polycystic ovaries (PCO) and/or PCOS in patients with CS. The aim of this study was to investigate their presence among women of reproductive age presenting with CS by analysing clinical, endocrinological and ultrasonographic features. DESIGN: Prospective study of all women within the reproductive age (range 18-40 years) who presented with CS between August 1994 and January 2000. SUBJECTS AND METHODS: Thirteen women (median age 32 years, range 18-39 years) with CS were evaluated. The diagnosis of CS was based on the presence of appropriate clinical features and an elevated serum midnight cortisol with failure to suppress 0900 hours serum cortisol to less than 50 nmol/l following a formal low-dose dexamethasone suppression test (LDDST). All women had their clinical features relevant to possible hyperandrogenism, menstrual disorder and infertility recorded, and circulating gonadotrophins, oestradiol, androgens and SHBG levels measured; ovarian ultrasonography was performed during their initial assessment. Relevant MR/CT imaging of the pituitary and/or adrenal glands was performed. RESULTS: Eleven women had ACTH-dependent CS [nine Cushing's disease (CD), one ectopic ACTH syndrome due to a bronchial carcinoid, one periodic CS of unknown origin); two patients had ACTH-independent CS (adrenal adenomas). All women with CS had at least one symptom/sign of hyperandrogenism (13 hirsutism, seven acne, five male-pattern alopecia). Nine women (70%) had menstrual disturbances (four oligomenorrhoea, four amenorrhoea, one polymenorrhoea) while four women (30%) had a normal menstrual pattern. Serum oestradiol levels for the group as a whole were similar to those observed in the early follicular phase of normally menstruating women; however, seven women had low oestradiol, LH and FSH levels suggestive of hypogonadotrophic hypogonadism. Serum androgen levels (testosterone, androstendione and DHEAS), even in the presence of symptoms/signs of hyperandrogenism, were within the normal reference range but SHBG levels were uniformly decreased even in women with normal menstrual cycles. There was a negative correlation between urinary free cortisol, but not mean serum cortisol, and serum oestradiol, testosterone and SHBG levels (r = - 0.8, r = - 0.86 and r = - 0.66, P<0.02, P<0.01 and P<0.05, respectively), but not LH or FSH levels. Despite the fact that seven of these 13 patients lacked normal gonadotrophin stimulation, ovarian volumes of both ovaries were relatively preserved: right 7.3 ml, range 2.8-12.8 ml, and left 5.3 ml, range 2.3-13 ml. Women who were defined as oestrogen sufficient (E2 > 140 pmol/l) had higher serum androstenedione, and lower urinary free cortisol levels, than women who were oestrogen deficient (E2 < 140 pmol/l). Six of the 13 women (46%) had ovarian morphology suggestive of PCO, four of six oestrogen sufficient women and two of seven oestrogen deficient women. The results did not differ according to the underlying cause of CS. CONCLUSIONS: PCO and PCOS are common in women with Cushing's syndrome; women with Cushing's syndrome and only moderately elevated cortisol secretion maintain gonadotrophin stimulation to the ovary with normal oestradiol levels, in contrast to women with Cushing's syndrome and higher cortisol secretion who develop hypogonadotrophic hypogonadism. However, even in the latter group, high ovarian volumes were maintained and some had ovarian morphology suggestive of PCO.

Adult↗
PubMed2000

Optimal dosage interval for depot somatostatin analogue therapy in acromegaly requires individual titration.

BACKGROUND: The recent introduction of the depot somatostatin analogues octreotide LAR and lanreotide represent major advances in the medical treatment of acromegaly. However, it is uncertain whether the recommended dose intervals of 4 weeks and 10-14 days, respectively, are applicable to all patients. AIMS: To determine the optimum intervals between depot injections of either octreotide LAR and lanreotide for the suppression of serum GH and IGF-I in patients with acromegaly. Twenty-seven patients with acromegaly were randomly allocated to receive either three injections at 4 week intervals of octreotide LAR (n = 18) or five injections at 14 day intervals of lanreotide (n = 11); two patients participated in both arms. Prior to the first injection, at 4 and 6 weeks after the last injection of LAR, and at 10, 14 and 21 days after the last injection of lanreotide, serum mean GH and IGF-I levels were measured. RESULTS: In the LAR-treated group, at 4 and 6 weeks after the third injection 13 patients (72%) and 12 patients (67%), respectively, had a mean GH < 5 mU/l. IGF-I was normalized in 12 and 11 patients at these times. In the lanreotide-treated group, five (45%), four (36%) and three (27%) patients, respectively, had a GH < 5 mU/l at 10, 14 and 21 days after the last injection and eight, six and five patients had a normal serum IGF-I. CONCLUSION: There is marked variability in individual patient responses to depot somatostatin analogues. The establishment of optimal drug intervals requires careful assessment. For octreotide LAR many patients may be as adequately controlled with 6 weekly injections as with 4 weekly injections. It is important to measure serum GH profiles at intervals after initiating therapy with these drugs to individualize doses for each patient and hence minimize cost.

Acromegaly↗
PubMed2000

'Gangliocytomas' of the pituitary: a heterogeneous group of lesions with differing histogenesis.

Hamartomatous or neoplastic ganglion cells in the sella turcica are an unusual cause of symptoms. They have been reported in association with a functioning or nonfunctioning pituitary adenoma, with pituitary cell hyperplasia, and occasionally as masses unassociated with an adenoma, again with variable endocrinologic findings. Fewer than 50 cases of intrasellar ganglion cell lesions have been reported in the literature, only six of them associated with Cushing's syndrome. We describe the clinicopathologic features of another eight patients, three of whom presented with acromegaly, four with apparently nonfunctioning adenohypophyseal masses, and one with Cushing's syndrome. On histology, six of them were found to have sparsely granulated growth hormone (GH)-producing adenomas with ganglion cell areas, one appeared to have a gangliocytoma not associated with an adenoma, whereas the eighth had a ganglion cell lesion in the posterior pituitary. The morphologic and immunohistochemical findings suggest that the ganglion cell component of seven of these tumors has resulted from neuronal differentiation in a GH-producing adenoma, despite the lack of demonstrable adenoma in one case. A true sellar "gangliocytoma" or hamartoma of ectopic hypothalamic-type neurons appears to be a rarer explanation for the presence of ganglion cells in a pituitary biopsy.

Acromegaly↗