Ten-year follow-up results of transsphenoidal microsurgery in acromegaly

Fifty-nine acromegalic patients, transsphenoidally operated by a single neurosurgeon (H.v.D.) were followed for at least 10 yr to assess the late outcome of surgery. Mean follow-up was 16 +/- 0.4 yr (range, 10-22). Criteria for remission were a serum GH concentration below 2.5 microg/L, a normal glucose-suppressed GH (oral glucose tolerance test), and a normal serum insulin-like growth factor I (IGF-I) concentration. Mean serum GH concentration decreased from 59 +/- 8.7 microg/L to 5.6 +/- 1.4 microg/L after surgery. Early postoperative remission rates were 61% (GH, <2.5 microg/L), 67% (suppressed GH), and 60% (both GH <2.5 microg/L and suppressed GH). Early postoperative remission was significantly related to preoperative serum GH concentration (P: = 0.023), but not to tumor size. Of 36 patients with postoperative remission (GH, <2.5 microg/L), 9 patients received (prophylactic) radiotherapy for persistent paradoxical reaction to TRH or probable invasive tumor growth. All nine patients are in remission at the end of follow-up. Of the other 27 patients with postoperative remission, 5 (19%) developed recurrence, becoming evident within 5 yr in 4 patients and after 10 yr in 1 patient. Of these 27 patients, surgical remission rates at the end of follow-up are 78% (random GH, <2.5 microg/L), 73% (normal glucose-suppressed GH), 74% (normal IGF-I), and 65% (normal IGF-I and GH suppression). Of the patients with postoperative persistent disease, 18 patients were irradiated and 5 patients were followed without further treatment. Two of five nontreated patients had spontaneous normalization of GH concentration at the 6 months visit and remained in remission by surgery only. The long-term efficacy of multimodality treatment was evaluated after exclusion of the prophylactically irradiated patients. At the end of follow-up, 48% of patients had not required adjuvant therapy and the rest received radiotherapy (34%), octreotide (10%), or both (8%). Remission rates of multimodality therapy were 96% (serum GH, <2.5 microg/L) and 94% (normal serum IGF-I concentration). Remission rates of transsphenoidal surgery alone were 46% (serum GH, <2.5 microg/L), 44% (normal IGF-I concentration), 41% (suppressed serum GH), and 37% (normal serum IGF-I and suppressed GH). In this first report on separate 10 or more years results of transsphenoidal surgery for acromegaly, using strict criteria for remission, 19% of patients with postoperative remission developed recurrence. Nevertheless, about 40% of patients remain in remission after only surgical intervention, even after a mean follow-up of 16 yr.     

Hormonal and metabolic effects of radiotherapy in acromegaly: long-term results in 128 patients followed in a single center

Conventional radiotherapy is usually indicated in acromegaly when surgery fails to normalize GH secretion. However, the benefits of radiotherapy are delayed. This has raised questions about the potency of this treatment for reaching the safe GH level of 2.5 microg/L and for normalizing insulin-like growth factor I (IGF-I) levels, both of which are currently recommended as the therapeutic goal. To evaluate the long-term hormonal and metabolic effects of radiotherapy in acromegaly, a retrospective analysis was undertaken studying 128 patients followed for 11.5+/-8.5 yr (mean +/- SD) in a single center. The preradiation GH levels decreased as a function of time to 50% at 2 yr, 20% at 5 yr, and 10% at 10 yr. Basal GH levels below 2.5 microg/L were obtained in 7% of the patients at 2 yr, 35% at 5 yr, 53% at 10 yr, and 66% at 15 yr. A basal GH level below 2.5 microg/L was associated with suppression of GH below 2 microg/L during an oral glucose tolerance test and normalization of IGF-I levels in 9 of 10 patients. Preradiation GH levels was the sole factor that could predict the delay in GH fall to below 2.5 microg/L (P = 0.008). At the last follow-up, IGF-I levels were normalized in 79% of the patients (37 of 47; mean follow-up, 15.0+/-11.3 yr). In the 32 patients presenting with diabetes mellitus, improvement of glucose tolerance was associated with lower GH levels after treatment (35+/-78 microg/L in the group of 13 patients still presenting diabetes; 9+/-12 microg/L in the group of 4 patients with glucose intolerance; 5+/-8 microg/L in the 14 patients with normal glucose tolerance; P = 0.04). Ten years after termination of radiotherapy gonadotroph, thyreotroph and corticotroph deficiencies were observed in 80%, 78%, and 82% of the patients, respectively. In conclusion, conventional radiotherapy can reduce GH levels below the optimal level of 2.5 microg/L and normalize IGF-I levels in acromegaly. However, the incidence of late hypopituitarism is high, and the delay to obtain this safe GH secretory status can be long, depending on the preradiation GH level. These parameters should be considered when adjuvant therapy is needed after surgery.     

Postoperative persistent thyrotrophin releasing hormone-induced growth hormone release predicts recurrence in patients with acromegaly

OBJECTIVE: To assess the predictive value of postoperative thyrotrophin releasing hormone (TRH)-induced GH responsiveness in relation to (late) postoperative outcome in patients in remission after surgery for acromegaly. PATIENTS: and methods One hundred and twenty-nine patients underwent surgery for acromegaly in our institution between 1977 and 1996. TRH tests and oral glucose tolerance tests (GTT) were performed and serum IGF-I concentrations were measured pre- and postoperatively and during follow-up. Criteria for postoperative remission were a mean serum GH concentration < 5 mU/l and/or serum GH after an oral glucose tolerance test < 1 mU/l immunofluorometric assay (IFMA) or < 2.5 mU/l (radioimmunosassay), together with a normal serum IGF-I concentration. RESULTS: Preoperatively, the TRH-induced GH response was highly variable, with gradual overlap between 'nonresponders' and 'responders'. Arbitrarily defined as a doubling of serum GH concentration, 45.6% of patients were 'responders' to TRH. GH response after TRH injection was significantly correlated to the TRH-induced prolactin response but not to preoperative GH concentration or adenoma size. After surgery, remission was achieved in 83 of the 129 patients. Postoperative remission was significantly correlated to mean preoperative serum GH concentration and preoperative glucose-suppressed serum GH but not to tumour class. Seventy-one patients with early postoperative remission were followed without adjuvant treatment for a mean of 9.4 +/- 0.7 years (range 0-23 years). Forty-one of these patients were TRH responsive as defined by at least doubling of the serum GH concentration preoperatively. Of the 71 patients, 12 developed recurrence of disease, as defined by insufficient GH suppression during oral GTT, and elevated IGF-I and mean serum GH concentration. Irrespective of the preoperative response to TRH, the initial postoperative TRH test was predictive of developing disease recurrence with a sensitivity of 75% and a specificity of 100% when an absolute GH increase of 3.75 mU/l was chosen to define paradoxical responsiveness. A stimulated GH 1.6 times basal was predictive of recurrence with a sensitivity of 83% and a specificity of 73%, and 2.1 times basal was predictive with a sensitivity of 75% and a specificity of 80%. None of the 32 patients with postoperative normalization of the preoperatively present TRH-induced GH response, defined as a postoperative GH increase < 3.75 mU/l, developed recurrence of disease, while all nine patients with a GH increase above this level developed recurrence of acromegaly. CONCLUSION: To our knowledge this is the first report which addresses the value of early postoperative TRH-induced GH responsiveness in predicting late surgical outcome using receiver-operating characteristic (ROC) curves to redefine a postoperative paradoxical response instead of arbitrarily chosen criteria. An absolute postoperative GH response of more than 3.75 mU/l was associated with recurrence in all nine patients, while all 32 patients with normalization of previously paradoxical response are still in remission. Our findings from this study demonstrate that the TRH test is a valuable tool in the early identification of patients at risk of developing postoperative recurrence of acromegaly.     

Lanreotide 60 mg, a new long-acting formulation: effectiveness in the chronic treatment of acromegaly

Lanreotide (LAN) 60 mg (LAN60), a new long-acting formulation of LAN alleged to suppress GH/IGF-I hypersecretion for 28 d in acromegalic patients, was administered in a prospective open multicenter study to 92 patients with active acromegaly (61 women and 31 men, aged 20-79 yr). LAN60 was given as adjuvant treatment (AT) in 62 patients; the other 30 patients [primary treatment (PT)] were de novo (n = 20) or previously treated only by pharmacotherapy (n = 10). After wash-out from previous treatments, LAN60 was started im every 28 d for 3 injections; the dose was then individually tailored, aiming at lowering GH to less than 2.5 micro g/liter and IGF-I to the normal range. After a median follow-up of 24 months (range, 6-48 months), IGF-I normalized in 65% of patients, decreasing from 199 +/- 8% (expressed as a percentage of the upper limit of normal range; mean +/- SE) to 87 +/- 4% (P < 0.0001). GH fell to less than 2.5 microg/liter in 63% of patients and to less than 1 microg/liter in 25%, decreasing from 20 +/- 3 to 3 +/- 0.4 microg/liter (P < 0.0001). A progressive increase in the rate of IGF-I normalization was observed (from 49% at 1 yr to 77% at 3 yr). The rate of GH/IGF-I normalization was 72% at 36 months by Kaplan-Meier analysis. No tachyphylaxis was observed throughout the study. Shortening the interval between injections to 21 d improved GH/IGF-I suppression. PT and AT patients achieved similar final GH/IGF-I levels and rates of normalization. Tumor shrank in 39% of assessable patients and in 50% of PT. Plasma glucose levels did not change, and high density lipoprotein cholesterol increased (by 19.3 +/- 5.1%; P = 0.0215). Gallstones appeared or worsened in 13% of patients. LAN60 is a new, very effective and long-lasting formulation for the treatment of acromegaly. The persistence of a powerful suppression of GH/IGF-I levels, the progressive increase in the rate of IGF-I normalization, and the similarity in the efficacy achieved in PT and AT patients point to a role for LAN60 in the primary treatment of acromegaly.     

Significance of "abnormal" nadir growth hormone levels after oral glucose in postoperative patients with acromegaly in remission with normal insulin-like growth factor-I levels

Our initial study in postoperative patients with acromegaly identified a group of patients in remission, as defined by normal IGF-I levels, but who had a subtle abnormality of GH suppression after oral glucose. To investigate the significance of this abnormality, we have undertaken further detailed testing of GH secretion and a longitudinal follow-up of some of these patients. Of the 110 postoperative patients with acromegaly evaluated by oral glucose tolerance test, 76 were in remission (i.e. normal IGF-I level), and of these subjects with acromegaly in remission, 50 had normal nadir GH (<0.14 microg/ml) (group I), and 26 had abnormal nadir GH (>0.14 microg/ml) (group II). Fourteen subjects in remission, seven from remission group I and seven from remission group II, underwent additional testing consisting of both hourly GH sampling over 8 h and, on a separate day, arginine stimulation testing. The mean of hourly GH was higher in group II (0.47 +/- 0.04 microg/liter) than in group I (0.19 +/- 0.07 microg/liter; P = 0.002). GH response to arginine was greater in group II than in group I (P < 0.01). Of those patients in remission from the initial cohort studied, 49 (30 subjects from group I and 19 from group II) underwent serial longitudinal oral glucose tolerance testing every 1-2 yr over a 1- to 6.5-yr period (mean follow-up, 3.2 yr). The initial pattern of GH suppression persisted in most patients. IGF-I levels remained normal in all patients in group II, but five subjects from group II developed an elevated IGF-I level and, thus, a biochemical recurrence. The rate of disease recurrence was greater in group II than in group I (P = 0.003). We have found that some postoperative subjects with acromegaly in remission with normal IGF-I levels have persistently abnormal nadir GH levels after oral glucose that may be accompanied by other evidence of greater GH secretion than postoperative patients with normal GH suppression. This abnormal pattern of GH suppression may be associated with increased risk of disease recurrence in some patients.     

Postoperative radiotherapy in acromegaly is effective in reducing GH concentration to safe levels

OBJECTIVE: Several studies have established that in treated acromegaly mortality is only normalized in patients achieving a serum GH concentration below 5 mU/l. Few studies however, have addressed results of radiotherapy using this strict criterion. The aim of our study was to assess the efficacy of postoperative radiotherapy in reducing serum GH concentration below 5 mU/l. PATIENTS AND METHODS: Forty acromegalic patients who underwent radiotherapy for postoperative persistent disease after transsphenoidal surgery were studied. Mean time of follow-up after radiotherapy was 123+/-11.1 months. A serum GH concentration of <5 mU/l was used to define remission. RESULTS: Following surgery mean GH concentration decreased from 120.8+/-21 mU/l to 24.4+/-5.2 mU/l and mean GH concentration prior to radiotherapy, administered after a mean of 8.2+/-2.7 (0.5-96) months postoperatively was 26.0+/-5.1 mU/l. Using individual regression plots, GH was reduced to 50% by radiotherapy after a mean of 27+/-5 months (range 3-105 months). The observed mean GH concentration as measured at follow-up visits was reduced by 55% (-36-95%) after the first year, by 65% (-29-97.3%) after 2 years and by 78% (-29-99%) after 5 years. We could not demonstrate a significant correlation between a normalized GH concentration on the one hand and tumour size, preradiotherapy GH concentration or duration of follow-up on the other hand. During follow-up, GH-suppressive medical therapy was used in 11 patients, five of whom were still using medication at the end of follow-up. Eight patients had a follow-up of less than 5 years and three of them had a serum GH concentration of <5 mU/l at their latest follow-up visit (38%). At 5 years of follow-up after radiotherapy, 24 out of 32 patients had a GH level of <5 mU/l without medication (75%). At 10 years following irradiation, 16 of 21 patients (76%) had a GH level of <5 mU/l without medical treatment. At 15 years follow-up, a serum GH concentration of <5 mU/l was observed in 13 out of 15 patients (87%) without GH suppressive medication. At the latest follow-up visit, serum GH concentration below 5 mU/l was present in 75% of patients (30 out of 40) without medical therapy after a mean of 10.4+/-0.9 years, but five patients required octreotide up to the end of follow-up. Twenty-seven out of 37 patients with available IGF-I data had normal IGF-I at the end of follow-up (73%). Fifty percent of patients needed substitution therapy for (partial) hypopituitarism after 10 years and 75% after 15 years of radiotherapy. CONCLUSION: In our group of patients who were incompletely cured by surgery, but had a significant postoperative decrease of serum GH concentrations, radiotherapy was able to achieve 'safe' serum GH concentrations in the majority in the long term.     

Quality of life in treated patients with acromegaly

CONTEXT: It is not known to what extent quality of life of patients treated for acromegaly is dependent on levels of GH and IGF-I attained. OBJECTIVE: The objective of this study is to examine the health-related quality of life (HRQoL) and its dependence on treatment outcome and modality in a nationwide survey of acromegalic patients. DESIGN, SETTING, AND PATIENTS: All eligible patients with acromegaly, diagnosed from January 1980 through December 1999 in Finland, were invited to a follow-up study, carried out 11.4 +/- 5.7 (mean +/- sd) yr after initial treatment. HRQoL of the patients, measured by the generic 15D instrument, was compared with that of the general population. Factors related to HRQoL were analyzed by logistic regression. MAIN OUTCOME MEASURE: HRQoL was the main outcome measure. RESULTS: Of 277 eligible patients, 231 (83.4%) participated in the follow-up study. Of them, 51.1% were in remission according to consensus criteria. The patients reported reduced HRQoL in comparison to the age- and gender-standardized general population (P < 0.001). HRQoL was related to nadir GH in oral glucose tolerance test (GHOGTT) in an inverted U-shaped fashion (overall P = 0.021). Patients with GHOGTT nadir values between 0.3-1.0 microg/liter had a better HRQoL than those with lower or higher values. A normal IGF-I (P = 0.038) and not having had radiotherapy (P = 0.004) were also associated with a better HRQoL. CONCLUSIONS: HRQoL is reduced in treated patients with acromegaly. The best HRQoL may be achieved by normalization of IGF-I and by targeting the GHOGTT nadir to levels between 0.3 and 1.0 microg/liter. Radiotherapy is associated with adverse HRQoL.     

Outcome of radiotherapy for acromegaly using normalization of insulin-like growth factor I to define cure

Radiation therapy (RT) has traditionally been considered a useful additional therapy for patients with acromegaly not achieving biochemical remission after surgery. However, recent evidence has suggested that RT is not curative in most patients with acromegaly when normalization of the serum insulin-like growth factor I (IGF-I) level is used to define remission. Therefore, we evaluated the success of RT based on IGF-I level in the 47 patients who received RT as part of their treatment from the cohort of 161 patients with acromegaly seen by us between 1981 and 1999. Four patients in whom no post-RT IGF-I level was available were excluded from the analysis. Of the remaining 43 patients, 32 patients received external beam RT, 6 received fractionated stereotactic radiosurgery, 4 received gamma-knife RT, and 1 received proton beam RT. The most recent IGF-I levels in these 43 patients, obtained a mean of 5.2 yr post-RT (range, 0.8-13.2 yr), were compared to age-adjusted normal ranges. IGF-I levels were normal in 17 patients (39.5%) without the addition of medical therapy. The percentage of patients with a normal IGF-I level generally increased with time post-RT; 27% of patients less than 6 yr post-RT, but 69.2% of patients 6 yr or more post-RT had normal IGF-I levels. Using the more traditional criterion for cure, a random GH measurement, 74% of patients had a GH level below 5 ng/mL, and 44% had a GH level below 2.5 ng/mL and would have been considered in remission based on these criteria. We conclude that with time RT remains a useful adjunctive treatment for many patients with acromegaly. RT should be considered along with appropriate medical therapy in selected patients who do not achieve normalization of IGF-I level after surgery or for those resistant to medical therapy.     

Outcome of gamma knife radiosurgery in 82 patients with acromegaly: correlation with initial hypersecretion

CONTEXT: Because surgical and medical therapies of acromegaly all have specific limitations, radiotherapy has been used as an adjunctive strategy. Stereotactic radiosurgery has not yet been widely evaluated. OBJECTIVE: The objective was to perform an analysis of long-term hormonal effects and tolerance of gamma knife radiosurgery. DESIGN: Eighty-two patients were prospectively studied over a decade, with a mean follow-up of 49.5 months. SETTING: All patients were treated at the Department of Functional Neurosurgery of Marseille, France. PATIENTS: The patients included 82 with active acromegaly, of whom 63 had previous transsphenoidal surgery. INTERVENTION: Intervention included radiosurgery using the Leksell Gamma Unit B model. MAIN OUTCOME MEASURES: Remission was diagnosed when mean GH levels were less than 2 ng/ml and IGF-I was normal for age off somatostatin agonists (at least 3 months). RESULTS: Seventeen percent of the patients were in remission without any treatment. Twenty-three percent previously uncontrolled on somatostatin agonists fulfilled the same criteria after gamma knife while maintained on medical treatment. Initial GH and IGF-I levels off somatostatin agonists were significantly higher in uncured than in remission group (P = 0.01 and 0.047, respectively). Withdrawal of somatostatin agonists at the time of radiosurgery had no incidence on the outcome. No significant difference was found in success rate whether patients had previously been treated or not. Long-term side effects included complete (n = 2) or partial (n = 12) hypopituitarism diagnosed 1-7 yr after gamma knife. CONCLUSIONS: Gamma knife radiosurgery may represent a therapeutic approach in patients with moderate initial or residual GH hypersecretion.     

Long-term biochemical status and disease-related morbidity in 53 postoperative patients with acromegaly

Assessment of postoperative disease activity of acromegaly is a major challenge. The consensus criteria for cure, which are glucose-suppressed GH less than 1 micro g/liter and normal IGF-I levels, might be discrepant, and their respective relationship to acromegaly-related morbidity is not well known. The aims of our study were: firstly, to correlate plasma IGF-I with plasma glucose-suppressed GH concentrations; and secondly, to correlate each of these biochemical parameters with morbidity [impaired glucose tolerance (IGT), diabetes, and hypertension] in postoperative patients with acromegaly. Fifty-three patients with long-term follow-up (mean, 12.7 yr; range, 1-30 yr) after transsphenoidal surgery for acromegaly and 20 healthy subjects matched for age, sex, and body mass index were evaluated for plasma glucose [by 75-g oral glucose tolerance test (OGTT)], GH (by immunoradiometric assay), plasma IGF-I (by immunoradiometric assay), and blood pressure (BP) measurements. Remission was defined by a normal IGF-I. We identified 34 acromegalics in remission and 19 with active disease. There was no statistical difference between all three groups for age, sex, BMI, and for fasting and 2-h post-OGTT plasma glucose. The time elapsed since surgery was similar in both groups of acromegalics. The OGTT-GH nadir was less than 1 micro g/liter in 31 patients in remission (91.2%) and in nine patients with active disease (47.4%). Prevalence of IGT was lower in acromegalics in remission (14.7%) in comparison with patients with active disease (47.4%; P = 0.01). Plasma IGF-I and GH nadir cut-off of 0.25 microg/liter were strong predictors of abnormal glucose tolerance (odds ratio, 13.6; confidence interval, 2.5-73.7; P = 0.003). GH nadir cut-off of 1 microg/liter and basal GH of 2.5 microg/liter failed to predict abnormal glucose tolerance. There was no statistical difference for prevalence of hypertension and systolic BP values, but diastolic BP was significantly lower in patients in remission than in those with active disease (P < 0.05). Our observations indicate that the validity of the GH threshold of 1 microg/liter post OGTT might be inadequate as a criterion of biochemical remission of acromegaly and as a marker of associated comorbidities. However, normalized IGF-I concentrations and a lower GH cut-off value less than 0.25 micro g/liter are strongly associated with a lower prevalence of IGT and lower diastolic BP in long-term postoperative acromegaly.     

A nationwide survey of mortality in acromegaly

CONTEXT: Increased mortality in acromegaly has been confined to those with posttreatment basal GH of 2.5 microg/liter or greater, but the impact of IGF-I and pituitary radiotherapy on mortality has remained controversial. OBJECTIVE: The purpose of this nationwide survey was to examine the all-cause mortality of patients with acromegaly and evaluate the impact of treatment outcome and mode of treatment on survival. DESIGN, SETTING, AND PATIENTS: All-cause mortality of all patients with acromegaly diagnosed during January 1980 and December 1999 in the five university hospitals of Finland was followed up by the end of 2002 (12.5 +/- 5.6 yr) and compared with that of the general population by using age- and gender-adjusted standardized mortality ratios (SMRs). Logistic regression analysis was used to investigate factors related to mortality within the survey population. MAIN OUTCOME MEASURE: Mortality was the main outcome measure. RESULTS: Of the 334 patients, 56 (16.8%) had died during follow-up. SMR of the patients was 1.16 [confidence interval (CI) 0.85-1.54, not significant (NS)]. However, patients with basal serum GH concentration 2.5 microg/liter or greater (SMR 1.63, CI 1.10-2.35, P < 0.001) measured 5.2 +/- 4.4 yr after the initial treatment, and those irradiated (SMR 1.69, CI 1.05-2.58, P < 0.001) showed excess mortality. In a multivariate model, the effect of radiotherapy was of borderline significance only (P = 0.083). Posttreatment IGF-I levels, available for 72.2% of the patients, did not have impact on mortality. CONCLUSIONS: The posttreatment basal GH concentration less than 2.5 microg/liter in acromegalic patients is associated with a normal lifespan. Excess mortality is confined to poorly controlled patients and possibly those who have received conventional radiotherapy.     

Treatment of acromegaly: is there still a place for radiotherapy?

Objective To evaluate efficacy and safety of radiotherapy on acromegaly treatment. Design and patients We followed retrospectively 99 acromegalic patients for at least one year after radiotherapy (RT). RT had been performed after unsuccessful surgery in 91 patients and as primary treatment in eight. Time elapsed between surgery and RT was 1.4 ± 2.4 years. Mean follow-up after RT was 5.9 ± 4.7 years (1–16 years). All patients were treated with linear accelerator, 89 by conventional (3240–6000 cGY) and ten by stereotactic RT. Measurements Biochemical remission was defined as GH < 2.5 ng/ml and IGF-I normalization. Results At latest follow-up, 54% of patients had serum GH level <2.5 ng/ml; 42% had normal IGF-I and 38% of patients achieved normalization of both. Controlled patients had lower baseline GH and IGF-I levels compared to uncontrolled ones. They achieved remission after 3.8 ± 2.4 years, a significantly lower time length compared to maximum follow-up of uncontrolled (6.0 ± 4.9 year). Results regarding GH and IGF-I levels were similar in patients treated either primarily or after surgery. No patient showed tumor growth. Visual field defects were observed in four, seizures in one, and mental disorders in two patients, although cognitive function were not properly assessed. At the last follow-up, 47% of patients had acquired at least one hormonal deficiency. Conclusions There is still a place for RT in acromegaly treatment, mainly for: after non-curative surgery and poor response or inaccessibility to medical treatment; growth restraining of aggressive macroadenomas; co-morbidities that contraindicate surgery and surgery refusal. However, side effects and latency period to achieve disease control should be kept in mind.     

Relationship between disease-related morbidity and biochemical markers of activity in patients with acromegaly

The criteria for biochemical control of acromegaly that will best reduce disease-related morbidity in acromegaly are debated. We therefore studied the relationship of biochemical markers with an important metabolic parameter, insulin sensitivity, and clinical parameters reflecting disease activity in acromegaly. Newly diagnosed and postoperative patients with acromegaly underwent assessment of fasting IGF-I and fasting and postoral glucose tolerance test GH and insulin levels and completed a numeric signs and symptoms questionnaire. Insulin sensitivity was estimated by the quantitative insulin sensitivity check index (QUICKI) and the composite insulin sensitivity index. Patients were divided into three groups: group I, normal IGF-I and nadir GH less than 0.14 mug/liter (n = 21); group II, normal IGF-I and nadir GH 0.14 mug/liter or more (n = 20); group III (active), elevated IGF-I (n = 25). Age, sex, and body mass index were comparable in these groups. Insulin sensitivity was reduced in group III (QUICKI: 0.33 +/- 0.01 and composite index: 3.44 +/- 0.54), compared with group II (0.38 +/- 0.01, P = 0.002 and 8.18 +/- 1.21, P = 0.0008), group I (0.38 +/- 0.01, P = 0.0008 and 8.91 +/- 1.34, P = 0.00001), and healthy controls (0.37 +/- 0.008, P = 0.009). When other nadir GH cut-offs were analyzed, insulin sensitivity remained relatively reduced in the elevated IGF-I group. IGF-I was a significant predictor for decreasing insulin sensitivity as calculated by QUICKI (r = 0.6, P < 0.0001) independently of nadir GH. Signs and symptom scores were higher in group III (mean 38.5 +/- 3.6%), compared with group II (mean 23.5 +/- 3.2%, P = 0.004) and group I (mean 20.5 +/- 3.7%, P = 0.0008) but not between the latter two groups. Our data indicate that overall and specifically in the presence of discordant serum IGF-I and nadir GH levels, IGF-I was more predictive than GH levels of insulin sensitivity and clinical symptom score in patients with acromegaly.     

Determinants of survival in treated acromegaly in a single center: predictive value of serial insulin-like growth factor I measurements

We evaluated survival after optimal treatment for acromegaly and assessed the predictive effects of different remission criteria for survival in 164 consecutive acromegalic patients, treated by transsphenoidal surgery and adjuvant therapy between 1977 and 2002. The goal of treatment was a mean GH less than 5 mU/liter, a normal glucose-suppressed GH, and a normal IGF-I for age in all patients. Surgery initially cured 108 patients (66%). Adjuvant therapy for persistent disease was given to 49 patients. At the end of follow-up (mean, 12.3 yr), remission rates for surgery and multimodality treatment were 54% and 90%, respectively. In 2033 person-years of follow-up, 28 of 164 patients died, resulting in an observed:expected mortality ratio of 1.3 (confidence interval, 0.87-1.87). Significant predictors for survival were the duration of disease and the postoperative glucose-suppressed GH. The effects of these predictors became less significant with increasing follow-up duration. A time-dependent effect on survival was observed for serial IGF-I concentrations, but not for serial GH concentrations. Of the three remission criteria, IGF-I was the only one to be significantly associated with survival in this study, with a relative risk of 4.78 for an elevated as opposed to a normal IGF-I concentration.     

Four-year treatment with octreotide-long-acting repeatable in 110 acromegalic patients: predictive value of short-term results?

The effects of a very prolonged treatment with octreotide (OC)-long-acting repeatable (LAR) were retrospectively evaluated in 110 patients with acromegaly, showing a GH/IGF-I decrease of at least 20% vs. baseline after a short-term (6-month) OC-LAR challenge. OC-LAR was given (20 mg, im, every 28 d for 3 injections, then individually tailored) as adjuvant treatment (AT) in 59. The other 51 [primary treatment (PT)] were naive or previously treated by pharmacotherapy. IGF-I normalized in 83 patients [75%; from 770 +/- 26 (mean +/- SE) to 276 +/- 15 micro g/liter; P < 0.0001; median follow-up, 30 months; range, 18-54 months). A progressive increase in the rate of IGF-I normalization was observed. GH fell to less than 2.5 micro g/liter in 72% and to less than 1 micro g/liter in 27% (from 20.7 +/- 2.4 to 2.2 +/- 0.2 micro g/liter; P < 0.0001). PT and AT patients achieved similar final GH/IGF-I levels and rates of normalization. Patients attaining safe GH and normal IGF-I had GH levels below 5 micro g/liter after 3 months and IGF-I levels below 550 micro g/liter after 6 months. No tachyphylaxis was observed. The up-titration to 30 mg improved IGF-I suppression. Elderly patients had greater sensitivity. Tumor shrank in 46% of assessable patients, in 77% of PT patients, and in 91% of naive patients. The powerful suppression of GH/IGF-I levels without tachyphylaxis, the finding of progressive increase in the rate of IGF-I normalization and of superimposable effects in PT and AT patients, and the predictive value of short-term results support the role of PT of acromegaly with OC-LAR in at least some patients.     

The role of stereotactic radiotherapy in patients with growth hormone-secreting pituitary adenoma

CONTEXT: Single-session stereotactic radiotherapy (SR) may be a potential adjuvant treatment in acromegaly. OBJECTIVE: We analyzed the safety and efficacy of SR in patients who had previously received maximal surgical debulking at our center. DESIGN: The study was a retrospective analysis of hormonal, radiological, and ophthalmologic data collected in a predefined protocol from 1994 through 2006. SETTING: The study was performed at a university hospital. PATIENTS: Eighty-three acromegalic patients, 52 women and 31 men, with a mean age of 42.6 +/- 1.2 yr, participated in the study. The median follow-up was 69 months (interquartile range 44-107 months). INTERVENTION: The patients were treated with SR for residual or recurrent GH-secreting adenoma. MAIN OUTCOME MEASURE: Normalization of age- and sex-adjusted IGF-I levels together with a basal GH level below 2.5 microg/liter without concomitant GH-suppressive drugs was the goal of therapy. RESULTS: Fifty patients (60.2%) reached the main outcome of the study. The rate of remission was 52.6% at 5 yr [95% confidence interval (CI) 40.6-64.6%]. Another 13 patients (15.7%), who were resistant to somatostatin analogs, were in remission after SR. Multivariate analysis showed that low basal GH and IGF-I levels were associated with a favorable outcome. No serious side effects occurred after SR. The 5-yr cumulative risk of new onset hypogonadism, hypothyroidism, or hypoadrenalism was 3.6% (95% CI 0-8.6%), 3.3% (95% CI 0-7.7%), and 4.9% (95% CI 0-10.4%), respectively. CONCLUSION: In a highly selected group of acromegalic patients, SR treatment had good efficacy and safety. This may lead to reconsider the role of SR in the therapeutic algorithm of acromegaly.     

Clinical indicators of biochemical remission in acromegaly: does incomplete disease control always mean therapeutic failure?

OBJECTIVE: Correction of GH and IGF-I levels are associated with improvements in insulin secretion, cardiac performance and body composition in patients with acromegaly, but whether these parallel post-treatment levels of GH-IGF-I axis activity is undefined. We investigate whether various biochemical outcomes after transsphenoidal pituitary surgery (TSS) in these patients are associated with clinically relevant differences in cardiac performance, insulin resistance and body composition. DESIGN: Cross-sectional study of consecutive patients with acromegaly admitted to the hospital between 2001 and 2002. PATIENTS AND METHODS: Forty-one patients after TSS for somatotroph pituitary adenoma and 23 patients with naive acromegaly serving as positive controls were enrolled in the study. Mean daily GH levels (mGH), IGF-I, leptin and lipid levels, glucose, insulin and GH concentrations during oral glucose tolerance test (oGTT) were measured in all study participants. Insulin resistance was measured by homeostatic model index (R(HOMA)). Body composition was assessed by dual-energy X-ray absorptiometry. Left ventricular mass index (LVM(i)) and cardiac index (C(i)) were determined by echocardiography. RESULTS: We found no difference in cardiac indices, insulin resistance, body composition and leptin levels between patients with complete biochemical remission and those with inadequately controlled disease (P > 0.05 for all) after TSS. Cured patients had lower values (mean +/- SD) of cardiac index (2.2 +/- 0.7 vs. 3.0 +/- 1.0 l/min/m(2); P = 0.04) compared with naive patients. A similar decrease in LVM(i) was observed in controlled (108.4 +/- 30.0 g/m(2); P = 0.015) and inadequately controlled disease (108.8 +/- 30.7 g/m(2); P = 0.03) in comparison with naive disease (160.3 +/- 80.6 g/m(2)). Insulin resistance and leptin changed in opposite ways. In controlled and inadequately controlled disease, R(HOMA) index was lower (2.2 +/- 1.4; P = 0.001 and 3.1 +/- 2.0; P = 0.05 vs. 5.1 +/- 3.1) while leptin concentration was higher (14.9 +/- 8.7 microg/l, P = 0.004 and 12.8 +/- 7.8 microg/l, P = 0.05 vs. 7.4 +/- 3.8 microg/l) than in naive disease. In all patients, leptin correlated negatively with cardiac index (r = -0.46; P = 0.001) and IGF-I levels (r = -0.45; P < 0.001). Independent predictors of biochemical remission, based on normal IGF-I levels only, were cardiac [P = 0.04, odds ratio (OR) 0.4; 95% confidence interval (CI) 0.2-0.9] and R(HOMA) index (P = 0.009, OR 0.6; 95% CI 0.4-0.8). Similar results were obtained if the definition of cure included both normal IGF-I levels and the ability to achieve GH nadir < 1 microg/l during oGTT. Insulin resistance (P = 0.02, OR 0.6; 95% CI 0.4-0.9) and leptin level (P = 0.002, OR 1.3; 95% CI 1.1-1.6) were independent predictors of normalized mGH values. CONCLUSION: This study shows that cardiac indices, insulin resistance and body composition were not different between patients with complete biochemical remission and those with discordant GH and IGF-I levels. It appears that even incomplete disease control after TSS can result in improvement of these clinical markers.     

Morbidity after long-term remission for acromegaly: persisting joint-related complaints cause reduced quality of life

Active acromegaly is associated with significant comorbidity and reduced quality of life. However, the prevalence of comorbidity after long-term remission is not established. Therefore, we assessed the presence of comorbidity in 118 patients in long-term remission after surgery, radiotherapy, and/or somatostatin analog treatment according to strict biochemical criteria of serum GH and IGF-I concentrations and evaluated the impact of comorbidity on quality of life. The mean duration of remission was 12.0 +/- 7.4 yr, and mean actual IGF-I sd scores were 0.6 +/- 1.7. Self-reported joint problems occurred in 77% of patients, hypertension in 37%, a history of myocardial infarction in 9%, and diabetes mellitus in 11%. The presence of joint problems was not related to GH and IGF-I levels, active disease duration, or age. Joint complaints had significant negative impact on quality of life. Patients with a history of myocardial infarction had reduced scores for general health, depression, and fatigue, and diabetes mellitus was associated with reduced scores for anxiety and sleep. In conclusion, acromegalic patients had a high prevalence of joint-related comorbidity and hypertension despite long-term control of GH excess. Especially, joint complaints contributed to a reduced perceived quality of life in these patients.     

The role of IGF binding protein-3 as a parameter of activity in acromegalic patients.

OBJECTIVE: The production of insulin-like growth factor binding protein-3 (IGFBP-3), the main IGF-I binding protein, is regulated by GH, and its serum levels are increased in acromegaly. We investigated its potential value as a parameter of acromegaly activity or remission in comparison with IGF-I, taking GH suppression below 2 microg/l after glucose load as the normal standard. METHODS: Data from 40 acromegalic patients (12 males and 28 females, aged 28 to 79 years) were obtained retrospectively from stored samples. From these, 145 pairs of IGF-I/IGFBP-3 values were collected; in 67 of them, simultaneous measurement of GH after glucose loading allowed their classification as active or inactive acromegaly. Relationships between IGF-I, IGFBP-3 and GH after glucose load were assessed, as well as differences between IGF-I and IGFBP-3 levels in active and inactive acromegaly. RESULTS: Significant positive correlation between IGF-I and IGFBP-3 in 145 samples was observed (r=0.49, P<0. 0001). As for the 67 samples in which activity or remission could be defined in terms of GH after glucose load, 50 were active and 17 inactive. Both IGF-I and IGFBP-3 significantly correlated with minimum GH (r=0.53, P<0.0001 and r=0.41, P<0.001 respectively). For both parameters, significant differences of means between active and inactive cases were observed (623+/-296 vs 300+/-108 ng/ml, P<0.0001 for IGF-I, and 4.1+/-1.3 vs 3.2+/-0.9 microg/ml, P<0.006 for IGFBP-3). Yet, when comparing in individual cases their classification as active or inactive with the finding of normal or increased IGF-I and IGFBP-3, among active cases 16% appeared as normal according to IGF-I, and 50% appeared as normal in terms of IGFBP-3. Among inactive cases, 23.5% appeared as active according to IGF-I, while 17.5% appeared as active in terms of IGFBP-3. CONCLUSION: Even though IGFBP-3 reflects GH secretion, it offers no advantage over IGF-I in the assessment of acromegaly, and it may underestimate disease activity in acromegalic patients.     

Growth hormone and pituitary radiotherapy, but not serum insulin-like growth factor-I concentrations, predict excess mortality in patients with acromegaly

Increased mortality in patients with acromegaly has been confirmed in a number of retrospective studies, but causative factors and relationship to serum IGF-I remain uncertain. The West Midlands Pituitary database contains details of 419 patients (241 female) with acromegaly. Serum IGF-I data from the Regional Endocrine Laboratory were available for 360 patients (86%). At diagnosis, mean age was 47 yr (range, 12-84) and mean duration of follow-up was 13 yr (0.5-48). Sixty-one percent were treated by surgery and 39% by nonsurgical means. Radiotherapy was used alone or as adjuvant therapy in 50%. All patients were registered with the Office of National Statistics to obtain information on deaths. At the date of analysis (31 December 2001), 95 of the 419 patients had died (43 males), giving a standardized mortality ratio of 1.26 [confidence interval (CI), 1.03-1.54; P = 0.046]. After controlling for age and sex, data indicated that mortality was increased in subjects with posttreatment GH levels more than 2 micro g/liter, compared with those with levels less than 2 micro g/liter [ratio of mortality rates (RR), 1.55 (range, 0.97-2.50); P = 0.068]. By contrast, a much smaller increase was observed for subjects with elevated posttreatment IGF-I levels compared with those with normal levels [RR, 1.20 (range, 0.71-2.03); P = 0.50]. Treatment with radiotherapy was associated with increased mortality [RR, 1.67 (range, 1.09-2.56); P = 0.018], with cerebrovascular disease the predominant cause of death [standardized mortality ratio, 4.42 (range, 2.71-7.22); P = 0.005]. These results confirm the increased mortality in acromegaly and suggest that reduction of GH levels to less than 2 micro g/liter is beneficial in terms of improving long-term outcome. The sole use of IGF-I as a marker for effective treatment of acromegaly is not justified by this data. This study also highlights the potential deleterious effect of radiotherapy.