Discordant GH and IGF-1 Results in Treated Acromegaly: Impact of GH Cutoffs and Mean Values Assessment.

CONTEXT: Discordant growth hormone (GH) and insulin-like growth factor-1 (IGF-1) values are frequent in acromegaly. OBJECTIVE: To evaluate the impact of different GH cutoffs on discordance rate. To investigate whether the mean of consecutive GH measurements impacts discordance rate when matched to the last available IGF-1 value. DESIGN: Retrospective study. SETTING: Referral center for pituitary diseases. PATIENTS: Ninety acromegaly patients with at least 3 consecutive evaluations for GH and IGF-1 using the same assay in the same laboratory (median follow-up 13 years). INTERVENTIONS: Multimodal treatment of acromegaly. MAIN OUTCOME MEASURES: Single fasting GH (GHf) and IGF-1 (IGF-1f). Mean of 3 GH measurements (GHm), collected during consecutive routine patients' evaluations. RESULTS: At last evaluation GHf values were 1.99 ± 2.79 µg/L and age-adjusted IGF-1f was 0.86 ± 0.44 × upper limit of normality (mean ± SD). The discordance rate using GHf was 52.2% (cutoff 1 µg/L) and 35.6% (cutoff 2.5 µg/L) (P = 0.025). "High GH" discordance was more common for GHf <1.0 µg/L, while "high IGF-1" was predominant for GHf <2.5 µg/L (P < 0.0001). Using GHm mitigated the impact of GH cutoffs on discordance (GHm <1.0 µg/L: 43.3%; GHm <2.5 µg/L: 38.9%; P = 0.265). At receiver-operator characteristic curve (ROC) analysis, both GHf and GHm were poor predictors of IGF-1f normalization (area under the curve [AUC] = 0.611 and AUC = 0.645, respectively). The prevalence of disease-related comorbidities did not significantly differ between controlled, discordant, and active disease patients. DISCUSSION: GH/IGF-1 discordance strongly depends on GH cutoffs. The use of GHm lessen the impact of GH cutoffs. Measurement of fasting GH levels (both GHf and GHm) is a poor predictor of IGF-1f normalization in our cohort.

Etiology of short stature in Indian children and an assessment of the growth hormone-insulin-like growth factor axis in children with idiopathic short stature.

Background Our objectives were to evaluate the etiology of short stature, assess the prevalence of idiopathic short stature (ISS) and assess the growth hormone (GH)-insulin-like growth factor (IGF) axis in children with ISS. Methods A stepwise diagnostic evaluation was done in 394 children aged 4-16 years with short stature. Children with no definitive etiology were labeled as ISS. In these children, baseline IGF-1, IGF binding protein-3 (IGFBP-3) and stimulated IGF-1 after administration of GH for 4 days were measured. Results Hypothyroidism (in 18.1%) and ISS (in 15.5%) were the commonest causes of short stature. In children with ISS (n=61), the mean baseline and stimulated IGF-1 standard deviation scores (SDSs) were -1.2±1.0 and -0.3±1.4, respectively, with levels below -2 SDS in 13 (21%) and six (10%) children, respectively. In 33 (54%) of the ISS patients, response to GH was suboptimal (increment in the IGF-1 level <40%). There was no difference in the mean peak GH, IGFBP-3 and baseline and stimulated IGF-1 levels between children with familial and non-familial ISS. A significant positive correlation of height SDS with baseline IGF-1 SDS (r=0.28, p=0.026), stimulated IGF-1 SDS (r=0.32, p=0.010) and ΔIGF-1 SDS (r=0.26, p=0.036) was observed in children with ISS. Conclusions Hypothyroidism and ISS were the commonest etiologies for short stature. The baseline IGF-1 was below -2 SDS in 21% and the increment after GH stimulation was suboptimal in 54% of children, indicating that a substantial proportion of children with ISS had an impaired GH-IGF axis.

Postoperative Changes in Metabolic Parameters of Patients with Surgically Controlled Acromegaly: Assessment of New Stringent Cure Criteria.

The criteria for surgical cure of acromegaly have become more stringent during the past decades and a change from Cortina to new consensus criteria has recently been proposed. However, the superiority of the new consensus over Cortina criteria with respect to postoperative metabolic parameters remains to be ascertained. We retrospectively assessed metabolic parameters, the body habitus, and other health-related parameters of 48 patients with surgically controlled acromegaly who met the Cortina criteria [normalized insulin-like growth factor-1 (IGF-1) level and nadir growth hormone (GH) level <1.0 ng/ml during postoperative oral glucose tolerance test]. The 48 patients were divided into two groups. Group A (n = 33) met the new consensus criteria (normalized IGF-1 and nadir GH level <0.4 ng/ml). Group B (n = 15) met Cortina criteria, but their nadir GH ranged from 0.4 to 1.0 ng/ml. In both groups, the level of triglyceride and homeostasis model assessment-insulin resistance (HOMA-IR) was significantly decreased 1 year after the operation (P < 0.05). High-density lipoprotein cholesterol showed a significant increase only in group B (P = 0.02). However, the two groups did not differ with respect to the postoperative improvement rate of these parameters and the other health-related parameters including body mass index, blood pressure, anterior pituitary function, and self-estimated quality of life scale. In conclusion, our findings show that with respect to changes in metabolic parameters and the body habitus assessed 1 year after surgery, the stricter consensus criteria seemed not to be superior to Cortina criteria.

Childhood-Onset Adult Growth Hormone Deficiency: Clinical, Hormonal, and Radiological Assessment in a Single Center in China.

BACKGROUND: Although growth hormone deficiency (GHD) is an important issue in pediatric patients, adult GHD (AGHD) is a neglected field of endocrinology in China. The aim of this study is to characterize the clinical, hormonal, and radiological features in childhood-onset AGHD (CO AGHD) in a single center in China and to compare them with counterparts from Japan. METHODS: The medical records of 78 Chinese patients with CO AGHD were reviewed and compared with data from the HypoCCS database study from Japan (N = 69). RESULTS: The majority of our patients had pituitary stalk interruption, while hypothalamo-pituitary tumors were the most common cause of CO AGHD in Japan. Chinese patients had a lag of 6 years for diagnosis. The majority of both groups had multiple pituitary hormone deficiencies. Body mass index and lipid profiles were similar between the 2 patient groups. Dyslipidemia and hyperuricemia were the most common metabolic disturbances in Chinese patients. CONCLUSIONS: Our findings confirm that there are possible regional differences in the etiology, metabolic characteristics, and hormonal status in CO AGHD patients in different countries in Asia.

Growth and Growth hormone - Insulin Like Growth Factor -I (GH-IGF-I) Axis in Chronic Anemias.

Anaemia is a global public health problem affecting both developing and developed countries with major consequences for human health as well as social and economic development. It occurs at all stages of the life cycle, but is more prevalent in pregnant women and young children. Iron deficiency anaemia (IDA) was considered to be among the most important contributing factors to the global burden of disease. Prolonged and/or chronic anemia has a negative effect on linear growth especially during the rapid phases (infancy and puberty). Additionally infants with chronic IDA have delayed cognitive, motor, and affective development that may be long-lasting. In view of the significant impact of chronic anemias on growth, pediatricians endocrinologists and hematologists should advocate primary prevention and screening for growth disturbance in these forms of anemias. The extent of the negative effect of different forms of chronic anemias on linear growth and its possible reversibilty is addressed in this review. The possible mechanisms that may impair growth in the different forms of anemias are addressed with special attention to their effect on the growth hormone (GH) - insulin like growth factor -I (IGF-I).

Assessment of lung function in a large cohort of patients with acromegaly.

OBJECTIVE: Acromegaly is associated with increased mortality due to respiratory disease. To date, lung function in patients with acromegaly has only been assessed in small studies, with contradicting results. We assessed lung function parameters in a large cohort of patients with acromegaly. DESIGN: Lung function of acromegaly patients was prospectively assessed using spirometry, blood gas analysis and body plethysmography. Biochemical indicators of acromegaly were assessed through measurement of growth hormone and IGF-I levels. This study was performed at the endocrinology outpatient clinic of a tertiary referral center in Germany. METHODS: We prospectively tested lung function of 109 acromegaly patients (53 male, 56 female; aged 24-82 years; 80 with active acromegaly) without severe acute or chronic pulmonary disease. We compared lung volume, air flow, airway resistance and blood gases to normative data. RESULTS: Acromegaly patients had greater lung volumes (maximal vital capacity, intra-thoracic gas volume and residual volume: P < 0.001, total lung capacity: P = 0.006) and showed signs of small airway obstruction (reduced maximum expiratory flow when 75% of the forced vital capacity (FVC) has been exhaled: P < 0.001, lesser peak expiratory flow: P = 0.01). There was no significant difference between active and inactive acromegaly. Female patients had significantly altered lung function in terms of subclinical airway obstruction. CONCLUSIONS: In our cross-sectional analysis of lung function in 109 patients with acromegaly, lung volumes were increased compared to healthy controls. Additionally, female patients showed signs of subclinical airway obstruction. There was no difference between patients with active acromegaly compared with patients biochemically in remission.

Biochemical assessment of disease control in acromegaly: reappraisal of the glucose suppression test in somatostatin analogue (SA) treated patients.

BACKGROUND: It is recommended not to measure growth hormone during oral glucose suppression (oral glucose tolerance test) during somatostatin analog treatment in acromegaly. However, we have observed that failure to suppress growth hormone in response to oral glucose tolerance test during somatostatin analog unmasks insufficient disease control and hypothesize that somatostatin analog also induces insufficient growth hormone suppression to mixed meals. METHODS: We therefore compared serum growth hormone levels during two mixed meals in patients with controlled insulin-like growth factor-I levels after either surgery alone (n = 9) or somatostatin analog treatment (n = 9). The patients were unbiasedly matched for gender and insulin-like growth factor-I and studied twice in the following order: (1) during a 6 h growth hormone day curve including two mixed meals and (2) during a 3 h growth hormone profile including 60 min fasting followed by a 2-h oral glucose tolerance test. RESULTS: During the day curve growth hormone levels were elevated in the somatostatin analog group (P = 0.008) and growth hormone levels 1 h after each meal declined significantly only in the surgery group (P = 0.02). During the oral glucose tolerance test the two groups had similar growth hormone levels prior to the glucose load (P = 0.6), whereas a significant 66% suppression was observed after glucose only in the surgery group (P = 0.001). CONCLUSIONS: (1) Patients controlled by somatostatin analog fail to suppress growth hormone in response to both mixed meals and oral glucose tolerance test (2) This phenomenon is likely to result in elevated serum growth hormone levels during everyday life in somatostatin analog-treated patients, (3) We postulate that measuring growth hormone levels during oral glucose tolerance test is useful to unmask potential somatostatin analog under-treatment in the presence of 'safe' insulin-like growth factor-I levels.

Assessment of sFRP4 as a bio-marker for predicting aggressiveness and recurrence of growth hormone-secreting pituitary adenomas.

The association of sFRP4 expression with aggressiveness and recurrence of growth hormone (GH)-secreting pituitary adenomas was investigated. Ten normal pituitary and 52 GH-secreting pituitary adenoma specimens were classified into three groups: normal pituitary (control) group, non-aggressive group, and aggressive group, according to preoperative evaluation by magnetic resonance imaging (MRI)/computed tomography (CT). Expression of sFRP4 was determined by quantitative real-time polymerase chain reaction (qRT-PCR), western blot analysis, and tissue microarrays, to assess the association between sFRP4 and aggressiveness. Follow-up information of all 52 patients was collected to evaluate the impact of sFRP4 expression on the recurrence/progression of GH-secreting pituitary adenomas. qRT-PCR results showed a lower level of sFRP4 mRNA in the aggressive group, as compared to that in the non-aggressive group (P=0.001). A similar trend was observed on western blot analysis for sFRP4 protein expression (P=0.004). On analysis by tissue microarrays, weak sFRP4 expression was detected in the aggressive group (10/15, 66.7%). Univariate analysis showed a significant relationship between low sFRP4 expression and aggressiveness (P=0.024). On multivariate analysis weak sFRP4 expression was found to be an independent factor of recurrence/progression (odds ratio: 0.063, P=0.026). Methylation of the sFRP4 promoter was increased in low sFRP4 staining group compared to that in the high sFRP4 staining group (P<0.001). In this study, weak sFRP4 expression appeared to predict aggressive behavior, and was associated with recurrence/progression of GH-secreting pituitary adenomas. Methylation of the sFRP4 promoter may account for the low sFRP4 expression.

Alteration of the growth hormone axis, visceral fat dysfunction, and early cardiometabolic risk in adults: the role of the visceral adiposity index.

The aim of the study is to clarify the relationship between adipose tissue dysfunction, metabolic profile and growth hormone (GH)/insulin-like growth factor (IGF)-I secretion in healthy adult subjects. We investigated the metabolic profile in a cohort of 231 consecutive healthy subjects in relation to GH, IGF-I levels, and visceral adiposity index (VAI). Anthropometric measures, lipid profile, and glucose and insulin levels during oral glucose tolerance test, Homa-IR and ISI Matsuda, IGF-I and GH peak after GHRH plus Arginine test were analyzed. The subjects with high VAI showed lower GH peak (22.8 ± 11.1 vs. 42.2 ± 21.3 µg/L; p = 0.049) and lower IGF-I (presented as IGF-I under normal range, UNR) (0.54 ± 0.14 vs. 0.64 ± 0.12; p = 0.005) than group with normal VAI. ROC curve analysis identified the cut-off, able to detect subjects with high VAI, i.e., 31.8 µg/L for GH peak and 0.63 for IGF-1 UNR. The subjects with GH peak and IGF-I UNR under the cut-off showed significantly higher levels of VAI, systolic and diastolic blood pressure, glucose and insulin levels, Homa-IR, and lower ISI Matsuda, with a concomitant worse lipid profile (all p < 0.001). A strong relationship between GH axis, VAI and metabolic risk has been demonstrated. A percentage of apparently healthy subjects show a degree of visceral adipose dysfunction associated with GH and IGF-I levels that do not meet the criteria of overt GH deficiency (GHD). Long-term prospective studies could help to clarify and confirm whether a hypothetical condition of subclinical GHD could be taken into account as a new clinical entity.

Assessment of bone mineral density in patients with Sheehan's syndrome.

INTRODUCTION: The number of studies concerning bone mineral density (BMD) in patients with Sheehan's syndrome (SS) are scarce. We aimed to investigate the relationship between BMD and deficient hormones in patients with newly diagnosed SS. MATERIAL AND METHODS: Thirty-four patients with SS and age-gender-weight matched 22 controls were included in the study. RESULTS: We found osteoporosis in 61.8%, osteopenia in 32.3%, and normal dual energy X-ray absorptiometry (DEXA) findings in 5.9% patients. In the control group, 68.2% of individuals were osteopenic and 31.8% of them were normal. The number of osteoporotic patients was found to be higher and BMD values were lower in the patient group compared with the control group. There was no relation of DEXA measurements with the period between the last delivery and the initial diagnosis and the estradiol levels. While there was no relation between insulin-like growth factor 1 (IGF-1) and T and Z scores of femur head, the relation between the IGF-1 and L1-L4 T scores was statistically significant. There was a significant relation between the IGF-1 and L1-L4 Z scores. CONCLUSIONS: SS patients should also be assessed in terms of osteoporosis at the time of diagnosis and then proper treatment should be initiated afterwards.

Pituitary dysfunction after traumatic brain injury in children: is there a need for ongoing endocrine assessment?

BACKGROUND: Hypopituitarism has been widely described in adults after traumatic brain injury (TBI); however, the available data in paediatric populations are scarce. Here, we report the results of a prospective, long-term study in children, adolescents and young adults. STUDY GROUP: Thirty-seven children (age, 2 months to 19·9 years) of 51 eligible patients were followed for 1 year. Clinical and baseline endocrine variables were assessed in all 3 and 12 months after TBI; children ≥ 6 years underwent two stimulation tests (glucagon stimulation and megatest). RESULTS: In the group ≥6 years, 11 of 23 patients (47·8%) had a subnormal GH peak 3 months after TBI that persisted in 8 of 23 patients (34%) after 1 year. The GH response showed no correlation with injury severity (GCS, Marshall classification). Growth velocity was normal in all patients, except for one. Body mass index (BMI) SDS increased significantly in the group with low GH response. A suboptimal cortisol was observed in 10 of 23 subjects, which normalized in all but three, 1 year thereafter. All patients but one showed a pubertal response to GnRH testing. No clinical or hormonal abnormalities were detectable in children <6 years. CONCLUSION: Our results recommend to prospectively follow children after TBI: firstly, because the impairment of pituitary function cannot be predicted, and secondly, to avoid the potential consequences of pituitary dysfunction. Prospective clinical trials are needed before recommending a systematic screening after TBI and/or GH therapy either in postpubertal children or in prepubertal children who grow normally.

Reduced arterial stiffness in patients with acromegaly: non-invasive assessment by the cardio-ankle vascular index (CAVI).

In patients with acromegaly, cardiovascular diseases are the most common cause of death. Arterial stiffness is increasingly recognized as a valuable surrogate marker for predicting cardiovascular events. To evaluate the vascular status of acromegalic patients, we used the cardio-ankle vascular index (CAVI) to reflect the arterial stiffness from the heart to the ankles. We analyzed 21 acromegalic patients, comprising five patients with untreated active acromegaly, one patient treated with medication and 15 patients who underwent transsphenoidal surgery. Among the 15 patients with surgery, 10 received additional therapies with dopamine agonists and/or somatostatin analogs. All patients with acromegaly unexpectedly showed significant reductions in the CAVI, indicating reduced arterial stiffness, compared with age- and sex-matched controls, regardless of whether they underwent surgery. There was a significant negative correlation between the CAVI and the serum insulin-like growth factor (IGF)-I level in these patients. Active acromegalic patients were associated with lower CAVI than controlled patients. Sequential measurements of the CAVI and serum IGF-I before and after treatment with octreotide and transsphenoidal surgery revealed that a reduced IGF-I level after treatment was accompanied by CAVI elevation. The present findings indicate that the CAVI is negatively correlated with the serum IGF-I level in acromegaly. These findings are consistent with previous reports indicating that the GH/IGF-I axis reduces peripheral vascular resistance. This non-invasive assessment can reflect the present vascular status and would be a useful marker for evaluation of therapeutic effects in patients with acromegaly.

Diagnosis of growth hormone deficiency is affected by calibrators used in GH immunoassays.

Growth hormone (GH) values vary among immunoassays depending on different factors, such as the assay method used, specificity of antibodies, matrix difference between standards and samples, and interference with endogenous GH binding proteins (GHBPs). We evaluated whether the use of different calibrators for GH measurement may affect GH values and, consequently, the formulation of GH deficiency (GHD) diagnosis in children. Twenty-three short children (5 F, 18 M; age 11.4±3.1 years), with the clinical characteristics of GHD (height: -2.3±0.5 SDS; height velocity -2.3±1.5 SDS; IGF-I -1.2±0.9 SDS), underwent GH stimulation tests to confirm the clinical diagnosis of GHD. Serum GH values were measured with Immulite 2000, using 2 different calibrators, IS 98/574, a recombinant 22 kDa molecule of more than 95% purity, and IS 80/505, of pituitary origin and resembling a variety of GH isoforms. We found blunted GH secretion in 20 subjects with the Immulite assay using the IS 98/574 GH as a calibrator, confirming the diagnosis of GHD. Subsequently, using IS 80/505 GH as a calibrator, in the same samples only 14 children showed reduced GH levels. The total cost for the first year of GH therapy of patients diagnosed with IS 98/574 as a calibrator was higher than that for patients diagnosed with IS 80/505 as a calibrator. These data confirm that GH values may depend on different calibrators used in the GH assay, affecting the formulation of GHD diagnosis and the consequent decision to start GH treatment.

Functional and total IGFBP3 for the assessment of disorders of the GH/IGF1 axis in children with chronic kidney disease, GH deficiency, or short stature after SGA status at birth.

OBJECTIVE: IGFBP3 immunoreactivity may appear elevated in patients with chronic kidney disease (CKD), in part due to accumulation of low molecular fragments. The importance of these IGFBP3 variants for binding and inactivation of IGF1 and their relevance for the impaired growth of uremic children are unclear. Nevertheless, IGFBP3, measured as total (t-)IGFBP3, is frequently used as a diagnostic parameter in pediatric CKD patients. A new assay for functional (f-)IGFBP3 exclusively detects IGFBP3 capable of IGF binding. The aim of the study was to evaluate the significance of f-IGFBP3 measurements for the assessment of uremic abnormalities of the GH/IGF1 axis. DESIGN: Prospective cross-sectional study. METHODS: t-IGFBP3, f-IGFBP3, and IGF1 were measured in pediatric CKD patients, including patients with CKD stage 3-4 not on dialysis (CKD, n=33), on dialysis treatment (DT, n=26), patients after renal transplantation (RTx, n=89), healthy children (n=29), children with GH deficiency (GHD, n=42), and small for gestational age (SGA) children (SGA, n=34). RESULTS: Mean t-IGFBP3 SDS was elevated in CKD, DT, and RTx children compared with controls and GHD patients (P≤0.0004). Highest values were reached in DT (P<0.0001 vs all groups). In contrast, mean f-IGFBP3 was similar in all groups (P=0.30). CONCLUSIONS: Pediatric CKD patients displayed elevated serum concentrations of t-IGFBP3 but not f-IGFBP3, supporting the hypothesis that IGFBP3 fragments not binding IGF1 accumulate during uremia. f-IGFBP3 is an indicator of IGFBP3 fragmentation and seems to reflect IGF1 binding in CKD better than t-IGFBP3. However, the role of f-IGFBP3 for the diagnosis of disturbances of the GH/IGF hormonal axis appears to be limited.

Polycythemia as rare secondary direct manifestation of acromegaly: management and single-centre epidemiological data.

Polycythemia associated with acromegaly is usually caused by the systemic manifestations of the disease, such as sleep-apnea or concomitant erythropoietin-secreting kidney tumors. The recognition of underlying pathologies requires a thorough diagnostic process. We report a unique case of acromegaly with polycythemia, not caused by commonly described manifestations of the disease, and receding with octreotide therapy. The medical history of 141 acromegalic patients followed by the Endocrinology Unit of the San Martino University Hospital in Genoa has been also reviewed, together with the literature evidence for similar cases. The diagnostic workflow and 2-years follow-up of a 43-years old acromegalic, polycythemic man with a history of past smoking, moderate hypertension, and mental retardation are described. The hematological parameters of our cohort was retrospectively compared with those of a healthy, age/gender-related control group as well. Therapy with octreotide LAR, 20 mg i.m. q28d was begun soon after diagnosis of acromegaly in the polycythemic patient. Haematocrit level, hormonal setting, as well as pituitary tumor size and visual perimetry during treatment were recorded. Octreotide LAR treatment normalized hormonal alterations, as well as hematological parameters. Polycythemia has not recurred after 2 years of therapy. The median hemoglobin and hematocrit levels of the retrospectively analyzed cohort of acromegalic were significantly lower than normal ranges of a healthy, age/sex- related control population. In conclusions, polycythemia can be a direct, albeit rare, secondary manifestation of acromegaly, that must be considered during the diagnostic work-up of acromegalic patients presenting with such disorder.

Biochemical diagnosis and assessment of disease activity in acromegaly: a two-decade experience.

The objective of this study is to assess the secretory pattern of GH after Oral Glucose Tolerance Test (OGTT) or day-curve (DC), in relation with IGF-I and to evaluate the influence of therapy on OGTT. A retrospective analysis in 279 OGTTs performed in 93 acromegalic patients in our unit from January 1988 to December 2005, in 77 patients also DC data were retrived. GH concentration was evaluated by 3 different systems (RIA, IRMA and chemiluminescence assays), and IGF-I by two RIAs. About 12% of OGTT samples were discordant with the baseline, while discordance between nadir and 120th minute was much lower (5%), with all discordant values, except one, near the cut-off lines. Correlation between DC and OGTT data was around 0.99 among all values, discordance rate between nadir and minimum DC was much lower than that with mean DC. In almost 80% of cases there was a complete concordance between OGTT and DC results, and in about 30% IGF-I was discordant with GH. Correlation analysis between IGF-I and GH was highest with DC data and lowest with OGTT baseline (T0). Considering different treatments discrepancy rates between GH and IGF-I were comparable. The best GH parameter is the minimum GH DC, although in the clinical practice the evaluation of OGTT GH in association with IGF-I is the most practical approach. In this case, the basal and T120 GH values can replace multiple sampling. Different treatment modalities do not influence the discordance rate between GH and IGF-I.

Neuroendocrine assessment of serotonergic, dopaminergic, and noradrenergic functions in alcohol-dependent individuals.

BACKGROUND: Alcohol dependence has been associated with reduced function of serotonin, dopamine as well as noradrenaline activities in several neuroendocrine studies. To our knowledge, there is, however, no study investigating all these 3 systems with the use of neuroendocrine methods in one and the same alcohol-dependent individual. METHODS: Alcohol-dependent individuals (n = 42) and controls (n = 28) participated in the neuroendocrine test series. Central serotonergic neurotransmission was assessed by the prolactin (PRL) response to citalopram (CIT). The postsynaptic DRD2 function was measured by the growth hormone (GH) response to apomorphine (APO) and the postsynaptic α2-adrenoceptor function by GH response to clonidine (CLON). RESULTS: In the alcohol-dependent individuals, the PRL concentrations were significantly lower at the time points 240 minutes and 300 minutes after CIT administration and mean delta PRL value was significantly reduced by 45% in comparison with controls. There were no significant differences in APO-GH and CLON-GH concentrations at any time points or in mean delta GH values between the groups. An impaired monoaminergic profile, including all 3 systems, was significantly more frequent in alcohol-dependent individuals than controls (43% vs. 6% respectively). CONCLUSIONS: The monoaminergic dysfunction was restricted to an impairment of the serotonergic system, suggesting that this system is especially vulnerable to long-term and excessive alcohol consumption. Moreover, impaired monoaminergic profiles, including low responses in 2 or 3 systems, were more frequently observed in alcohol-dependent individuals than in controls. Such impaired profiles may be of clinical importance, but further studies are needed.

Assessment of biochemical control of acromegaly during treatment with somatostatin analogues by oral glucose load and insulin-like growth factor I.

BACKGROUND: The use of oral glucose tolerance test (OGTT) in evaluating biochemical control in acromegalic patients on somatostatin analogues (SSA) has recently been questioned. AIM: To gain further insights into this topic, we analyzed basal and nadir GH levels during OGTT in acromegalic patients on SSA. SUBJECTS AND METHODS: Basal IGF-I and GH values, as well as GH levels along the test, were analyzed in 115 standard OGTT performed in 33 acromegalic patients followed up between 1993 and 2009. All patients were on SSA at the time of the study; 22 of them had previously undergone unsuccessful surgery. No patient had undergone radiotherapy. GH suppression was considered normal when the hormonal value fell to <1 µg/l during OGTT. Diagnostic accuracy was analyzed by receiver operating characteristic (ROC) curves. RESULTS: ROC analysis showed that the GH basal value yielding the best specificity (100%) was 3.9 µg/l. All patients with basal GH>3.9 µg/l displayed lack of GH suppression after OGTT and 80% also displayed high IGF-I. Conversely, patients with basal GH<3.9 µg/l presented a variable biochemical pattern with half of them failing to suppress GH after OGTT and 36.6% displaying high IGF-I levels. CONCLUSIONS: Our results show that baseline GH levels >3.9 µg/l are predictive of absent OGTT-dependent GH suppression; however, 20% of these patients display partial biochemical control (normal IGF-I levels). On the other hand, basal GH values <3.9 µg/l are not predictive of GH suppressibility by glucose and are often discordant with IGF-I levels.

Diabetes in acromegaly, prevalence, risk factors, and evolution: data from the French Acromegaly Registry.

OBJECTIVES: The French Acromegaly Registry records data of acromegalic patients' since 1992 in French, Belgian (Liège), and Swiss (Lausanne) centers. We studied the prevalence of diabetes in this population looking for risk factors. Patients from one of the centers (Reims) were then analyzed more thoroughly. METHODS: This study has been conducted on all the patients recorded from 1999 until 2004 (519 patients). Evolution of cohorts' was reassessed in 2009. Of the different variables recorded in the registry: age, sex, body mass index (BMI), duration of acromegaly, GH, IGF1 and prolactin levels, pituitary tumor size, hormonal deficiencies, presence, duration and treatment of diabetes, hypertension, and rheumatological disease were analyzed. RESULTS: The prevalence of diabetes in the registry was 22.3%. Diabetic patients were older and had a higher BMI. Compared with the data of the French Social Security, acromegalic patients showed a more precocious apparition of diabetes and prevalence was higher in each age group. Compared with non-diabetic acromegalic subjects, diabetic patients had a more prolonged evolution of acromegaly before diagnosis. The levels of GH and IGF1 were not significantly different between the two groups. Only hypertension was significantly more frequent in diabetic patients. CONCLUSIONS: In our population, the prevalence of diabetes was estimated to be 22.3%. The GH and IGF1 levels did not appear as predictive factors for the presence of diabetes. On the contrary, age, BMI, and hypertension were significant risk factors as in the general population of type 2 diabetics.

Safety of insulin tolerance test for the assessment of growth hormone deficiency in children.

OBJECTIVE: To determine the safety of insulin tolerance test (ITT) for assessing growth hormone (GH) deficiency in children. METHODS: This hospital based study was conducted at the National Institute of Child Health, Karachi from 1st November 2008 till 30th October 2009. All children suspected of growth hormone deficiency, were included after excluding all other causes of short stature. Verbal informed consent was taken from the parents. Children less than 2 years of age, weighing less than 10 kg, untreated/inadequately treated hypothyroidism or Addison's disease, epilepsy, having history of hypoglycaemic fits or cardiac disease were excluded. All children were subjected to the international standard protocol of ITT and their samples of growth hormone and blood sugars were drawn. Complications during the procedure like hypoglycaemia, hypothermia, loss of consciousness, fits, vomiting and failure to achieve hypoglycaemia were recorded. Insulin tolerance test was performed on a total of 168 subjects. The data was entered in SPSS version 17 for analysis. RESULTS: A total of 168 children were subjected to the ITT. Four of them were abandoned as they could not achieve hypoglycaemia despite repeating the dose of insulin. Results were analyzed on 164 children whose mean age was 10 +/- 3.5 years, There were 96 (58%) males and 68 (41%) females. Over all 79.8% children achieved hypoglycaemia. None of the subjects developed any complication (fits, loss of consciousness,) or required intravenous glucose during the test and it was completed in all children with close monitoring. The results showed that there was a significant effect of time after insulin administration on both the blood glucose level (BG) and growth hormone (GH) levels. The blood glucose level decreased rapidly after administration of insulin and was lowest 30 minutes after injection and showed an increasing trend in subsequent readings, becoming almost equal to the baseline value 120 min after injection. From the study group 111 (66%) children were diagnosed as having growth hormone deficiency, 52 (31.3%) were normal and 1 (0.6%) had growth hormone insensitivity. CONCLUSION: ITT in children was found to be a safe and reliable test but can be potentially dangerous and requires very close monitoring and supervision and should be performed in a center with experienced staff.