Effect of Cabergoline on weight and glucose metabolism in patients with acromegaly.

PURPOSE: Cabergoline (CAB) has shown to have benefic effects on the metabolism in different clinical settings but its metabolic role in acromegaly disease has not been studied yet. Aim of our study was to evaluate the impact of CAB on glucose metabolism and weight in patients with acromegaly. METHODS: All patients with acromegaly undergoing continuous treatment with CAB for at least 6 months were retrospectively screened. Exclusion criteria were discontinuation of CAB for more than one month, change of antidiabetic or other therapy for acromegaly, concomitant untreated hormonal deficiency, initiation of pregnancy and/or breastfeeding. All patients were evaluated in terms of biochemical disease control, glucose metabolism and weight at baseline (T0) and after the introduction of CAB therapy at 6 (T6) and 12 months (T12). RESULTS: Twenty-six patients (15 females and 11 males) were evaluated at T0 and T6 and 19 patients (12 females and 7 males) were also evaluated at T12. Insulin-like growth factor I (IGF-I) and prolactin (PRL) levels were significantly lower at T6 and T12 compared to baseline (p < 0.001 for IGF-I, p < 0.05 for PRL) even if no further differences were observed between T12 and T6. Considering the entire cohort, no differences were appreciated regarding the metabolic parameters but a significant reduction in weight and body mass index (BMI) was observed at both T6 (p = 0.009 for weight, p = 0.021 for BMI) and T12 (p = 0.014 for weight, p = 0.017 for BMI) compared to baseline. CONCLUSION: Our results confirm the efficacy of CAB in providing a significant improvement in the biochemical disease control but do not demonstrate a marked benefit on glucose metabolism of acromegaly patients. In such patients, CAB appears to have a rapid effect on weight and BMI, with significant changes noticeable as early as 6 months and persisting for at least 12 months.

Excess mortality in patients with non-functioning pituitary adenoma: a systematic review and meta-analysis.

BACKGROUND: Patients with non-functioning pituitary adenoma (NFPA) often present with a variety of clinical manifestations and comorbidities, mainly determined by the local mass effect of the tumor and by hypopituitarism. Whether this has an impact on overall mortality, however, is still unclear. METHODS: PubMed/Medline, EMBASE, and Cochrane Library databases were systematically searched until May 2023 for studies reporting data either about standardized mortality ratios (SMRs) or about predictors of mortality in patients with NFPA. Effect sizes were pooled through a random-effect model. This systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO, #CRD42023417782). RESULTS: Eleven studies were eligible for inclusion in the systematic review; among these, five studies reported data on SMRs, with a total follow-up time of approximately 130,000 person-years. Patients with NFPA showed an increased mortality risk compared to the general population (SMR = 1.57 [95%CI: 1.20-1.99], p < 0.01). Age and sex appeared to act as effect modifiers, with a trend towards higher SMRs in females (SMR = 1.57 [95%CI: 0.91-2.41], p = 0.10) than in males (SMR = 1.00 [95%CI: 0.89-1.11], p = 0.97), and in patients diagnosed at age 40 years or younger (SMR = 3.19 [95%CI: 2.50-3.97], p < 0.01) compared to those with later onset of the disease (SMR = 1.26 [95%CI: 0.93-1.65], p = 0.13). The trend towards excess mortality was similar in patients with normal (SMR = 1.22 [95%CI: 0.94-1.53], p = 0.13) or deficient (SMR = 1.26 [95%CI: 0.82-1.79], p = 0.27) pituitary function. CONCLUSIONS: Excess mortality is observed in patients with NFPA, regardless of pituitary function, especially in women and in patients with a younger age at diagnosis.

Neuroendocrine response to diclofenac in healthy subjects: a pilot study.

PURPOSE: The precise effects of non-steroidal anti-inflammatory drugs on the neuroendocrine hydro-electrolytic regulation are not precisely understood. The aim of this pilot study was to evaluate, in healthy subjects, the neuroendocrine response of the antidiuretic system to intravenous diclofenac infusion. METHODS: For this single-blinded, cross-over study, we recruited 12 healthy subjects (50% women). Test sessions were divided into three observation times (pre-test; test; 48 h post-test), which were repeated equally on two different occasions, with the administration of diclofenac (75 mg in saline solution 0.9% 100 cc) on 1 day, or placebo (saline solution 0.9% 100 cc) on another day. The night before the test the subjects were asked to collect a salivary cortisol and cortisone sample, which was repeated on the night of the procedure session. Serial urine and blood samples were collected on the test day (for osmolality, electrolytes, ACTH, cortisol, copeptin, MR-proADM, MR-proANP; the last three represent more stable and analytically reliable molecules than their respective active peptides). Moreover, the subjects were evaluated with the bioimpedance vector analysis (BIVA) before and after the test. Forty-eight hours after the end of the procedure urine sodium, urine potassium, urine osmolality, serum sodium and copeptin were revaluated together with BIVA. RESULTS: No significant changes in circulating hormone levels were observed; anyway, 48 h after diclofenac, BIVA showed a significant water retention (p < 0.00001), especially in extracellular fluid (ECF) (16.47 ± 1.65 vs 15.67 ± 1.84, p < 0.001). Salivary cortisol and cortisone tended to increase only the night after placebo administration (p = 0.054 cortisol; p = 0.021 cortisone). CONCLUSION: Diclofenac resulted in an increased ECF at 48 h, but this phenomenon seems to be associated with a greater renal sensibility to the action of vasopressin rather than with an increase in its secretion. Moreover, a partial inhibitory effect on cortisol secretion can be hypothesized.

GHRH + arginine test and body mass index: do we need to review diagnostic criteria for GH deficiency?

INTRODUCTION: The proportion of patients with low GH response to provocative tests increases with the number of other pituitary hormone deficiencies, reason why in panhypopituitary patients GH stimulation tests may be unnecessary to diagnose GH deficiency (GHD) PURPOSE: To re-evaluate the diagnostic cut-offs of GH response to GHRH + arginine (ARG) test related to BMI, considering the patients' pituitary function as the gold standard for the diagnosis of GHD. METHODS: The GH responses to GHRH + ARG were studied in 358 patients with history of hypothalamic-pituitary disease. GHD was defined by the presence of at least 3 other pituitary deficits (n = 223), while a preserved somatotropic function was defined by the lack of other pituitary deficits and an IGF-I SDS ≥ 0 (n = 135). The cut-off with the best sensitivity (SE) and specificity (SP), was identified for each BMI category using the ROC curve analysis. To avoid over-diagnosis of GHD we subsequently searched for the cut-offs with a SP ≥ 95%. RESULTS: The best GH cut-off was 8.0 µg/l (SE 95%, SP 100%) in lean, 7.0 µg/l (SE 97.3%, SP 82.8%) in overweight, and 2.8 µg/l (SE 84.3%, SP 91.7%) in obese subjects. The cut-off with a SP ≥ 95% was 2.6 µg/l (SE 68.5%, SP 96.6%) in overweight and 1.75 µg/l (SE 70.0%, SP 97.2%) in obese subjects. CONCLUSIONS: This is the first study that evaluates the diagnostic cut-offs of GH response to GHRH + ARG related to BMI using a clinical definition of GHD as gold standard. Our results suggest that with this new approach, the GHRH + ARG cut-offs should be revised to avoid GHD over-diagnosis.

Development and internal validation of a predictive score for the diagnosis of central adrenal insufficiency when morning cortisol is in the grey zone.

BACKGROUND: When evaluating a patient for central adrenal insufficiency (CAI), there is a wide range of morning cortisol values for which no definite conclusion on hypothalamus-pituitary-adrenal (HPA) axis function can be drawn; in these cases, a stimulation test is required. Aim of this study was to develop an integrated model for CAI prediction when morning cortisol is in the grey zone, here defined as 40.0-160.0 µg/L. METHODS: Overall, 119 patients with history of sellar tumour which underwent insulin tolerance test (ITT) for the evaluation of HPA axis were enrolled. Supervised regression techniques were used for model development. RESULTS: An integrated predictive model was developed and internally validated, and showed a significantly better diagnostic performance than morning cortisol alone (AUC 0.811 vs 0.699, p = 0.003). A novel predictive score (CAI-score) was retrieved, on a 5.5-point scale, by considering morning cortisol (0 points if 130.1-160.0 µg/L, 1 point if 100.1-130.0 µg/L, 1.5 points if 70.1-100.0 µg/L, 2.5 points if 40.0-70.0 µg/L), other pituitary deficits (2 points if ≥ 3 deficits), and sex (1 point if male). A diagnostic algorithm integrating CAI-score and ITT was finally proposed, with an overall accuracy of 99%, and the possibility to avoid the execution of stimulation tests in 25% of patients. CONCLUSIONS: This was the first study that proposed an integrated score for the prediction of CAI when morning cortisol is in the grey zone. This score might be helpful to reduce the number of patients who need a stimulation test for the assessment of HPA axis function.

Sex-specific fat mass ratio cutoff value identifies a high prevalence of cardio-metabolic disorders in people living with HIV.

BACKGROUND AND AIMS: HIV-associated lipodystrophy syndrome (HALS) contributes to the increased cardiovascular risk connoting people living with HIV (PLHIV). HALS recognition, based on clinical ground, may be inaccurate urging an objective instrumental diagnosis. The aim of this study is to search for the DXA-derived fat mass ratio (FMR) threshold, among those suggested for the diagnosis of HALS, able to identify PLHIV at high cardiovascular risk. METHODS AND RESULTS: In a cross-sectional analysis of 101 PLHIV (age 53 ± 11 years, men 55%) and 101 age- and sex-matched uninfected controls, DXA-derived FMR and anthropometric as well as cardio-metabolic parameters were assessed. PLHIV showed a higher FMR (1.15 ± 0.42 vs 0.95 ± 0.18, p < 0.01) together with a greater cardio-metabolic derangement than controls, in spite of lower BMI (24.3 ± 4.3 vs 26.9 ± 4.0 kg/m2, p < 0.01) and fat mass index (FMI, 6.6 ± 3.0 vs 9.2 ± 3.1 kg/m2, p < 0.01). Particularly, PLHIV with HALS (n = 28), defined as those with a FMR above 1.260 and 1.329 for men and women, respectively, had a greater prevalence of type 2 diabetes mellitus (18% vs 1%), insulin resistance (68% vs 27%), hypertriglyceridemia (50% vs 29%), hypertension (61% vs 30%) and metabolic syndrome (32% vs 10%) than those without HALS (p < 0.05 for all comparisons) and controls. At multivariate analyses, FMR in PLHIV was significantly associated (p < 0.05) with fasting glucose (ß [95%CI] = 0.5, [0.1-0.9]), insulin (44.6, [14.9-74.2]), HOMA-IR (1.6, [0.5-2.7]), triglycerides (1.0, [ 0.2-1.8]) and HDL-cholesterol (-2.1, [-3.9/-0.4]) levels. CONCLUSION: Sex-specific FMR thresholds, proposed for diagnosis of HALS, could represent new indices of cardio-metabolic derangement in PLHIV.

Mean GH profile is more accurate than single fasting GH in the evaluation of acromegaly disease control during somatostatin receptor ligands therapy.

PURPOSE: This study aims to compare the accuracy of mean GH profile (GHP) < 2.5 ng/ml and single fasting GH (SGH) < 1 ng/ml in the evaluation of disease control in acromegaly patients during somatostatin receptor ligands (SRLs) therapy. METHODS: We retrospectively enrolled 100 acromegaly patients, 68 responder, and 32 partial responder to SRLs. Controlled disease has been defined as IGF-I levels within age-related normal limits, while partial response as pathological IGF-I values despite a reduction ≥ 50%. In all patients, GHP, SGH, IGF-I, and IGFBP-3 were evaluated. RESULTS: Median GHP levels (1.2 ng/ml, IQR 0.5-2.3 ng/ml) were lower (p = 0.001) than SGH (1.9 ng/ml, IQR 1.0-3.6 ng/ml). Accuracy of GHP was 81%, whereas that of SGH was 55%, with a Kappa index of 0.520 and 0.237, respectively. In multivariable analysis GHP (p = 0.002) and IGFBP-3 (p = 0.004), but not SGH, were independently associated with normal IGF-I levels. At receiver-operator characteristic curve (ROC) analysis GHP cut-off sensitivity and specificity were 94.1% and 50.0%, respectively, while SGH sensitivity and specificity were 35.3% and 93.7%, respectively. Finally, in obese patients the GH cut-off level (both as SGH and GHP) associated to good disease control was significantly different with respect to not obese ones. CONCLUSIONS: GHP associates with IGF-I (and therefore with appropriate control of disease) with higher accuracy than SGH. When GH evaluation is needed, the measurement of mean GHP should be preferred and use of BMI-related cut-offs is suggested.

Optimal timing of blood samplings to detect GH inhibition during oral glucose tolerance test.

BACKGROUND: In patients with suspected acromegaly, evaluation of IGF-I is recommended as first-line test, while the assessment of GH-nadir during oral glucose tolerance test (OGTT) is advised as confirmatory test. The procedure of this test generally involves GH measurement every 30 min (30') from baseline to +120' or +180'. However, the optimal timing of samplings for the distinction between patients with or without active acromegaly is still a matter of debate. METHODS: Sixty-seven healthy subjects and 46 acromegalic patients who achieved documented and persistent long-term cure were enrolled. A greedy algorithm was used to identify the minimal subset of time-points that sufficed to correctly detect GH suppression. RESULTS: The sampling at 90' was the one in which a GH level < 1 µg/L was most frequently achieved (i.e., in 91.3% of cured acromegalic patients and in 91.0% of healthy subjects). Considering the whole cohort, the best combination of 2 time-points was +90' and +150' and achieved 95.6% accuracy; the best combination of 3 time-points was +60', +90' and +150' and achieved 99.1% accuracy. The minimal subset of GH determinations that demonstrated perfect accuracy (100%) needed the inclusion of 4 time-points, namely +60', +90', +120' and +150'. CONCLUSION: A subset of 4 time-points (60' - 90' - 120' - 150') was identified as the most relevant to detect GH suppression at OGTT, with a perfect classification of 100% of subjects. This supports the possibility to restrict the blood samplings to these time-points when assessing disease cure, with possible advantages in terms of saving time and lowering costs.