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.

Efficacy and safety of high-dose long-acting repeatable octreotide as monotherapy or in combination with pegvisomant or cabergoline in patients with acromegaly not adequately controlled by conventional regimens: results of an open-label, multicentre study.

INTRODUCTION: Long-acting repeatable (LAR) octreotide i.m. is a potent, synthetic somatostatin analogue (SSA) that requires less frequent dosing and offers quality of life (QoL) benefits in acromegaly patients compared to its shorter-acting predecessor. This study investigated the efficacy and safety of high-dose Sandostatin® LAR® as monotherapy or in combination with pegvisomant or cabergoline in acromegalic patients with pituitary adenomas following previous failure of conventional SSA treatment. MATERIAL AND METHODS: After three months of high-dose Sandostatin® LAR® monotherapy (40 mg), patients who achieved biochemical control (n = 7) continued to receive the same treatment for an additional four months, whereas uncontrolled patients were randomised to receive high-dose Sandostatin® LAR® in combination with pegvisomant (n = 31) or cabergoline (n = 32). Outcomes included biochemical response at eight months, QoL, and safety. RESULTS: After three months, 3 of 68 (4.4%) evaluable patients achieved a biochemical control (BC) as assessed by levels of growth hormone and insulin-like growth factor-1. At eight months, 4 of 67 (6.0%) patients achieved BC, including one receiving monotherapy and three receiving Sandostatin® LAR® plus cabergoline. Partial response rate, improvements in acromegaly signs and symptoms, and changes in QoL were similar for all three groups. All treatments were well tolerated with a slight excess of adverse events in the combination arms. There were no deaths or serious adverse events leading to treatment discontinuation. CONCLUSION: These data demonstrate that high-dose Sandostatin® LAR® as monotherapy or in combination with pegvisomant or cabergoline is a feasible salvage option in patients with pituitary adenomas not adequately controlled on conventional SSA regimens.

No greater incidence or worsening of cardiac valve regurgitation with somatostatin analog treatment of acromegaly.

CONTEXT: Excess GH and IGF-I in acromegaly are associated with reduced life expectancy due to cardiovascular complications. OBJECTIVE: The objective of the study was to investigate the prevalence, incidence, and severity of cardiac valve regurgitation before and after somatostatin-analog treatment in acromegaly. DESIGN: This was a prospective, observer-blinded, multicenter, 12-month study. SETTING: The study was conducted at 33 specialist centers. PATIENTS: The study population consisted of 225 adult patients with acromegaly without significant cardiac valve abnormalities or prior valve-replacement surgery, matched for age, sex, and center/country/study. INTERVENTIONS: Interventions included initiation/continuation of lanreotide (n = 107) or octreotide treatment (n = 118), tailored for optimal disease control. MAIN OUTCOME MEASURES: Relative risk of new/worsening regurgitation in any valve at 12 months compared with baseline, was measured. RESULTS: At baseline, almost 80% of patients had some degree of cardiac valve regurgitation, although none was severe. The risk of developing new/worsening regurgitation in any valve at 12 months was nonsignificant and similar for the cohorts [adjusted odds ratio 0.86; 95% confidence interval (CI) 0.41-1.82; P = 0.694; relative risk 1.04; 95% CI 0.67-1.60; risk difference 0.01; 95% CI -0.13 to 0.16]. For 54% of patients, the severity of regurgitation stayed the same during the study. At baseline, significant valve regurgitation occurred in 18% of patients (lanreotide cohort) and 13% (octreotide cohort) and at 12 months in 18% of each cohort. CONCLUSIONS: The incidence of valve regurgitation did not change over 12 months of treatment with somatostatin analogs, and most cases were physiologic or mild in severity. There was no significant difference between somatostatin analogs in the risk of developing new/worsening valve regurgitation or significant regurgitation after 1 yr.

Effect of environment on growth: auxological and hormonal parameters in African and Italian children.

OBJECTIVE: Genetic factors are the most important determinant of final height in developed countries, while in underprivileged countries food intake is crucial. Nutrients, in turn, may importantly affect IGF-IGFBP system which is a critical regulator of growth. The aim of this study was to evaluate the influence of nutrition on IGF system components, as well as on growth by comparing these variables in two selected populations of children living either in poor or in privileged environmental conditions. DESIGN: Height and weight were recorded in 38 normal African children, living in a Catholique Mission in Ivory Coast, and in 93 normal Italian children. IGF-I, IGF-II, IGFBP-3 and ALS were evaluated in all subjects. RESULTS: A normal height in spite of markedly reduced IGF-I, IGFBP-3, ALS and BMI was observed in African children, while the ratio IGF-I/IGFBP-3 was comparable in the two populations. IGF-II was slightly but significantly higher in Africans than in Italians. CONCLUSIONS: In Africans a suboptimal nutritional condition may produce a dramatic reduction of IGF-I, ALS and IGFBP-3, although the final height results minimally affected. This suggests that only a small fraction of the circulating IGF-I is sufficient for growth and confirms what has been reported on liver IGF-I-deficient and ALS knock-out mice. The secular statural trend observed in developed countries is probably due to the increase of IGF-I consequent to the improved nutritional conditions.