Retrospective Analysis of Endocrine Dysfunctions in a Population of Adult Polytransfused Patients: Correlation of GH-IGF1 Axis Alteration with Cardiac Performance

Endocrine complications of haemochromatosis and heart failure mostly affect morbidity and mortality in polytransfused patients. This study analyzes endocrine dysfunctions and the impact of GH-IGF-1 axis alteration on cardiac performance in a population of 31 patients. A retrospective study on 31 Caucasian polytransfused outpatients, 27 adults and 4 pediatric, residing in Apulia, Italy, followed from 2005 to 2016, was conducted. Patients underwent basal and dynamic hormonal evaluation. GHRH plus arginine test was performed in 21 patients (19 adults and 2 children). Among them, 9 patients were affected by left ventricle diastolic dysfunction and/or atrial or ventricular dilatation (HD group) and 12 patients did not have cardiovascular disease (non-HD group). Twenty-nine out of 31 patients (94%) had at least one endocrinopathy. We found severe or mild GH deficit (GHD) in all HD patients versus 3 patients in the non-HD group (p=0.001). Mean IGF-1 levels were significantly lower in the HD group than in non-HD subjects (53±30 versus 122±91 μg/L, p=0.04). Our study confirms the need to perform a dynamic evaluation of the GH-IGF1 axis in polytransfused patients, especially when heart dysfunction emerges. An intervention study with GH replacement therapy in a larger randomized adult population will clarify the role of GH/IGF axis on cardiovascular outcomes in this patient population.

Growth hormone and the cardiovascular system

This review highlights current concepts of physiological and pathophysiological effects of growth hormone on the heart. The data of international clinical studies concerning the influence of GH deficit and excess on the cardiovascular system are discussed with special reference to such clinical conditions as somatotrophic pituitary insufficiency and acromegaly. Result of analysis of parameters of the cardiovascular system in the patients receiving growth hormone substitution therapy for somatotrophic insufficiency and GH-suppressive therapy of acromegaly are presented

Impact of different cut-off limits of peak GH after GHRH-arginine stimulatory test, single IGF1 measurement, or their combination in identifying adult patients with GH deficiency

ObjectiveTo evaluate the impact of different peak GH cut-off limits after GHRH-Arg test, IGF1 measurement, or their combination in identifying patients with GH deficit (GHD).Design and patientsTotally, 894 normal subjects (used for determining IGF1 normative limits) and 302 patients with suspected GHD were included. Different peak GH cut-off limits (used by European (depending on body mass index (BMI)) or North American (4.1 μg/l) Endocrine Societies, by HypoCCs (2.5 μg/l), or with 95% specificity (based on BMI), Method 1, 2, 3, or 4 respectively) and IGF1 were considered.MethodsPeak GH after GHRH-Arg and IGF1.ResultsDifferent peak GH cut-off limits recognized different proportions of GHD (range, 24.8–62.9%). Methods 1 and 2 with high sensitivity recognized a higher proportion (95.5 and 92.5% respectively) of GHD among patients with three (T) pituitary hormone deficits (HD), whereas Method 4 (with high specificity) identified 96.7% normal subjects among those without pituitary HD; on the contrary, Method 4 identified only 75% GHD among patients with THD, whereas Method 1 recognized a high proportion (40%) of GHD among subjects without HD. Of the total patients, 82% with THD and 84.5% without HD were recognized as GHD or normal respectively by IGF1. Among the remaining patients with THD and normal IGF1, 75% was recognized as GHD by Method 1; among patients without HD and abnormal IGF1, 87.5% was identified as normal by Method 4. Overall, combination of IGF1 and Method 1 or Method 4 identified 95.5% GHD among patients with THD and 98.1% normal subjects among those without HD.ConclusionsSingle peak GH cut-offs have limits to sharply differentiate GHD from normal subjects; IGF1 may be used for selecting patients to be submitted to the GHRH-Arg test; the peak GH cut-off limits to be used for identifying healthy or diseased patients depend mainly on the clinical context.

Auxological criteria for the diagnosis of GH-dependent short stature and prescription of rGH: problems and pitfalls

Recombinant growth hormone (rGH) administration is a cornerstone in the treatment of short stature secondary to GH deficit. Since its introduction in the 80s, the population of short patients with an indication to rGH therapy has clearly broadened, probably because of increased awareness by patients and physicians. Since rGH therapy is demanding for patients and expensive, the Italian National Health Service, like other third payers and regulatory authorities, regulates its prescription according to criteria listed in the Nota AIFA 39. This paper illustrates pitfalls and difficulties paediatricians may encounter when assessing short stature patients in order to decide upon the opportunity and possibility to initiate rGH therapy through the exposition of four emblematic, though hypothetical, clinical histories. In the discussion, the Authors highlight some of the most critical points in the formulation of the Nota 39, among which are the lack of clear reference values, neglecting of parental height targets and therapeutic responses, as well as some omissions in methodology specifications.

Functional aspects of genetic variability in the GH genomic region

Because of the small differences among genotypes, it would be difficult in basal conditions to detect the effect of genetic polymorphism in endocrine function, but this could emerge during provocative tests. We have studied four polymorphic sites of the GH gene region (17q24.2), MSPIA, MSPIB, BGLIIA, and BGLIIB. Gene and haplotype distributions in classes of growth retardation have been studied. The outcome of GH diagnostic test in relation to GH region genotypes has been evaluated by the analysis of area under the GH secretory curve. Ninety-eight growth retarded children have been studied. On the basis of provocative GH test these children were classified as total GH deficit (TD), partial GH deficit (PD), and familial short stature (FSS) with no deficit of GH. Sixty-three healthy controls were also considered. An increased frequency of MSPIA*2 allele in PD and TD as compared with FSS children and controls has been observed suggesting that this allele is associated with a decreased GH release. BGLIIA*2 allele appears decreased in PD and TD as compared with FSS and controls, suggesting that this allele is associated with an increased release of GH. Carriers of MSPIA*2 allele show a lower GH release as compared with MSPIA *1/*1 subjects on the provocative test by insulin, while carriers of BGLIIA*2 allele show a higher GH release as compared with BGLIIA *1/*1 subjects on the provocative test by clonidine. The functional aspects of genetic variability within the GH genomic area parallel the genetic differences observed between TD and PD versus FSS and control children.