Cardiac function in growth hormone deficient patients before and after 1 year with replacement therapy: a magnetic resonance imaging study

Abstract

Assessed by conventional echocardiography the influence of growth hormone deficiency (GHD) and effects of replacement therapy on left ventricle (LV) function and mass (LVM) have shown inconsistent results. We aimed to evaluate cardiac function before and during replacement therapy employing the gold standard method cardiac magnetic resonance imaging (CMRI) and measurements of circulating levels of B-type natriuretic peptides. Sixteen patients (8 males and 8 females, mean age 49 years (range 18-75)) with severe GHD and 16 matched control subjects were included. CMRI was performed at baseline and after 1 year of GH replacement therapy. IGF-I, B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP) were measured after 0, 1, 2, 3, 6 and 12 months of treatment. IGF-I Z-score increased from (median (IQR)) -2.3 (-3.8 to -1.4) to 0.5 (-0.3 to 1.7). LVM index (LVMI), ejection fraction (range 63-80%), cardiac output index and levels of BNP and NT-proBNP were similar at baseline in patients compared to controls (P-values from 0.09 to 0.37). The patients had significantly smaller LV end-diastolic volume index (P = 0.032) and end-systolic volume index (P = 0.038). No significant change in LV systolic function or LVM occurred during 1 year of GH treatment. BNP levels were unchanged (P = 0.88), whereas NT-proBNP tended to decrease (P = 0.052). Assessed by the highly sensitive and precise CMRI method, untreated GHD was not associated with impaired systolic function or reduced LVMI and 1 year of GH replacement using physiological doses did not influence cardiac mass or function.

Characterisation of myocardial structure and function in adult-onset growth hormone deficiency using cardiac magnetic resonance

“…Despite using lower GH doses than many older studies, we were able to show that GHD patients demonstrate a significant increase in LVMi with 1 year of GH treatment. Andreasson’s CMR study of 16 AO-GHD patients receiving similar doses of GH to this study showed a strong trend towards increased LV mass over 1 year ( p  = 0.059), validating this finding [22]. The improved accuracy of CMR over previous methods of measuring cardiac mass has been able to show that untreated AO-GHD is likely to be associated with reduced cardiac mass, although larger numbers would be needed to fully demonstrate this, and that GH replacement increases cardiac mass in GHD.…”

“…CMR has been used to study a range of cardiomyopathies, including hypertrophic cardiomyopathy, Marfan and Turner syndromes [19–21]. Currently, there is only one other CMR study assessing the impact of GH deficiency on the heart and this study confined itself to reporting the effects on the left ventricle (LV) [22]. The effects of GH deficiency on the right ventricle (RV) and aortic area (AA) have not previously been studied in these patients using CMR.…”

GH activity and markers of inflammation: a crossover study in healthy volunteers treated with GH and a GH receptor antagonist

“…After 3 weeks of GH treatment, IGF1 levels were comparable to levels measured in untreated acromegalic patients using the same IGF1 assay (31). IGF1 levels after 3 weeks of GH receptor blockage were somewhat higher than in our last series of untreated GH-deficient patients (91 (78-114) vs 60 (43-84) mg/l) (32). Serum GH showed a stepwise increase parallel to the escalating doses of injected GH (Fig.…”

Active acromegaly is associated with decreased hs-CRP and NT-proBNP serum levels: insights from the Belgian registry of acromegaly

“…High levels of NT-proBNP are observed in patients with severe GH deficiency and are corrected by GH therapy (13,34,35). However, in such conditions, the observed changes in these natriuretic peptides are not correlated with changes in cardiac structure or function (35,36,37), thus suggesting that effects of GH are here independent of cardiovascular alterations. Alternatively, indirect effects of GH through its effects on kidney filtration and fluid equilibrium may also be considered.…”