Cardiac Abnormalities in Acromegaly

Cardiovascular disease is claimed to be one of the most severe complications of acromegaly, contributing significantly to mortality in this disease. In fact, an excess of growth hormone (GH) and insulin-like growth factor 1 (IGF-I) causes a specific derangement of cardiomyocytes, leading to abnormalities in cardiac muscle structure and function, inducing a specific cardiomyopathy. In the early phase of acromegaly the excess of GH and IGF-I induces a hyperkinetic syndrome, characterized by increased heart rate and increased systolic output. Concentric hypertrophy is the most common feature of cardiac involvement in acromegaly, found in more than two thirds of patients at diagnosis. This abnormality is commonly associated with diastolic dysfunction and eventually with impaired systolic function ending in heart failure, if the GH/IGF-I excess is left untreated. In addition, abnormalities of cardiac rhythm and of heart valves have also been described in acromegaly. The coexistence of other complications, such as arterial hypertension and diabetes mellitus, aggravates acromegalic cardiomyopathy. Successful control of acromegaly induces a decrease in left ventricular mass and an improvement in diastolic function, while the effects of GH/IGF-I suppression on systolic function are more variable. However, since cardiovascular alterations in young patients with short disease duration are milder than in those with longer disease duration, it is likely to be easier to reverse and/or arrest acromegalic cardiomyopathy in young patients with early-onset disease. In conclusion, careful assessments of cardiac function, morphology, and activity are required in patients with acromegaly. An early diagnosis and prompt effective treatment are important in order to reverse acromegalic cardiomyopathy.     

Cardiovascular complications in acromegaly

Cardiovascular morbidity and mortality are increased in acromegaly. In fact, GH and IGF-I excess induces a specific cardiomyopathy. The early stage of acromegaly is characterized by the hyperkinetic syndrome (high heart rate and increased systolic output). Frequently, concentric biventricular hypertrophy and diastolic dysfunction occur in acromegaly, leading to an impaired systolic function ending in heart failure if the disease is untreated or unsuccessfully untreated. Besides, abnormalities of cardiac rhythm and of valves have been also described in acromegaly. The coexistence of other complications, such as arterial hypertension and diabetes, aggravates the acromegalic cardiomyopathy. The suppression of GH/IGF-I following an efficacious therapy could decrease left ventricular mass and improve cardiac function. In conclusion, a careful evaluation of cardiac function, morphology and activity seems to be mandatory in acromegaly.     

The GH-IGF-I axis and the cardiovascular system: clinical implications

Background GH and IGF‐I affect cardiac structure and performance. In the general population, low IGF‐I has been associated with higher prevalence of ischaemic heart disease and mortality. Both in GH deficiency (GHD) and excess life expectancy has been reported to be reduced because of cardiovascular disease. Objective To review the role of the GH–IGF‐I system on the cardiovascular system. Results Recent epidemiological evidence suggests that serum IGF‐I levels in the low‐normal range are associated with increased risk of acute myocardial infarction, ischaemic heart disease, coronary and carotid artery atherosclerosis and stroke. This confirms previous findings in patients with acromegaly or with GH‐deficiency showing cardiovascular impairment. Patients with either childhood‐ or adulthood‐onset GHD have cardiovascular abnormalities such as reduced cardiac mass, diastolic filling and left ventricular response at peak exercise, increased intima‐media thickness and endothelial dysfunction. These abnormalities can be reversed, at least partially, after GH replacement therapy. In contrast, in acromegaly chronic GH and IGF‐I excess causes a specific cardiomyopathy: concentric cardiac hypertrophy (in more than two‐thirds of the patients at diagnosis) associated to diastolic dysfunction is the most common finding. In later stages, impaired systolic function ending in heart failure can occur, if GH/IGF‐I excess is not controlled. Abnormalities of cardiac rhythm and of cardiac valves can also occur. Successful control of acromegaly is accompanied by decrease of the left ventricular mass and improvement of cardiac function. Conclusion The cardiovascular system is a target organ for GH and IGF‐I. Subtle dysfunction in the GH–IGF‐I axis are correlated with increased prevalence of ischaemic heart disease. Acromegaly and GHD are associated with several abnormalities of the cardiovascular system and control of GH/IGF‐I secretion reverses (or at least stops) cardiovascular abnormalities.     

Beginning to end: Cardiovascular implications of growth hormone (GH) deficiency and GH therapy

Both growth hormone (GH) and insulin-like growth factor I (IGF-I) are involved in heart development and in maintenance of cardiac structure and performance. Cardiovascular disease has been reported to reduce life expectancy in both GH deficiency (GHD) and GH excess. Patients with GHD suffer from a cluster of abnormalities associated with increased cardiovascular risk, including abnormal body composition, unfavorable lipid profile, increased fibrinogen and C-reactive protein levels, insulin resistance, early atherosclerosis and endothelial dysfunction, and impaired left ventricular (LV) performance (i.e., reduced diastolic filling and impaired response to peak exercise). Long-term GH replacement therapy reverses most of these abnormalities. More consistently, GH replacement reduces body fat and visceral adipose tissue, reduces low-density lipoprotein cholesterol and triglyceride levels, and improves endothelial function. GH replacement also reduces intima media thickness at major arteries and improves LV performance, but these results have been observed only in small series of patients treated on a short-term basis. This review discusses the roles of GHD and GH replacement therapy in the development of cardiovascular disease.     

Growth hormone and the heart

Impaired cardiovascular function has recently been demonstrated to potentially reduce life expectancy both in GH deficiency and excess. Experimental and clinical studies have supported the evidence that GH and IGF-I are implicated in cardiac development. In most patients with acromegaly a specific cardiomyopathy, characterized by myocardial hypertrophy with interstitial fibrosis, lympho-mononuclear infiltration and areas of monocyte necrosis, results in biventricular concentric hypertrophy. In contrast, patients with childhood or adulthood-onset GH deficiency (GHD) may suffer both from structural cardiac abnormalities, such as narrowing of cardiac walls, and functional impairment, that combine to reduce diastolic filling and impair left ventricular response to peak exercise. In addition, GHD patients may have an increase in vascular intima-media thickness and a higher occurrence of atheromatous plaques, that can further aggravate the haemodynamic conditions and contribute to increased cardiovascular and cerebrovascular risk. However, several lines of evidence have suggested that the cardiovascular abnormalities can be partially reversed by suppressing GH and IGF-I levels in acromegaly or after GH replacement therapy in GHD patients.
Recently, much attention has been focussed on the ability of GH to increase cardiac mass suggesting its possible use in the treatment of chronic nonendocrine heart failure. In fact, GH administration can induce an improvement in haemodynamic and clinical status in some patients. Although these data need to be confirmed in more extensive studies, such promising results seem to open new perspectives for GH treatment in humans.     

Cardiovascular consequences of early-onset growth hormone excess

Acromegaly has relevant effects on the cardiovascular system, but few data deal with the early effects of GH and IGF-I excess. To study the early stage of acromegalic cardiomyopathy and give indirect evidence of the mechanisms underlying GH and IGF-I action on the human heart, 25 patients with uncomplicated acromegaly [15 young subjects with short-term (< or =5 yr) disease and 10 with long-term (>5 yr) disease] and 25 sex- and age-matched controls were studied. Cardiovascular risk parameters were studied by standard methods; cardiac morphology by M-mode and Doppler echocardiography, cardiac function at rest and at peak exercise by equilibrium radionuclide angiography, and vascular disease at common carotid arteries by Doppler ultrasonography. In the patient group these measurements were repeated after 6 months of treatment with octreotide-LAR (20-40 mg, im, every 28 d). Glucose, glycosylated hemoglobin, insulin, low density lipoprotein cholesterol, triglycerides, and fibrinogen levels were higher, and high density lipoprotein cholesterol levels were lower in acromegalic patients than in controls. Resting blood pressure was similar in patients and controls, whereas heart rate at rest and systolic blood pressure at peak exercise were higher in the patients. The left ventricular mass index was higher in acromegalic patients than in controls (123.3 +/- 8.9 vs. 81.5 +/- 4.3 g/m(2); P < 0.001); seven patients had left ventricular hypertrophy. Diastolic function was similar in the two groups. The ejection fraction at rest, but not at peak exercise, was significantly increased in the patients compared with controls. As a consequence the exercise-induced changes in the ejection fraction were lower in patients than controls (8.7 +/- 1.1% vs. 21.9 +/- 3.5%; P < 0.001). At common carotid ultrasonography, young patients with acromegaly had increased diastolic peak velocity and increased intima media thickness, even if neither patient nor controls had atherosclerotic plaques. Six months after OCT-LAR treatment, GH and IGF-I levels remarkably decreased in all patients; 8 (53.3%) achieved disease control. Insulin, total cholesterol, and fibrinogen levels reduced, whereas high density lipoprotein cholesterol levels increased. Both at rest and at peak exercise, heart rate significantly decreased, whereas systolic and diastolic blood pressures did not change. The left ventricular mass index was significantly reduced, but it was still higher than the control value (101.6 +/- 3.5 g/m(2); P < 0.01). The left ventricular ejection fraction at rest was significantly reduced, but its response at peak exercise was increased (16.3 +/- 2.4%), becoming similar to the control value. At common carotids, the intima media thickness of right and left arteries was significantly reduced as was the diastolic peak velocity without any change in systolic peak velocity. Short-term GH excess, despite causing enhanced cardiac performance at rest, reduces cardiac performance on effort and impairs vascular morphology. These deleterious effects of early-onset acromegaly are ameliorated by suppressing GH/IGF-I levels for 6 months.     

Influence of Growth Hormone on Cardiovascular Health and Disease

Experimental and clinical studies indicate that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) are involved in heart development. Impaired cardiovascular function, as recently demonstrated, could potentially reduce life expectancy both in GH deficiency (GHD) and excess. Patients with childhood- or adult-onset GHD may have both cardiac structural and functional abnormalities, i.e. reduced cardiac mass, reduced diastolic filling, and impaired left ventricular response to peak exercise. In addition, GHD patients may present with an increase in vascular intima-media thickness and a higher occurrence of atheromatous plaques that can further aggravate the hemodynamic conditions and contribute to the increased cardiovascular and cerebrovascular risk. However, some evidence has been provided to show that cardiovascular abnormalities can be partially reversed after somatropin (recombinant GH) therapy in patients with GHD. Recently, somatropin administration was shown to induce improvement in hemodynamics and clinical status in some patients with heart failure. Although these data need to be confirmed in more extensive studies, such promising results open new perspectives for somatropin therapy. The role of GH secretagogues in heart failure is still unknown.     

Conditional cardiovascular response to growth hormone therapy in adult patients with Prader-Willi syndrome

CONTEXT: In Prader-Willi syndrome (PWS), an altered GH secretion has been related to reduced cardiac mass and systolic function when compared with controls. OBJECTIVES: The objective of the study was to evaluate the cardiovascular response to GH therapy in adult PWS patients. STUDY PARTICIPANTS: Thirteen obese PWS adults (seven males and six females, aged 26.9+/-1.2 yr, body mass index 46.3+/-1.6 kg/m2) participated in the study. METHODS: Determination of IGF-I, metabolic parameters, echocardiography, and cardioscintigraphy with dobutamine stimulation was made during 12 months GH therapy, with results analyzed by repeated-measures ANOVA. RESULTS: GH therapy increased IGF-I (P<0.0001); decreased C-reactive protein levels (P<0.05); and improved lean mass (P<0.001), fat mass (P<0.05), and visceral fat (P<0.001). Echocardiography showed that 6- and 12-month GH therapy increased left ventricle mass in 76 and in 61% of patients, respectively (P<0.05), did not change diastolic function, and slightly decreased the left ventricle ejection fraction (LVEF) (P=0.054). Cardioscintigraphy documented stable values of LVEF throughout the study, whereas right ventricle ejection fraction decreased significantly (P<0.05) being normally responsive to dobutamine infusion. A positive association between IGF-I z-scores and LVEF occurred at the 6- and 12-month follow-up (P<0.05). CONCLUSIONS: In PWS, GH therapy increased cardiac mass devoid of diastolic consequences. The observation of a slight deterioration of right heart function as well as the association between IGF-I and left ventricular function during GH therapy suggest the need for appropriate cardiac and hormonal monitoring in the therapeutic strategy for Prader-Willi syndrome.     

The cardiovascular risk of adult GH deficiency (GHD) improved after GH replacement and worsened in untreated GHD: a 12-month prospective study

Increased cardiovascular morbidity and mortality were reported in GH deficiency (GHD), and GH replacement can ameliorate cardiac abnormalities of adult GHD patients. To test the potential progression of untreated GHD on the cardiovascular risk and cardiac function, cardiovascular risk factors, cardiac size, and performance were prospectively evaluated in 15 GHD patients (age, 18-56 yr) who were treated with recombinant GH at the dose of 0.15-1.0 mg/d, 15 GHD patients (age, 18-56 yr) who refused GH replacement, and 30 healthy subjects (age, 18-53 yr). Electrocardiogram, systolic and diastolic blood pressure, and heart rate measurement, serum IGF-I, total cholesterol, low- and high-density lipoprotein (LDL, HDL) cholesterol, triglycerides, and fibrinogen level assay, echocardiography, and equilibrium radionuclide angiography were performed basally and after 12 months. At study entry, low IGF-I levels, unfavorable lipid profile, and inadequate cardiac and physical performance were found in GHD patients compared with controls. After 12 months of GH treatment, IGF-I levels normalized; HDL-cholesterol levels, left ventricular (LV) mass index (LVMi), left ventricular ejection fraction (LVEF) at peak exercise, peak filling rate, exercise duration and capacity significantly increased; total- and LDL-cholesterol levels significantly decreased. After 12 months in GH-untreated GHD patients, IGF-I levels remained stable, and HDL-cholesterol levels, LVEF both at rest and at peak exercise, and exercise capacity were further reduced; total- and LDL-cholesterol levels increased slightly. LVEF at rest and its response at peak exercise normalized in 60 and 53.3%, respectively, of GH-treated patients and in none of the GH-untreated patients. In conclusion, 12 months of GH replacement normalized IGF-I and improved lipid profile and cardiac performance in adult GHD patients. A similar period of GH deprivation induced a further impairment of lipid profile and cardiac performance. This finding strongly supports the need of GH replacement in adult GHD patients.     

Systemic hypertension and impaired glucose tolerance are independently correlated to the severity of the acromegalic cardiomyopathy

Increased mortality from cardiovascular diseases has been reported in acromegaly. Our objective was to evaluate the impact of glucose tolerance abnormalities and/or systemic hypertension in further worsening the acromegalic cardiomyopathy. The study design was open transversal. The subjects studied were 130 consecutive naive acromegalic patients (74 women and 56 men; age, 17-80 yr). Interventricular septum (IST) and left ventricular (LV) posterior wall thickness (PWT), LV mass index (LVMi), maximal early to late diastolic flow velocity ratio (E/A), isovolumic relaxation time (IRT), and LV ejection fraction (EF) were measured by echocardiography. The results were analyzed in line with the presence of glucose tolerance abnormalities (normal in 60, impaired in 38, diabetes mellitus in 32) and the presence (in 46) or absence (in 84) of hypertension. Patients with impaired glucose tolerance and diabetes mellitus had significantly higher age (P = 0.01), and systolic (P = 0.01) and diastolic (P = 0.01) blood pressures and lower E/A (P = 0.01) and EF (P = 0.01) than those with normal glucose tolerance. Disease duration, circulating GH and insulin-like growth factor I (IGF-I) levels, IST, LVPWT, LVMi, and IRT were similar in the 3 groups. Normotensive patients had significantly lower age (P<0.001), LVPWT (P<0.001), IST (P = 0.003), LVMi (P<0.001), and IRT (P = 0.02) and significantly higher E/A (P<0.001) and EF (P<0.001) than hypertensive subjects. Disease duration, circulating GH, and IGF-I levels were similar in the 2 groups. Multiple regression analysis showed that systolic blood pressure was the strongest predictor of LVMi (P = 0.0004), followed by GH levels (P = 0.02), whereas diastolic blood pressure was the strongest predictor of LVEF reduction (P<0.0001), followed by glucose tolerance status (P = 0.02). Age was the strongest predictor of both E/A impairment (P<0.0001) and IRT (P = 0.01), followed by IGF-I levels (P = 0.02). Compared to patients with uncomplicated acromegaly, those with hypertension but without abnormalities of glucose tolerance had an increased prevalence of LV hypertrophy (75% vs. 37.2%) as well as of impaired diastolic (50% vs. 7.8%) and systolic function (18.7% vs. 3.9%), whereas patients with glucose tolerance abnormalities but without hypertension had only an increased prevalence of impaired diastolic (39.7%) and systolic function (31.7%). The subgroup of acromegalic patients suffering from hypertension and diabetes mellitus had the highest prevalence of LV hypertrophy (84.6%), diastolic filling abnormalities (69.2%), and impaired systolic function at rest (53.9%). A careful cardiac investigation should thus be performed in all acromegalic patients showing these complications.     

Noninvasive assessment of left ventricular diastolic function by pulsed Doppler echocardiography in patients with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy is a primary myocardial disease in which symptoms may frequently result from impaired left ventricular relaxation, filling and compliance. In the present investigation, Doppler echocardiography was utilized to measure transmitral flow velocity and thereby assess left ventricular diastolic performance noninvasively in a group of 111 patients representative of the broad clinical spectrum of hypertrophic cardiomyopathy. In patients with hypertrophic cardiomyopathy, all Doppler indexes of diastolic relaxation and filling differed significantly (p less than 0.001) from those obtained in 86 control subjects without heart disease, namely, prolongation of isovolumic relaxation (94 +/- 24 versus 78 +/- 12 ms) and of the early diastolic peak of flow velocity (244 +/- 55 versus 220 +/- 28 ms), as well as slower deceleration (3.4 +/- 1.4 versus 4.9 +/- 1.3 m/s2) and reduced maximal flow velocity in early diastole (0.5 +/- 0.2 versus 0.6 +/- 0.1 m/s). As an apparent compensation for impaired relaxation and early diastolic filling, the atrial contribution to left ventricular filling was increased, as shown by increased late diastolic flow velocity (0.4 +/- 0.3 versus 0.3 +/- 0.1 m/s) and reduced ratio of maximal flow velocity in early diastole to that in late diastole (1.4 +/- 0.8 versus 2.1 +/- 0.9). The vast majority of patients with hypertrophic cardiomyopathy (91 [82%] of 111) showed evidence of impaired left ventricular diastolic performance, as assessed from the Doppler waveform. Abnormal Doppler diastolic indexes were identified with similar frequency in patients with (78%) or without (83%) left ventricular outflow obstruction, as well as in patients with (84%) or without (80%) cardiac symptoms. However, patients with nonobstructive hypertrophic cardiomyopathy showed more severe alterations in the Doppler indexes of diastolic function than did patients with obstruction. Thus, abnormal diastolic performance as assessed by Doppler echocardiography was apparent in the vast majority of the study patients with hypertrophic cardiomyopathy, independent of the presence or absence of cardiac symptoms or a subaortic pressure gradient. The high frequency with which diastolic abnormalities are identified in asymptomatic patients with hypertrophic cardiomyopathy suggests that impaired diastolic performance may be present at a time in the natural history of the disease when functional limitation is not yet evident.     

Management of obesity cardiomyopathy

Therapy of acute exacerbations of congestive heart failure associated with obesity cardiomyopathy consists of dietary salt restriction, inspired oxygen, diuretics, and angiotensin-converting enzyme inhibitors or, if left ventricular systolic dysfunction is present, hydralazine/isosorbide dinitrate. Digitalis may be indicated in selected cases. These measures may also be useful chronically in association with weight loss. Substantial weight loss is capable of reversing all of the hemodynamic abnormalities associated with obesity except elevation of left ventricular filling pressure. Substantial weight loss may also reduce left ventricular mass and improve left ventricular diastolic filling in those with left ventricular hypertrophy before weight loss. Left ventricular systolic function also improves after weight loss in those with impaired pre-weight-loss systolic function. These beneficial effects of weight loss occur partly because of favorable alterations in left ventricular loading conditions. Substantial weight loss in patients with congestive heart failure associated with obesity cardiomyopathy produces a reversal of many of the clinical manifestations of cardiac decompensation and improves New York Heart Association functional class in most patients.     

Cardiovascular involvement in patients affected by acromegaly: An appraisal

Cardiovascular complications are frequent in acromegalic patients. Several studies reported increased prevalence of traditional cardiovascular risk factors and early development of endothelial dysfunction and of structural vascular alterations, with subsequent increased risk of coronary artery disease. Furthermore, chronic exposure to high levels of GH and IGF-I leads to the development of the so called “acromegalic cardiomyopathy”, characterized by concentric biventricular hypertrophy, diastolic dysfunction and, additionally, by progressive impairment of systolic performance leading to overt heart failure. Cardiac valvulopathies and arrhythmias have also been documented and may concur to the deterioration of cardiac function. Together with strict control of cardiovascular risk factors, early control of GH and IGF-I excess, by surgical or pharmacological therapy, has been reported to ameliorate cardiac and metabolic abnormalities, leading to a significant reduction of left ventricular hypertrophy and to a consistent improvement of cardiac performance.     

Growth hormone and cardiac function

Impaired cardiovascular function, which may reduce life expectancy, has recently been demonstrated both in GH deficiency and excess. Moreover, experimental and clinical studies support the evidence implicating GH and/or IGF-I in the regulation of heart development. The existence of a specific acromegalic cardiomyophathy characterized by myocardial hypertrophy with interstitial fibrosis, lympho-mononuclear infiltration and areas of monocyte necrosis which often result in biventricular concentric hypertrophy has been recenty demonstrated. By contrast, patients with childhood or adulthood-onset GH deficiency (GHD) present with abnormalities of structure and function of the left ventricle. In these patients, a significant increase in the vascular intima-media thickness and an increased number of atheromatous plaques have also been reported. The abnormalities of cardiovascular system could be partially reverted by suppressing GH and IGF-I levels in acromegaly or after GH remplacement therapy in GHD patients. The evidence that GH is able to increase cardiac mass suggested its use in the -treatment of chronic heart failure of diverse etiologies. GH administration was -demonstrated to induce an improvement in hemodynamics and clinical status in some patients. Although these data should be confirmed in double-blind placebo controlled studies in larger series, the promising results open new perspectives for GH treatment in humans.     

Left ventricular diastolic function abnormalities in hypopituitary patients with GH deficiency: evidence for a subclinical cardiomyopathy

The aim of this study was to evaluate cardiac performance, in particular diastolic function, in adult patients with adulthood onset GH deficiency. The study group was composed of 19 GH deficient adult hypopituitary patients with at-least 3 additional pituitary hormone deficits and 19 age, sex and BMI matched healthy controls. Mean duration of hypopituitarism was 108.6 +/- 77.0 months. None of the patients and controls presented with or had previous diagnosis of concomitant diseases that could affect cardiac function. All hormone deficiencies, except for GH, were appropriately replaced in the patients. Left ventricular function and geometry were evaluated by two-dimensional, M-mode and Doppler echocardiography. Body composition was evaluated by bioelectrical impedance analysis. Not significant differences were observed with respect to left heart dimensions and left ventricular systolic function between patients and controls. Nevertheless 2 of the left ventricular diastolic function parameters, deceleration time and isovolumetric relaxation time, were significantly prolonged in the patients compared with controls (247.88 +/- 70.65 vs 143.26 +/- 31.70 milliseconds (ms) and 122.31 +/- 18.24 vs 89.47 +/- 12.12 ms respectively, p<0.001). Duration of hypopituitarism was significantly correlated with percent body fat mass (r=0.6119, p<0.01) and percent lean body mass (r=-0.5949, p<0.01). It is concluded that in adults affected by hypopituitarism, GH deficiency predominantly impairs diastolic function while systolic function at rest is spared. This observation might indicate a preclinical stage of a cardiomyopathy.     

Left ventricular morphology and diastolic function in uraemia: echocardiographic evidence of a specific cardiomyopathy.

OBJECTIVE--To see whether cardiac morphological and functional abnormalities in uraemic patients are determined by high blood pressure or if they are an expression of a specific cardiomyopathy. DESIGN--Cross sectional study. SETTING--City general hospital in Italy. SUBJECTS--35 uraemic patients receiving haemodialysis (17 men, 18 women; mean age 60.3 (11.2); mean duration of dialysis 52 months) were selected from the 64 patients in Venice who were receiving dialysis; subjects with diabetes, haemochromatosis, valvar dysfunction, regional dyskinesias, and pericarditis were excluded. 19 control normotensive subjects (6 men and 13 women), matched for age. MAIN OUTCOME MEASURES--Echocardiographic measurements of left atrium, left ventricular end diastolic and end systolic volume, aortic root diameter, posterior wall and interventricular septum thickness, left ventricle mass index, and ejection fraction in controls and in patients according to whether they were normotensive (five men, eight women) or hypertensive (12 men, 10 women) on 48 hour ambulatory monitoring; left ventricular diastolic function by Doppler ultrasonography. RESULTS--Mean systolic and diastolic pressures, daytime systolic and diastolic pressures, and night time systolic and diastolic pressures were significantly higher in the hypertensive patients than in the normotensive patients. The normotensive patients had similar blood pressures to the controls. Left ventricular mass correlated significantly with the mean diastolic pressure and mean night time systolic and diastolic pressures. Parathyroid hormone concentrations were similar in the two groups of patients. Diastolic relaxation was impaired to the same degree in the two groups of patients. Parameters of diastolic function showed no relation to left ventricular mass, which was significantly higher in the hypertensive than in the normotensive patients. CONCLUSIONS--Uraemia is likely to induce specific changes in the relaxation properties of the myocardium. These changes are responsible for the impaired diastolic function independently of blood pressure, degree of hypertrophy, and metabolic changes, which suggests the existence of a specific cardiomyopathy. Hypertension remains a determinant of left ventricular mass.     

Cardiac and metabolic effects of chronic growth hormone and insulin-like growth factor I excess in young adults with pituitary gigantism

Chronic growth hormone (GH)/insulin-like growth factor I (IGF-I) excess is associated with considerable mortality in acromegaly, but no data are available in pituitary gigantism. The aim of the study was to evaluate the long-term effects of early exposure to GH and IGF-I excess on cardiovascular and metabolic parameters in adult patients with pituitary gigantism. Six adult male patients with newly diagnosed gigantism due to GH secreting pituitary adenoma were studied and compared with 6 age- and sex-matched patients with acromegaly and 10 healthy subjects. Morphologic and functional cardiac parameters were evaluated by Doppler echocardiography. Glucose metabolism was assessed by evaluating glucose tolerance and homeostasis model assessment index. Disease duration was significantly longer (P<.05) in patients with gigantism than in patients with acromegaly, whereas GH and IGF-I concentrations were comparable. Left ventricular mass was increased both in patients with gigantism and in patients with acromegaly, as compared with controls. Left ventricular hypertrophy was detected in 2 of 6 of both patients with gigantism and patients with acromegaly, and isolated intraventricular septum thickening in 1 patient with gigantism. Inadequate diastolic filling (ratio between early and late transmitral flow velocity<1) was detected in 2 of 6 patients with gigantism and 1 of 6 patients with acromegaly. Impaired glucose metabolism occurrence was higher in patients with acromegaly (66%) compared with patients with gigantism (16%). Concentrations of IGF-I were significantly (P<.05) higher in patients with gigantism who have cardiac abnormalities than in those without cardiac abnormalities. In conclusion, our data suggest that GH/IGF-I excess in young adult patients is associated with morphologic and functional cardiac abnormalities that are similar in patients with gigantism and in patients with acromegaly, whereas occurrence of impaired glucose metabolism appears to be higher in patients with acromegaly, although patients with gigantism are exposed to GH excess for a longer period.     

Myocardial systolic strain abnormalities in patients with acromegaly: a prospective color Doppler imaging study

BACKGROUND: Heart abnormalities are frequent findings in patients with acromegaly: systolic abnormalities are considered to be secondary to diastolic changes. AIM: The aim of the study was to evaluate whether early systolic abnormalities might be revealed in acromegalic patients using the high sensitive color Doppler myocardial imaging (CDMI) technique. PATIENTS AND METHODS: Twenty-two consecutive acromegalic patients with active untreated disease (ACROUNTR) were evaluated at baseline and after a 6-month course with SS analogs (SSa) (ACROSSa); 25 healthy subjects served as controls. All subjects underwent conventional 2D-color Doppler echocardiography, pulse wave tissue Doppler imaging (PW-TDI) and CDMI. RESULTS: Mean left ventricular (LV) ejection fraction did not differ in ACROUNTR and in controls; at variance, ACROUNTR patients had reduced mean LV diastolic function (E/A ratio: 0.96+/-0.3 vs controls: 1.6+/-0.3; p<0.002). Impairment of global LV diastolic function was confirmed by PW-TDI in ACROUNTR patients having a normal systolic function. Regional myocardial systolic strain (epsilon) and strain rate (SR) values, indices of regional systolic heart deformation, were lower in ACROUNTR [epsilonsys (S) -19.8+/-2.9 and epsilonsys (L): -17.7+/-2.2] than in controls [epsilonsys (S): -27.9+/-3.8; p<0.001 and epsilonsys (L): -25.3+/-2.6; p<0.001]. In addition, the early phase of diastolic function, evaluated using SR parameters, was impaired in acromegalic patients (p<0.005 vs controls). Strain and SR values were related to serum GH and IGF-I levels (p<0.02) and greatly improved after a 6-month course with SSa [epsilonsys (S) improved to -23.8+/-3.8 (p<0.05) and epsilonsys (L) improved to -24.7+/-2.4 (p<0.03)]. CONCLUSIONS: Our study confirms that ACROUNTR patients have impaired diastolic function. More important, our study clearly shows that ACROUNTR patients have an impairment of regional myocardial systolic function, which is not secondary to diastolic changes. These intramyocardial functional abnormalities improved during medical treatment of acromegaly. It is conceivable that GH-IGF-I excess has detrimental effects either on the diastolic or the systolic phases of heart function.     

生长激素对心功能作用的探讨

目的探讨生长激素（ＧＨ）对心功能的作用。方法用平衡法核素心血池显象技术及运动试验对特发性生长激素缺乏症（ＩＧＨＤ）患者在ＧＨ治疗前后进行左心室功能评价。结果６７例儿童及青少年两组患者左心室总体射血分数（ＬＶＥＦ）明显低于对照组（分别为Ｐ＜０．０５及Ｐ＜０．０１）,青少年组其左心室舒张末期高峰充盈率（ＰＦＲ）也显著低于对照组（Ｐ＜０．０５）;３５例（５２．２％）左心室总体收缩或（和）舒张功能降低;２９例（４７．３％）运动试验后出现心率、ＳＴ段及Ｔ波异常。１３例心功能异常者接受重组人生长激素（ｒｈＧＨ）治疗６个月后,ＬＶＥＦ及ＰＦＲ较治疗前显著提高（分别为Ｐ＜０．０５及Ｐ＜０．０１）。结论约半数生长激素缺乏症（ＧＨＤ）患者在没有ＧＨ治疗的情况下,其左心室收缩和舒张功能明显受损,并伴有心肌缺血和劳损。ＧＨ治疗可显著改善ＧＨＤ患者的心功能。     

The impact of growth hormone/insulin-like growth factor-I axis and nocturnal breathing disorders on cardiovascular features of adult patients with Prader-Willi syndrome

CONTEXT: Adult patients with Prader-Willi syndrome (PWS) are prone to develop obesity, GH deficiency (GHD), and their related complications, with cardiopulmonary failure explaining more than half of PWS fatalities. OBJECTIVE AND STUDY PARTICIPANTS: This study was undertaken to examine the effect of GHD and sleep breathing disorders on cardiovascular risk factors and heart features of 13 PWS (age 26.9 +/- 1.2 yr) and 13 age-, gender-, and body mass index-matched obese individuals (age 26.2 +/- 0.8 yr). RESULTS: Compared with controls, PWS patients had lower GH response to arginine+GHRH, IGF-I levels, triglycerides, total and LDL-cholesterol, insulin, and insulin resistance measured by a homeostatic model approach. Dual-energy x-ray absorptiometry, abdominal computed tomography scans, and polysomnography revealed a greater fat mass, similar abdominal fat, but greater sleep breathing disorders in PWS than obese subjects. Echocardiography showed no systolic or diastolic alteration, although PWS had lower left ventricle (LV) mass (135.7 +/- 7.7 vs. 163.5 +/- 8.4 g, P < 0.05) and near significantly lower values of LV end-diastole diameter (P = 0.08), compared with obese controls. Baseline radionuclide angiography documented comparable values of systolic and diastolic values between groups. However, adrenergic stimulation with dobutamine caused a lower increase of LV ejection fraction (71.9 +/- 1.9 vs. 76.3 +/- 1.2%, P < 0.05) and heart rate (103 +/- 6.9 vs. 128 +/- 2.8 beats/min, P < 0.05) in PWS than obese individuals. By multivariate analysis, nocturnal oxygen desaturation and IGF-I levels were main significant predictors of LV mass and heart rate in PWS patients. CONCLUSIONS: PWS differs from simple obesity by a healthier metabolic profile, impaired nocturnal breathing, decreased heart geometry, and systolic and chronotropic performance. GHD and the predictive role of IGF-I on structural and functional heart parameters suggest a GH/IGF-I-mediated control of cardiac risk in PWS.