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Query: UMLS:C0004153 (
atherosclerosis
)
77,401
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
At present, there is growing evidence implicating GH and/or
IGF-I
in the intricate cascade of events connected with the regulation of heart development and hypertrophy. Moreover, GH excess and/or deficiency have been shown to include in their advanced clinical manifestations almost always an impaired cardiac function, which may reduce life expectancy. This finding is related both to a primitive impairment of heart structure and function and to metabolic changes such as hyperlipidemia, increase of body fat and premature
atherosclerosis
. Patients with childhood or adulthood-onset GH deficiency have a reduced left ventricular mass and ejection fraction and the indexes of left ventricular systolic function remain markedly depressed during exercise. Conversely, in acromegaly the cardiac enlargement, which is disproportionate to the increase in size of other internal body organs, has been a rather uniform finding. The severity of the acromegalic cardiomyopathy was reported to be correlated better with the disease duration than with circulating GH and/or
IGF-I
levels. Myocardial hypertrophy with interstitial fibrosis, lymphomononuclear infiltration and areas of monocyte necrosis often results in concentric hypertrophy of both ventricles. The treatment of GH deficiency and excess improved cardiac function. Interestingly, based on the evidence that GH increases cardiac mass, recombinant GH was administered to patients with idiopathic dilated cardiomyopathy. It increased the myocardial mass and reduced the size of the left ventricular chamber, resulting in improvement of hemodynamics, myocardial energy metabolism and clinical status. These promising results open new perspectives for the use of GH in heart failure.
...
PMID:Is growth hormone bad for your heart? Cardiovascular impact of GH deficiency and of acromegaly. 938 93
GH deficiency (GHD) is associated with increased prevalence of
atherosclerosis
and cardiovascular morbidity. Because monocytes play a crucial role in the development of
atherosclerosis
, we investigated in the present study the effect of GH deficiency and subsequent GH replacement on monocytic function in hypopituitary subjects. Twelve patients were randomized to receive GH replacement therapy (either 3 or 6 microg/kg x day, s.c.) for 3 months. Plasma levels and monocyte production of cytokines and monocyte adhesion to endothelium were determined in controls and patients with GHD before and after GH treatment. Before GH therapy, patients with GHD had increased basal plasma tumor necrosis factor-alpha (TNF alpha; 220% over control values; P = 0.004) and interleukin-6 (IL-6; 340% over control values; P 0.0009) levels. Basal monocyte production of both cytokines was also significantly higher in patients with GHD [484% over control values for TNF alpha (P = 0.0007); 1479% over control values for IL-6 (P = 0.035)]. GH treatment for 3 months led to a reduction in plasma TNF alpha (135% over control values; P = 0.03, pre- vs. post-GH therapy), monocyte TNF alpha production (204% over control values; P = 0.01), plasma IL-6 (219% over control values; P = 0.07), and monocyte IL-6 production (448% over control values; P = 0.01). Plasma TNF alpha levels positively correlated with monocyte TNF alpha production in patients with GHD both before and after GH therapy (P = 0.003 and P = 0.049, respectively). A positive correlation (P = 0.0003) was also observed between monocyte TNF alpha production and monocyte IL-6 production. There were no correlations between these plasma cytokine levels or monocyte cytokine production and parameters of body composition, lipid profile, or
IGF-I
and IGF-binding protein-3 levels. Before GH treatment, adhesiveness of monocytes to cultured aortic endothelial cells was also enhanced. This alteration was not reversed by GH administration. In conclusion, our results demonstrate that markers of monocyte activation are increased in patients with GHD and that GH replacement partly reduces these abnormalities. Reduction of cellular activation of monocytes by GH therapy could potentially contribute to reduce the risk of cardiovascular events in patients with GHD.
...
PMID:Alterations of monocyte function in patients with growth hormone (GH) deficiency: effect of substitutive GH therapy. 1048 24
Insulin-like growth factors I and II (
IGF-I
and -II) and their regulatory proteins are secreted by cells of the cardiovascular system. They are growth promoters for arterial cells and mediators of cardiovascular disease. IGFs are bound to IGF binding proteins (IGFBPs), which modulate IGF ligand-receptor interaction and consequently to IGF action. IGFBPs are in turn posttranslationally modulated by specific proteases. This dynamic balance (IGFs, IGFBPs, and IGFBP proteases) constitutes the IGF axis and ultimately determines the extent of IGF-dependent cellular effects. Dysregulated actions of this axis influence coronary
atherosclerosis
through effects on vascular smooth muscle cell growth, migration, and extracellular matrix synthesis in the atherosclerotic plaque.
IGF-I
promotes macrophage chemotaxis, excess LDL cholesterol uptake, and release of proinflammatory cytokines. Endothelial cells also receive the effects of IGFs stimulating their migration and organization forming capillary networks. Neointimal hyperplasia of restenosis after coronary artery injury is also modulated by the IGF axis. IGFs stimulate vascular smooth muscle cell proliferation and migration to form the neointima and upregulate tropoelastin synthesis after disruption of the elastic layer. Understanding IGF axis regulation establishes a scientific basis for strategies directed to limit or reverse plaque growth and vulnerability in
atherosclerosis
and in the neointimal hyperplasia of restenosis.
...
PMID:The insulin-like growth factor axis: A review of atherosclerosis and restenosis. 1066 6
High vascular morbidity and mortality is associated with acromegaly. The aim of the present study was to assess the effects of octreotide therapy on several known cardiovascular risk factors and to correlate them with octreotide-induced hormonal changes. Lipid levels, LDL particle size distribution as evaluated by single vertical spin density gradient ultracentrifugation, apolipoproteins AI and B, lipoprotein (a) [Lp(a)] concentrations and apo(a) phenotypes were evaluated in 20 non-diabetic acromegalic patients (6 M, 14 F), with normal thyroid, adrenal and gonadal function, aged 29-66 years. Normal subjects (20), matched for age, sex and BMI served as control for lipid variables. Acromegalic patients were characterized by lower HDL cholesterol (and apoA-I) and by higher Lp(a) concentrations in comparison to controls. Treatment with octreotide (100 microg t.i.d. for 3 months) led to: an increase in HDL cholesterol (median: + 22%), a decrease in LDL cholesterol (-14%) and a decrease of the Lp(a) levels (all phenotypes) (-28%). The expected decreases of
IGF-I
levels (median: -48%) and 7-h AUC of GH (-50%), insulin (-40%) and glucagon (-20%) were observed. Only Lp(a) modifications showed a correlation with GH modifications. The study of LDL physical properties showed that acromegalic patients had smaller and/or more dense LDL particles, in comparison with normal controls (relative flotation rate, Rf: 0.40 +/- 0.03 versus 0.42 +/- 0.02 P < 0q05), an alteration that might contribute to the high vascular risk of acromegalic patients. However, the LDL subfraction distribution remained unmodified during octreotide therapy (Rf 0.39 +/- 0.03). In conclusion, this study shows that in acromegalic patients octreotide treatment is indeed associated with an amelioration of some lipoprotein parameters, i.e. LDL, HDL, and Lp(a) concentrations. However, this treatment has no effect on the small and/or dense LDL particles present in these patients.
Atherosclerosis
2000 Aug
PMID:LDL physical properties, lipoprotein and Lp(a) levels in acromegalic patients. Effects of octreotide therapy. Italian Multicenter Octreotide Study Group. 1092 34
In combination with other factors, hyperglycemia may cause the accelerated progression of
atherosclerosis
in people with diabetes. Arterial smooth muscle cell (SMC) proliferation and accumulation contribute to formation of advanced atherosclerotic lesions. Therefore, we investigated the effects of hyperglycemia on SMC proliferation and accumulation in vivo and in isolated arteries and SMCs by taking advantage of a new porcine model of diabetes-accelerated
atherosclerosis
, in which diabetic animals are hyperglycemic without receiving exogenous insulin. We show that diabetic animals fed a cholesterol-rich diet, like humans, develop severe lesions of
atherosclerosis
characterized by SMC accumulation and proliferation, whereas lesions in nondiabetic animals contain fewer SMCs after 20 weeks. However, high glucose (25 mmol/l) does not directly stimulate the proliferation of SMCs in isolated arterial tissue from diabetic or nondiabetic animals, or of cultured SMCs from these animals or from humans. Furthermore, the mitogenic actions of platelet-derived growth factor,
IGF-I
, or serum are not enhanced by high glucose. High glucose increases SMC glucose metabolism through the citric acid cycle and the pentose phosphate pathway by 240 and 90%, respectively, but <10% of consumed glucose is metabolized through these pathways. Instead, most of the consumed glucose is converted into lactate and secreted by the SMCs. Thus, diabetes markedly accelerates SMC proliferation and accumulation in atherosclerotic lesions. The stimulatory effect of diabetes on SMCs is likely to be mediated by effects secondary to the hyperglycemic state.
...
PMID:Diabetes accelerates smooth muscle accumulation in lesions of atherosclerosis: lack of direct growth-promoting effects of high glucose levels. 1128 52
Adult hypopituitarism is known to be associated with reduced life expectancy related to excess vascular events, and endothelial dysfunction is present in patients with this condition. We studied the relationship between biophysical and biochemical markers of endothelial dysfunction, including E-selectin, intercellular cell adhesion molecule-1, von Willebrand factor, and thrombomodulin in 52 adult patients with hypopituitarism and severe GH deficiency (<2 ng/ml on provocative testing) compared with 54 age-, sex-, and smoking-matched normal controls. We also examined endothelium-dependent dilatation of the brachial artery to postischemic occlusion and carotid artery morphology (intima-media thickness) by high-resolution ultrasonography. The patients were stable on conventional hormone replacement therapy but not on GH therapy, and none of the subjects had a known risk factor for vascular disease. Levels of E-selectin [57 +/- 3 vs. 49 +/- 2 ng/ml (mean +/- SEM)] (P < 0.043), intercellular cell adhesion molecule-1 (308 +/- 11 vs. 266 +/- 10 ng/ml) (P < 0.001), thrombomodulin (49 +/- 3 vs. 35 +/- 2 ng/ml) (P < 0.001), and von Willebrand factor (132 +/- 7% vs. 105 +/- 5%) (P < 0.004) were significantly higher in patients than in controls. Brachial artery endothelium-dependent dilatation was significantly lower in patients than in controls [4.7% (0.00-9.77) vs. 10.5% (6.4-16.2) (median, interquartile range)] (P < 0.001). This difference in endothelium-dependent dilatation was more marked in female patients than in controls (P < 0.003), although it disappeared when estrogen-sufficient female patients were compared with controls (P = 0.31). However, the female patients who were not replaced with estrogen continued to show a striking difference compared with estrogen-deficient control females (P < 0.004). There was no difference in carotid intima-media thickness between patients of either sex and controls. On univariate analysis, brachial artery endothelium-dependent dilatation correlated inversely with intercellular cell adhesion molecule-1 (r = -0.225, P < 0.033). Intercellular cell adhesion molecule-1 correlated positively with E-selectin (r = 0.466, P < 0.0001) and negatively with
IGF-I
(r = -0.238, P < 0.016). E-selectin correlated with thrombomodulin (r = 0.215, P < 0.034) and von Willebrand factor (r = 0.218, P < 0.03) and negatively with
IGF-I
(r = -0.255, P < 009). Thrombomodulin correlated positively with von Willebrand factor (r = 0.422, P < 0.0001) and inversely with
IGF-I
(r = -0.266, P < 0.008). These correlations persisted after correction for age, sex, body mass index, and waist to hip ratio, with the exception of
IGF-I
, which now correlated with thrombomodulin only. These results confirm significant endothelial dysfunction in hypopituitarism and provide insight into the relationship of biochemical and biophysical markers of early
atherosclerosis
in hypopituitary GH-deficient adults. The negative correlation of
IGF-I
with some biochemical markers of endothelial dysfunction and the predictive nature of GH deficiency in stepwise regression analysis in this study supports the hypothesis that GH deficiency may play a role in these abnormalities. Future studies will determine whether GH treatment can reverse these abnormalities. Furthermore, the more significant endothelium-dependent dilatation abnormality in the female estrogen-deficient subjects compared with those who were estrogen replete suggests that estrogen replacement in these patients is a crucial element in protecting against vascular disease.
...
PMID:Biochemical and biophysical markers of endothelial dysfunction in adults with hypopituitarism and severe GH deficiency. 1154 53
Low density lipoproteins (LDL) are an independent risk factor for
atherosclerosis
and show synergism with some growth factors in vascular smooth muscle cell (VSMC) proliferation.
IGF-I
has mitogenic actions on VSMC, which, in turn, show enhanced expression of
IGF-I
and its receptor when exposed to hypercholesterolemic diets in vivo. To investigate the molecular basis of a possible interaction between LDL and the
IGF-I
signaling system in VSMC, we used A10 cells, where synergism between both factors in DNA synthesis was demonstrated.
IGF-I
activates phosphatidylinositol 3-kinase (PI3 kinase) and extracellular signal-regulated MAPK pathways in A10 cells, although insulin receptor substrate-1 (IRS-1)-associated PI3 kinase is more closely linked to
IGF-I
induced proliferation. LDL, in pathophysiological concentrations, affect the
IGF-I
signaling pathway at multiple levels: 1) they induce phosphorylation of IGF-I receptor beta and IRS-1 in a time- and dose-dependent manner; 2) they up-regulate IRS-1-associated PI3 kinase/Akt activation in response to
IGF-I
at early times; and 3) they show additive effects with
IGF-I
on extracellular signal-regulated MAPK 1/2 phosphorylation. These actions are not present in very low density lipoprotein treatments. Taken together, these results indicate specific cooperation between LDL and the
IGF-I
signaling pathways and may represent a more general mechanism through which proatherogenic lipoproteins modulate VSMC response to growth factors.
...
PMID:Cooperation between low density lipoproteins and IGF-I in the promotion of mitogenesis in vascular smooth muscle cells. 1160 53
Cardiovascular risk is increased in GH deficiency (GHD). GHD adults are frequently abdominally obese and display features of the metabolic syndrome. Otherwise healthy abdominally obese subjects have low GH levels and show features of the metabolic syndrome as well. We investigated in healthy nonobese males the effect of the GH receptor antagonist pegvisomant in different metabolic conditions. This is a model for acute GHD without the alterations in body composition associated with GHD. We compared the effect of pegvisomant with that of placebo before and after 3 d of fasting. In addition, we investigated the effect of pegvisomant under normal, i.e. fed, conditions. Three days of fasting as well as pegvisomant alone decreased serum free
IGF-I
levels (1.0 +/- 0.15 vs. 0.31 +/- 0.05 ng/ml and 0.86 +/- 0.23 vs. 0.46 +/- 0.23 ng/ml, respectively). Fasting in combination with pegvisomant also decreased serum free
IGF-I
levels (1.0 +/- 0.15 vs. 0.31 +/- 0.07 ng/ml). Treatment with pegvisomant had no additional influence on the decline of free
IGF-I
induced by fasting. Pegvisomant alone had no influence on insulin sensitivity. The increase in insulin sensitivity induced by fasting was comparable to the increase in insulin sensitivity induced by fasting combined with pegvisomant. Among serum lipid concentrations, only serum triglycerides increased significantly as a result of pegvisomant alone (1.0 +/- 0.2 vs. 1.6 +/- 0.4 mmol/liter). The changes in lipid concentrations induced by fasting alone or pegvisomant were not different from those induced by pegvisomant alone. von Willebrand factor antigen levels declined significantly under the influence of pegvisomant alone (1.1 +/- 0.07 vs. 0.8 +/- 0.06 U/ml). In conclusion, in different metabolic conditions the GH receptor antagonist pegvisomant induces no significant acute changes in the major risk markers for cardiovascular disease. These data suggest that the secondary metabolic changes, e.g. abdominal obesity or inflammatory factors, that develop as a result of long-standing GHD are of primary importance in the pathogenesis of
atherosclerosis
in patients with GHD.
...
PMID:Acute effect of pegvisomant on cardiovascular risk markers in healthy men: implications for the pathogenesis of atherosclerosis in GH deficiency. 1170 72
The leucine 7 to proline 7 (Leu7Pro) polymorphism in the signal peptide of NPY is associated with high blood lipid concentrations and accelerated rate of
atherosclerosis
as well as diabetic retinopathy. Also, healthy subjects with this polymorphism have increased NPY secretion during sympathetic stimulation. Because NPY may regulate GH release and ghrelin may regulate NPY formation, we studied the effects of the Leu7/Pro7 genotype on GH, ghrelin, and
IGF-I
secretion during standardized cycle-ergometer exercise. Furthermore, we studied the effect of the Leu7/Pro7 genotype on diurnal GH secretion in rest in a separate study. The subjects with Leu7/Pro7 genotype had 54% higher maximal increases in the plasma GH concentrations than the controls during exercise. There were no significant differences in the ghrelin or
IGF-I
concentrations during exercise among the groups. Furthermore, there were no differences in diurnal GH secretion between the genotypes. The results indicate that the prepro-NPY genotype has an influence on GH response during exercise in humans. The clinical significance of this finding is not known, and further studies are needed to evaluate whether the observed change in GH secretion during exercise could play a role in promoting diseases.
...
PMID:Enhanced exercise-induced GH secretion in subjects with Pro7 substitution in the prepro-NPY. 1170 4
Patients with hypopituitarism have increased cardiovascular mortality. A high prevalence of conventional cardiovascular risk factors, including obesity, central fat distribution, insulin resistance, and dyslipidemia, have been described in these patients. The inflammatory markers C-reactive protein (CRP) and IL-6 are predictors of cardiovascular events, and high levels of CRP have been reported in men with hypopituitarism and GH deficiency. However, little is known about inflammatory cardiovascular risk markers in women with hypopituitarism. We therefore investigated whether inflammatory and traditional cardiovascular risk markers are elevated in women with hypopituitarism. Fifty-three women with hypopituitarism and 111 healthy control women were included in this cross-sectional study. Morning blood samples were drawn after an overnight fast. Serum was assayed for CRP, IL-6, glucose, insulin,
IGF-I
, triglycerides, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein (HDL) cholesterol, lipoprotein(a), E2, total testosterone (total T) and free testosterone (free T), and dehydroepiandrosterone sulfate. IL-6 and CRP levels were higher in women with hypopituitarism than in healthy controls (P < 0.0001 for comparison between groups). In a multivariate model, CRP levels depended on hypopituitarism, body mass index (BMI), and estrogen use. There was an interaction between the effect of BMI and hypopituitarism on CRP levels, such that the importance of hypopituitarism in determining CRP levels disappeared at high BMIs. In a similar multivariate model, IL-6 levels depended on hypopituitarism and BMI. Total cholesterol, the total to HDL cholesterol ratio, and triglycerides were higher in hypopituitary patients, but only triglycerides and the total to HDL cholesterol ratio depended on hypopituitarism when controlling for BMI. There was no significant difference in lipoprotein(a) levels between hypopituitary women and control subjects. However, when controlling for estrogen use, lipoprotein(a) levels showed a trend toward being lower in the hypopituitary group (P = 0.075). In patients with hypopituitarism, CRP correlated negatively with
IGF-I
(r = -0.35; P = 0.010), total T (r = -0.42; P = 0.0020), and free T (r = -0.30; P = 0.031). Similarly, IL-6 correlated negatively with total T (r = -0.39; P = 0.0040) and androstenedione (r = -0.27; P = 0.048) in hypopituitary patients. In conclusion, hypopituitary women have increased levels of IL-6 and CRP, both of which are inflammatory markers of
atherosclerosis
. GH deficiency and androgen deficiency may contribute to these findings. Chronic inflammation may contribute to the high cardiovascular risk seen in this population.
...
PMID:Inflammatory cardiovascular risk markers in women with hypopituitarism. 1210 75
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