The role of elevated growth hormone on the increased atherosclerosis in patients with acromegaly

Growth Hormone, Atherosclerosis and Peripheral Arterial Disease: Exploring the Spectrum from Acromegaly to Growth Hormone Deficiency

Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) are increasingly recognised for their role in cardiovascular (CV) physiology. The GH-IGF-1 axis plays an essential role in the development of the CV system as well as in the complex molecular network that regulates cardiac and endothelial structure and function. A considerable correlation between GH levels and CV mortality exists even among individuals in the general population without a notable deviation in the GHIGF- 1 axis functioning. In addition, over the last decades, evidence has demonstrated that pathologic conditions involving the GH-IGF-1 axis, as seen in GH excess to GH deficiency, are associated with an increased risk for CV morbidity and mortality. A significant part of that risk can be attributed to several accompanying comorbidities. In both conditions, disease control is associated with a consistent improvement of CV risk factors, reduction of CV mortality, and achievement of standardised mortality ratio similar to that of the general population. Data on the prevalence of peripheral arterial disease in patients with acromegaly or growth hormone deficiency and the effects of GH and IGF-1 levels on the disease progression is limited. In this review, we will consider the pivotal role of the GH-IGF-1 axis on CV system function, as well as the far-reaching consequences that arise when disorders within this axis occur, particularly in relation to the atherosclerosis process.

Low serm Fibroblast Growth Factor-21 levels is not associated with Carotid intima-media thickness in acromegaly patients

INTRODUCTION

Elevated fibroblast growth factor-21 (FGF-21) levels are related to carotid intima-media thickness (CIMT), a well-established marker of atherosclerosis. Acromegaly has also been linked to increased CIMT. There has been no data considering the association between FGF-21 levels and atherosclerosis in acromegaly patients. This study aimed to evaluate FGF-21 levels and CIMT in acromegalic patients in relation to atherosclerotic complications.

DESIGN

Case-control study.

MATERIALS AND METHODS

The study group included 70 acromegaly patients and 72 healthy volunteers from the Department of Endocrinology and Metabolism Disease, Marmara University Medical School. FGF-21, growth hormone, insulin-like growth factor I, lipids, glucose, insulin levels were assessed. CIMT was measured from the common carotid artery wall on B-mode ultrasound.

RESULTS

Median FGF-21 levels were significantly lower in the acromegaly group than in the control group. CIMT was higher in acromegaly patients compared to controls. Although there was no correlation between FGF-21 levels and CIMT in patients with acromegaly, a positive correlation was found between high-density lipoprotein-cholesterol and FGF-21 levels. Glucose metabolic markers were the determining factors of the FGF-21 levels in acromegaly patients.

CONCLUSION

Our study is the first to examine the relationship between serum FGF-21 levels and atherosclerosis in acromegaly patients. The lower serum FGF-21 levels in acromegaly subjects might be associated with the improving effects of growth hormone on liver fat. Acromegaly was linked to higher CIMT, but there was no correlation between FGF-21 levels and CIMT. The role of FGF-21 in acromegaly as a marker of atherosclerosis requires additional research.

Chronic limb-threatening ischemia could benefit from growth hormone therapy for wound healing and limb salvage

Revascularization for chronic limb-threatening ischemia (CLTI) is necessary to alleviate symptoms and wound healing. When it fails or is not possible, there are few alternatives to avoid limb amputation in these patients. Although experimental studies with stem cells and growth factors have shown promise, clinical trials have demonstrated inconsistent results because CLTI patients generally need arteriogenesis rather than angiogenesis. Moreover, in addition to the perfusion of the limb, there is the need to improve the neuropathic response for wound healing, especially in diabetic patients. Growth hormone (GH) is a pleiotropic hormone capable of boosting the aforementioned processes and adds special benefits for the redox balance. This hormone has the potential to mitigate symptoms in ischemic patients with no other options and improves the cardiovascular complications associated with the disease. Here, we discuss the pros and cons of using GH in such patients, focus on its effects on peripheral arteries, and analyze the possible benefits of treating CLTI with this hormone.

Growth Hormone (GH) and Cardiovascular System

This review describes the positive effects of growth hormone (GH) on the cardiovascular system. We analyze why the vascular endothelium is a real internal secretion gland, whose inflammation is the first step for developing atherosclerosis, as well as the mechanisms by which GH acts on vessels improving oxidative stress imbalance and endothelial dysfunction. We also report how GH acts on coronary arterial disease and heart failure, and on peripheral arterial disease, inducing a neovascularization process that finally increases flow in ischemic tissues. We include some preliminary data from a trial in which GH or placebo is given to elderly people suffering from critical limb ischemia, showing some of the benefits of the hormone on plasma markers of inflammation, and the safety of GH administration during short periods of time, even in diabetic patients. We also analyze how Klotho is strongly related to GH, inducing, after being released from the damaged vascular endothelium, the pituitary secretion of GH, most likely to repair the injury in the ischemic tissues. We also show how GH can help during wound healing by increasing the blood flow and some neurotrophic and growth factors. In summary, we postulate that short-term GH administration could be useful to treat cardiovascular diseases.