Silent cardiovascular involvement in patients with diffuse systemic sclerosis: a controlled cross-sectional study.

OBJECTIVE: An association between systemic autoimmune diseases and atherosclerosis has been described in many connective tissue diseases, and this association is known to lead to increased cardiovascular morbidity and mortality. Systemic sclerosis (SSc) is characterized by multisystem organ inflammation, endothelial wall damage, and vasculopathy. There are many markers of endothelial dysfunction and/or atherosclerotic risk, such as asymmetric dimethylarginine (ADMA), arterial stiffness parameters, carotid intima-media thickness (CIMT), and coronary flow reserve (CFR) assessed by transthoracic echocardiography. The aim of this pilot study was to use various endothelial and atherosclerosis markers to identify early cardiovascular involvement in a group of SSc patients. METHODS: The study involved 20 patients (2 men and 18 women with a mean ± SD age of 52.96 ± 12.51 years) with diffuse SSc who had no signs or symptoms of cardiovascular disease (CVD) and 20 age- and sex-matched controls. All subjects underwent a dipyridamole echocardiographic stress test that included a determination of CFR and an evaluation of CIMT, arterial stiffness, and plasma ADMA levels. RESULTS: All of the arterial wall measurements of the patients with diffuse SSc were significantly different from those of the controls, and both right and left CIMT, pulse wave velocity, and stiffness index (ß) were significantly elevated in the SSc patients compared to the healthy controls. Moreover, in patients with diffuse SSc, CFR was significantly lower (P = 0.0033) and plasma ADMA levels were higher (P < 0.0001) than in healthy controls. CONCLUSION: SSc patients without any clinical evidence of CVD seem to have had subclinical atherosclerosis, which was suggested by early impairment of coronary microcirculation and macrovascular involvement.

GH-related and extra-endocrine actions of GH secretagogues in aging.

Growth hormone (GH) secretion declines with aging in mammals, including humans. Defective pituitary function does not play a major role in this event. Rather, age-related changes involving the function of specific hypothalamic peptides for GH regulation, GH-releasing hormone (GHRH) and somatostatin (SS), appear to be the fundamental factors. Experimental evidence indicates that GHRH synthesis is impaired with aging in the rat hypothalamus, and that a relative hyperfunction of the SS-ergic system is present. In the elderly, systemic, short-term administration of GHRH enhances GH secretion and increases the formation of the GH-dependent peptide IGF-1. In old dogs, a combination of GHRH and clonidine (CLO), an alpha(2)-adrenoceptor agonist, reportedly acting via GHRH stimulation and SS inhibition, is the most effective stimulus to rejuvenate the apulsatile GH secretion. Discovery of GH secretagogues (GHSs), a series of peptydil and non-peptydil synthetic molecules endowed with a strong GH-releasing activity, the cloning of a GHS receptor (GHS-R), present in the hypothalamus and the pituitary, the isolation of the endogenous ligand of GHS-R, ghrelin, a 28-amino acid peptide whose main source is the stomach, pose the issue for the physiologic role of the GHS/ghrelin system and forces revision of our current understanding of GH regulation in different GH deficiency (GHD) states, including aging. GHSs are very effective for enhancing GH secretion in old subjects, but long-term studies are needed to assess their safety and the real biological impact of GHS replacement therapy in aging. Therapeutic use of GHSs can also be envisaged to restore, via GH-independent mechanisms, functional, and structural age-related alterations, such as anorexia, sexual dysfunction, cardiovascular damage, bone loss.