Plasma levels of adrenomedullin, a vasoactive peptide, in type 2 diabetic patients with and without retinopathy.
ABSTRACT The aim of this study was to investigate whether adrenomedullin (AM) secretion is modified in type 2 diabetic patients with and without retinopathy.
The study was performed on 92 patients with type 2 diabetes, 65 of whom had uncomplicated diabetes, 27 had retinopathy, and 40 had mild to moderate hypertension. Patients with serum creatinine levels >1.2 mg/dL, were excluded. Circulating AM was assayed using a specific radioimmunoassay.
AM concentrations were significantly higher in type 2 diabetic patients (25+/-2.1 pg/mL) than in the 31 normal subjects (11+/-0.8 pg/mL) (P<0.001). Type 2 diabetic patients with retinopathy had significantly greater AM levels (30.8+/-3.4 pg/mL) than both controls (P<0.001) and type 2 diabetic patients without retinopathy (25.2+/-2 pg/mL same as previous value) (P<0.001). No statistical difference was found between diabetic patients with pre-proliferative retinopathy (27.3+/-4.7 pg/mL) and proliferative retinopathy (24+/-3.1 pg/mL) (P=0.543). In type 2 diabetic patients, a significant correlation between plasma AM levels and HbA1c values (r=0.467; P<0.01) was found.
Our findings indicate that circulating AM is increased in type 2 diabetic patients and that increase correlates with poor glucose metabolic control and presence of retinopathy.
Full-textDOI: · Available from: Enzo Maria Vingolo, Sep 02, 2015
- SourceAvailable from: Mairaj Siddiquei
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- "Endothelial dysfunction in the pathogenesis of DR is characterized by an imbalance between endothelium-derived vasodilator and vasoconstrictor substances. Adrenomedullin, a multifunctional vasodilator peptide, was found to be increased in plasma and vitreous of DR patients and may have potential involvement in the pathogenesis of DR (Caliumi et al., 2007; Er, Doğanay, Ozerol, & Yürekli, 2005). "
ABSTRACT: One of the major complications in patients with diabetes is diabetic retinopathy (DR), a leading cause of blindness worldwide. It takes several years before any clinical signs of retinopathy appear in diabetic patients, which gives an ample opportunity for scientists to uncover biochemical and molecular mechanism implicated early in the development and progression of the disease. During the past few decades, research progress has been made in investigating the pathophysiology of the disease; however, due to nonavailability of human retinal samples at different stages of the disease and also due to lack of a proper animal model of DR, the exact molecular mechanism has not been elucidated, making therapeutic a difficult task. In this review article, we have discussed a number of diabetes-induced metabolites such as glucose, lipids, amino acids, and other related factors and molecules that are implicated in the pathophysiology of the DR. Furthermore, we have highlighted neurodegeneration and regulation of neurotrophic factors, being recognized as early events that may be involved in the pathology of the disease in the course of DR. An understanding of the biochemical and molecular changes especially early in the diabetic retina may lead to new and effective therapies towards prevention and amelioration of DR, which is important for the millions of individuals who already have or are likely to develop the disease before a cure becomes available.Journal of diabetes and its complications 01/2012; 26(1):56-64. DOI:10.1016/j.jdiacomp.2011.11.004 · 1.93 Impact Factor
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- "Also, there was a significant correlation between AM levels and HbA1c with higher HbA1c levels among diabetics with MVC. Similarly, Caliumi et al.  reported that increased circulating AM correlates with poor glucose metabolic control in type 2 diabetics. The elevated plasma AM level originates from vascular AM expression induced by hyperglycemia through protein kinase C-dependent pathway . "
ABSTRACT: Adrenomedullin (AM) is known to be elevated in different clinical situations including diabetes mellitus (DM), but its potential role in the pathogenesis of vascular complications in diabetic children and adolescents is to be clarified. Hence, the study aimed at assessment of plasma adrenomedullin levels in children and adolescents with type 1 DM and correlation of these levels with metabolic control and diabetic microvascular complications (MVC). The study was performed in the Diabetes Specialized Clinic, Children's Hospital of Ain Shams University in Cairo, Egypt. It included 55 diabetic children and adolescents (mean age 13.93 +/- 3.15 years) who were subdivided into 40 with no MVC and 15 with MVC. Thirty healthy subjects, age-and sex-matched, were included as control group (mean age 12.83 +/- 2.82 years). Patients and controls were assessed for glycosylated hemoglobin (HbA1c) and plasma adrenomedullin assay using ELISA technique. Mean plasma AM levels were significantly increased in patients with and without MVC compared to control group, (110.6 pg/mL, 60.25 pg/mL and 39.2 pg/mL respectively) (P < 0.01) with higher levels in those with MVC (P < 0.05). Plasma AM levels were positively correlated with both duration of diabetes (rho = 0.703, P < 0.001) and glycemic control (HbA1c) (rho = 0.453, P < 0.001). Higher plasma AM levels in diabetics particularly in those with MVC & its correlation with diabetes duration and metabolic control may reflect the role of AM in diabetic vasculopathy in the pediatric age group.Diabetology and Metabolic Syndrome 02/2010; 2:12. DOI:10.1186/1758-5996-2-12 · 2.50 Impact Factor
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ABSTRACT: The nitric oxide (NO) signaling pathway is integrally involved in visual processing and changes in the NO pathway are measurable in eyes of diabetic patients. The small peptide adrenomedullin (ADM) can activate a signaling pathway to increase the enzyme activity of neuronal nitric oxide synthase (nNOS). ADM levels are elevated in eyes of diabetic patients and therefore, ADM may play a role in the pathology of diabetic retinopathy. The goal of this research was to test the effects of inhibiting the ADM/NO signaling pathway in early diabetic retinopathy. Inhibition of this pathway decreased NO production in high-glucose retinal cultures. Treating diabetic mice with the PKC β inhibitor ruboxistaurin for 5 weeks lowered ADM mRNA levels and ADM-like immunoreactivity and preserved retinal function as assessed by electroretinography. The results of this study indicate that inhibiting the ADM/NO signaling pathway prevents neuronal pathology and functional losses in early diabetic retinopathy.Journal of ocular biology, diseases, and informatics 06/2011; 4(1-2):70-82. DOI:10.1007/s12177-011-9072-8