Relationship between the A(8002)G intronic polymorphism of pre-pro-endothelin-1 gene and the endothelin-1 concentration among Tunisian coronary patients

Identification of Important Genes Associated with the Development of Atherosclerosis

Atherosclerosis is one of the most important medical problems due to its prevalence and significant contribution to the structure of temporary and permanent disability and mortality. Atherosclerosis is a complex chain of events occurring in the vascular wall over many years. Disorders of lipid metabolism, inflammation, and impaired hemodynamics are important mechanisms of atherogenesis. A growing body of evidence strengthens the understanding of the role of genetic and epigenetic factors in individual predisposition and development of atherosclerosis and its clinical outcomes. In addition, hemodynamic changes, lipid metabolism abnormalities, and inflammation are closely related and have many overlapping links in regulation. A better study of these mechanisms may improve the quality of diagnosis and management of such patients.

Association of pre-pro-endothelin gene polymorphism and serum endothelin-1 with intradialytic hypertension in an Egyptian population

BACKGROUND

Intradialytic hypertension (IDH) is a major problem of hemodialysis and it is a multifactorial disorder and need early identification and management.

AIM

Evaluate the serum concentration of endothelin-1 in patients with IDH and healthy control and the impact of pre-pro-endothelin gene polymorphism on level of endothelin-1 and susceptibility to IDH in Egyptian population.

METHODS

The patient groups divided into group I, End stage renal disease (ESRD) on chronic hemodialysis with IDH (112); group II, ESRD on chronic hemodialysis without IDH (112); group III, healthy control (112). All undergone to full history, clinical examination, routine laboratory investigations, echocardiography, serum ET-1 level by ELISA and A(8002)G polymorphism detection in pre-pro-endothelin gene by PCR-RFLP.

RESULTS

Our results showed significantly higher concentration of Endothelin-1 (ET-1) in both patient groups than healthy control and in group with IDH than cases without IDH (p < 0.001). GG, GA and mutated G allele carry the risk of IDH (OR = 15.94, 13.5, 5.51 respectively p < 0.001). There was association between GG and GA genotypes and higher ET-1 level in both patient groups (p < 0.001) and association between GG and GA genotype and higher mean arterial pressure (MAP), delta MAP (DMAP) and increased left ventricular mass index (LVMI) in both patient groups (p = 0.001, 0.028).

CONCLUSION

Pre-pro-endothelin gene polymorphism A(8002)G is an independent risk factor for IDH through changing the level of ET-1 concentration in Egyptian population undergoing chronic hemodialysis.

Efficacy of continuous positive airway pressure treatment in treating obstructive sleep apnea hypopnea syndrome associated with carotid arteriosclerosis

Sleep apnea negatively impacts patients' ability to oxygenate the bloodstream during sleep and has far-reaching, deleterious effects. The present study sought to assess the correlation between obstructive sleep apnea hypopnea syndrome (OSAHS), carotid atherosclerosis, and blood pressure variability (BPV), and to evaluate the therapeutic effects of continuous positive airway pressure (CPAP). Patients with OSAHS were classified as mild, moderate, or severe according to their condition and compared with healthy control participants. CPAP treatment was used to treat patients with OSAHS for 6 months. Prior to CPAP treatment, the apnea-hypopnea index (AHI), lowest blood oxygen saturation (LSaO₂), carotid intima media thickness (IMT), and plasma levels of endothelin-1 (ET-1), nitric oxide (NO), and tumor necrosis factor-α (TNF-α) were measured in all participants, along with the low frequency components of BPV (BPV LF). The results demonstrated that carotid IMT, AHI, plasma ET-1, and plasma TNF-α were significantly higher in patients with OSAHS than those in the control group (P<0.05); whereas LSaO₂ and plasma NO levels were significantly higher in the control group (P<0.05). The degree to which these indices differed was associated with the severity of OSAHS. Furthermore, the carotid IMT of patients with OSAHS was significantly correlated with AHI (P=0.037), plasma ET-1 (P=0.001), plasma NO (P<0.001), BPV LF before retiring (P<0.001). Following CPAP treatment, the observation indices of patients with moderate or severe OSAHS improved significantly (P<0.01). These results support the use of CPAP to improve the significant vascular endothelial dysfunction, increased inflammatory response, and high blood pressure variability correlated with carotid atherosclerosis observed in patients with OSAHS.