Association of polymorphisms of leptin, leptin receptor and apelin receptor genes with susceptibility to coronary artery disease and hypertension

Association of genetic variants in Leptin, leptin receptor and adiponectin with hypertension risk and circulating Leptin/Adiponectin changes

BACKGROUNDS

Hypertension is inheritable, and some candidate genes such as leptin and adiponectin have drawn special concerns.

OBJECTIVES

We performed a meta-analysis on the association of 7 genetic variants in genes encoding leptin, leptin receptor and adiponectin with hypertension risk and circulating leptin/adiponectin changes.

METHODS

Literature search, report selection and data extraction were performed by two authors independently. Effect sizes are expressed as odds ratio (OR) or standard mean difference (SMD) with 95% confidence interval (CI).

RESULTS

Total 32 reports (7432 cases with hypertension and 9218 controls) were meta-analyzed. Overall analyses indicated that rs7799039 (dominant model: OR = 1.67; 95 % CI: 1.03 to 2.71; P = 0.038) and (TTTC)_n (allelic model: OR = 1.53; 95 % CI: 1.05 to 2.23; P = 0.028) were significantly associated with hypertension risk. Subgroup analyses indicated that hypertension type, race, diabetes, genotyping method and quality score might be potential causes for between-study heterogeneity. Besides rs2241766, no evidence of publication bias existed for the other variants. Carriers of rs7799039-AG genotype had significantly higher leptin concentrations than carriers of rs7799039-GG genotype (SMD = 1.98; 95 % CI: 0.07 to 3.89; P = 0.042). In Mendelian randomization analyses, an increment of leptin concentrations by 1 ng/mL was causally associated with a 25 % significantly increased risk of hypertension (95 % CI: 1.02 to 10+; P < 0.05).

CONCLUSIONS

Our findings indicated that leptin gene rs7799039 and (TTTC)_n were potential hypertension-candidacy loci, and importantly high circulating leptin concentrations causally precipitated the development of hypertension.

Gene polymorphism of leptin and risk for heart disease, obesity, and high BMI: a systematic review and pooled analysis in adult obese subjects

Objectives

Leptin polymorphism (LEP) has been associated with coronary heart disease (CAD), obesity, and high body mass index (BMI). However, we performed a systematic review and meta-analysis to discover the association because previous studies reached different conclusions.

Methods

Review Manager, version 5.3.5, and Stata, version 15.0, were used for statistical analysis. We calculated the effect size of the studies using the OR with the corresponding 95% CI, and two-sided (bilateral) p-values of 0.05 were considered significant. To determine heterogeneity among the selected studies, the Q test and I2 statistics were used. Meta-regression was used to examine the disease (heart disease, obesity, and high BMI) and heterogeneity between these subgroups.

Results

Eleven studies with 18,984 subjects were included in this study. The G-2548A (rs12112075), rs7799039, and A19G (rs2167270) polymorphisms of the leptin gene (but not the Lys656Asn (rs1805094) polymorphism) are associated with an increased risk of cardiovascular disease. Our pooled analysis revealed an association between the G-2548A (rs12112075) polymorphism and heart disease, high BMI, and obesity. This indicates that individuals carrying the AA allele are at an increased risk for heart disease, high BMI, and obesity. People with heart failure and coronary artery disease did not have the rs7799039 polymorphism or its alleles linked to them.

Conclusions

Combined analysis of data from current and published research suggests that the leptin gene polymorphisms G-2548A (rs12112075), rs7799039, and A19G (rs2167270) (but not the Lys656Asn (rs1805094) polymorphism) are associated with an increased risk of cardiovascular disease. Further research is needed to understand this association.

Association of rs1137101 with hypertension and type 2 diabetes mellitus of Mongolian and Han Chinese

BACKGROUND

Hypertension (HTN) and type 2 diabetes mellitus (T2DM) are often coincident, and each condition is considered a risk factor for the other. Both occur frequently in the Inner Mongolia region of China. The reasons for differences in risk between Han and Mongolian ethnic groups are not known. The LEPR gene and its polymorphism, rs1137101 (Gln223Arg), are both considered risk factors for HTN and T2DM, but any role of rs1137101 in the occurrence of HTN + T2DM remains unclear for Mongolian and Han populations in the Inner Mongolia region.

AIM

To investigate the relationship between rs1137101 and the occurrence of HTN with T2DM in Mongolian and Han populations in Inner Mongolia.

METHODS

A total of 2652 subjects of Han and Mongolian ethnic origins were enrolled in the current study, including 908 healthy controls, 1061 HTN patients and 683 HTN patients with T2DM.

RESULTS

The association between the rs1137101 polymorphism and HTN with T2DM was analyzed, and differences between Han and Mongolian individuals assessed. There was a significant correlation between rs1137101 and HTN (co-dominant, dominant, over-dominant and log-additive models) and HTN + T2DM (co-dominant, dominant, over-dominant and log-additive models) after adjustment for sex and age in individuals of Mongolian origin. rs1137101 was significantly associated with HTN (co-dominant, recessive and log-additive models) and HTN + T2DM (co-dominant, dominant, over-dominant and log-additive models) in the Han Chinese population.

CONCLUSION

Mongolian and Han subjects from Inner Mongolia with HTN who had rs1137101 were protected against the development of T2DM. Allele A has the opposite impact on the occurrence of HTN in Mongolian and Han Chinese populations.

Apelin and its ratio to lipid factors are associated with cardiovascular diseases: A systematic review and meta-analysis

Background

The present systematic review and meta-analysis aimed to ascertain if the circulating levels of apelin, as an important regulator of the cardiovascular homeostasis, differ in patients with cardiovascular diseases (CVDs) and controls.

Methods

A comprehensive search was performed in electronic databases including PubMed, Scopus, EMBASE, and Web of Science to identify the studies addressing apelin in CVD up to April 5, 2021. Due to the presence of different units to measure the circulating levels of apelin across the included studies, they expressed the standardized mean difference (SMD) and their 95% confidence interval (CI) as summary effect size. A random-effects model comprising DerSimonian and Laird method was used to pool SMDs.

Results

Twenty-four articles (30 studies) comprised of 1793 cases and 1416 controls were included. Pooled results obtained through random-effects model indicated that apelin concentrations in the cases’ blood samples were significantly lower than those of the control groups (SMD = -0.72, 95% CI: -1.25, -0.18, P = 0.009; I2 = 97.3%, P<0.001). New combined biomarkers showed a significant decrease in SMD of apelin/high-density lipoprotein cholesterol (apelin/HDL-C) ratio [-5.17; 95% CI, -8.72, -1.63, P = 0.000; I2 = 99.0%], apelin/low-density lipoprotein cholesterol (apelin/LDL-C) ratio [-4.31; 95% CI, -6.08, -2.55, P = 0.000; I2 = 98.0%] and apelin/total cholesterol (apelin/TC) ratio [-17.30; 95% CI, -22.85, -11.76, P = 0.000; I2 = 99.1%]. However, no significant differences were found in the SMD of apelin/triacylglycerol (apelin/TG) ratio in cases with CVDs compared to the control group [-2.96; 95% CI, -7.41, 1.49, P = 0.000; I2 = 99.2%].

Conclusion

The association of apelin with CVDs is different based on the region and disease subtypes. These findings account for the possible usefulness of apelin as an additional biomarker in the diagnosis of CVD in diabetic patients and in the diagnosis of patients with CAD. Moreover, apelin/HDL-c, apelin/LDL-c, and apelin/TC ratios could be offered as diagnostic markers for CVD.

Oxidative Stress in Ischemia/Reperfusion Injuries following Acute Ischemic Stroke

Recanalization therapy is increasingly used in the treatment of acute ischemic stroke. However, in about one third of these patients, recanalization is followed by ischemia/reperfusion injuries, and clinically to worsening of the neurological status. Much research has focused on unraveling the involved mechanisms in order to prevent or efficiently treat these injuries. What we know so far is that oxidative stress and mitochondrial dysfunction are significantly involved in the pathogenesis of ischemia/reperfusion injury. However, despite promising results obtained in experimental research, clinical studies trying to interfere with the oxidative pathways have mostly failed. The current article discusses the main mechanisms leading to ischemia/reperfusion injuries, such as mitochondrial dysfunction, excitotoxicity, and oxidative stress, and reviews the clinical trials with antioxidant molecules highlighting recent developments and future strategies.

Ghrelin and ghrelin/total cholesterol ratio as independent predictors for coronary artery disease: a systematic review and meta-analysis

The present meta-analysis aimed to summarize the available data regarding the circulating levels of ghrelin in patients with cardiovascular diseases (CVDs). A comprehensive search was performed in electronic databases including PubMed, Scopus, EMBASE, and Web of Science up to January 20, 2021. Since the circulating levels of ghrelin were measured in different units across the included studies, they were expressed as the standardized mean difference (SMD) and 95% CI (summary effect size). A random-effects model comprising the DerSimonian and Laird method was used to pool SMDs. Sixteen articles (20 studies) comprised of 1087 cases and 437 controls were included. The pooled results showed that there were no significant differences between cases and controls in terms of ghrelin levels (SMD=-0.61, 95% CI -1.38 to 0.16; p=0.120; I²=96.9%, p<0.001). The ghrelin concentrations in the CAD stratum were significantly lower than in controls, whereas they increased in other disease strata. New combined biomarkers demonstrated a significant decrease in the SMD of the ghrelin/total cholesterol (TC) ratio (-1.02; 95% CI -1.74 to -0.29, p=0.000; I²=94.5%). However, no significant differences were found in the SMD of the ghrelin/high-density lipoprotein cholesterol ratio, ghrelin/low-density lipoprotein cholesterol ratio, and ghrelin/triglyceride (TG) ratio in cases with CVDs compared with the control group. Ghrelin was associated with CAD; therefore, it may be considered a biomarker for distinguishing between patients with and without CAD. Furthermore, the ghrelin/TC ratio could be proposed as a diagnostic marker for CVD.

Effect of lisinopril therapy on serum leptin, oxidative stress and C-reactive protein in hypertensive patients

The pathogenesis of essential hypertension through the interaction with elements of the rennin angiotensin aldosterone system is affected by oxidative stress and inflammation. The present study aimed to assess the effects of ACE-Inhibitor, lisinopril, on blood pressure, lipid profiles (total cholesterol, triglycerides, LDL and HDL), MDA, and TAS, hsCRP, and serum leptin levels n hypertensive patients. A case control study included 100 newly diagnosed mild to moderate hypertensive patients and another 100 apparently healthy aged and sex matched subjects as controls. The patients were treated with 10 mg lisinopril orally per day for three months’ duration. Venous blood sample was taken to test levels of MDA, GSH and TAS, hsCRP, lipid profiles and leptin in the serum before and after lisinopril therapy for both patients and controls. Systolic and diastolic blood pressure were also assessed before and after lisinopril therapy for both patients and controls. In hypertensive patients treated with lisinopril, markers of oxidative stress (MDA, TAS and GSH), high sensitive C-reactive protein and leptin were all found to be decreased significantly after drug treatment (p &lt; 0.01). Lisinopril affectively lowered systolic and diastolic BP values (p &lt; 0.01). A significant decrease in lipid profile (p &lt; 0.01) with a significant increase in HDL-C and TAS levels (p &lt; 0.01) were found in lisinopril treated group in comparison with their values before treatment. Lisinopril may be used as a treatment for high blood pressure, as well as for the insulin resistance, hyperleptinemic, and low-grade inflammatory states that are associated with the disease.

The New Kid on the Block: The Mechanisms of Action of Hyperleptinemia in Coronary Artery Disease and Atherosclerosis

Leptin is an adipocytokine that consists of 167 amino acids. It functions as a regulator of hunger and energy expenditure. Leptin loses its ability to carry out its physiological function at high serum levels, and many studies have associated this loss of function with the development of coronary artery disease (CAD). This literature review aims to outline the steps by which leptin leads to CAD and atherosclerosis. Two independent researchers extracted animal and human studies from PubMed and Google Scholar databases. We applied PubMed search builder options: pathology, pathophysiology, metabolism, and physiology to focus the search results. This study concluded that the mechanism by which leptin might lead to CAD via pressor and depressor effects on vascular tone, enhancing atherosclerotic plaques, and through numerous single nucleotide polymorphisms, the most common being that of the leptin receptor gene rs113701. 

The Causes and Potential Injurious Effects of Elevated Serum Leptin Levels in Chronic Kidney Disease Patients

Leptin is an adipokine that regulates appetite and body mass and has many other pleiotropic functions, including regulating kidney function. Increased evidence shows that chronic kidney disease (CKD) is associated with hyperleptinemia, but the reasons for this phenomenon are not fully understood. In this review, we focused on potential causes of hyperleptinemia in patients with CKD and the effects of elevated serum leptin levels on patient kidney function and cardiovascular risk. The available data indicate that the increased concentration of leptin in the blood of CKD patients may result from both decreased leptin elimination from the circulation by the kidneys (due to renal dysfunction) and increased leptin production by the adipose tissue. The overproduction of leptin by the adipose tissue could result from: (a) hyperinsulinemia; (b) chronic inflammation; and (c) significant lipid disturbances in CKD patients. Elevated leptin in CKD patients may further deteriorate kidney function and lead to increased cardiovascular risk.

The APLNR gene polymorphism rs7119375 is associated with an increased risk of development of essential hypertension in the Chinese population: A meta-analysis

Hypertension (HT) has recently been defined as a systolic blood pressure (BP) of ≥130 mm Hg and/or a diastolic BP of ≥80 mm Hg. It is important to further understand the pathophysiology of essential HT as its proportion is larger among most of the diagnosed HT cases. The apelin and apelin receptor (APLNR) are known to play roles in regulating BP, but the putative associations of single nucleotide polymorphisms in the APLNR gene with the risk of development of essential HT have not yet been fully investigated. Herein, we conducted a meta-analysis to investigate the relationship between single nucleotide polymorphisms in the APLNR gene and the risk of essential HT.We conducted a search in the PubMed and Web of Science databases for eligible studies. The pooled odds ratios (ORs) with their 95% confidence intervals (CI) were calculated using random-effects models when heterogeneity was expected across the studies. Otherwise, fixed-effect models were used.Regarding the SNP rs7119375, 5 studies were analyzed, which included a total of 3567 essential HT patients and 3256 healthy controls. Four of the 5 studies were from China and 1 was from Mexico. The meta-analysis showed the existence of a significant association between the AA genotype of rs7119375 and the risk of developing essential HT in the Chinese population, as determined using additive and recessive models (OR, 2.11; 95% CI, 1.12-3.96; I = 86% for AA vs GG. OR, 1.53; 95% CI, 1.21-1.94; I = 28% for AA vs AG. OR, 1.88; 95% CI, 1.13-3.12; I = 79% for AA vs AG + GG).Our study showed, for the first time, the existence of an association between rs7119375 and the risk of development of essential HT in the Chinese population, although the sample size was small and there was considerable population heterogeneity. The apelin/APLNR system could be a novel therapeutic target for the treatment of essential HT, and more studies are warranted to further investigate the association.

Association of genetic defects in the apelin-AGTRL1 system with myocardial infarction risk in Han Chinese

We aimed to test the hypothesis that apelin (APLN) and its receptor AGTRL1 (APLNR) genes may contribute to the pathogenesis of myocardial infarction in Han Chinese. This is a hospital-based, case-control association study, involving 1067 patients with myocardial infarction and 942 healthy controls. Myocardial infarction is diagnosed by electrocardiogram or anatomopathological examination. Eight polymorphisms in APLN gene and 5 in APLNR gene were genotyped using the TaqMan assay. Risk was summarized as odds ratio (OR) and 95% confidence interval (CI). In males, rs56204867-G allele (adjusted OR, 95% CI, p: 0.21, 0.08-0.55, 0.002) and rs2235309-T allele (0.60, 0.42-0.84, 0.004) was associated with a significantly reduced risk of myocardial infarction, and the mutations of rs2235310 was associated with an increased risk (1.41, 1.06-2.52, 0.021), as well as for rs948847-GG genotype (1.85, 1.23-2.91, 0.007). In females, the presence of rs56204867-AG and -GG genotypes was significantly associated with 44% and 50% reduced risk (0.56 and 0.50, 0.40-8.04 and 0.29-0.86, 0.007 and 0.036), respectively; for rs2235310, CC genotype was associated with 72% increased risk (1.72, 1.09-3.22, 0.016), and the odds of myocardial infarction was 3.47 for rs9943582-TT genotype (95% CI: 1.53-7.57, 0.009). The gender-specific association of APLN and APLNR genes with myocardial infarction was reinforced by further linkage and haplotype analyses. Finally, nomograms based on significant polymorphisms are satisfactory, with the C-indexes over 80% for both genders. Taken together, our findings indicate that APLN and APLNR genes are potential candidates in the pathogenesis of myocardial infarction in Han Chinese, and importantly their contribution is gender-dependent.

Association of Apelin and Apelin Receptor Polymorphisms With the Risk of Comorbid Depression and Anxiety in Coronary Heart Disease Patients

The Apelin (APLN)/apelin receptor (APLNR) signaling pathway is a newly identified regulator in various cardiovascular diseases, which is considered as a candidate pathway for the occurrence of coronary heart disease (CHD), depression, and anxiety. The goal of this study was to investigate the association between APLN/APLNR gene polymorphisms and the risk of depression and anxiety in CHD patients. To this end, a case-control study involving 269 CHD patients and 184 healthy control individuals was conducted. The 269 patients with CHD including 122 patients with and 147 patients without depression, and 56 patients with and 213 patients without anxiety Four single nucleotide polymorphisms were selected and successfully genotyped using Sanger sequencing. The APLN rs2235310T allele and APLNR rs9943582C allele were found to be associated with an increased risk of CHD after multiple test correction (P-adjust < 0.05). The patients with CHD who carried the rs9943582C allele had a higher risk of depression, after adjusting for alcohol drinking habits, insomnia, hypertension, and stroke history, with the Bonferroni correction (P-adjust = 0.018). The APLNR rs2282623 T allele was associated with an increased risk of anxiety in CHD patients after adjusting for related disease complications, with the Bonferroni correction (P-adjust = 0.022). We reported for the first time that the APLN rs2235310 and APLNR rs2282623 polymorphisms are associated with the risks of psychiatric disorders in CHD patients and may serve as novel biomarkers for therapy.

The Relationship Between Selected CNR1, MC4R, LEP, FTO and VDR Gene Polymorphisms and Several Basic Toxicological Parameters Among Persons Occupationally Exposed to Arsenic, Cadmium and Lead

The purpose of this work was to assess the influence of selected CNR1, MC4R, LEP, FTO and VDR FOKI gene polymorphisms on blood and urine concentration markers of lead, cadmium and arsenic in a population directly exposed to these metals. Eighty-five people exposed to lead, arsenic and cadmium were qualified to take part in the study. Standard urine samples and 25mL of venous blood from each worker were collected to assay basic laboratory and toxicological markers as well as selected single nucleotide polymorphisms (SNPs) within CNR1-cannabinoid receptor 1 gene (rs806368, rs806381, rs1049353, rs12720071), MC4R-melanocortin 4 receptor gene (rs17782313), LEP-leptin promoter gene (rs7799039), FTO-alpha-ketoglutarate-dependent dioxygenase gene (rs9939609) and VDR-vitamin D receptor (rs10735810) genes. It appeared that, except for the MC4R SNP, all the other polymorphisms were found to be associated with various laboratory parameters. Arsenic concentration in urine was associated with all four CNR1 and LEP SNPs, while cadmium concentration in blood was affected by the VDR polymorphism. Moreover, some significant relationships were also observed between CNR1 rs1049353 and FTO rs9939609 gene variants and markers of lead exposure. These results imply SNPs within genes coding for proteins involved in development of metabolic syndrome may be of prognostic value for persons directly exposed to lead, cadmium and arsenic.

Association of leptin and leptin receptor polymorphisms with coronary artery disease in a North Chinese Han population

INTRODUCTION:

Leptin (LEP) is a peptide hormone that acts via leptin receptor (LEPR) binding. Genetic evidence from different human populations has implicated LEP/LEPR in the pathogenesis of coronary artery disease (CAD), and suggests that certain LEP/LEPR gene polymorphisms may increase the risk of CAD. The aim of this study was to assess two single nucleotide polymorphisms (SNPs) in LEP genes (rs2167270 and rs7799039) and two in LEPR genes (rs6588147, rs1137100) for association with CAD.

METHODS:

We enrolled 271 North Chinese Han CAD patients, and 113 healthy age- and sex-matched controls. Genomic DNA was extracted from whole blood, and the four SNPs were assessed using a MassArray system.

RESULTS:

The G allele frequency at rs2167270 was significantly higher among CAD cases than among controls. The AG genotype at rs7799039 was associated with a significantly decreased risk of CAD unlike the AA genotype used as the reference. The A allele was significantly associated with the CAD patient group. Interestingly, statistically significant differences in genotype and allele frequency at LEP rs2167270 and rs7799039 existed among females but not among males.

CONCLUSIONS:

The current study detected a significant association between genetic variations at LEP rs7799039 and rs2167270 and the risk of CAD in a north Chinese population, and revealed that LEP rs2167270 and rs7799039 gene polymorphisms might act as predisposing factors for CAD.

The association between apelin polymorphisms and hypertension in China: A meta-analysis

INTRODUCTION:

Apelin plays an important part in regulating blood pressure, metabolism, and the development of cancer. Recent studies have investigated the association of apelin polymorphisms and hypertension risk, but no meta-analysis has been conducted.

MATERIALS AND METHODS:

Five studies were included in this meta-analysis in total. The pooled odds ratio and its corresponding 95% confidence interval were calculated by the random-effect model.

RESULTS:

The overall pooled odds ratio of the distribution of rs3761581 G allelic frequency was 0.90 (95% confidence interval: 0.82-1.00). In female participants, the pooled odds ratio of the frequency of G allele was 1.01 (95% confidence interval: 0.89-1.14). For males, the pooled odds ratio of the frequency of G allele was 0.69 (95% confidence interval: 0.46-1.03). As for rs56204867, the overall pooled odds ratio of the frequency of G allele was 1.09 (95% confidence interval: 0.86-1.37). In females, the pooled odds ratio of the frequencies of the G allele was 1.05 (95% confidence interval: 0.86-1.29). In male participants, the frequency of G allele did not show significant correlation with hypertension (pooled odds ratio=1.21 95% confidence interval: 0.81-1.79).

CONCLUSION:

This meta-analysis revealed that there was no correlation between apelin polymorphisms, rs3761581 and rs56204867, and the prevalence of hypertension.

APLN/APJ pathway: The key regulator of macrophage functions

Macrophages play key roles during cardiovascular diseases (CVD) and their related complications. Apelin (APLN) is a key molecule, whose roles during CVD have been documented previously. Therefore, it has been hypothesized that APLN may perform its roles via modulation of macrophages. Additionally, due to the widespread distribution of the CVD, more effective therapeutic strategies need to be developed to overcome the related complications. This review article collected recent information regarding the roles of APLN on the macrophages and discusses its potential chance to be a target for molecular/cellular therapy of APLN and the APLN treated macrophages for CVD.

Associations of leptin and leptin receptor genetic variants with coronary artery disease: a meta-analysis

Background: Some pilot studies already tried to investigate potential associations of leptin (LEP) and LEP receptor (LEPR) variants with coronary artery disease (CAD). However, the results of these studies were not consistent. Thus, we performed the present meta-analysis to explore associations between LEP/LEPR variants and CAD in a larger pooled population.

Methods: Systematic literature research of PubMed, Web of Science, Embase and CNKI was performed to identify eligible case–control studies on associations between LEP/LEPR variants and CAD. The initial search was conducted in September 2018 and the latest update was performed in December 2018. Q test and I² statistic were employed to assess between-study heterogeneities. If probability value(P-value) of Q test was less than 0.1 or I² was greater than 50%, random-effect models (REMs) would be used to pool the data. Otherwise, fixed-effect models (FEMs) would be applied for synthetic analyses.

Results: A total of ten studies published between 2006 and 2018 were eligible for analyses (1989 cases and 2601 controls). Pooled analyses suggested that LEP rs7799039 variant was significantly associated with CAD under over-dominant model (P=0.0007, odds ratio (OR) = 1.36, 95% confidence interval (CI): 1.14–1.63, I² = 41%, FEM) in overall population, and this significant finding was further confirmed in East Asians in subsequent subgroup analyses. However, no positive findings were observed for LEPR rs1137100 and rs1137101 variants in overall and subgroup analyses.

Conclusions: Our meta-analysis suggested that LEP rs7799039 variant might affect individual susceptibility to CAD.

CD36 gene polymorphism rs1761667 (G > A) is associated with hypertension and coronary artery disease in an Iranian population

Background

CD36 is associated with regulation of lipid metabolism, atherosclerosis, and blood pressure. Moreover, its variation may be involved in the development of hypertension and/or coronary artery disease (CAD). The present study was conducted to investigate the possible association of CD36 rs1761667 (G > A) polymorphism with hypertension and/or CAD in the southeastern of Iran.

Methods

The present observational study was composed of 238 subjects who were admitted for coronary angiography, and divided into four groups: 1) hypertensive without CAD (H-Tens, n = 52); 2) hypertensive with CAD (CAD + H-Tens, n = 57); 3) CAD without hypertension (CAD, n = 65); and 4) non-hypertensive without CAD as the control group (Ctrl, n = 64). The CD36 rs1761667 polymorphism was genotyped with PCR-RFLP method. Association between CD36 rs1761667 genotypes and the risk of CAD and hypertension was assessed using multinomial regression by adjusting for age, sex, creatinine, fasting blood sugar (FBS), systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Results

In the present study, minor allele (A) frequency was 0.36. The genotype, but not allele frequency of the CD36 rs1761667 was significantly different between the four study groups (p = 0.003). Furthermore, using a recessive inheritance model CD36 rs1761667 polymorphism was significantly associated with an increased risk of CAD with hypertension (OR = 5.677; 95% CI = 1.053–30.601; p = 0.043). However, using the dominant model of CD36 rs1761667 had a protective effect on H-Tens and CAD patients.

Conclusion

The present findings revealed an association between CD36 rs1761667 polymorphism and susceptibility to hypertension and/or CAD in a southeastern Iranian population.

Protective effects of leptin against cerebral ischemia/reperfusion injury

In recent years, the use of thrombolytic therapy for treating ischemia/reperfusion injury has resulted in damage to the self-regulatory mechanisms of the brain. This is due to the increased production of free radicals, excitatory amino acids and pro-inflammatory cytokines causing secondary damage to the brain. Simple thrombolytic therapy has not been the best approach for treating ischemia/reperfusion injury. Excessive perfusion leads to failure of the body's self-regulatory functions, which in turn increases the area of cerebral edema and aggravates cerebral ischemia. Previous studies have evaluated the satiety hormone leptin as a link between energy expenditure and obesity. Of note, leptin, which is involved in brain development, synaptic transmission and angiogenesis following ischemia/reperfusion injury, has been considered an important factor for treating ischemia/reperfusion injury. The present review outlines the discovery of leptin and discusses its association with cerebral ischemia/reperfusion.

Association of Klotho gene polymorphism with hypertension and coronary artery disease in an Iranian population

Background

Klotho, possibly an age-regulating protein, is considered an important factor contributing to the lifespan and pathophysiology of hypertension and coronary artery disease (CAD). The present study was carried out aiming to investigate the association of Klotho-rs564481 (C1818T) gene polymorphism with hypertension and CAD.

Methods

A total of 286 CAD-suspicious subjects were entered into this case-control study. The polymorphism was investigated in hypertensive patients with no CAD (H-Tens, n = 60); hypertensive patients with CAD (CAD + H-Tens, n = 95); CAD patients with no hypertension (CAD, n = 61); and non-hypertensive non-CAD subjects, which were regarded as the control group (Ctrl, n = 70). Genotype and allele frequencies were assessed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

A significant difference was found in allele frequency of Klotho C1818T among the four research groups (P = 0.03). It was also found that wild-type homozygote subjects were negatively associated with hypertension as compared to heterozygote ones (OR = 0.07 [95% CI: 0.008–0.69] P = 0.02). Moreover, in the subgroups older than 57 years old, dominant genetic model demonstrated a negative association with CAD combined with hypertension (OR = 0.31 [95% CI: 0.10–0.95] P = 0.04).

Conclusions

In conclusion, Klotho C1818T variant may be associated with a decreased risk of hypertension. Moreover, aging enhanced positive effects of the Klotho polymorphism on CAD combined with hypertension, indicating the possibility that the KLOTHO gene might play a part in the age-related occurrence of CAD combined with hypertension.

Atorvastatin and losartan may upregulate renalase activity in hypertension but not coronary artery diseases: The role of gene polymorphism

The aim is to explore the treatment effect of coronary artery disease (CAD) and hypertension on plasma levels of renalase activity and also the possible association of renalase rs10887800 gene polymorphism with CAD and hypertension. A total of 286 patients who received coronary angiography were included in the study. Subjects were divided into four groups including (1) hypertensive with no CAD (H-Tens, n = 60); (2) CAD with hypertension (CAD + H-Tens, n = 71); (3) CAD with no hypertension (CAD, n = 61); and (4) nonhypertensive with no CAD as a control group (Con, n = 69). The plasma renalase activity was measured using the Amplex Red Monoamine Oxidase Assay Kit. Renalase rs10887800 single-nucleotide polymorphisms (SNPs) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Atorvastatin (P = 0.005), losartan (P < 0.001), and captopril (P = 0.001) were administered significantly more in case groups compared with the Con group. Significant higher and lower levels of renalase activity were observed in H-Tens and CAD patients compared with control subjects (P < 0.001 for both comparisons). Furthermore, no significant differences were obtained in the risk or protective effects of renalase rs10887800 SNP against hypertension and/or CAD in both recessive and dominant genetic models (P > 0.05). According to the findings of the present study, atorvastatin and losartan therapy assumes considerable significance in alleviating hypertension, but not CAD, by increasing the renalase activity. Furthermore, it was found that renalase rs10887800 is less likely a predisposing factor for susceptibility to hypertension and/or CAD in an Iranian southeast population.

Atorvastatin, losartan and captopril may upregulate IL-22 in hypertension and coronary artery disease; the role of gene polymorphism

AIMS

Interleukin-22 (IL-22) may be considered as an important cytokine in maintenance and progression of hypertension and coronary artery disease (CAD). The aim of the present study was to investigate the effect of treatment of hypertension and CAD on serum levels of IL-22 and the possible association of IL-22-rs1179251 gene polymorphism with hypertension and CAD.

MATERIALS AND METHODS

A total of 286 subjects with suspected CAD were enrolled. Serum levels and gene polymorphism of IL-22 were investigated in hypertensive patients with no CAD (H-Tens), hypertensive patients with CAD (CAD + H-Tens); 3), CAD patients with no hypertension (CAD); and non-hypertensive with no CAD subjects as a control group (Ctr). The patients received routine medications for hypertension and CAD. Serum IL-22 levels and IL-22-rs1179251 gene polymorphism were evaluated using ELISA and RFLP-/PCR techniques, respectively.

KEY FINDINGS

Findings demonstrated that there were significantly higher levels of IL-22 in case groups (H-Tens, CAD + H-Tens, and CAD) compared to the Ctr group (P = 0.001, P = 0.014, and P < 0.001, respectively). Moreover, atorvastatin, losartan and captopril were administered significantly more in patients compared to the Ctr group. The results indicated a decreased risk of CAD + H-Tens of rs1179251 dominant genetic model (OR = 0.324; 95% CI = 0.121-0.873; P = 0.026).

SIGNIFICANCE

Atorvastatin, losartan and captopril may be led to upregulation of IL-22 in CAD and hypertensive patients. Meanwhile, higher levels of circulating IL-22 could contribute to alleviating the hypertension and CAD conditions. The G allele of IL-22 rs1179251 may be a protective factor for concomitant hypertension and CAD.