Angiotensin-converting enzyme insertion/deletion gene polymorphisms associated with risk of atrial fibrillation: A meta-analysis of 23 case-control studies

Pathophysiological Mechanisms of Psychosis-Induced Atrial Fibrillation: The Links between Mental Disorder and Arrhythmia

Atrial fibrillation (AF) is a common phenomenon of sustained arrhythmia leading to heart failure or stroke. Patients with mental disorders (MD), particularly schizophrenia and bipolar disorder, are at a high risk of AF triggered by the dysregulation of the autonomic nervous system, atrial stretch, oxidative stress, inflammation, and electrical or structural remodeling. Moreover, pathophysiological mechanisms underlying MD may also contribute to the genesis of AF. An overactivated hypothalamic-pituitary-adrenal axis, aberrant renin-angiotensin-aldosterone system, abnormal serotonin signaling, disturbed sleep, and genetic/epigenetic factors can adversely alter atrial electrophysiology and structural substrates, leading to the development of AF. In this review, we provide an update of our collective knowledge of the pathophysiological and molecular mechanisms that link MD and AF. Targeting the pathogenic mechanisms of MD-specific AF may facilitate the development of therapeutics that mitigate AF and cardiovascular mortality in this patient population.

Contribution of the ACE (rs1799752) and CYP11B2 (rs1799998) Gene Polymorphisms to Atrial Fibrillation in the Tunisian Population

BACKGROUND

This study investigated the association of angiotensin-converting enzyme (ACE I/D) and aldosterone synthase (CYP11B2-344C/T) gene polymorphisms in the renin-angiotensin-aldosterone system (RAAS) with atrial fibrillation (AF) in the Tunisian population.

MATERIALS AND METHODS

The study population included 120 patients with AF and 123 age-matched controls. Genotyping of the I/D polymorphism in the ACE gene and the -344C/T polymorphism in the CYP11B2 gene was performed by polymerase chain reaction (PCR) and PCR-RFLP methods, respectively.

RESULTS

The genotype distribution of the ACE I/D and CYP11B2-344C/T polymorphisms was significantly different between AF patients and control participants (p < 0.01 and p < 0.006 respectively). In addition, ACE I/D increased the risk of AF significantly by 3.41-fold for the DD genotype (OR = 3.41; 95% CI [1.39-8.34]; p < 0.007), and after adjusting for confounding factors (age, diabetes, hypertension, and dyslipidemia), the risk was higher (OR = 5.71; 95% CI [1.48-21.98]; p < 0.01). Likewise, the CYP11B2-344C/T polymorphism increased the incidence of AF for the TT genotype (OR = 3.66; 95% CI [1.62-8.27]; p < 0.002) and the CT genotype (OR = 2.68; 95% CI [1.22-5.86]; p < 0.01). After adjusting for confounding factors (age, diabetes, hypertension and dyslipidemia), the risk remained higher for the TT genotype (OR = 3.58; 95% CI [1.08-11.77]; p < 0.03). Furthermore, the haplotype-based association of the ACE I/D and CYP11B2-344C/T polymorphisms showed that the D-T haplotype increased the risk for AF.

CONCLUSION

Our study suggests a significant association of the ACE (I/D) and CYP11B2-344C/T polymorphisms with AF in the Tunisian population.

Pharmacogenomics of heart failure: a systematic review

BACKGROUND

Heart failure (HF) and multiple HF-related phenotypes are heritable. Genes implicated in the HF pathophysiology would be expected to influence the response to treatment.

METHODS

We conducted a series of systematic literature searches on the pharmacogenetics of HF therapy to assess the current knowledge on this field.

RESULTS

Existing data related to HF pharmacogenomics are still limited. The ADRB1 gene is a likely candidate to predict response to β-blockers. Moreover, the cytochrome P450 2D6 coding gene (CYP2D6) clearly affects the pharmacokinetics of metoprolol, although the clinical impact of this association remains to be established.

CONCLUSION

Given the rising prevalence of HF and related costs, a more personalized use of HF drugs could have a remarkable benefit for patients, caregivers and healthcare systems.

ACE Insertion/Deletion Polymorphism Associated with Caries in Permanent but Not Primary Dentition in Czech Children

OBJECTIVE

Dental caries is a multifactorial, infectious disease where genetic predisposition plays an important role. Insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) has very recently been associated with caries in Polish children. The aim of this study was to analyze ACE I/D polymorphism in a group of caries-free children versus subjects affected by dental caries in the Czech population.

MATERIALS AND METHODS

In this case-control study, 182 caries-free children (with decayed/missing/filled teeth, DMFT = 0), 561 subjects with dental caries (DMFT ≥1) aged 13-15 years and 220 children aged 2-6 years with early childhood caries (ECC, dmft ≥1) were included. Genotype determination of ACE I/D polymorphism in intron 16 was based on the TaqMan method.

RESULTS

Although no significant differences in the allele or genotype frequencies between the caries-free children and those affected by dental caries were observed, statistically significant differences between the children with DMFT = 0 and the subgroup of 179 patients with high caries experience (DMFT ≥4; p < 0.01 and p < 0.05, respectively) were detected. The comparison of DD versus II+ID genotype frequencies between the patients with DMFT ≥1 or DMFT ≥4 and healthy children also showed significant differences (31.5% or 35.6% vs. 23.6%, p < 0.05 or p < 0.01, respectively). A gender-based analysis identified a significant difference in the DD versus II+ID genotype frequencies only in girls (p < 0.05). In contrast, no significant association of ACE I/D polymorphism with ECC in young children was found (p > 0.05).

CONCLUSIONS

ACE I/D polymorphism may be associated with caries in permanent but not primary dentition, especially in girls in the Czech population.