Angiotensin Converting Enzyme Gene Polymorphism and its Association with Hypertension in South Indian Population

ACE Gene I/D Polymorphism and Cardiometabolic Risk Factors: A Cross Sectional Study of Rural Population

The D allele has been identified as being linked to cardiovascular disease since the discovery of an insertion/deletion (I/D) polymorphism in the ACE gene, this polymorphism has been found to have significant associations with a variety of cardiovascular risk factors. Recent findings indicate a rising prevalence of metabolic disorders among rural populations in developing nations. Research on health matters has been predominantly focused on urban populations, with relatively less attention given to their rural counterparts Hence, the present study attempts to estimate the prevalence of ACE gene I/D polymorphism and explore its association with various cardiovascular risk factors among Rural Yadav population from India. In the present study, 207 (Male 47, Female 160) members of the Yadav community participated in the cross-sectional study. All the socio-demographic factors, somatometric (anthropometric) variables, and the intravenous blood was collected and Physiological (blood pressure), and biochemical (fasting glucose and lipid profile) parameters were measured as recommended by the American Heart Association, allele-specific PCR of the ACE gene I/D polymorphism was carried out, the PCR products were genotyped on 2% agarose gel Electrophoresis and ACE gene polymorphism was analysed for its association with various cardiovascular risk factors. Among the analysed individuals, 34 (16.4%) were found to have the II genotype, 58 (28.0%) had the ID genotype, and 115 (55.6%) had the DD genotype. The allele frequency of the I allele was found to be 0.31, and the frequency of the D allele was 0.69. The frequency of the DD genotype was found to be significantly higher among individuals with high TC, high TG, and low non-HDL levels (p value < 0.05). When considered collectively, the findings of this study are consistent with the hypothesis that the DD genotype of ACE polymorphism represents a correlation with cardiovascular disease risk factors in this population.

Analysis of the Pattern, Alliance and Risk of rs1799752 (ACE I/D Polymorphism) with Essential Hypertension

Studies in spontaneously hypertensive rat had revealed an elevated level of ACE gene expression in the tissues and is substantiated by experimental clinical studies for a positive correlation between ACE I/D polymorphism and hypertension. Aim: To determine whether the polymorphic variant of ACE gene in intron 16 confers susceptibility to essential hypertension. I/D polymorphism at the locus intron 16 of the ACE gene were amplified from the genomic DNA of the total 571 (hypertensive patients, n: 279; controls, n: 292) participants using polymerase chain reaction and gel electrophoresis methods and were examined in a case-control approach. Suitable descriptive statistics was used for different variables. Result revealed significant heterogeneity under the allele (p: 0.0002) and genotype (p: 0.0001) contrast in hypertensive patients than in normal controls, with an increased frequency of D allele (62.72%; p < 0.0001; OR: 1.8144; 95% CI: 1.4327-2.2979) and DD genotype (41.93%; p: < 0.0001). A significant association was found in the DD variant with disease phenotype (p: 0.0018, 95% CI: 1.3303-3.4907; OR: 2.1549; Table 31) and is substantiated by the data of multivariate analysis, demonstrating a statistically significant increase in odds of hypertension with the ACE D/D genotype (OR: 2.09; 95% CI: 1.24-2.91). Conspicuously, subgroup analysis by gender did not change this pattern of results. Albeit the allele distribution resulted in a higher frequency of the D/D genotype in the cases than controls, testing genetic equilibrium between the observed and expected genotypes using Hardy-Weinberg equilibrium showed ACE gene variants were confirming to the law in hypertensive as well as in non-hypertensive participants. I/D polymorphism in the angiotensin-I-converting enzyme gene at the 16th intron can be useful for outcome predictions during diagnostic processes can be implicated in an individual's propensity for hypertension and thus implies that genetic variants of ACE I/D might serve as a predictor for the susceptibility to hypertension.

Association of ACE I/D gene polymorphism and related risk factors in impaired fasting glucose and type 2 diabetes: a study among two tribal populations of North-East India

BACKGROUND

Type 2 diabetes is a serious public health concern in India, even the indigenous tribal populations are not left unaffected. The present study aims to understand the association of major risk factors i.e. obesity, hypertension, dyslipidemia, ACE I/D polymorphism with impaired fasting glucose (IFG) and type 2 diabetes (T2D) among two different Mendelian populations of North East India.

METHODS

Demographic, somatometric, physiological variables along with fasting blood samples were collected from 609 individuals. The participants were screened for ACE I/D polymorphism.

RESULTS

ACE I/D polymorphism was found to follow HWE among Liangmai tribe but not among Mizo tribe. Distribution of DD genotype/D allele was found to be significantly higher for T2D among Mizo tribe. Significant association were observed between DD genotype/D allele of ACE I/D polymorphism and TC as well as LDL with both IFG and T2D only in Mizo tribe.

CONCLUSIONS

The present study is an example of gene-environment interaction where DD genotype or D allele and dyslipidemia (high TC and high LDL) are posing risk for IFG and T2D both independently and in combination only among Mizo tribe with relatively less physical activity attributed to their residence in less hilly terrain however Liangmai tribe which resides in high hilly terrain shows no such association.

Epidemiological links between malaria parasitaemia and hypertension: findings from a population-based survey in rural Côte d'Ivoire

Background:

Although potential links between malaria parasitaemia and hypertension have been hypothesized, there is paucity of epidemiologic evidence on this link. We investigated in a population-based survey, the association between malaria parasitaemia and hypertension in Ivorian adults.

Methods:

We estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) of hypertension in relation to malaria parasitaemia using multinomial regression, in 997 randomly selected adults in the ‘Côte d’Ivoire Dual Burden of Disease Study’ (CoDuBu), in south-central Côte d’Ivoire. We defined malaria parasitaemia as a positive rapid diagnostic test or identification of Plasmodium spp. on microscopy. Using the mean of the last two of three blood pressure (BP) measurements and questionnaire data, we defined hypertension as SBP at least 140 mmHg or DBP at least 90 mmHg or clinician-diagnosed hypertension.

Results:

Prevalence of malaria parasitaemia and hypertension were 10 and 22%, respectively. Malaria parasitaemia was negatively associated with hypertension in participants with body temperature 36.5 °C or less [OR 0.23 (95% CI 0.06–0.84)]. Contrastingly, microscopic malaria parasitaemia showed positive associations with hypertension in participants with elevated body temperature [>36.5 °C; OR: 2.93 (95% CI 0.94–9.14)]. Participants having microscopic malaria parasitaemia with elevated body temperature had three-fold higher odds of hypertension [OR: 3.37 (95% CI 1.12–10.0)] than malaria parasitaemia-negatives with lower body temperature.

Conclusion:

Malaria parasitaemia and hypertension are prevalent and seemingly linked comorbidities in African settings. This link may depend on malaria parasitaemia symptomaticity/latency where individuals with more latent/asymptomatic malaria parasitaemia have lower risk of hypertension and those with more acute/symptomatic malaria parasitaemia have a tendency toward higher BP. The cross-sectional nature of the study limited the distinction of short-term BP elevation (interim pathophysiological stress) from hypertension development. Future longitudinal studies considering malaria/hypertension phenotypes and host molecular variations are needed to clarify involved biological mechanisms, toward comorbidity management.

Blood pressure response to resistance training in hypertensive and normotensive older women

PURPOSE

The purpose of the present study was to identify the variability of blood pressure response to a 10-week resistance training (RT) program in hypertensive and normotensive elderly women.

PARTICIPANTS AND METHODS

Twenty-seven untrained hypertensive and 12 normotensive elderly women participated in the present study. A whole-body RT program was performed on two nonconsecutive days per week for 10 weeks. The responsiveness of resting systolic blood pressure (SBP) was determined based on the percent decline between the pre- and post-training time points T1 and T4. The term responders were used to describe subjects who exhibited a percent SBP decline ≥-2.58% and the term nonresponders for subjects who exhibited a percent SBP decline <-2.58%, respectively.

RESULTS

Both the responders and nonresponders in the hypertensive group presented significant changes in SBP (-7.83 ± 5.70 mmHg vs 3.78 ± 7.42 mmHg), respectively. Moreover, the responders and nonresponders in the normotensive group presented significant changes in SBP as well (-8.58 ± 5.52 mmHg vs 5.71 ± 3.84 mmHg).

CONCLUSION

SBP presents a heterogeneous response to a controlled RT program in hypertensive and normotensive elderly women. A different modality of training and additional therapies should be used for nonresponders in order to decrease resting SBP.

Angiotensin-Converting Enzyme Gene Insertion/Deletion Polymorphism and Cardiometabolic Risk Factors: A Study Among Bhil Tribal Population from Two Environmental Settings

Studies have investigated the association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and cardiometabolic risk factors (CMRFs), however with varying results, which could be due to ethnicity differences. Therefore, the present study was conducted among Bhil tribal population (a mendelian population with the common gene pool and same sociocultural attributes), residing in two different environmental settings. The study attempts to understand the distribution and extent of association of ACE I/D gene polymorphism with cardiometabolic risk factors among Bhils from rural and urban settings. All the obesity and blood pressure variables were collected form 432 recruited subjects from both sexes aged 25-65 years and ACE I/D polymorphism was analysed on 299 subjects. Almost all the studied CMRFs were found to be significantly higher among urban Bhils. ACE gene was found to be polymorphic in the studied groups. DD genotype was found to pose more than threefold significant risk for low HDLC only in rural area. Estimate change analysis revealed an increasing D allele dose leads to more than one unit increase in Blood Pressure, and more than three units decrease in HDLC. The study highlights the differential effect of ACE I/D gene polymorphism in different environmental settings.

Association of DD genotype of angiotensin-converting enzyme gene (I/D) polymorphism with hypertension among a North Indian population

Hypertension, a major risk factor for cardiovascular diseases, is among the leading causes of morbidity and mortality worldwide. Genetic predisposition to the risk of developing hypertension due to angiotensin-converting enzyme (ACE) gene insertion(I)/deletion(D) polymorphism (through altered serum ACE activity) is well documented among various populations. The present study investigated the possible association between ACE (DD) genotype and hypertension using a nested case-control study design including 451 individuals (of either sex in the age group 30-65 years) from a rural North Indian population practicing agriculture and lacto-vegetarianism. Blood Pressure was classified using JNC-7 criterion. Age- and sex-matched individuals were selected from normotensive (N-122), pre-hypertensive (N-123), hypertensive not on medication (N-122), and hypertensive on medication (N-84) categories. Amplification of DNA and genotyping of PCR product was done using standard protocols. From the analysis, comparatively higher frequency of individuals with DD genotype in the hypertensive category was observed, indicating a possible relation between DD genotype and hypertension. The odds ratio analysis revealed 2.225 (1.13-4.37)-fold significant increased risk for hypertension among cases, validating the vulnerability of individuals with DD genotype towards hypertension. Thus, the present study highlights the increased risk for developing hypertension due to ACE DD genotype in the studied population.

Beneficial role of D allele in controlling ACE levels: a study among Brahmins of north India

India being a country with vast diversity is expected to have different dietary and life style patterns which in turn may lead to population-specific environmental risk factors. Further, the interaction of these risk factors with the genetic makeup of population makes it either susceptible or resistant to cardiovascular disease. One such candidate gene is angiotensin converting enzyme (ACE) for various cardiovascular mechanisms. ACE is the key enzyme of the renin angiotensin aldosterone system pathway which maintains homeostasis blood pressure in the body and any variation in the levels is reported to be associated with various complex diseases. The DD genotype is found to increase ACE levels, which is associated with cardiovascular diseases and decrease in ACE levels are associated with kidney diseases. The aim of this study was to understand the distribution of ACE I/D polymorphism and ACE levels among Brahmins of National Capital Region (NCR) north India, with respect to age and sex ratio distribution. In this study, 136 subjects of which 50 males and 86 females, who were unrelated up to first cousin, aged 25 to70 years were studied. ACE gene was found to be polymorphic with high frequency of heterozygote (ID) followed by II and DD genotypes. The studied population was found to be in Hardy-Weinberg equilibrium with respect to ACE I/D polymorphism (P = 0.55). I allele frequency was found to be higher (0.560) than the D allele (0.44). The median level of ACE was found to be 65.96 ng/mL (48.12-86.24) which is towards lower side of the normal range. ACE levels were found to be increased among individual having either of the homozygotes that is II or DD and higher frequency of heterozygote (ID) is indicative of advantage in the population by maintaining lower ACE levels. The limitation of the present study is low sample size, however, the merit is that the subjects belonged to a Mendalian population with a common gene pool.

Role of angiotensin converting enzyme and angiotensinogen gene polymorphisms in angiotensin converting enzyme inhibitor-mediated antiproteinuric action in type 2 diabetic nephropathy patients

AIM

To investigate the role of genetic variants of angiotensin converting enzyme (ACE) and angiotensinogen (AGT) genes in the antiproteinuric efficacy of ACE inhibitor therapy in diabetic nephropathy (DN) patients.

METHODS

In the present study, 270 type 2 diabetes mellitus patients with nephropathy were enrolled and treated with ACE inhibitor (ramipril) and followed at 6 mo for renal function and albumin excretion by estimating serum creatinine, end stage renal disease, and albumin/creatinine ratio (ACR) in urine. Genotyping of ACE I/D and AGT M235T polymorphisms were performed by using primer specific polymerase chain reaction (PCR) and PCR-RFLP techniques, respectively.

RESULTS

Forty-eight percent of DN patients (responders) benefited with respect to proteinuria from ACE inhibitor therapy at 6 mo follow-up. A significant reduction in ACR was observed after 6 mo treatment with ACE inhibitor irrespective of whether DN patients were micro-albuminuric (≥ 30 and < 300 mg/g creatinine) or macro-albuminuric (≥ 300 mg/g creatinine) at the time of enrollment. However, macro-albuminuric patients (55%) showed better response to therapy. A reduction in urinary ACR was found independent of genotypes of ACE I/D and AGT M235T polymorphisms although macro-albuminuric patients having TT genotype showed statistically insignificant increased response (72%).

CONCLUSION

ACE inhibitor therapy reduced urinary ACR by ≥ 30% in 50% of DN patients and the response is independent of ACE I/D and AGT M235T polymorphisms.

Association of Angiotensin-Converting Enzyme and Glutathione S-Transferase Gene Polymorphisms with Body Mass Index among Hypertensive North Indians

OBJECTIVES

This study aimed to examine the association of angiotensin-converting enzyme (ACE) and glutathione S-transferase (GST) gene polymorphisms with body mass index (BMI) in hypertensive North Indians.

METHODS

This case-control study was carried out between May 2013 and November 2014 at the Era's Lucknow Medical College & Hospital, Lucknow, India, and included 378 subjects divided into three groups. One group constituted 253 hypertensive individuals (sustained diastolic blood pressure of >90 mmHg and systolic blood pressure of >140 mmHg) who were subcategorised according to normal (<25 kg/m(2)) or high (≥25 kg/m(2)) BMI. The third group consisted of 125 age-, gender- and ethnically-matched normotensive controls with a normal BMI. Gene polymorphisms were evaluated by polymerase chain reaction. The genotypic and allelic frequency distribution among both groups were analysed.

RESULTS

A significant difference was found between GST theta 1-null and GST mu 1-positive genotype frequencies among the hypertensive overweight/obese individuals and controls (P = 0.014 and 0.033, respectively). However, no difference was observed in the frequency of ACE polymorphisms. ACE insertion/insertion genotype (P = 0.006), insertion and deletion alleles (P = 0.007 each) and GST theta 1-null and GST theta 1-positive genotypes (P = 0.006 each) were found to differ significantly between hypertensive cases and controls, regardless of BMI.

CONCLUSION

ACE and GST gene polymorphisms were not associated with BMI but were significantly associated with hypertension among the studied group of North Indians.

Association of angiotensin-converting enzyme and angiotensin-converting enzyme-2 gene polymorphisms with essential hypertension in the population of Odisha, India

BACKGROUND

Hypertension is a serious health issue worldwide and essential hypertension, which includes 90-95% of the cases, is influenced by both genetic and environmental factors. Identification of these factors may help in control of this disease. The Insertion/Deletion (I/D) polymorphism in Angiotensin-Converting Enzyme (ACE) gene and rs2106809 (C > T) polymorphism in Angiotensin-Converting Enzyme 2 (ACE2) gene have been reported to be associated with essential hypertension in different populations.

AIM

To investigate the association of ACE I/D and ACE2 rs2106809 polymorphisms with essential hypertension in the population of Odisha, an eastern Indian state.

SUBJECTS AND METHODS

A total of 246 hypertensives (159 males and 87 females) and 274 normotensives (158 males and 116 females) were enrolled in the study. Detailed anthropometric data, tobacco, alcohol and food habits were recorded and 2 ml of venous blood was collected for biochemical and genetic analysis.

RESULTS

The DD genotype of ACE and TT genotype of ACE2 were significantly high among female hypertensives, while T allele of ACE2 was linked to male hypertensives. In the male population, alcohol was also identified as a potential risk factor.

CONCLUSION

Among females, ACE I/D and ACE2 rs2106809 polymorphisms, while among males, ACE2 rs2106809 polymorphism and alcohol consumption are associated with essential hypertension in the study population.