Gender difference of serum angiotensin-converting enzyme (ACE) activity in DD genotype of ACE insertion/deletion polymorphism in elderly Chinese

The roles of ACE I/D and ACTN3 R577X gene variants in heat acclimation

Roles of genes in heat acclimation (HA, repeated exercise-heat exposures) had not been explored. ACE I/D and ACTN3 R577X genetic polymorphisms are closely associated with outstanding exercise performances. This study investigated whether the two polymorphisms influenced the response to HA. Fifty young Han nationality male subjects were selected and conducted HA for 2 weeks. Exercise indicators (5-km run, push-up and 100-m run) were tested and rest aural thermometry (RTau) was measured before and after HA. ACE gene was grouped by I homozygote and D carrier, and ACTN3 gene was grouped by R homozygote and X carrier. Results showed that there were no differences between groups in age, body mass index, exercise indicators and RTau before HA. After HA, RTau of ACE I homozygote was lower than that of D carrier [F (1, 48) = 9.12, p = 0.004, η = 0.40]. Compared with RTau before HA, that of I homozygote decreased after HA (Δ = -0.26 °C, 95 % CI -0.34-0.18, p < 0.001), while that of D carrier did not change. There was a ACE gene × HA interaction in RTau [F (1, 48) = 14.26, p < 0.001, η = 0.48]. No effect of ACTN3 gene on RTau was observed. For exercise indicators, there were no differences between groups after HA, and no gene × HA interactions were observed. There may be a strong interaction of ACE gene and HA in the change of rest core temperature. I homozygote may have an advantage on improving heat tolerance.

ACE Phenotyping in Human Blood and Tissues: Revelation of ACE Outliers and Sex Differences in ACE Sialylation

Angiotensin-converting enzyme (ACE) metabolizes a number of important peptides participating in blood pressure regulation and vascular remodeling. Elevated ACE expression in tissues (which is generally reflected by blood ACE levels) is associated with an increased risk of cardiovascular diseases. Elevated blood ACE is also a marker for granulomatous diseases. Decreased blood ACE activity is becoming a new risk factor for Alzheimer's disease. We applied our novel approach-ACE phenotyping-to characterize pairs of tissues (lung, heart, lymph nodes) and serum ACE in 50 patients. ACE phenotyping includes (1) measurement of ACE activity with two substrates (ZPHL and HHL); (2) calculation of the ratio of hydrolysis of these substrates (ZPHL/HHL ratio); (3) determination of ACE immunoreactive protein levels using mAbs to ACE; and (4) ACE conformation with a set of mAbs to ACE. The ACE phenotyping approach in screening format with special attention to outliers, combined with analysis of sequencing data, allowed us to identify patient with a unique ACE phenotype related to decreased ability of inhibition of ACE activity by albumin, likely due to competition with high CCL18 in this patient for binding to ACE. We also confirmed recently discovered gender differences in sialylation of some glycosylation sites of ACE. ACE phenotyping is a promising new approach for the identification of ACE phenotype outliers with potential clinical significance, making it useful for screening in a personalized medicine approach.

Urinary ACE Phenotyping as a Research and Diagnostic Tool: Identification of Sex-Dependent ACE Immunoreactivity

BACKGROUND

Angiotensin-converting enzyme (ACE) is highly expressed in renal proximal tubules, but ACE activity/levels in the urine are at least 100-fold lower than in the blood. Decreased proximal tubular ACE has been associated with renal tubular damage in both animal models and clinical studies. Because ACE is shed into urine primarily from proximal tubule epithelial cells, its urinary ACE measurement may be useful as an index of tubular damage.

OBJECTIVE AND METHODOLOGY

We applied our novel approach-ACE phenotyping-to characterize urinary ACE in volunteer subjects. ACE phenotyping includes (1) determination of ACE activity using two substrates (ZPHL and HHL); (2) calculation of the ratio of hydrolysis of the two substrates (ZPHL/HHL ratio); (3) quantification of ACE immunoreactive protein levels; and (4) fine mapping of local ACE conformation with mAbs to ACE.

PRINCIPAL FINDINGS

In normal volunteers, urinary ACE activity was 140-fold less than in corresponding plasma/serum samples and did not differ between males and females. However, urinary ACE immunoreactivity (normalized binding of 25 mAbs to different epitopes) was strongly sex-dependent for the several mAbs tested, an observation likely explained by differences in tissue ACE glycosylation/sialylation between males and females. Urinary ACE phenotyping also allowed the identification of ACE outliers. In addition, daily variability of urinary ACE has potential utility as a feedback marker for dieting individuals pursuing weight loss.

CONCLUSIONS/SIGNIFICANCE

Urinary ACE phenotyping is a promising new approach with potential clinical significance to advance precision medicine screening techniques.

Quadriceps muscle power and optimal shortening velocity are inversely related to angiotensin converting enzyme activity in older men

Background: Methods which potentially could prevent age-related loss of muscle mass and function are still being sought. There are various attempts to use pharmacological agents to prevent loss of muscle mass, but the effectiveness of many of them still needs to be confirmed. One of the promising therapeutics are Angiotensin Converting Enzyme Inhibitors (ACEIs) and lowering of serum ACE activity. The goal of this study was to assess if taking Angiotensin Converting Enzyme Inhibitors (ACEI) and other angiotensin system blocking medications (ASBMs) can modify muscle performance in older men as well as to assess the association of serum ACE activity with muscle strength, power, muscle contraction velocity and functional performance. Methods: Seventy-nine older men took part in the study. Muscle function was assessed with hand grip strength, maximum power relative to body mass (Pmax) and optimal shortening velocity (Ʋopt) of the knee extensor muscles. Anthropometric data, ACE activity and functional performance were also measured. Results: Negative correlations between ACE activity and Pmax (rho=-0.29, p=0.04) as well as Ʋopt  (rho=-0.31, p=0.03) in a group of patients not taking ACEI and between ACE activity and Ʋopt (rho=-0.22, p=0.05) in the whole group of men were found. Positive relationship between age and ACE activity was demonstrated (rho=0.26, p=0.02). Age was the only selected variable in the multiple regression analyses to determine both Pmax and Ʋopt. Conclusions: Serum ACE activity negatively associates to muscle power and muscle contraction velocity. The issues related to the impact of taking ACEI on the maintenance of muscle function and functional performance in older man require further studies.

Quadriceps muscle power and optimal shortening velocity are inversely related to angiotensin converting enzyme activity in older men

Background: Methods which potentially could prevent age-related loss of muscle mass and function are still being sought. There are various attempts to use pharmacological agents to prevent loss of muscle mass, but the effectiveness of many of them still needs to be confirmed. One of the promising therapeutics are Angiotensin Converting Enzyme Inhibitors (ACEIs) and lowering of serum ACE activity. The goal of this study was to assess if taking Angiotensin Converting Enzyme Inhibitors (ACEI) and other angiotensin system blocking medications (ASBMs) can modify muscle performance in older men as well as to assess the association of serum ACE activity with muscle strength, power, muscle contraction velocity and functional performance. Methods: Seventy-nine older men took part in the study. Muscle function was assessed with hand grip strength, maximum power relative to body mass (Pmax) and optimal shortening velocity (Ʋopt) of the knee extensor muscles. Anthropometric data, ACE activity and functional performance were also measured. Results: Negative correlations between ACE activity and Pmax (rho=-0.29, p=0.04) as well as Ʋopt  (rho=-0.31, p=0.03) in a group of patients not taking ACEI and between ACE activity and Ʋopt (rho=-0.22, p=0.05) in the whole group of men were found. Positive relationship between age and ACE activity was demonstrated (rho=0.26, p=0.02). Age was the only selected variable in the multiple regression analyses to determine both Pmax and Ʋopt. Conclusions: Taking ACEI is not associated with a functional performance in older men of the same age and with the same anthropometric parameters. Serum ACE activity negatively associates to muscle power and muscle contraction velocity.

Genetic Hypothesis and Pharmacogenetics Side of Renin-Angiotensin-System in COVID-19

The importance of host genetics and demography in coronavirus disease 2019 (COVID-19) is a crucial aspect of infection, prognosis and associated case fatality rate. Individual genetic landscapes can contribute to understand Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) burden and can give information on how to fight virus spreading and the associated severe acute respiratory distress syndrome (ARDS). The spread and pathogenicity of the virus have become pandemic on specific geographic areas and ethnicities. Interestingly, SARS-CoV-2 firstly emerged in East Asia and next in Europe, where it has caused higher morbidity and mortality. This is a peculiar feature of SARS-CoV-2, different from past global viral infections (i.e., SARS-1 or MERS); it shares with the previous pandemics strong age- and sex-dependent gaps in the disease outcome. The observation that the severest COVID-19 patients are more likely to have a history of hypertension, diabetes and/or cardiovascular disease and receive Renin-Angiotensin-System (RAS) inhibitor treatment raised the hypothesis that RAS-unbalancing may have a crucial role. Accordingly, we recently published a genetic hypothesis on the role of RAS-pathway genes (ACE1, rs4646994, rs1799752, rs4340, rs13447447; and ACE2, rs2285666, rs1978124, rs714205) and ABO-locus (rs495828, rs8176746) in COVID-19 prognosis, suspecting inherited genetic predispositions to be predictive of COVID-19 severity. In addition, recently, Genome-Wide Association Studies (GWAS) found COVID-19-association signals at locus 3p21.31 (rs11385942) comprising the solute carrier SLC6A20 (Na+ and Cl- coupled transporter family) and at locus 9q34.2 (rs657152) coincident with ABO-blood group (rs8176747, rs41302905, rs8176719), and interestingly, both loci are associated to RAS-pathway. Finally, ACE1 and ACE2 haplotypes seem to provide plausible explanations for why SARS-CoV-2 have affected more heavily some ethnic groups, namely people with European ancestry, than Asians.

COVID-19 and Individual Genetic Susceptibility/Receptivity: Role of ACE1/ACE2 Genes, Immunity, Inflammation and Coagulation. Might the Double X-chromosome in Females Be Protective against SARS-CoV-2 Compared to the Single X-Chromosome in Males?

In December 2019, a novel severe acute respiratory syndrome (SARS) from a new coronavirus (SARS-CoV-2) was recognized in the city of Wuhan, China. Rapidly, it became an epidemic in China and has now spread throughout the world reaching pandemic proportions. High mortality rates characterize SARS-CoV-2 disease (COVID-19), which mainly affects the elderly, causing unrestrained cytokines-storm and subsequent pulmonary shutdown, also suspected micro thromboembolism events. At the present time, no specific and dedicated treatments, nor approved vaccines, are available, though very promising data come from the use of anti-inflammatory, anti-malaria, and anti-coagulant drugs. In addition, it seems that males are more susceptible to SARS-CoV-2 than females, with males 65% more likely to die from the infection than females. Data from the World Health Organization (WHO) and Chinese scientists show that of all cases about 1.7% of women who contract the virus will die compared with 2.8% of men, and data from Hong Kong hospitals state that 32% of male and 15% of female COVID-19 patients required intensive care or died. On the other hand, the long-term fallout of coronavirus may be worse for women than for men due to social and psychosocial reasons. Regardless of sex- or gender-biased data obtained from WHO and those gathered from sometimes controversial scientific journals, some central points should be considered. Firstly, SARS-CoV-2 has a strong interaction with the human ACE2 receptor, which plays an essential role in cell entry together with transmembrane serine protease 2 (TMPRSS2); it is interesting to note that the ACE2 gene lays on the X-chromosome, thus allowing females to be potentially heterozygous and differently assorted compared to men who are definitely hemizygous. Secondly, the higher ACE2 expression rate in females, though controversial, might ascribe them the worst prognosis, in contrast with worldwide epidemiological data. Finally, several genes involved in inflammation are located on the X-chromosome, which also contains high number of immune-related genes responsible for innate and adaptive immune responses to infection. Other genes, out from the RAS-pathway, might directly or indirectly impact on the ACE1/ACE2 balance by influencing its main actors (e.g., ABO locus, SRY, SOX3, ADAM17). Unexpectedly, the higher levels of ACE2 or ACE1/ACE2 rebalancing might improve the outcome of COVID-19 in both sexes by reducing inflammation, thrombosis, and death. Moreover, X-heterozygous females might also activate a mosaic advantage and show more pronounced sex-related differences resulting in a sex dimorphism, further favoring them in counteracting the progression of the SARS-CoV-2 infection.

Genetic variants in rheumatic fever and rheumatic heart disease

Genetic association studies in rheumatic heart disease (RHD) have the potential to contribute toward our understanding of the pathogenetic mechanism, and may shed light on controversies about RHD etiology. Furthermore, genetic association studies may uncover biomarkers that can be used to identify susceptible individuals, and contribute toward developing vaccine and novel therapeutic targets. Genetic predisposition to rheumatic fever and RHD has been hypothesized by findings from familial studies and observed associations between genes located in the human leukocyte antigens on chromosome 6p21.3 and elsewhere in the genome. We sought to summarize, from published Genetic association studies in RHD, evidence on genetic variants implicated in RHD susceptibility. Using HuGENet™ systematic review methods, we evaluated 66 studies reporting on 42 genes. Existing meta-analyses of candidate gene studies suggest that TGF-β1 [rs1800469], and IL-1β [rs2853550] single nucleotide polymorphisms (SNPs) contribute to susceptibility to RHD, whereas the TNF-α [rs1800629 and rs361525], TGF-β1 [rs1800470 and rs4803457], IL-6 [rs1800795], IL-10 [rs1800896] were not associated with RHD. However, candidate gene studies in RF/RHD are relatively small, thus lacking statistical power to identify reliable and reproducible findings, emphasizing the need for large-scale multicenter studies with different populations.

ACE insertion/deletion genetic polymorphism, serum ACE levels and high dietary salt intake influence the risk of obesity development among the Saudi adult population

Introduction:

Angiotensin-converting enzyme (ACE), which contributes to adipocyte growth, differentiation and function, has recently been linked with both salt metabolism and obesity development. Therefore, this study has aimed to investigate the putative relationship between ACE genetic polymorphism, serum ACE levels and salt consumption on the risk of developing obesity in the Saudi population.

Materials and methods:

ACE genotype status of 267 adult Saudi volunteers (124 obese and 143 non-obese) was correlated with their serum ACE activity and dietary salt intake amounts.

Results:

Obesity was more prevalent in deletion-deletion genotype individuals (p<0.03), under dominant, co-dominant and monoallelic conditions (p<0.04). Deletion allele corresponds to serum ACE activity in obese patients (p<0.05). The amount of salt intake (<6 g/d) was significantly associated with obesity and particularly high in deletion-deletion and insertion-deletion genotype carriers (p<0.001). STITCH analysis underlined interactions of the ACE protein with sodium molecule, REN, ACE2, KNG1 and AGTR1 in a biological network.

Conclusions:

Our findings suggest the positive association between ACE deletion genotype, serum ACE activity and sodium intake with risk of obesity development in the Saudi population.

Angiotensin-Converting Enzyme ID Polymorphism in Patients with Heart Failure Secondary to Chagas Disease

Background

Changes in the angiotensin-converting enzyme (ACE) gene may contribute to the increase in blood pressure and consequently to the onset of heart failure (HF). The role of polymorphism is very controversial, and its identification in patients with HF secondary to Chagas disease in the Brazilian population is required.

Objective

To determine ACE polymorphism in patients with HF secondary to Chagas disease and patients with Chagas disease without systolic dysfunction, and to evaluate the relationship of the ACE polymorphism with different clinical variables.

Methods

This was a comparative clinical study with 193 participants, 103 of them with HF secondary to Chagas disease and 90 with Chagas disease without systolic dysfunction. All patients attended the outpatient department of the General Hospital of the Federal University of Goias general hospital. Alleles I and D of ACE polymorphism were identified by polymerase chain reaction of the respective intron 16 fragments in the ACE gene and visualized by electrophoresis.

Results

In the group of HF patients, 63% were male, whereas 53.6% of patients with Chagas disease without systolic dysfunction were female (p = 0,001). The time from diagnosis varied from 1 to 50 years. Distribution of DD, ID and II genotypes was similar between the two groups, without statistical significance (p = 0,692). There was no difference in clinical characteristics or I/D genotypes between the groups. Age was significantly different between the groups (p = 0,001), and mean age of patients with HF was 62.5 years.

Conclusion

No differences were observed in the distribution of (Insertion/Deletion) genotype frequencies of ACE polymorphism between the studied groups. The use of this genetic biomarker was not useful in detecting a possible relationship between ACE polymorphism and clinical manifestations in HF secondary to Chagas disease.

Preeclampsia is associated with ACE I/D polymorphism, obesity and oxidative damage in Mexican women

OBJECTIVE

This study sought to determine whether the angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism, obesity and oxidative damage are risk factors for the development of preeclampsia in Mexican women.

STUDY DESIGN

A total of 66 women with preeclampsia (PE) and 37 women with normal pregnancies (NP) were included in the study. DNA was extracted from whole blood, and the ACE I/D polymorphism was evaluated by polymerase chain reaction. ACE activity and oxidative damage were assessed in plasma. The intergroup comparisons were analyzed by an analysis of variance (ANOVA) with post hoc tests. Hardy-Weinberg equilibrium (HWE) was tested by x² analysis, odds ratios (OR) were calculated as a measure of the degree of relative risk of preeclampsia, and for correlations, we used Spearman's correlation coefficient.

RESULTS

The frequency of the DD genotype was higher in PE (34.84%) than NP (10.82%). The OR of the DD genotype and D allele were associated with a 4.4-fold (CI=95% 2.24-14) and 3-fold (CI=95% 1.69-5.62) increased risk of developing PE, respectively. Major ACE activity in the DD genotype and obesity were features of the PE group; oxidative damage to proteins and a reduction in the activity of the antioxidant system showed a correlation with BMI (p<0.01).

CONCLUSION

Our results suggest that ACE I/D polymorphism, high ACE activity, body mass index and oxidative damage may play key roles in the pathogenesis of PE in the Mexican population. Furthermore, these findings could be used as predictive factors of PE.

Correlation of angiotensin I-converting enzyme gene insertion/deletion polymorphism with rheumatic heart disease: a meta-analysis

Rheumatic heart disease (RHD) is a serious cardiovascular disorder worldwide. Several articles have reported the effect of angiotensin I-converting enzyme gene insertion/deletion (ACE I/D) polymorphism in RHD risk. However, the results still remain inconsistent. The objective of the present study was to assess more precise estimations of the relationship between ACE I/D variant and RHD susceptibility. Relevant case–control studies published between January 2000 and 2016 were searched in the electronic databases. The odds ratio (OR) with its 95% confidence interval (CI) was employed to calculate the strength of the effect. A total of nine articles were retrieved, including 1333 RHD patients and 1212 healthy controls. Overall, our result did not detect a significant association between ACE I/D polymorphism and RHD risk under each genetic model (P > 0.05). Subgroup analysis by ethnicity showed no positive relationship in Asians as well (P > 0.05). With respect to the severity of RHD, our result found that the frequency differences between mitral valve lesion (MVL), combined valve lesion (CVL) and healthy controls were not significantly different. Furthermore, no significant association was found between female, male RHD patients and the controls regarding to the ACE I/D polymorphism. In conclusion, our result indicated that ACE I/D polymorphism might not be a risk factor for RHD progression based on the existing research results. Additional well-designed studies with larger samples are still needed to confirm these findings.

Association between angiotensin converting enzyme gene insertion/deletion polymorphism and renal scar risk in children vesicoureteral reflex: a reappraise meta-analysis

Vesicoureteral reflex(VUR) is a common disease in children. Some studies indicated that the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism associated with the renal scar in VUR, but not all researchers agreed with it. To clarify the effect of ACE I/D polymorphism on renal scar risk in children with VUR, we performed the present meta-analysis. PubMed, CNKI, CBM, and Embase databases were searched for studies that examined the relationship between ACE I/D polymorphism and renal scar risk in children with VUR. The Stata 12.0 software was used for statistical analyses. 11 case-control studies with 1,032 VUR patients were analyzed. The results showed that the DD genotype and D allele were associated with renal scar risk in overall VUR patients, DD vs. DI + II: OR = 1.61, 95% CI = 1.04–2.49, P = 0.03; DD vs. II: OR = 1.78, 95% CI = 1.20–2.65, P < 0.01; D vs. I: OR = 1.38, 95% CI = 1.02–1.86, P = 0.04. Similar results were revealed in Turks, but not in Caucasians and Asians. Our meta-analysis indicated that the ACE DD genotype may increase the risk of renal scar in children with VUR.

Angiotensin Converting Enzyme Gene Insertion/Deletion Polymorphism and Vesicoureteral Reflux in Children: A Meta-Analysis of 14 Case-Control Studies

Vesicoureteral reflux (VUR) is a common and serious urinary disease in children. It usually causes renal scar, urinary tract infection, and chronic renal failure. Previous studies showed the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism might be associated with VUR; however, the conclusions were inconsistent. Therefore we used the meta-analytic approach to clarify the effect of ACE I/D polymorphism on VUR risk.We systematically searched the PubMed, CNKI, and EMBASE databases to identify all the potentially related studies published up to February 4, 2015. Two reviewers independently selected studies and extracted data. The strength of the association was assessed using odd ratio (OR) with its 95% confidence interval (CI) based on fixed or random effects model. The STATA 12.0 software was used for data analysis.A total of 14 case-control studies involving 1197 VUR patients and 1320 healthy controls met the eligibility criteria. Results of meta-analysis showed significant association between ACE I/D polymorphism and VUR risk (D vs. I: OR = 1.28, 95% CI = 1.06-1.54, P = 0.01; DD vs. II: OR = 1.44, 95% CI = 1.12-1.85, P = 0.01; DD vs. DI + II: OR = 1.49, 95% CI = 1.23-1.79, P < 0.01; DD + DI vs. II: OR = 1.20, 95% CI = 0.84-1.72, P = 0.31). Subgroup analyses revealed varied results. In Turkish people, results of all the genetic models other than DI vs. II showed statistical significance; in Caucasians, DD vs. DI + II showed statistical significance; and in Asians, DI versus II showed statistical significance.Our meta-analysis indicated that the ACE I/D polymorphism might be associated with increased risk of VUR in children. However, due to the limitations, we suggest conducting additional studies with larger sample size and adjustment for various risk factors, in the future for further clarification.

Vascular Response to Graded Angiotensin II Infusion in Offspring Subjected to High-Salt Drinking Water during Pregnancy: The Effect of Blood Pressure, Heart Rate, Urine Output, Endothelial Permeability, and Gender

Introduction. Rennin-angiotensin system and salt diet play important roles in blood pressure control. We hypothesized that the high-salt intake during pregnancy influences the degree of angiotensin-dependent control of the blood pressure in adult offspring. Methods. Female Wistar rats in two groups (A and B) were subjected to drink tap and salt water, respectively, during pregnancy. The offspring were divided into four groups as male and female offspring from group A (groups 1 and 2) and from group B (groups 3 and 4). In anesthetized matured offspring mean arterial pressure (MAP), heart rate and urine output were measured in response to angiotensin II (AngII) (0-1000 ng/kg/min, iv) infusion. Results. An increase in MAP was detected in mothers with salt drinking water (P < 0.05). The body weight increased and kidney weight decreased significantly in male offspring from group 3 in comparison to group 1 (P < 0.05). MAP and urine volume in response to AngII infusion increased in group 3 (P < 0.05). These findings were not observed in female rats. Conclusion. Salt overloading during pregnancy had long-term effects on kidney weight and increased sex-dependent response to AngII infusion in offspring (adult) that may reveal the important role of diet during pregnancy in AngII receptors.

Angiotensin-converting enzyme insertion/deletion polymorphism contributes high risk for chronic kidney disease in Asian male with hypertension--a meta-regression analysis of 98 observational studies

Background

Associations between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphisms and chronic kidney disease (CKD) have been extensively studied, with most studies reporting that individuals with the D allele have a higher risk. Although some factors, such as ethnicity, may moderate the association between ACE I/D polymorphisms and CKD risk, gender-dependent effects on the CKD risk remain controversial.

Objectives

This study investigated the gender-dependent effects of ACE I/D polymorphisms on CKD risk.

Data sources

PubMed, the Cochrane library, and EMBASE were searched for studies published before January 2013.

Study eligibility criteria, participants, and interventions

Cross-sectional surveys and case–control studies analyzing ACE I/D polymorphisms and CKD were included. They were required to match the following criteria: age >18 years, absence of rare diseases, and Asian or Caucasian ethnicity.

Study appraisal and synthesis methods

The effect of carrying the D allele on CKD risk was assessed by meta-analysis and meta-regression using random-effects models.

Results

Ethnicity [odds ratio (OR): 1.24; 95% confidence interval (CI): 1.08–1.42] and hypertension (OR: 1.55; 95% CI: 1.04–2.32) had significant moderate effects on the association between ACE I/D polymorphisms and CKD risk, but they were not significant in the diabetic nephropathy subgroup. Males had higher OR for the association between ACE I/D polymorphisms and CKD risk than females in Asians but not Caucasians, regardless of adjustment for hypertension (p<0.05). In subgroup analyses, this result was significant in the nondiabetic nephropathy group. Compared with the I allele, the D allele had the highest risk (OR: 3.75; 95% CI: 1.84–7.65) for CKD in hypertensive Asian males.

Conclusions and implications of key findings

The ACE I/D polymorphisms may incur the highest risk for increasing CKD in hypertensive Asian males.