Effect of mitochondrial tRNA(Lys) mutation on the clinical and biochemical characteristics of Chinese essential hypertensive subjects

Mitochondrial dysfunction has been potentially implicated in both human and experimental hypertension. We performed the mutational analysis of tRNA(Lys) gene by PCR amplification and subsequent sequence analysis of the PCR fragments from 990 Chinese essential hypertensive subjects. We also made a comparative analysis of the collected data of the essential hypertension subjects who carried tRNA(Lys) mutation and those who did not carry the mutation using the methods of 1:1 case-control study. We totally found 7 mutation sites in 10 subjects. The onset ages of the individuals carrying the mutation were earlier than those who did not bear them. The level of blood urea nitrogen in hypertension subjects who carried tRNA(Lys) mutation was higher than the hypertension subjects who did not carried tRNA(Lys) mutation, while the serum potassium was significantly lower. The level of platelet count in hypertension subjects who carried tRNA(Lys) mutation was lower. The level of ventricular septal thickness in hypertension subjects who carried tRNA(Lys) mutation was higher and the level of left ventricular end diastolic diameter in hypertension subjects was significantly lower. Mitochondrial tRNA(Lys) mutations might result in the change of their structure and function, and then damaged the blood metabolism, the balance of the blood electrolyte, the steady-state of the blood cells and the heart structure and function, which were involved in the progress of the essential hypertension. Part of the essential hypertension patients clinically presented the characters of maternal inheritance, which might be associated with the tRNA(Lys) mutation.

Association between 1019C/T polymorphism in the connexin 37 gene and essential hypertension

OBJECTIVE

To investigate the association between the CX 37 1019C/T polymorphism and the susceptibility to essential hypertension (EH).

METHODS

A total of 1126 cases of EH were diagnosed in the People's Hospital of Wuxi City, China. A control group consisted of 874 healthy people, i.e., non-EH patients. All cases were genotyped by DNA sequencing.

RESULTS

Polymorphism C1019T on the Connexin37 gene was found in the whole population. The distribution of three genotype frequencies in both groups was in accordance with the Hardy-Weinberg equilibrium. The frequency of the CX37C allele was higher in EH patients (57.4% vs. 42.1%, χ(2)=92.5, P<0.01) compared to the control group. The frequency of C carriers (CC+TC) was 80.5% in EH patients compared to 66.7% in the control (χ(2)=49.0, P<0.01). EH risk was significantly increased in carriers of C the allele (CC+TC) over that in the TT homozygote (OR=2.06, 95% CI: 1.68 ∼ 2.52). Subsequent stratified analyses demonstrate that a significant difference exists in the frequency of C carriers between male EH patients and controls (79.2% vs. 69.1%, χ(2)=13.4, P<0.01) and in female EH patients and the control group (81.8% vs. 64.4%, χ(2)=38.7, P<0.01). The carriers of the C allele had higher EH risk compared with the TT homozygote without sex differences (male: OR=1.71, 95% CI: 1.28 ∼ 2.27; female: OR=2.48, 95%CI: 1.85 ∼ 3.31).

CONCLUSION

The C allele in the CX37 gene might be associated with the susceptibility to EH in population of Wuxi, China.

Transitions in skin blood flow fractal scaling: the importance of fluctuation amplitude in microcirculation

Detrended fluctuation analysis (DFA) of laser Doppler flowmetry (LDF) time series from volar skin reveals three scaling regions: cardiac, cardio-respiratory and local. Scaling exponents, slopes (αC, αCR and αL) of the straight lines, in these regions indicate correlation properties of LDF signal. Transitions from uncorrelated to positive in cardiac (αC) and positive to negative correlations in the cardio-respiratory (αCR) exponent have been observed for vasodilatation signals in response to local heating. However, positive correlation in local region (αL) did not change with vasodilatation. We studied whether the transitions in scaling exponents are correlated with the increase in peak to peak fluctuation amplitude (AF) of LDF signal. LDF signals were normalized to unity using average values of their pulsatile parts: baseline and saturation signals. If AF of normalized LDF signal is ≥0.5, we observed transitions in αC and in αCR but not in αL, in healthy subjects. It is suggested that the transition from positive to negative correlation in αCR with increasing amplitude may be explained by intact arteriolar myogenic activity in healthy young (Y) and middle aged (MA) subjects. In contrast, we did not observe transition in αCR suggesting impaired myogenic activity in patients with essential hypertension (EHT).

The association between angiotensin-converting enzyme 2 polymorphisms and essential hypertension risk: A meta-analysis involving 14,122 patients

BACKGROUND

Some studies have evaluated the associations between the angiotensin-converting enzyme 2 (ACE2) gene polymorphisms and essential hypertension (EH) risk. However, the results remain uncertain. We carried out a meta-analysis to derive a more comprehensive estimation of these associations.

METHODS

Case-control studies were identified by searching PubMed, EMBASE, Chinese National Knowledge Infrastructure (CNKI) and Wangfang databases. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the associations.

RESULTS

Significant associations were found between the ACE2 G8790A polymorphism and EH risk in males (OR = 1.27; 95% CI, 1.11-1.44; p = 0.0004; I(2) = 34%) and females (OR = 1.21; 95% CI, 1.09-1.34; p = 0.0003; I(2) = 31%), respectively. Significant associations were also observed between the ACE2 rs2106809 polymorphism and EH risk in males (OR = 1.24; 95% CI, 1.10-1.39; p = 0.0004; I(2) = 18%) and females (OR = 1.39; 95% CI, 1.27-1.51; p < 0.00001; I(2) = 0%), respectively. However, there was no significant association between the ACE2 A1075G polymorphism and EH risk in males (OR = 1.27; 95% CI, 0.77-2.10; p = 0.35; I(2) = 69%) and females (OR = 1.02; 95% CI, 0.83-1.26; p = 0.84; I(2) = 33%), respectively.

CONCLUSIONS

These results suggest that the ACE2 G8790A and rs2106809 polymorphisms may be associated with EH risk.

Ginkgo biloba extract for essential hypertension: a systemic review

BACKGROUND

Ginkgo biloba extract (GBE), a traditional natural herbal product, is often used in the treatment of essential hypertension (EH) as complementary therapy in China and European countries.

AIM

To critically assess the current clinical evidence of efficacy and safety of GBE for EH.

METHODS

7 electronic databases (Cochrane Library, PubMed, EMBASE, VIP, CBM, Wanfang data, and CNKI) were searched to identify randomized controlled trials (RCTs) of GBE for EH. Methodological quality was assessed independently using the Cochrane Handbook for Systematic Reviews of Interventions.

RESULTS

A total of 9 RCTs with 1012 hypertensive patients were identified and reviewed. Most RCTs were of high risk of bias with flawed study design and poor methodological quality. 6 trials demonstrated potential positive effect of GBE as complementary therapy on BP reduction when compared with antihypertensive drug therapy; however, it was not associated with a statistically significant effect on both SBP and DBP reduction in 3 other trials. Despite the positive findings, there were so many methodological limitations and significant clinical heterogeneity. Most of the trials did not report adverse effects, and the safety of GBE is still uncertain.

CONCLUSION

No confirmative conclusions on the efficacy and safety of GBE for EH could be drawn. More rigorous trials are warranted to support their clinical use.

Telmisartan in combination with hydrochlorothiazide 12.5 mg for the management of patients with hypertension

OBJECTIVE

To compare the efficacy and safety of telmisartan 40 mg (T40) or 80 mg (T80) plus hydrochlorothiazide 12.5 mg (H12.5) single-pill combinations (SPCs) with telmisartan monotherapies, in a pooled analysis of patients with mild to moderate hypertension.

METHODS

Six phase 3, double-blind studies of 8 weeks' duration that assessed the T/H12.5 SPC and T40 or T80 monotherapy, were included in the analysis. Data was pooled separately for the two T40 non-responder studies (T40 NR group, two T80 non-responder studies (T80 NR group), and the two factorial design dose-response studies (FD-DR group).

RESULTS

After 8 weeks' treatment, the adjusted mean reduction in systolic blood pressure (SBP) and diastolic blood pressure (DBP), and the SBP, DBP, and blood pressure (BP) goal rates were significantly higher with the T40/H12.5 SPC than T40 in the T40 NR group and with the T80/H12.5 SPC than T80 in the T80 NR group. In the FD-DR group, the adjusted mean reduction in SBP and DBP, and DBP goal rates were significantly higher for T40/H12.5 versus T40. The percentage of patients with an adverse event was numerically higher with T40/H12.5 versus T40 in the T40 NR group, and was similar in telmisartan monotherapies and the T/H12.5 SPCs in the T80 NR group and FD-DR group. A limitation of this study is the retrospective and pooled nature of the analysis. Also, >75% of patients were <65 years of age, which limits the applicability of the results to older patients.

CONCLUSIONS

In patients with mild to moderate hypertension, 8 weeks' treatment with the T/H12.5 SPC is significantly more efficacious than telmisartan monotherapies. The safety and tolerability of the T/H12.5 SPC are comparable to that of telmisartan monotherapy and consistent with that reported in previous studies.

1-Year outcomes of hypertension management in 13,000 outpatients under practice conditions: prospective 3A registry

BACKGROUND

Current data on characteristics and outcomes of patients with high blood pressure (BP) managed under clinical practice conditions are limited.

METHODS AND RESULTS

The 3A registry is an open, prospective observational cohort study in German primary care offices, with a 4:1:1 inclusion ratio to either aliskiren (ALIS), an ACE inhibitor/angiotensin receptor blocker (ACEI/ARB), or to an antihypertensive agent not affecting the renin angiotensin system (non-RAS). A nonlinear mixed regression model was used to assess BP changes during follow-up regarding different BP values at inclusion in the various groups. ClinicalTrial.gov identifier is NCT01454583. In the total cohort of 13,433 patients with 1-year follow-up results, the mean age of patients was 64.7 years, 54% were men. Mean number of antihypertensive drugs was higher in the ALIS group compared to the other groups (3.0 drugs versus 2.5 in ACEI/ARB versus 1.6 in non-RAS; p<0.0001). Statistical regression analysis revealed baseline BP as the dominant covariate. After adjustment for baseline BP and 12 other confounders, no significant differences in BP reduction between the three groups were observed. The rate of major cardiac events (death, myocardial infarction, and stroke) was 1.3% in the total cohort, and did not differ across groups.

CONCLUSIONS

ALIS at beginning of the observation was mostly used by the physicians in patients with higher BP at entry and in higher risk populations. By study end, in all groups, stringent BP lowering measures, usually with combination therapy, led to significant improvements; more than half of these at-risk patients reached the BP targets.

The hypothalamic neuropeptide FF network is impaired in hypertensive patients

BACKGROUND

The human hypothalamus contains the neuropeptide FF (NPFF) neurochemical network. Animal experiments demonstrated that NPFF is implicated in the central cardiovascular regulation. We therefore studied expression of this peptide in the hypothalamus of individuals who suffered from essential hypertension (n = 8) and died suddenly due to acute myocardial infarction (AMI), and compared to that of healthy individuals (controls) (n = 6) who died abruptly due to mechanical trauma of the chest.

METHODS

The frozen right part of the hypothalamus was cut coronally into serial sections of 20 μm thickness, and each tenth section was stained immunohistochemically using antibody against NPFF. The central section through each hypothalamic nucleus was characterized by the highest intensity of NPFF immunostaining and thus was chosen for quantitative densitometry.

RESULTS

In hypertensive patients, the area occupied by NPFF immunostained neuronal elements in the central sections through the suprachiasmatic nucleus (SCh), paraventricular hypothalamic nucleus (Pa), bed nucleus of the stria terminalis (BST), perinuclear zone (PNZ) of the supraoptic nucleus (SON), dorso- (DMH), ventromedial (VMH) nuclei, and perifornical nucleus (PeF) was dramatically decreased compared to controls, ranging about six times less in the VMH to 15 times less in the central part of the BST (BSTC). The NPFF innervation of both nonstained neuronal profiles and microvasculature was extremely poor in hypertensive patients compared to control.

CONCLUSIONS

The decreased NPFF expression in the hypothalamus of hypertensive patients might be a cause of impairment of its interaction with other neurochemical systems, and thereby might be involved in the pathogenesis of the disease.

Relationships between mild hyperuricaemia and aortic stiffness in untreated hypertensive patients

BACKGROUND AND AIMS

Clinical studies exploring the relationship between serum uric acid (SUA) and arterial stiffness yielded conflicting results. Only in a few of these studies, arterial distensibility was examined by measuring aortic pulse wave velocity (PWV), which is considered the gold standard for evaluating arterial stiffness. In none of the previous investigations was the influence of SUA on aortic distensibility assessed, taking into account the effect of albuminuria. The purpose of our study was to comprehensively analyse the relationships between SUA and aortic PWV in a group of essential hypertensive patients.

METHODS AND RESULTS

We enrolled 222 untreated and uncomplicated hypertensive subjects (mean age: 44 ± 10 years; 60% males), without gout. In all patients, SUA and urinary albumin excretion rate (AER) were determined. Moreover, carotid-femoral (c-f) PWV was measured. C-f PWV was significantly higher in hypertensive patients belonging to the uppermost tertile of SUA distribution, compared to subjects of the lowest tertiles (10.9 ± 2.2 vs. 10 ± 1.8 vs. 9.9 ± 1.7 m s(-1); p = 0.001). In univariate analysis, SUA correlated with c-f PWV (r = 0.24; p < 0.001). This association disappeared when AER was added in a multiple regression model, including SUA, age, mean arterial pressure, gender, metabolic syndrome components and glomerular filtration rate.

CONCLUSION

The results of our study showed that, in essential hypertensive subjects, there is a positive relationship between mild hyperuricaemia and aortic stiffness. This association weakened after adjustment for covariates and lost statistical significance after further correction for albuminuria.

β-T594M epithelial sodium channel gene polymorphism and essential hypertension in individuals of Indo-Aryan ancestry in Northern India

BACKGROUND

The T594M variant of the β-subunit of the sodium epithelial channel (ENaC) gene may contribute to hypertension in individuals of Indo-Aryan origin.

METHODS

Present study was performed to assess the role of the ENaC gene variant as an independent risk factor for hypertension in subjects of Indo-Aryan ancestry. A total of 150 patients of recently detected essential hypertension and 150 matched controls were genotyped for the T594M polymorphism of the ENaC gene by PCR-RFLP method.

RESULTS

β-T594M mutation was found to be non-polymorphic. There was major genotype call in both the groups i.e. cases and controls. Other phenotypic parameters like age, sex and body mass index were also similar among hypertensive patients and controls (P > 0.05). Hypertensive patients had significantly higher total cholesterol and triglycerides compared with controls (P < 0.0001).

CONCLUSION

These results do not suggest an important role for the T594M variant of the ENaC gene contributing to either the development or severity of hypertension in subjects of Indo-Aryan ancestry.

Elevated blood pressure: Our family’s fault? The genetics of essential hypertension

AIM: To provide an updated review on current genetic aspects possibly affecting essential hypertension (EH), and to further elucidate their role in EH.

METHODS: We searched for genetic and epigenetic factors in major studies associated with EH between Jan 2008-Oct 2013 using PubMed. We limited our search to reviews that discussed mostly human studies, and were accessible through the university online resource. We found 11 genome wide association studies (GWAS), as well as five methylation and three miRNA studies that fit our search criteria. A distinction was not made between genes with protective effects or negative effects, as this article is only meant to be a summary of genes associated with any aspect of EH.

RESULTS: We found 130 genes from the studies that met our inclusion/exclusion criteria. Of note, genes with multiple study references include: STK39, CYP17A1, MTHFR-NPPA, MTHFR-NPPB, ATP2B1, CSK, ZNF652, UMOD, CACNB2, PLEKHA7, SH2B3, TBX3-TBX5, ULK4, CSK-ULK3, CYP1A2, NT5C2, CYP171A, PLCD3, SH2B3, ATXN2, CACNB2, PLEKHA7, SH2B3, TBX3-TBX5, ULK4, and HFE. The following genes overlapped between the genetic studies and epigenetic studies: WNK4 and BDKRB2. Several of the identified genes were found to have functions associated with EH. Many epigenetic factors were also correlated with EH. Of the epigenetic factors, there were no articles discussing siRNA and its effects on EH that met the search criteria, thus the topic was not included in this review. Among the miRNA targets found to be associated with EH, many of the genes involved were also identified in the GWAS studies.

CONCLUSION: Genetic hypertension risk algorithms could be developed in the future but may be of limited benefit due to the multi-factorial nature of EH. With emerging technologies, like next-generation sequencing, more direct causal relationships between genetic and epigenetic factors affecting EH will likely be discovered creating a tremendous potential for personalized medicine using pharmacogenomics.

Dietary patterns and 1-h post-load glucose in essential hypertension

BACKGROUND AND AIMS

Normoglucosetolerants (NGT) are considered at low risk, even if a 1-h post-load glucose (PLG) value ≥ 155 mg dl(-1) identifies NGTs at high risk of type-2 diabetes (T2D) and sub-clinical organ damage. Specific dietary factors may affect insulin sensitivity and the risk of T2D. However, it is unknown whether dietary components affect 1-h PLG in hypertensive NGT. Therefore, we investigate the effect of dietary patterns on 1-h PLG.

METHODS AND RESULTS

We selected 188 subjects (94 NGTs < 155 mg dl(-1) and 94 NGTs ≥ 155 mg dl(-1) PLG), well matched for age, gender and body mass index (BMI). Insulin sensitivity was evaluated using the Matsuda index. Dietary intake was quantified by a semiquantitative food frequency questionnaire (FEQ) validated in the European Investigation into Cancer and Nutrition (EPIC) study. The NGT ≥ 155 group had significantly reduced insulin sensitivity (40.3 ± 19.8 vs. 73.3 ± 28.8; P < 0.0001). With the exclusion of total calories, lipids, alcohol and fiber consumption we observed a significant difference, between groups, in starch (214.1 ± 52.4 vs. 268.8 ± 71.8 g; P < 0.0001), saturated (27.4 ± 8.7 vs. 24.1 ± 8.5 g; P = 0.009), monounsaturated (45.5 ± 8.9 vs. 48.8 ± 10.7 g; P = 0.023) and polyunsaturated fatty acids (FAs) (14.5 ± 4.0 vs. 16.8 ± 4.7 g; P < 0.0001), fructose (14.5 ± 5.3 vs. 11.2 ± 4.8 g; P < 0.0001), and oligosaccharides (103.2 ± 26.6 vs. 89.9 ± 29.2 g; P = 0.001) consumption. In the whole population, starch was the major predictor of 1-h PLG, explaining 23.2% of variation (P < 0.0001). In the NGT < 155 group, fructose was the strongest predictor, accounting for 15.4% of the variation; BMI, gender and polyunsaturated FAs added another 6.6%, 3.6% and 3.2%, respectively. In the NGT ≥ 155 group, saturated and polyunsaturated FAs were retained as the major predictors of 1-h PLG, explaining 18.2% and 11.4% of the variation.

CONCLUSIONS

The present data demonstrate that dietary patterns affect 1-h PLG, remarking the importance of both quantitative and qualitative composition of a diet.

Relationships between mild hyperuricaemia and aortic stiffness in untreated hypertensive patients

BACKGROUND AND AIMS

Clinical studies exploring the relationship between serum uric acid (SUA) and arterial stiffness yielded conflicting results. Only in a few of these studies, arterial distensibility was examined by measuring aortic pulse wave velocity (PWV), which is considered the gold standard for evaluating arterial stiffness. In none of the previous investigations was the influence of SUA on aortic distensibility assessed, taking into account the effect of albuminuria. The purpose of our study was to comprehensively analyse the relationships between SUA and aortic PWV in a group of essential hypertensive patients.

METHODS AND RESULTS

We enrolled 222 untreated and uncomplicated hypertensive subjects (mean age: 44 ± 10 years; 60% males), without gout. In all patients, SUA and urinary albumin excretion rate (AER) were determined. Moreover, carotid-femoral (c-f) PWV was measured. C-f PWV was significantly higher in hypertensive patients belonging to the uppermost tertile of SUA distribution, compared to subjects of the lowest tertiles (10.9 ± 2.2 vs. 10 ± 1.8 vs. 9.9 ± 1.7 m s(-1); p = 0.001). In univariate analysis, SUA correlated with c-f PWV (r = 0.24; p < 0.001). This association disappeared when AER was added in a multiple regression model, including SUA, age, mean arterial pressure, gender, metabolic syndrome components and glomerular filtration rate.

CONCLUSION

The results of our study showed that, in essential hypertensive subjects, there is a positive relationship between mild hyperuricaemia and aortic stiffness. This association weakened after adjustment for covariates and lost statistical significance after further correction for albuminuria.

Role of apolipoprotein AI gene polymorphism (G-75A and C+83T) in essential hypertension in Indian population

Hypertension is becoming a public health emergency worldwide. It has been seen that both genetics and gene-environment interactions are major determinants of lipoprotein abnormalities and hypertension. This study elucidates the effect of apolipoprotein AI gene polymorphism (G-75A and C+83T) in 50 cases of essential hypertension and equal number of age & sex matched control subjects in the Indian population. Higher instances of obesity and more adverse biochemical profiles were found in hypertensives [GA (74%) and CT (56%) most commonly observed genotypes]. Presence of A and T alleles and GA (-75 bp) and CT (+83 bp) heterozygosity in apolipoprotein AI gene play an important role in essential hypertension (GA genotype had an odds ratio of 4.27 (1.69-10.96) of developing essential hypertension). The odds ratio for the GA genotype was 3.74 (95%CI, 0.83-9.0) in the presence of confounding factors including total proteins, albumin, amylase, cholesterol, triglycerides, LDL, VLDL and body mass index. It indicates one of the potential areas where population studies may be taken up for identifying the genetic basis of essential hypertension.

Serum retinol-binding protein 4 levels are elevated but do not contribute to insulin resistance in newly diagnosed Chinese hypertensive patients

BACKGROUND

Insulin resistance (IR) is closely correlated with cardiovascular disease (CVD). Retinol-binding protein 4 (RBP4) is a novel adipokine that modulates the action of insulin in various diseases. This study addressed the relationship between RBP4 and IR in newly diagnosed essential hypertension.

METHODS

Serum RBP4, anthropometric and metabolic parameters were determined in 267 newly diagnosed essential hypertensive patients not taking antihypertensive medications. The patients along with 64 control (NC) normotensive and lean subjects paired by age and sex were divided into two groups depending on body mass index (BMI), hypertension with obesity (HPO) and hypertension without obesity (HP).

RESULTS

A striking difference was observed in RBP4 levels between the HP and NC groups. Significantly higher levels were noted in the HP group compared with the NC group; slightly, but not significantly, lower levels were observed in the HPO group compared with the HP group. After adjusting for BMI, WC and WHR, a modestly linear relationship was observed between RBP4 levels and SBP (r = 0.377; p = 0.00), DBP (r = 0.288; p = 0.00) and HOMA-β(r = 0.121; p = 0.028). Multiple stepwise regression analysis showed that SBP, WHR and drinking were independently related with serum RBP4 levels.

CONCLUSIONS

The results of this study indicated that RBP4 levels were increased in naive hypertensive patients; however, no differences were observed in obese or non-obese hypertensive subjects. Our data suggest for the first time that RBP4 levels are significantly increased but do not contribute to the development of IR in newly diagnosed hypertensive Chinese patients.

Absence of an independent association between serum uric acid and left ventricular mass in Caucasian hypertensive women and men

BACKGROUND AND AIM

Experimentally uric acid may induce cardiomyocyte growth and interstitial fibrosis of the heart. However, clinical studies exploring the relationship between serum uric acid (SUA) and left ventricular (LV) mass yielded conflicting results. The aim of our study was to evaluate the relationships between SUA and LV mass in a large group of Caucasian essential hypertensive subjects.

METHODS AND RESULTS

We enrolled 534 hypertensive patients free of cardiovascular complications and without severe renal insufficiency. In all subjects routine blood chemistry, including SUA determination, echocardiographic examination and 24 h ambulatory blood pressure (BP) monitoring were obtained. In the overall population we observed no significant correlation of SUA with LV mass indexed for height(2.7) (LVMH(2.7)) (r = 0.074). When the same relationship was analysed separately in men and women, we found a statistically significant correlation in female gender (r = 0.27; p < 0.001), but not in males (r = -0.042; p = NS). When we grouped the study population in sex-specific tertiles of SUA, an increase in LVMH(2.7) was observed in the highest tertiles in women (44.5 ± 15.6 vs 47.5 ± 16 vs 55.9 ± 22.2 g/m(2.7); p < 0.001), but not in men. The association between SUA and LVMH(2.7) in women lost statistical significance in multiple regression analyses, after adjustment for age, 24 h systolic BP, body mass index, serum creatinine and other potential confounders.

CONCLUSIONS

Our findings do not support an independent association between SUA and LV mass in Caucasian men and women with arterial hypertension.

Left ventricular mass formulae and prevalence rates of echocardiographic left ventricular hypertrophy in nigerians with essential hypertension

Background:

Left ventricular hypertrophy (LVH) as a marker of cardiac damage in hypertension has important prognostic implications. With high prevalence of hypertension in Nigeria and the untoward effect of LVH, it is essential that the prevalence of LVH be determined.

Aims:

To determine prevalence of LVH and its severity in clinical practice among hypertensive patients referred for echocardiographic assessment in Nigeria.

Materials and Methods:

Devereux and Troy formulae were used to calculate echocardiographic LV mass (LVM) in 401 subjects and thereafter normalized to body surface area (BSA), heigth² (ht²) and height^2.7 (ht^2.7) to define LVH to standard gender-specific thresholds.

Results:

Mean age was 53.22 ± 16.56 years (male = 53.18 ± 15.80; female = 53.27 ± 17.43; P = 0.958) with a male:female ratio of 1.13:1. Prevalence rates of LVH ranged between 38.9–51.3% using the Devereux Formula and 62.4–71.1% using the Troy formula. LVM/(ht^2.7) using the Troy formula gave the highest prevalence rate of LVH. Majority of the patients with LVH had severe form of hypertrophy with the prevalence rates ranging from 22.3% (LVM/BSA; Devereux formula) to 47.1% (LVM/ht^2.7; Troy formula).

Conclusion:

Prevalence of LVH by any echocardiographic criteria is high. There is a need to come to a consensus on the best formula and indexing variables, that will unify the reporting of LVH.

Primary non-alcoholic fatty liver disease in hypertensive patients

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is considered the most common liver disease affecting 15-25% of the general population.

AIMS

The aim of this study was to investigate the prevalence of NAFLD and the relationship between insulin sensitivity and NAFLD in grade III high and very high cardiovascular additional risk essential hypertensive patients according to the circadian blood pressure (BP) rhythm.

METHOD

This four-year prospective study was conducted at the Department of Internal Medicine at Cluj-Napoca's Diagnosis and Treatment Centre in Romania. The study included grade III essential hypertensive patients. Hypertensive patients were divided into four groups according to the diurnal index (DI) from ABPM monitoring: dipper (D), non-dipper (ND), reverse-dipper (RD), and extreme-dipper (ED). All hypertensive patients underwent 24 ABPM, blood tests and abdominal ultrasonography for the diagnosis of fatty liver disease.

RESULTS

Thirty-five hypertensive patients were included in the study, with 31.42% ND, 11.43% RD, 8.57% ED and 48.57% D. The prevalence of NAFLD was significantly higher in ND, RD and ED when compared to D. When compared to the dipper group of hypertensive patients a statistically significantly higher level of plasma insulin was observed: in non-dipper [86.3±17.9pmol/l vs. 62.2±203pmol/l, p<0.05], in reverse dipper [88.3±18.6pmol/l vs. 62.2±20.3pmol/l] and in extreme-dippers [86.7±16.88pmol/l vs. 62.2±20.3 pmol/l, p<0.05].

CONCLUSION

The altered dipping status (ND, RD, ED) of hypertension associated with a higher insulin resistance could be the pathogenetic link between the NAFLD and altered blood pressure status. Altered BP status could be a marker of NAFLD in hypertensive patients.

Association study of CD36 single nucleotide polymorphisms with essential hypertension in the Northeastern Han Chinese

We found that cluster determinant 36 (CD36) gene is up-regulated in essential hypertension (EH) patients in our former research, but the association between CD36 gene variations and EH has not yet been clearly demonstrated. The relationship between CD36 gene single nucleotide polymorphisms (SNPs) and EH in the northeastern Han Chinese was examined in the present study through direct sequencing and genotype-detection. A total of 589 unrelated northeastern Han Chinese including 276 with EH and 313 controls were studied. SNPs in exon 7, exon 13 and intron 4 were detected using PCR-sequencing. The genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) or polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). +216T/C, +273A/G, +132C/T, +217T/C, +212T/G and +233T/C polymorphisms were identified. Distributions of genotypes AA, GA and GG of +273A/G polymorphism were significantly different between EH group and the control group (χ2: 9.056, p=0.011) and G allelic frequency was higher in EH (p=0.006, OR=1.629, 95% CI [1.224-2.168]). Logistic regression analysis showed that +273A/G polymorphism was closely associated with blood pressure (BP) after adjusting for ages. When subclassified by sex, the genotype distribution of +273A/G (p=0.011) and allelic frequency of G allele (p=0.006) were significantly different between EH participants and controls in males, but not in females. Subgroup analysis performed by body mass index (BMI) suggested that the genotype distribution of +273A/G and allelic frequency were significantly different in non-obese group and non-obese men, but the associations were not significant (non-obese group: p=0.016, OR=1.664, 95% CI [1.459-2.409]; non-obese men: p=0.073, OR=1.898, 95% CI [1.033-3.487]). +273A/G polymorphism in CD36 gene was associated with EH, and +273G could be an independent predictor.

Association of the level of heteroplasmy of the 15059G>A mutation in the MT-CYB mitochondrial gene with essential hypertension

AIM

To examine whether the heteroplasmy level for 15059G>A mutation in the mitochondrial genome might be associated with essential hypertension.

METHODS

This cross-sectional study involved 196 unrelated participants randomly selected from general population (90 males and 106 females) who underwent a regular medical check-up at the Institute for Atherosclerosis Research (Moscow, Russia). One hundred and twenty of them (61%) had essential hypertension, and 76 (39%) were apparently healthy normotensive persons. The level of heteroplasmy for 15059G>A mutation occurring in the coding region of cytochrome b gene (MT-CYB) of mtDNA isolated from the blood leukocytes, was quantified using DNA pyrosequencing method.

RESULTS

The 15059G>A heteroplasmy level ranged between 4% and 83%, with a median level of 31%. Between the upper and lower quartiles of 15059G>A heteroplasmy distribution, significant differences were observed for patients' age, systolic blood pressure, and triglyceride levels. 15059G>A heteroplasmy correlated both with age (r = 0.331, P < 0.001) and the presence of hypertension (r = 0.228, P = 0.002). Regression analysis revealed that the age explains 12% variability of 15059G>A heteroplasmy, and hypertension independently explains more 5% variability. The 15059G>A heteroplasmy exceeding 31% was found to be significantly associated with a higher risk of essential hypertension (odds ratio 2.76; P (Fisher) 0.019]. The study participants with high 15059G>A heteroplasmy level were found to have significantly higher age (P < 0.001) and the prevalence of essential hypertension (P = 0.033), as compared to those with low 15059G>A heteroplasmy level. These observations suggested a positive correlation between the level of 15059G>A heteroplasmy and essential hypertension.

CONCLUSION

This study provides the evidence of association of mtDNA 15059G>A mutation heteroplasmy with essential hypertension.

Association of sodium and potassium intake with ventricular arrhythmic burden in patients with essential hypertension

BACKGROUND

Hypertensive populations suffer from an increased susceptibility to ventricular arrhythmias and sudden cardiac death. A high-salt diet appears to be a major factor involved in cardiovascular complications in hypertension. We examined the relationship between dietary salt and potassium, as indicated by urinary sodium (UNa), urinary potassium (UK), and urinary sodium/potassium ratio (UNa/K), and the arrhythmic burden in patients with essential hypertension.

METHODS

We included 255 consecutive adult patients with well-controlled hypertension who were being followed in the hypertension outpatient clinic of a university tertiary hospital and complained of episodes of atypical chest pain and/or palpitations. All underwent 24-hour ambulatory electrocardiograph monitoring and their UNa, UK, and UNa/K ratio from 24-hour urinary excretion specimens were evaluated.

RESULTS

No significant correlation was found between premature supraventricular contractions and the parameters that were examined. However, the percentage of premature ventricular contractions (PVC%) showed a weak positive association with UNa (r = 0.2; P = .001) and a moderate negative association with UK (r = -0.396; P < .001). The partial correlation coefficient of PVC% with the UNa/UK ratio remained significant even after controlling for left ventricular mass index (r = 0.437; P < .001).

CONCLUSIONS

A higher UNa/UK excretion ratio is significantly associated with PVCs, indicating an increased susceptibility to ventricular arrhythmias even among hypertensives with well-controlled blood pressure. Our findings reinforce recommendations for dietary interventions in those populations.

The role of the endogenous antioxidant enzymes and malondialdehyde in essential hypertension

CONTEXT

Oxidative Stress is caused by an imbalance between the production of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates.

AIMS

1. To compare the levels of Malondialdehyde (MDA), in hypertensive and normotensive subjects. 2. To compare the levels of the antioxidant enzymes, namely, Catalase, Glutathione peroxidase (GPX) and Superoxide Dismutase (SOD) in hypertensive and normotensive subjects. 3. To determine the correlation between the MDA levels and the mean arterial pressure (MAP) among hypertensive subjects. 4. To determine the correlation between the antioxidant enzyme levels and MAP among the hypertensive subjects and to evaluate the effect of 6 months of antihypertensive therapy with a tight blood pressure control on the MDA levels. Materials and Methods : In this cross sectional study, 25 normotensive and 40 hypertensive subjects were recruited. The hypertensive subjects were further subdivided into three subgroups: Prehypertensives, Stage I hypertensives and Stage II hypertensives. All the subjects underwent a blood pressure measurement and the markers of oxidative stress in their sera were estimated. The subjects of Stage I hypertension and Stage II hypertension were given antihypertensive treatment for 6 months and their blood pressures were tightly regulated and brought to the normotensive state. After 6 months, the estimations of the markers of oxidative stress were done again.

RESULTS

The MDA levels were significantly increased in the stage I and stage II hypertension groups as compared to those of the control group (p<0.05). The antioxidant enzymes (SOD, Catalase and GPX) were significantly decreased (p<0.05) in the prehypertension and in the stage I and stage II hypertension groups as compared to those in the control group. There was a significant increase in the levels of the antioxidant enzymes after 6 months of a tight regulation and bringing of the blood pressure to the normotensive state by giving antihypertensive therapy.

CONCLUSION

On comparison of the present study with other studies in which the use of antioxidants were found to be ineffective in the blood pressure reduction, it can be concluded that oxidative stress is an effect rather than a cause of essential hypertension.

Correlation between Left Ventricular Mass Index and Calcium Metabolism in Patients with Essential Hypertension

OBJECTIVE

To determine the correlation between left ventricular mass index and calcium metabolism in patients with essential hypertension.

STUDY DESIGN

Cross sectional case-control study.

MATERIAL AND METHODS

Twenty-seven patients with essential hypertension and 20 healthy individuals were compared with respect to calciotropic hormones, left ventricular mass index (LVMI), and urinary and serum biochemical parameters. The correlations between parathormone, vitamin D, and calcitonin levels and LVMI and blood pressure elevation were determined.

RESULTS

The parathormone level was significantly higher (p=0.006) and vitamin D level was significantly lower (p=0.01) in the patient group compared with the control group. However, the two groups were similar in terms of albumin-corrected calcium levels, which were within the normal range (p=0.988). The serum sodium (p=0.014) and urinary calcium (p=0.003) levels and LVMI (p<0.01) were also significantly higher in the patient group. No significant correlations were determined between ambulatory blood pressure and parathormone and vitamin D levels, but a significant correlation was found between LVMI and parathormone level (p=0.06) in hypertensive patients.

CONCLUSION

Essential hypertension alters calcium metabolism, causing calciuresis by hypernatremia. Parathormone release increases to compensate for this, and leads to protein synthesis, which in turn provokes the development of myocardial hypertrophy.

Lipoprotein (a): More than a bystander in the etiology of hypertension? A study on essential hypertensive patients not yet on treatment

BACKGROUND

Hypertension (HTN) is a very common disorder with a substantial impact on public health because of its complications.

OBJECTIVES

To study the association of serum lipoprotein(a) [Lp(a)] elevation with essential hypertension (eHTN).

PATIENTS AND METHODS

This study was conducted on a group of essential hypertensive patients. Laboratory exams consisting of serum creatinine and Lp(a) were measured.

RESULTS

Ninety five essential hypertensive patients were enrolled to the study. Serum LP (a) in patients was 46.5±20. In patients an inverse correlation between serum Lp(a) andcreatinine clearance was seen (r = -0.175 p<0.05). There was a significant correlation between serum Lp(a) and age (r =0.191 p<0.05) or duration of HTN (known duration of hypertension period) (r =0.362 p<0.05).

CONCLUSIONS

Our data suggest that Lp(a) may be involved as a cofactor in essential hypertension, with a mechanism that remains to be elucidated.

Reversible suppression of nitric oxide system in essential hypertension

Despite enormous research in the field of hypertension, its pathophysiology still remains largely unresolved and appears to be multifactorial. In the present communication, we have analyzed the status of nitric oxide (NO) in the patients with essential hypertension and age matched controls. We have found that the levels of NO are lowered in essential hypertension. The normalization of blood pressure by administration of antihypertensive therapy causes rise in the NO level indicating that perturbed NO status in essential hypertension is reversible. Addition of antioxidant to the antihypertensive drugs causes a further, though non significant, rise in the levels of NO, suggesting that antioxidants may be combined with antihypertensive drugs as adjunct in the management of essential hypertension.

Effect of low-dose omega-3 fatty acids substitution on blood pressure, hyperinsulinemia and dyslipidemia in Indians with essential hypertension: A pilot study

The present study comprised 100 patients of essential hypertension who were screened for fasting hyperinsulinemia, which was detected in 77% cases. Twenty such hyperinsulinemic cases were subjected to 4 weeks of dietary control phase followed by 6 weeks of omega-3 fatty acids substitution [either 0.6 g/d (group 1) or 1.2 g/d (group 2)]. The mean basal fasting plasma insulin levels were significantly higher (p<0.001) in patients of hypertension when compared to normal controls (126.51±80.36 and 19.35±12.61 μU/ml respectively). At the end of 4 weeks of diet control only, no significant change was observed in any parameter. After substitution of omega-3 fatty acid, a significant reduction of fasting plasma insulin levels in both group 1 (29%) and group 2 (22.8%) was observed (p<0.001). Significant reduction of systolic and diastolic blood pressure (16.4% and 25% respectively), serum cholesterol, triglycerides and low density lipoprotein was also noted in both groups (p<0.001), while high density lipoprotein increased by ∼8 mg% in both groups. Thus omega-3 fatty acid substituion in low dose along-with curtailment of dietary omega-6 fatty acid may be used as an adjunctive measure in the management of essential hypertension.

Interaction of current alcohol consumption and abdominal obesity on hypertension risk

The high prevalence of alcohol consumption and abdominal obesity and increased incidence of essential hypertension (EH) in China indicates that there may be an interaction between alcohol consumption and abdominal obesity on EH risk. Therefore, we aimed to examine the independent and combined effects of alcohol consumption and abdominal obesity on risk of EH in a Chinese cohort. We analyzed data from a population-based prospective cohort of 2778 participants aged 35-74 years from Jiangsu China who were free of hypertension, diabetes and CVD at enrollment and were followed for hypertension events. Cox proportional hazards regression model was used to calculate the hazard ratio (HR) of hypertension and corresponding 95% confidence interval (CI). Logistic regression model was used to examine the interaction between alcohol consumption and abdominal obesity on risk of hypertension. After adjusting for age, sex, smoking status, family history of hypertension, current alcohol consumption significantly increased EH risk. Compared with those without alcohol consumption, the hazard ratio of EH for participants with alcohol consumption was 1.65 (95% confidence interval 1.29-2.12). There was a statistically significant additive interaction between current alcohol consumption and abdominal obesity on EH risk. The risk of EH for current alcohol consumers with abdominal obesity was 4.49 times as high as the sum of risks in participants with a single condition alone. Both alcohol consumption and abdominal obesity are strong risk factors of EH in the Chinese population. Moreover, this study further demonstrates an additive interaction of alcohol consumption and abdominal obesity on EH risk.

Risk conferred by FokI polymorphism of vitamin D receptor (VDR) gene for essential hypertension

BACKGROUND:

The vitamin D receptor (VDR) gene serves as a good candidate gene for susceptibility to several diseases. The gene has a critical role in regulating the renin-angiotensin system (RAS) influencing the regulation of blood pressure. Hence determining the association of VDR polymorphisms with essential hypertension is expected to help in the evaluation of risk for the condition.

AIM:

The aim of this study was to evaluate association between VDRFok I polymorphism and genetic susceptibility to essential hypertension.

MATERIALS AND METHODS:

Two hundred and eighty clinically diagnosed hypertensive patients and 200 normotensive healthy controls were analyzed for Fok I (T/C) [rs2228570] polymorphism by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) analysis. Genotype distribution and allele frequencies in patients and controls, and odds ratios (ORs) were calculated to predict the risk for developing hypertension by the individuals of different genotypes.

RESULTS:

The genotype distribution and allele frequencies of Fok I (T/C) [rs2228570] VDR polymorphism differed significantly between patients and controls (χ² of 18.0; 2 degrees of freedom; P = 0.000). FF genotype and allele F were at significantly greater risk for developing hypertension and the risk was elevated for both the sexes, cases with positive family history and habit of smoking.

CONCLUSIONS:

Our data suggest that VDR gene Fok I polymorphism is associated with the risk of developing essential hypertension

The effects of a 10-week water aerobic exercise on the resting blood pressure in patients with essential hypertension

PURPOSE

To investigate the effects of a 10-week water aerobic exercise on the resting blood pressure in patients with stage 1 or 2 hypertension referring to Tehran University Clinics.

METHODS

Forty men with stage 1 or 2 essential hypertension were assigned to two groups of intervention [n = 12; aged 48.33±10.74 years (mean±SD)] and control [n = 28; aged 46.96±11.58 years (mean±SD)]. Subjects in the intervention group participated in a supervised 10-week water aerobic training program of 55 min sessions, 3 days per week on alternate days, while those in the control group were not involved in any regular training program during this period. Blood pressure of the participants was recorded and compared at the beginning and at the end of the study (48 hours after the last training session).

RESULTS

Exercise lowered systolic blood pressure and mean arterial pressure by 11.71 (95% confidence interval: 5.07 to 18.35) and 5.90 (95% confidence interval: 1.17 to 10.63) mm Hg respectively. The lowering effect of exercise on diastolic blood pressure was neither statistically significant nor clinically important (0.55 mm Hg; P. value = 0.8). There was no significant effect of age, baseline body mass index and stage of hypertension on the exercise-induced changes in blood pressure.

CONCLUSION

A 10-week course of water aerobic exercise markedly reduced the systolic and mean arterial blood pressure of patients with essential hypertension and is especially recommended for the obese and the elderly who have orthopedic problems or bronchospasm.

Mutational analysis of KCNJ11 in Chinese elderly essential hypertensive patients

Objective

To compare the distribution of KCNJ11 polymorphisms between elderly Chinese population with and without hypertension.

Methods

We examined the mutation of KCNJ11 gene by directly sequencing. Data for the present study were obtained from 250 hypertensive subjects (60 to 83 years old) as well as 250 normotensive subjects (60 to 86 years old).

Results

We found nine different mutations in KCNJ11, including six novel mutations (I131M, L147I, L147V, L147L, Q235H, G245C). None of the novel mutations were found in the normotensive subjects, and all the residues were conserved in other species. These sequence variants in Chinese population indicate the diversity of the human library and the complexity of hypertension.

Conclusions

The consistent finding of our present study provided a basis for the development of new strategies to diagnosis and treat hypertension in the elderly.

Association of polymorphisms in prolylcarboxypeptidase and chymase genes with essential hypertension in the Chinese Han population

INTRODUCTION

The prolylcarboxypeptidase (PRCP) gene encodes a membrane protein that acts on angiotensin II (Ang II) and kallikrein to release vasoactive peptides. The chymase (CMA1) gene is important for Ang II generation. Therefore, the two genes might be involved in the pathogenesis of essential hypertension (EH).

MATERIALS AND METHODS

Eleven tag single nucleotide polymorphisms (SNPs) in the PRCP gene and four tag SNPs and G-1903A (rs1800875) polymorphism in the CMA1 gene were genotyped in the Chinese Han population (n=1020) using a polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

In the PRCP gene, single site analyses indicated that the rs7104980 G allele was a susceptible factor for EH (adjusted odds ratio (OR)=1.98, 95% confidence interval (CI) 1.62-2.43, p=0.3×10(-10)). The protective effect of Hap3 GAGCACTAACA was observed without carrying the susceptible rs7104908 G allele (OR=0.67, 95% CI 0.56-0.81, p=0.3×10(-4)) by haplotype analyses. In the case of the CMA1 gene, no associations with EH were found through single site analyses. However, haplotype analyses showed that Hap16 TTTA significantly increased the risk of EH with OR=3.15 (p=0.0002) which may be driven by interaction with a nearby SNP combination.

CONCLUSIONS

The present results indicated PRCP rs7104980 can be considered as a marker for EH and Hap3 GAGCACTAACA (PRCP) and Hap16 TTTA (CMA1) might be associated with EH in Chinese Han population.

The role of psychic factors in pathogenesis of essential hypertension and its management by Shirodhara and Sarpagandha Vati

This clinical trial was conducted to evaluate the efficacy of Shirodhara and that of Sarpagandha Vati in essential hypertension. A total 47 patients were selected for study, out of which 40 patients (20 in each group) completed the course of treatment. Study subjects were randomly allotted into two groups, with one group being treated with Shirodhara and the other with Sarpagandha Vati. Specialized Ayurvedic rating scales like Manasa Pariksha Bhava as well as the Hamilton Anxiety Rating Scale were adopted to assess the effect of therapy. The effects of treatment on the chief complaints and the associated complaints were also evaluated. The results in the Shirodhara group were better than that in the Sarpagandha group. Although both Sarpagandha Vati and Shirodhara helped in reducing systolic and diastolic pressures, the effect of Shirodhara was more marked.

Gly460Trp polymorphism of the ADD1 gene and essential hypertension in an Indian population: A meta-analysis on hypertension risk

BACKGROUND:

Essential hypertension is a complex genetic trait. Genetic variant of alpha adducin (ADD1) gene have been implicated as a risk factor for hypertension. Given its clinical significance, we investigated the association between ADD1 Gly460Trp gene polymorphism and essential hypertension in an Indian population. Further, a meta-analysis was carried out to estimate the risk of hypertension.

METHODS:

In the current study, 432 hypertensive cases and 461 healthy controls were genotyped for the Gly460Trp ADD1 gene polymorphism. Genotyping was determined by real time PCR using Taqman assay. Multiple logistic regression analysis was used to detect the association between Gly460Trp polymorphism and hypertension.

RESULTS:

No significant association was found in the genotype and allele distribution of Gly460Trp polymorphism with hypertension in our study. A total of 15 case-control studies were included in the meta-analysis. There was no evidence of the association of Gly460Trp polymorphism with hypertension in general or in any of the sub group.

CONCLUSIONS:

We found that the Gly460Trp polymorphism is not a risk factor for essential hypertension in a south Indian Tamilian population. However, the role of ADD1 polymorphism may not be excluded by a negative association study. Further, large and rigorous case-control studies that investigate gene–gene–environment interactions may generate more conclusive claims about the molecular genetics of hypertension.

High risk of essential hypertension in males with intron 4 VNTR polymorphism of eNOS gene

In this study 250 patients with essential hypertension were investigated in comparison to 218 normotensives for association with epidemiological parameters. Of these DNA samples from 176 patients and 168 controls were analyzed for intron 4 27bp repeat polymorphism of eNOS gene. The study revealed significantly high risk of essential hypertension for individuals who were obese, with a positive family history and with non-vegetarian food habits. Though the intron 4b/a polymorphism of eNOS gene did not reveal any association with essential hypertension in general, males with a/a genotype of the polymorphism did show significantly high risk for developing hypertension.

A comparative study of nebivolol and (S) atenolol on blood pressure and heart rate on essential hypertensive patients

Objectives:

To study the effect of nebivolol 5 mg once daily versus (S)-atenolol 25 mg once daily in patients with essential hypertension.

Materials and Methods:

A prospective study was conducted at RLJH and Research Centre which included 30 patients in each group with essential hypertension. The sex, age, presenting illness, and family history of the patients were recorded. Investigations such as blood sugar, urine analysis, kidney function test, lipid profile, and ECG were performed before starting the treatment. Any adverse effects during the treatment were noted. Blood pressure and heart rate were recorded at baseline and during follow-up. One group received nebivolol 5 mg once daily and other group (S)atenolol 25 mg once daily. Patients were followed-up every 15 days for 3 months.

Results:

Nebivolol group had 18 males and 12 females with mean age 50.6 ± 9.5 years, (S)-atenolol had 16 males and 14 females with mean age 54.4 ± 9 years. Patients receiving nebivolol and (S)-atenolol showed a significant fall (P <·0001) in systolic (SBP), diastolic blood pressure (DBP), and heart rate at the end of first, second, and third month when compared to baseline. The difference in fall in SBP and DBP was insignificant between the groups, but fall in heart rate was significant (P <·0001). Adverse effects such as headache, dizziness, and fatigue were reported with both drugs.

Conclusion:

Reduction of blood pressure with nebivolol and (S)atenolol was similar, but fall in blood pressure from baseline was highly significant in both groups.

Association of insertion/deletion polymorphism of alpha-adrenoceptor gene in essential hypertension with or without type 2 diabetes mellitus in Malaysian subjects

An insertion/deletion (I/D) polymorphism of Alpha2B-Adrenoceptor (ADRA2B) gene located on chromosome 2 has been studied extensively in related to cardiovascular diseases. The main aim of the present study was to examine the potential association of D allele frequency of I/D polymorphism of ADRA2B gene in Malaysian essential hypertensive subjects with or without type 2 diabetes mellitus (T2DM). This study includes 70 hypertensive subjects without T2DM, 65 hypertensive subjects with T2DM and 75 healthy volunteers as control subjects. Genotyping of I/D polymorphism was performed by conventional PCR method. There was significant difference found in age, body mass index, systolic/diastolic blood pressure and high density lipoprotein cholesterol level between the case and control subjects. DD genotypic frequency of I/D polymorphism was significantly higher in hypertensive subjects (42.84% vs. 29.33%; P­=0.029) and in hypertensive with T2DM subjects (46.15% vs. 29.33%; P=0.046) than control group. D allele frequency was higher in hypertensive group (67.41%) than control subjects (52.67%). However, no significant difference was found between the three genotypes of I/D polymorphism of ADRA2B gene and the clinical characteristics of the subjects. The result obtained in this study show D allele of ADRA2B gene was associated with essential hypertension with or without T2DM in Malaysian subjects.

Association study of aromatase gene (CYP19A1) in essential hypertension

BACKGROUND

As aromatase-deficient mice, which are deficient in estrogens, reportedly have reduced blood pressure, the aromatase gene (CYP19A1) is thought to be a susceptibility gene for essential hypertension (EH). The aim of the present study was to investigate the relationship between CYP19A1 and EH by examining single nucleotide polymorphisms (SNPs).

METHODS

Five SNPs in the human CYP19A1 gene (rs1870049, rs936306, rs700518, rs10046 and rs4646) were selected, and an association study was performed in 218 Japanese EH patients and 225 age-matched normotensive (NT) individuals.

RESULTS

There were significant differences between these groups in the distribution of genotypes rs700518 and rs10046 in male subjects, and genotypes rs700518, rs10046 and rs4646 in female subjects. On multiple logistic regression analysis, a significant association between rs700518 (p=0.023) and rs10046 (p=0.036) in male subjects and rs700518 in female subjects (p=0.018) was noted. Interestingly, the risk genotypes of rs700518 and rs10046 showed a sex-dependent inverse relationship. Both SBP and DBP levels were higher in total (cases and controls) male subjects with the G/G genotype with rs700518 or the T/T genotype with rs10046 than in male subjects without the G/G genotype or T/T genotype. SBP levels were lower in female subjects with the G/G genotype with rs700518 than in female subjects without G/G. The A-T haplotype constructed with rs1870049 and rs10046 was a susceptibility marker for EH.

CONCLUSIONS

We confirmed that rs700518 and rs10046, as well as a haplotype constructed with rs1870049 and rs10046, in the human CYP19A1 gene can be used as genetic markers for gender-specific EH.

Association of three polymorphisms in the gene coding for endothelin-1 with essential hypertension, overweight and smoking

OBJECTIVE

To evaluate the association of three endothelin-1 (ET-1) gene polymorphisms with essential hypertension, as well as with two cardiovascular risk factors: body mass index (BMI) and smoking.

DESIGN

Three gene polymorphisms and the genotype and allelic distributions were compared between normotensive healthy volunteers and patients with essential hypertension. The genetic association of the three genotypes with BMI and smoking status was calculated.

PATIENTS AND METHODS

CA/CT dinucleotide repeat polymorphism, G(8002)A polymorphism and -3A/-4A polymorphism (-138 insertion/deletion) were examined in the gene coding for ET-1 (6p21.3) in 398 subjects: 192 normotensives (healthy volunteers) and 206 patients with essential hypertension. Normotension was verified by 24 h ambulatory blood pressure monitoring.

RESULTS

Significant inner associations were observed between all three polymorphisms, which suggests possible complex interactions inside the gene. The only significant difference in a single gene case control study was in the lengths of allelic variants of CA/CT dinucleotide repeat polymorphism. In hypertensive patients, the alleles of G(8002)A and -3A/-4A ET-1 polymorphisms were found to be significantly associated (G with -3A and A with -4A). None of the ET-1 gene polymorphisms was associated with BMI. A highly significant increase of the -3A allele of the -3A/-4A ET-1 polymorphism was found in hypertensive men who were current smokers or had smoked at least seven cigarettes a week for at least one year at any time in their life compared with hypertensive men who had never smoked (odds ratio 1.54, 95% CI 1.03 to 2.32, P=0.009).

CONCLUSIONS

Smoking seems to be an independent cardiovascular risk factor genetically codetermined by the ET-1 gene variant.