Sex differences in environmental and genetic factors for hypertension

Sex and gender differences in cognitive resilience to aging and Alzheimer's disease

Sex and gender-biological and social constructs-significantly impact the prevalence of protective and risk factors, influencing the burden of Alzheimer's disease (AD; amyloid beta and tau) and other pathologies (e.g., cerebrovascular disease) which ultimately shape cognitive trajectories. Understanding the interplay of these factors is central to understanding resilience and resistance mechanisms explaining maintained cognitive function and reduced pathology accumulation in aging and AD. In this narrative review, the ADDRESS! Special Interest Group (Alzheimer's Association) adopted a multidisciplinary approach to provide the foundations and recommendations for future research into sex- and gender-specific drivers of resilience, including a sex/gender-oriented review of risk factors, genetics, AD and non-AD pathologies, brain structure and function, and animal research. We urge the field to adopt a sex/gender-aware approach to resilience to advance our understanding of the intricate interplay of biological and social determinants and consider sex/gender-specific resilience throughout disease stages. HIGHLIGHTS: Sex differences in resilience to cognitive decline vary by age and cognitive status. Initial evidence supports sex-specific distinctions in brain pathology. Findings suggest sex differences in the impact of pathology on cognition. There is a sex-specific change in resilience in the transition to clinical stages. Gender and sex factors warrant study: modifiable, immune, inflammatory, and vascular.

Systematic literature review and meta-analysis of cardiovascular risk factor management in selected Asian countries

Aim: There is a need to understand the management status of hypertension, dyslipidemia/hypercholesterolemia, and diabetes mellitus in the Asia-Pacific region (APAC). Methods: We conducted a systematic literature review and meta-analysis to summarize the awareness, treatment, and/or control rates of these risk factors in adults across 11 APAC countries/regions. Results: We included 138 studies. Individuals with dyslipidemia had the lowest pooled rates compared with those with other risk factors. Levels of awareness with diabetes mellitus, hypertension, and hypercholesterolemia were comparable. Individuals with hypercholesterolemia had a statistically lower pooled treatment rate but a higher pooled control rate than those with hypertension. Conclusion: The management of hypertension, dyslipidemia, and diabetes mellitus was suboptimal in these 11 countries/regions.

Prevalence and risk factors associated with hypertension among adults in a rural setting: the case of Ombe, Cameroon

INTRODUCTION

High blood pressure is the most common cardiovascular disorder affecting approximately one billion people globally and remains a major contributor to the global burden of non-communicable diseases and mortality. Hypertension, once rare in traditional African societies, is now a major public health problem probably because of a rise in its risk factors. In sub-Saharan Africa, an estimated 74.7 million individuals live with hypertension. This study was designed to determine the prevalence and identify risk factors associated with hypertension in adults aged 21 years and above in Ombe village, a rural Cameroonian setting in sub-Saharan Africa.

METHODS

This study was a cross-sectional community based survey from March to September 2016 (seven months) in the village of Ombe, a rural community in the southwest region of Cameroon. Following ethical clearance from the Institutional Review Board (IRB) of the Faculty of Health Science, University of Buea and administrative authorization, 243 participants (141 males and 102 females) through multi-stage sampling were randomly selected to take part in the study following consent which was voluntary and without any form of coercion. The principal research instrument was a questionnaire adapted from the WHO STEPwise approach to chronic disease risk factor surveillance- Instrument v2.1 which was administered to participants. The self-administered questionnaire collected socio-demographic information, data related to knowledge and practices related to hypertension, anthropometric data (weight and height from which the body mass index (BMI) was calculated). The blood pressure of study participants was measured. Data was entered using Microsoft Excel, then imported and analysed in SPSS v22.0. Frequencies and percentages were determined for categorical variables. Means and standard deviations (mean ± SD). Univariate and multivariate logistic regression analysis were used to investigate factors associated with high blood pressure (hypertension).

RESULTS

The results showed that 19.8% of the adult population had hypertension. Of the 243 respondents, 77.7% understood what is hypertension, 85% indicated that they could tell some consequences of high blood pressure (they indicated hypertension affects the heart, brain and kidneys) and 63.3% of study participants had never checked their blood pressure. Age greater than 40 years, harmful alcohol intake for more than 10 years, physical inactivity and obesity (BMI ≥ 25Kg/m2) were variables associated with hypertension on univariate analysis. Following multivariate analysis, independent risk factors for hypertension in our study were: physical inactivity (Adj. OR 2.6, 95%CI: 1.3-4.4, p = 0.021), regular alcohol consumption for more than 10 years (Adj. OR 2.9, 95%CI: 1.6-5.1, p = 0.014) and being older than 40 years of age: Adj. OR 2.5, 95%CI: 1.02-4.1, p = 0.002 in age category 41-60 years and this age related risk was even higher in persons older than 60 years of age Adj. OR 4.5, 95%CI: 2.1-6.3, p = 0.002.

CONCLUSION

The findings of this study showed the prevalence of high blood pressure among adults in Ombe (a rural community in Cameroon) was 19.8%. Old age, alcohol consumption, and physical inactivity were independent risk factors for hypertension. Despite the population demonstrating knowledge about hypertension and its possible poor consequences on health, less than half had ever gone for blood pressure checks. Interventions to improve physical activity, reduce alcohol consumption and boost health seeking (high blood pressure screening) behaviour will be beneficial as preventive measures in combatting hypertension.

The Influence of Sex on Cardiac Physiology and Cardiovascular Diseases

Cardiovascular disease (CVD) is the leading cause of death world-wide. Most of treatment strategies were based on studies conducted on male patients. Studies have shown that significant differences exist between the two sexes in the development of CVD. There are certain differences between men and women in the structure and physiological functions of the heart such as left ventricular mass index, resting heart rate, and contractile function. Accordingly, the pathological features of the heart such as the extend of hypertrophy, fibrosis, and remodeling are also different. In addition, different genders also affect clinical symptoms, responses to treatment and prognosis in the development of CVD. Therefore, it is important to take these differences into consideration when design treatment options for men and women.

Association between peroxisome proliferator-activated receptor γ-2 gene Pro12Ala polymorphisms and risk of hypertension: an updated meta-analysis

Previous studies investigate the relationship between peroxisome proliferator-activated receptor γ-2 (PPAR) gene Pro12Ala polymorphisms and risk of hypertension. However, the number of available studies was extremely limited. We updated this evidence and gave more significant results. We performed comprehensive computer-based searches in the PubMed, Web of Science, Embase, Google Scholar, the Cochrane library, Wanfang database, China National Knowledge Infrastructure, and China Biological Medicine Database. All studies that reported the association between the PPARγ2Pro12Ala polymorphisms and hypertension were identified. Twenty-one studies were finally included in the present study. In the domain model, the PPARγ1Pro12Ala polymorphism was not associated with hypertension (odds ratio (OR) = 0.85, 95% confidence interval (CI): 0.71-1.03, P=0.108). The significant relationship was found in the recessive model (OR = 0.67, 95% CI: 0.53-0.85), in the additive model (OR = 0.61, 95% CI: 0.48-0.77), and in the allele genetic model (OR = 0.81, 95% CI: 0.66-0.99). Subgroup analysis indicated that the PPARγ1Pro12Ala polymorphism from the all gene models was also not related to the risk of hypertension in Caucasians. In Asians, however, the results (P=0.002; I² = 57.6%) suggested a significant relationship between PPARγ1Pro12Ala and hypertension in the domain model (OR = 0.80, 95% CI: 0.65-0.99), in the recessive model (OR = 0.57, 95% CI: 0.44-0.75), in the additive model (OR = 0.51, 95% CI: 0.39-0.66), and in the allele model (OR = 0.75, 95% CI: 0.60-0.94). The PPARγ1Pro12Ala polymorphism could affect the risk of primary hypertension amongst Asians. The A allele gene was a protective genotype for primary hypertension. The PPARγ1Pro12Ala polymorphism was not associated with hypertension amongst Caucasians.

The mutation of Trp64Arg in β3-adrenoreceptor-encoding gene is significantly associated with increased hypertension risk and elevated blood pressure: a meta-analysis

This meta-analysis was implemented to test the association of a missense mutation, Trp64Arg, in β3-adrenoreceptor-encoding gene (ADRB3) with both hypertension risk and blood pressure (BP) changes. A systematic search of three publicly-available databases was launched to look for articles published as of December 2016. Qualification appraisal and data extraction were independently done by two researchers. Pooled estimates were expressed as odds ratio (OR) or weighted mean difference (WMD), and their 95% confidence intervals (95% CIs). There were separately 21 (3750/4225 patients/controls) and 17 (6100 subjects) individual studies for hypertension risk and BP changes. Integral analyses revealed that Trp64Arg mutation was associated with the significantly increased risk of hypertension, and particularly, the 64Trp/64Arg heterozygote carriers were 1.23-times more likely to develop hypertension compared with the 64Trp/64Trp homozygote carriers (OR = 1.23, 95% CI: 1.02∼1.46, P = 0.021). Publication bias was extremely low for all integral comparisons. In stratified analyses, significance was spotted in populations of Chinese descent, in retrospective studies, in hospital-based studies, in age-matched case-control studies, in studies enrolling patients with mean body mass index < 25 kg/m² and in studies with total sample size ≥ 240. Heterogeneity was improved for most stratified comparisons. Further in hypertensive patients, the 64Trp/64Arg heterozygote carriers had significantly higher systolic (WMD = 0.87 mmHg, 95% CI: 0.39∼1.35, P < 0.001) and diastolic (WMD = 0.88 mmHg, 95% CI: 0.59∼1.17, P < 0.001) BP than 64Trp/64Trp homozygote carriers. Altogether, ADRB3 gene Trp64Arg mutation was significantly associated with an increased predisposition toward hypertension and elevated systolic/diastolic BP in hypertensive patients, suggesting that Trp64Arg is an important hypertension-susceptibility marker.

Associations between PPARG polymorphisms and the risk of essential hypertension

Background

Peroxisome proliferator-activated receptor gamma (PPARG) plays an important role in the pathogenesis and maintenance of essential hypertension (EH). It has been suggested that polymorphisms of PPARG are associated with the risk of EH. However, findings to date remain controversial. To elucidate the associations between the PPARG Pro12Ala and C161T polymorphisms and EH risk, a meta-analysis was carried out.

Methods

A comprehensive literature search of PubMed, Embase, CNKI (Chinese National Knowledge Infrastructure), VIP and Wanfang databases was conducted. The pooled odds ratios (ORs) and 95% confidence interval (CI) were calculated to estimate the size of the effect using the random-effects model. At the same time, the pooled standardized mean difference (SMD) with 95% CI was used for the meta-analysis of the PPARG Pro12Ala polymorphism and blood pressure.

Results

Finally, Fifteen papers (seventeen studies) including 4,151 cases and 4,997 controls to evaluate the association of the PPARGPro12Ala polymorphism and EH risk, were included in this study. Overall, the results suggested that Ala allele was associated with the decreased EH risk (for allelic model, OR = 0.757, 95%CI: 0.624–0.918, P = 0.005; for dominant model, OR = 0.771, 95%CI: 0.627–0.946, P = 0.013). The subgroup analysis stratified by ethnicity showed that the significant association between the PPARG Pro12Ala polymorphism and EH was only detected in the Asian subgroup. There was no difference in blood pressure values between Ala carriers and non-carriers. For the C161T polymorphism, only 5 studies comprising 1,118 cases and 1,357 controls met the inclusion criteria. The overall results showed that the PPARG C161T polymorphism was not associated with the risk of EH. But in the subgroup analysis, we found that the PPARG C161T polymorphism significantly associated with the risk of EH in the Asian subgroup (for allelic model, OR = 0.719, 95% CI: 0.537–0.963, P = 0.027; for dominant model, OR = 0.653, 95% CI: 0.439–0.972, P = 0.036).

Conclusion

Our meta-analysis suggested that the PPARG polymorphisms might be associated with the risk of EH.

Testing a Model of Sodium Reduction in Hypertensive Older Thai Adults

Hypertensive older adults will benefit if there is a clear understanding of the factors related to sodium reduction. That would raise awareness of the causes, consequently reducing many health risks, lowering health care costs, and diminishing economic and social burden from high blood pressure. This study explored predictors of urinary sodium excretion. A cross-sectional, correlational study was conducted in 312 hypertensive older Thai adults. Questionnaires related to knowledge, self-care agency, self-care behavior of sodium reduction, and 24-hour urinary sodium analyses were used, followed by the application of structural equation modeling and the Analysis of Moment Structures program. Self-care agency, knowledge, self-care behavior, rural/urban location, and education accounted for 61% of urinary sodium excretion. Self-care agency, knowledge, and self-care behavior were the main predictors in the urinary sodium excretion model. This study suggests establishing supportive educative sodium reduction-related programs that improve knowledge and enhance self-care agency, as well as a comparison of the changes of sodium reduction self-care behavior and urinary sodium excretion over time after the intervention.

Identification of an interaction between VWF rs7965413 and platelet count as a novel risk marker for metabolic syndrome: an extensive search of candidate polymorphisms in a case-control study

Although many single nucleotide polymorphisms (SNPs) have been identified to be associated with metabolic syndrome (MetS), there was only a slight improvement in the ability to predict future MetS by the simply addition of SNPs to clinical risk markers. To improve the ability to predict future MetS, combinational effects, such as SNP—SNP interaction, SNP—environment interaction, and SNP—clinical parameter (SNP × CP) interaction should be also considered. We performed a case-control study to explore novel SNP × CP interactions as risk markers for MetS based on health check-up data of Japanese male employees. We selected 99 SNPs that were previously reported to be associated with MetS and components of MetS; subsequently, we genotyped these SNPs from 360 cases and 1983 control subjects. First, we performed logistic regression analyses to assess the association of each SNP with MetS. Of these SNPs, five SNPs were significantly associated with MetS (P < 0.05): LRP2 rs2544390, rs1800592 between UCP1 and TBC1D9, APOA5 rs662799, VWF rs7965413, and rs1411766 between MYO16 and IRS2. Furthermore, we performed multiple logistic regression analyses, including an SNP term, a CP term, and an SNP × CP interaction term for each CP and SNP that was significantly associated with MetS. We identified a novel SNP × CP interaction between rs7965413 and platelet count that was significantly associated with MetS [SNP term: odds ratio (OR) = 0.78, P = 0.004; SNP × CP interaction term: OR = 1.33, P = 0.001]. This association of the SNP × CP interaction with MetS remained nominally significant in multiple logistic regression analysis after adjustment for either the number of MetS components or MetS components excluding obesity. Our results reveal new insight into platelet count as a risk marker for MetS.

Sodium-to-potassium ratio and blood pressure, hypertension, and related factors

The potential cost-effectiveness and feasibility of dietary interventions aimed at reducing hypertension risk are of considerable interest and significance in public health. In particular, the effectiveness of restricted sodium or increased potassium intake on mitigating hypertension risk has been demonstrated in clinical and observational research. The role that modified sodium or potassium intake plays in influencing the renin-angiotensin system, arterial stiffness, and endothelial dysfunction remains of interest in current research. Up to the present date, no known systematic review has examined whether the sodium-to-potassium ratio or either sodium or potassium alone is more strongly associated with blood pressure and related factors, including the renin-angiotensin system, arterial stiffness, the augmentation index, and endothelial dysfunction, in humans. This article presents a systematic review and synthesis of the randomized controlled trials and observational research related to this issue. The main findings show that, among the randomized controlled trials reviewed, the sodium-to-potassium ratio appears to be more strongly associated with blood pressure outcomes than either sodium or potassium alone in hypertensive adult populations. Recent data from the observational studies reviewed provide additional support for the sodium-to-potassium ratio as a superior metric to either sodium or potassium alone in the evaluation of blood pressure outcomes and incident hypertension. It remains unclear whether this is true in normotensive populations and in children and for related outcomes including the renin-angiotensin system, arterial stiffness, the augmentation index, and endothelial dysfunction. Future study in these populations is warranted.

Association between polymorphisms in the TRHR gene, fat-free mass, and muscle strength in older women

A previous genome-wide association study suggested that polymorphisms in the thyrotrophin-releasing hormone receptor (TRHR) gene contribute to fat-free mass (FFM) variation. The aim of the present study was to examine the association between polymorphisms in the TRHR gene with FFM and muscle strength in older women. Volunteers (n = 241; age = 66.65 ± 5.5 years) underwent quadriceps strength assessment using isokinetics and fat-free mass by dual-energy X-ray absorptiometry. TRHR polymorphisms and ancestry-informative markers were genotyped through standard procedures. No significant difference was observed for rs7832552. Regarding the rs16892496, ANCOVA revealed that appendicular fat-free mass (AFFM) and relative AFFM were significantly different between groups (p = 0.04 and p = 0.05, respectively). Individuals carrying A/A and A/C genotypes respectively showed, on average, an extra 1 kg and 900 g of AFFM when compared to C/C genotype carriers. Also, the C/C genotype group presented a significantly higher chance to have reduced muscle strength. The observations presented here provide further evidence that the rs16892496 polymorphism in the TRHR gene may play a role in FFM variation. Moreover, the results bring the novel insight that this genetic variant can present a modest contribution to muscle strength in older women.

Sex-biased methylome and transcriptome in human prefrontal cortex

Brain function and cognitive performance differ between men and women in some measures. The phenotypic variation may be partially due to sex differences in epigenomes and transcriptomes in specific brain regions [e.g. the prefrontal cortex (PFC)]. Genome-wide DNA methylation and gene expression were examined in postmortem PFC of 32 males and 14 females (all were Caucasians) using Illumina's 450K Methylation and HT-12 v4 Gene Expression BeadChips, respectively. Multiple linear regression, Pearson correlation and DAVID functional annotation analyses were applied to investigate sex-biased DNA methylation and gene expression, DNA methylation-gene expression correlation and gene ontology (GO) annotations overrepresented by differentially methylated and expressed genes. A total of 22 124 CpGs showed differential methylation between males and females (2.6 × 10(-38) ≤ Pnominal ≤ 0.05), and the P-values of 8357 CpGs withstood multiple-testing correction (q < 0.05). A total of 1489 genes showed differential expression between males and females (4.1 × 10(-36) ≤ Pnominal ≤ 0.05), and the P-values of 35 genes survived multiple-testing correction (q < 0.05). A significant correlation (Pcorrelation < 0.05) was observed between methylation levels of 585 differentially methylated CpGs (Pnominal ≤ 0.05) and expression levels of 188 differentially expressed host genes (Pnominal < 0.05). The GO terms enriched by these 188 genes (134 on autosomes and 54 on sex chromosomes) were assigned to 24 clusters, and 33 genes involved in the top cluster (enrichment score: 4.7) mainly participate in ribosome structure and function, RNA binding and protein translation. This study demonstrated sex-specific methylomic and transcriptomic profiles in the human PFC. Our findings suggest that sex-biased DNA methylation and gene expression could be either the cause or consequence of differential brain development between males and females.

Sex-age differences in association with particulate matter and emergency admissions for cardiovascular diseases: a hospital-based study in Taiwan

OBJECTIVE

To explore the association between short-term exposure to particulate matter (PM) and cardiovascular diseases (CVDs) emergency room visits.

STUDY DESIGN

Case-control study.

METHODS

2785 Emergency visits with presented cardiovascular diseases and 24,572 controls from ten hospitals in 2005 were obtained from a Taiwan's National Health Database. Daily PM10 data and meteorological information collected from an air monitoring station near the ten hospitals were used to calculate the exposure levels. Using multiple logistic regression analysis, adjusted odds ratios (AOR) were estimated for the associations of PM and temperature with ischaemic heart disease (IHD) and hypertension heart disease (HHD).

RESULTS

A positive association (AOR = 1.05-1.75) between IHD emergency admission among women older than 65 and exposure to daily levels of PM10 pollution standard index (PSI) ≥50 compared with respondents exposed to PM10 PSI <50.

CONCLUSIONS

To prevent exacerbation of IHD, people, especially elderly women, should be urged to reduce exposure to unhealthy PSI levels.

Common genetic variants in the endothelial system predict blood pressure response to sodium intake: the GenSalt study

BACKGROUND We examined the association between 14 endothelial system genes and salt-sensitivity of blood pressure (BP). METHODS After a 3-day baseline examination, during which time the usual diet was consumed, 1,906 Chinese participants received a 7-day low-sodium diet (51.3 mmol of sodium/day) followed by a 7-day high-sodium diet (307.8 mmol of sodium/day). BP measurements were obtained at baseline and at the end of each intervention using a random-zero sphygmomanometer. RESULTS The DDAH1 rs11161637 variant was associated with reduced BP salt sensitivity, conferring attenuated systolic BP (SBP) and mean arterial pressure (MAP) decreases from baseline to the low-sodium intervention (both P = 2×10(-4)). Examination of genotype-sex interactions revealed that this relation was driven by the strong associations observed in men (P for interactions = 1.10×10(-4) and 0.008, respectively). When switching from the low- to high-sodium intervention, increases in diastolic BP (DBP) and MAP were attenuated by the COL18A1 rs2838944 minor A allele (P = 1.41×10(-4) and 1.55×10(-4), respectively). Conversely, the VWF rs2239153 C variant was associated with increased salt sensitivity, conferring larger DBP and MAP reductions during low-sodium intervention (P = 1.22×10(-4) and 4.44×10(-5), respectively). Ten variants from 3 independent SELE loci displayed significant genotype-sex interactions on DBP and MAP responses to low-sodium (P for interaction = 1.56×10(-3) to 1.00×10(-4)). Among men, minor alleles of 4 correlated markers attenuated BP responses to low-sodium intake, whereas minor alleles of another 4 correlated markers increased BP responses. No associations were observed in women for these variants. Further, qualitative interactions were shown for 2 correlated SELE markers. CONCLUSIONS These data support a role for the endothelial system genes in salt sensitivity.

Association between Serine/Threonine Kinase 39 Gene Polymorphism, Hypertension, and Other Cardiovascular Risk Factors in Koreans

Background and Objectives

Although the association between single nucleotide polymorphisms (SNPs) of Serine/Threonine Kinase 39 (STK39) and hypertension has been reported, the prior studies have been inconsistent. The aim of this study is to evaluate the association between rs3754777 and rs6749447, the two SNPs of STK39, and hypertension and other cardiovascular risk factors in Koreans, residing in the Republic of Korea.

Subjects and Methods

We included 238 hypertensive patients and 260 controls. The associations between genotype and haplotype combination and hypertension were examined. In addition, possible SNP-related differences in the adjusted blood pressure and other cardiovascular risk factors were analyzed.

Results

There was no significant association between the two SNPs and hypertension. However, the carriers of AA genotype of rs3754777 showed lower blood glucose and cholesterol levels, particularly in females. Genotype of rs6749447 was associated with the waist circumference, triglyceride, and high density lipoprotein-cholesterol levels, only in gender-stratified analysis. The effects of haplotype combinations on risk factors were compatible with genotype effects of each SNP.

Conclusion

Associations between the two SNPs of STK39, rs3754777 and rs6749447, and hypertension were not significant. However, the two SNPs showed genotype-related differences in blood glucose, lipids, and waist circumference, especially in women. Further studies are needed to clarify the effect of STK39 variants in these cardiovascular risk factors.

Interactions between the apolipoprotein a1/c3/a5 haplotypes and alcohol consumption on serum lipid levels

BACKGROUND

The interactions between apolipoprotein (Apo) A1/C3/A5 haplotypes and alcohol consumption on serum lipid profiles have not been previously explored. The present study was undertaken to detect the polymorphisms of ApoA1 -75 bp G>A (rs1799837), ApoC3 3238C>G (rs5128), ApoA5 -1131T>C (rs662799), ApoA5 c.553G>T (rs2075291), and ApoA5 c.457G>A (rs3135507) and the interactions between their haplotypes and alcohol consumption on serum lipid levels.

METHODS

Genotyping was performed in 1,030 unrelated subjects (516 nondrinkers and 514 drinkers) aged 15 to 89. The interactions between ApoA1/C3/A5 haplotypes and alcohol consumption on serum lipid levels were detected by factorial regression analysis after controlling for potential confounders.

RESULTS

The frequencies of ApoC3 3238 CG/GG genotypes and ApoA1 -75 bp A allele in nondrinkers were higher in females than in males (p < 0.05). The frequencies of ApoC3 3238 CG/GG genotypes and G allele in drinkers were higher in females than in males (p < 0.05). The frequencies of ApoA1 -75 bp GA/AA genotypes and A allele in males were higher, and those of ApoC3 3238 CG/GG genotypes were lower in drinkers than in nondrinkers (p < 0.05 to 0.01). The frequency of ApoC3 3238 GG genotype in male drinkers was also higher in ≥25 g/d than in <25 g/d subgroups (p < 0.05). There were 11 haplotypes with a frequency >1% in our study population. The haplotypes of G-G-T-C-G (in the order of c.553G>T, c.457G>A, -1131T>C, 3238C>G, and -75 bp G>A), G-G-T-C-A, and G-G-C-G-G were shown consistent interactions with alcohol consumption to increase serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), and ApoA1 levels (p < 0.05 to 0.001). The interactions between G-G-T-G-G (HDL-C and ApoA1), G-G-C-C-A (ApoA1), G-A-T-C-G (triglyceride), G-G-T-C-G (ApoA1/ApoB ratio), and G-G-C-G-G (ApoB) haplotypes and alcohol consumption on serum lipid levels were also detected (p < 0.05 to 0.001); the levels of these serum lipid parameters were significantly higher in drinkers than in nondrinkers.

CONCLUSIONS

The differences in serum lipid parameters between drinkers and nondrinkers might partly result from different interactions between the ApoA1/C3/A5 haplotypes and alcohol consumption.

Obesity and overweight prevalence and its association with undiagnosed hypertension in Shanghai population, China: a cross-sectional population-based survey

The aim of this study was to determine the prevalence of overweight and obese subjects in the Shanghai population of China and its association with undiagnosed hypertension, by taking age, gender and place of residence (urban or suburban) into account. A cross-sectional population-based survey was conducted in 2007. The sample included 13,359 participants aged 15-69 years.Weight, height, and blood pressure were recorded, and information about gender, age and place of residence was obtained. Overweight and obesity prevalence were calculated by the body mass index (BMI) definition recommended by Working Group on Obesity in China (normal weight, 18.5-23.9 kg/m(2); overweight, 24-27.9 kg/m(2); obesity, ≥ 28 kg/m(2)). Undiagnosed hypertension was defined by China criteria in accord with that of WHO-ISH (subjects with systolic pressure ≥ 140 mmHg, and/or diastolic pressure ≥ 90 mmHg). Multiple logistic regression analyses were used to assess the association of overweight or obesity with undiagnosed hypertension by adjusting for age, gender and place of residence. The overall overweight, obesity, and undiagnosed hypertension prevalence were 27.6% (95% CI: 26.8-28.4), 6.6% (95% CI: 6.2-7.0), and 15.5% (95% CI: 14.9-16.1), respectively. Compared to normal weight subjects, the odds ratios (OR) for subjects who were overweight and had hypertension was 2.33 (95% CI: 2.10-2.59); that for obesity and hypertension was 4.27 (95% CI: 3.66-4.99). These data suggest that overweight and obesity prevalence and their association with undiagnosed hypertension are high in our study population.

Hypertension in adult survivors of child abuse: observations from the Nurses' Health Study II

BACKGROUND

Limited research has shown a possible association between exposure to physical or sexual abuse prior to age 18 and the risk of developing hypertension as an adult. The factors mediating this relationship are unknown.

METHODS

Questionnaire data from 68 505 female participants in the Nurses' Health Study II were analysed regarding exposure to physical and sexual abuse prior to age 18. Cox proportional hazards regression was used to assess the relationship between abuse exposure and hypertension.

RESULTS

64% of the participants (n=41 792) reported physical and/or sexual abuse prior to age 18; 17% reported hypertension. All forms of abuse had a dose-response relationship with hypertension. Adjustments for smoking, alcohol, family history of hypertension, exercise and oral contraceptives did not alter risk estimates. Adjustment for body mass index (BMI) significantly attenuated the associations between abuse and risk of hypertension and accounted for approximately 50% of the observed association between abuse exposure and hypertension. Women experiencing forced sexual activity as a child and as an adolescent had a 20% increased risk for developing hypertension (95% CI 8% to 32%) that was independent of BMI. Similarly, women reporting severe physical abuse in childhood and/or adolescence had risk estimates ranging from 14% (95% CI 5% to 24%) to 22% (95% CI 11% to 33%).

CONCLUSION

Early interpersonal violence may be a widespread risk factor for the development of hypertension in women. BMI is a significant mediator in the relationship between early abuse and adult hypertension.

The role of 20-HETE in androgen-mediated hypertension

Androgen plays an important role in blood pressure regulation. Epidemiological studies have shown that men have a higher prevalence for developing hypertension than aged-matched, premenopausal women. Interestingly, postmenopausal women and women with polycystic ovary syndrome, both of which have increased endogenous androgen production, have elevated risks for hypertension suggesting that androgen may contribute to its development. Studies from our laboratory and others have provided substantial evidence that 20-hydroxyeicosatetraenoic acid (20-HETE) mediates the hypertension seen in rodents treated with androgen. 20-HETE is the cytochrome P450 (CYP)-derived ω-hydroxylated metabolite of arachidonic acid. 20-HETE plays a complex role in blood pressure regulation. In the kidney tubules, 20-HETE decreases blood pressure by promoting natriuresis, while in the microvasculature it has a pressor effect. In the microcirculation, 20-HETE participates in the regulation of vascular tone by sensitizing the smooth muscle cells to constrictor stimuli and contributes to myogenic, mitogenic and angiogenic responses. In addition, 20-HETE acts on the endothelium to promote endothelial dysfunction and endothelial activation. Recently, we have demonstrated that 20-HETE induces endothelial ACE thus setting forth a potential feed forward mechanism through activation of the renin-angiotensin-aldosterone system. In this review, we will discuss the pro-hypertensive effects of 20-HETE and its role in androgen-induced vascular dysfunction and hypertension.

Synopsis and data synthesis of genetic association studies in hypertension for the adrenergic receptor family genes: the CUMAGAS-HYPERT database

BACKGROUND

The adrenergic receptor (adrenoceptor) family genes have been extensively studied as candidate genes in hypertension but the results of individual genetic association studies (GAS) are controversial and inconclusive. To clarify these data, a systematic assessment of GAS for adrenoceptor family genes in hypertension was conducted.

METHODS

Data from 163 GAS involving 7 genes and 37 distinct genetic variants were analyzed and cataloged in CUMAGAS-HYPERT (Cumulative Meta-analysis of Genetic Association Studies-HYPERTension; a web-based information system, which allows the retrieval and synthesis of data from GAS in hypertension, available at http://biomath.med.uth.gr). Data from genome-wide association studies involving the adrenoceptor family genes were also systematically searched.

RESULTS

Individual GAS reported inconsistent associations and had limited power to detect modest genetic effects, with only 1.2% having power >80%. Thirteen variants were investigated by three or more studies and their results were subject to meta-analysis. In the main meta-analyses, significant results were shown for five variants (ADRB1 p.Arg389Gly, ADRB1 p.Ser49Gly, ADRB2 g.9368308A>G, ADRB3 p.Trp64Arg, and ADRA1A p.Cys347Arg) under the allelic contrast and/or the dominant model. Subgroup analyses by ethnicity and gender detected significant associations for three variants (ADRB1 p.Arg389Gly in east Asians, ADRB2 p.Gln27Glu in whites, and ADRB3 p.Trp64Arg in whites and in males). Heterogeneity ranged from none to high. No significant associations were recorded from genome-wide studies.

CONCLUSIONS

There is evidence to implicate adrenoceptor genes in hypertension, although future studies designed to investigate epistatic and gene-environment interactions would allow more solid conclusions to be drawn about the role of these genes in hypertension.

Influence of angiotensin-converting enzyme I/D gene polymorphism on clinical and histological correlates of chronic hepatitis C

AIM

This study aimed to verify the relationship between the insertion-deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE) and clinical and histological correlates of chronic hepatitis C.

METHODS

Two-hundred and fifty-eight, treatment naive, unselected hepatitis C virus (HCV) RNA-positive patients and 210 controls were studied. ACE allelic variants were determined by polymerase chain reaction.

RESULTS

Mean staging scores adjusted for age, body mass index (BMI) and alcohol consumption were: men, D/* = 2.283; men, I/I = 2.092; women, D/* = 2.241; and women, I/I = 3.283 (P = 0.028). Age-adjusted mean BMI were: men, D/* = 25.01; men, I/I = 24.87; women, D/* = 23.73; and women, I/I = 22.50 (P = 0.006). Age and BMI-adjusted mean low-density lipoprotein (LDL)/ high-density lipoprotein (HDL) cholesterol ratios were: men, D/* = 2.344; men, I/I = 2.283; women, D/* = 1.916; and women, I/I = 1.903 (P = 0.004). Histological grading correlated positively with triglycerides and negatively with HDL and LDL cholesterol (P < 0.0001).

CONCLUSION

Female ACE I/I homozygotes have higher liver fibrosis scores in comparison to D/* women and to men; moreover, they are leaner and have a lower LDL/HDL cholesterol ratio. These observations suggest a possible mutual influence between ACE polymorphism, serum lipid concentrations and outcome of chronic HCV infection.