Establishment of sex difference in circulating uric acid is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys

Men have higher circulating levels of uric acid than women. This sex difference is suspected to be a result of suppressive effects of estradiol on uric acid. If so, estradiol would be inversely associated with circulating uric acid. This study aimed to test this hypothesis. This cross-sectional study included 9472 participants (weighted sample size of 184,342,210) aged 12–80 years from the 2013 to 2016 US National Health and Nutrition Examination Survey. Associations of sex hormones with uric acid were analyzed using weighted least squares regression, adjusting for demographic characteristics, lifestyle risk factors, and comorbidities. Neither free nor bioavailable estradiol was inversely associated with circulating uric acid in adolescent boys or girls, or adult men or women, or perimenopausal women after full adjustment. The sex difference in uric acid was established during adolescence as a result of a dramatic increase in uric acid in adolescent boys. During adolescence, the increase in estradiol in girls over time was accompanied by a relatively unchanged level of uric acid. All three fractions of estradiol (free, bioavailable, and total) were positively associated with uric acid in adolescent boys and girls after full adjustment. In adolescent boys, all three fractions of testosterone were positively associated with serum uric acid, and sex hormone-binding globulin was inversely associated with uric acid after full adjustment. These results suggest that estradiol is not inversely associated with circulating uric acid in adolescents and the establishment of sex difference in circulating uric acid during adolescence is associated with higher testosterone and lower sex hormone-binding globulin in adolescent boys. © 2021, The Author(s)

A meta-analysis of gene expression signatures of blood pressure and hypertension

Genome-wide association studies (GWAS) have uncovered numerous genetic variants (SNPs) that are associated with blood pressure (BP). Genetic variants may lead to BP changes by acting on intermediate molecular phenotypes such as coded protein sequence or gene expression, which in turn affect BP variability. Therefore, characterizing genes whose expression is associated with BP may reveal cellular processes involved in BP regulation and uncover how transcripts mediate genetic and environmental effects on BP variability. A meta-analysis of results from six studies of global gene expression profiles of BP and hypertension in whole blood was performed in 7017 individuals who were not receiving antihypertensive drug treatment. We identified 34 genes that were differentially expressed in relation to BP (Bonferroni-corrected p<0.05). Among these genes, FOS and PTGS2 have been previously reported to be involved in BP-related processes; the others are novel. The top BP signature genes in aggregate explain 5%–9% of inter-individual variance in BP. Of note, rs3184504 in SH2B3, which was also reported in GWAS to be associated with BP, was found to be a trans regulator of the expression of 6 of the transcripts we found to be associated with BP (FOS, MYADM, PP1R15A, TAGAP, S100A10, and FGBP2). Gene set enrichment analysis suggested that the BP-related global gene expression changes include genes involved in inflammatory response and apoptosis pathways. Our study provides new insights into molecular mechanisms underlying BP regulation, and suggests novel transcriptomic markers for the treatment and prevention of hypertension. **Please note that there are multiple authors for this article therefore only the name of the Federation University Australia affiliate is provided in this record*

DNA copy number variations – Do these big mutations have a big effect on cardiovascular risk?

In simple terms, copy number variations or CNVs are replications or deletions in the DNA which, in humans, changes it from the normal number of two gene copies. These CNVs are caused by inherited or de novo structural changes such as duplications, insertions or deletions of repeated portions of genetic material (Fig. 1). These duplications can vary from one to ten or more copies and range in size from 50 DNA base pairs to several million [1]. Since their discovery in 1987 by Nakamura et al. [2], when they were initially named variable number tandem repeats, many studies have investigated their association with rare and common human diseases. Throughout evolution, some of these changes in copy number were beneficial such as the globin gene number duplication, while others such as the CNVs that cause Huntington's disease were not. In 2004, two landmark studies by Iafrate et al. [3] and Sebat et al. [4] found that large-scale copy-number variations, ranging in size from 100 kb to 2 Mb are common throughout the human genome, and that a high proportion of them are in known genes. These findings roused several association studies between CNVs and diseas

Reduced DNA methylation the human kidney is associated with increased blood pressure

Background and aims: There is increasing evidence that epigenetic modifications such as DNA methylation (addition of a methyl group to DNA (5mC) that leads to altered gene expression) is important to the development of common complex cardiovascular diseases. A recent study found that DNA methylation of blood cells is associated with blood pressure (BP). So far there has been no studies of epigenetic changes in the kidney, which is a key organ in BP regulation and the development of hypertension. The aim of this study was to examine associations between BP and the global methylation profiles of the kidney and blood. Methods and results: We used 93 human renal tissue samples from the TRANScriptome of RenaL HumAN TissueE (TRANSLATE) Study. All samples were collected from healthy, unaffected by cancer pole of the kidney after elective unilateral nephrectomies. DNA was extracted using the DNeasy Qiagen kit according to the protocol from blood and kidney samples. Global methylation was measured by ELISA assay to determine the percentage of 5mC in all DNA samples. A significant negative relationship was found between renal 5mC percentages and systolic (SBP) and diastolic (DBP) blood pressure (SBP r = -0.25, P = 0.018, DBP r = -0.32, P = 0.002). This correlation was also evident when BP is corrected for effects of antihypertensive medications (adjusted SBP P = 0.046, adjusted DBP P = 0.009). Comparatively, there was no significant relationship between 5mC percentage and BP in DNA extracted from peripheral blood leukocytes. Conclusions: We found a significant negative correlation between the percentage of 5mC and BP in the renal DNA samples indicating that reduced DNA methylation leads to increased blood pressure. No such relationship was established in the leukocyte DNA, indicating that blood may not be a good template for analysis of epigenetic modifications in the hypertensive population

Epigenetic modifications in essential hypertension

Essential hypertension (EH) is a complex, polygenic condition with no single causative agent. Despite advances in our understanding of the pathophysiology of EH, hypertension remains one of the world’s leading public health problems. Furthermore, there is increasing evidence that epigenetic modifications are as important as genetic predisposition in the development of EH. Indeed, a complex and interactive genetic and environmental system exists to determine an individual’s risk of EH. Epigenetics refers to all heritable changes to the regulation of gene expression as well as chromatin remodelling, without involvement of nucleotide sequence changes. Epigenetic modification is recognized as an essential process in biology, but is now being investigated for its role in the development of specific pathologic conditions, including EH. Epigenetic research will provide insights into the pathogenesis of blood pressure regulation that cannot be explained by classic Mendelian inheritance. This review concentrates on epigenetic modifications to DNA structure, including the influence of non-coding RNAs on hypertension development. © 2016 by the authors; licensee MDPI, Basel, Switzerland

Noncoding genes on sex chromosomes and their function in sex determination, dosage compensation, male traits, and diseases

The mammalian Y chromosome has evolved in many species into a specialized chromosome that contributes to sex development among other male phenotypes. This function is well studied in terms of protein-coding genes. Less is known about the noncoding genome on the Y chromosome and its contribution to both sex development and other traits. Once considered junk genetic material, noncoding RNAs are now known to contribute to the regulation of gene expression and to play an important role in refining cellular functions. The prime examples are noncoding genes on the X chromosome, which mitigate the differential dosage of genes on sex chromosomes. Here, we discuss the evolution of noncoding RNAs on the Y chromosome and the emerging evidence of how micro, long, and circular noncoding RNAs transcribed from the Y chromosome contribute to sex differentiation. We briefly touch on emerging evidence that these noncoding RNAs also contribute to some other important clinical phenotypes in humans. © 2021 S. Karger AG. All rights reserved

The differences in the prevalence of cardiovascular disease, its risk factors, and achievement of therapeutic goals among urban and rural primary care patients in Poland: Results from the LIPIDOGRAM 2015 study

A nationwide cross-sectional study, LIPIDOGRAM2015, was carried out in Poland in the years 2015 and 2016. A total of 438 primary care physicians enrolled 13,724 adult patients that sought medical care in primary health care practices. The prevalence of hypertension, diabetes mellitus, dyslipidaemia, and CVD were similar in urban and rural areas (49.5 vs. 49.4%; 13.7 vs. 13.1%; 84.2 vs. 85.2%; 14.4 vs. 14.2%, respectively). The prevalence of obesity (32.3 vs. 37.5%, p < 0.01) and excessive waist circumference (77.5 vs. 80.7%, p < 0.01), as well as abdominal obesity (p = 43.2 vs. 46.4%, p < 0.01), were higher in rural areas in both genders. Mean levels of LDL-C (128 vs. 130 mg/dL, p = 0.04) and non-HDL-C (147 vs. 148 mg/dL, p = 0.03) were slightly higher in rural populations. Altogether, 14.3% of patients with CVD from urban areas and 11.3% from rural areas reached LDL <70 mg/dL (p = 0.04). There were no important differences in the prevalence of hypertension, diabetes, dyslipidaemia, and CVD, or in mean levels of blood pressure, cholesterol fractions, glucose, and HbA1c between Polish urban and rural primary care patient populations. A high proportion of patients in cities and an even-higher proportion in rural areas did not reach the recommended targets for blood pressure, LDL-C, and HbA1c, indicating the need for novel CVD-prevention programs. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Fadi Charchar” is provided in this record*

The prevalence of cardiovascular risk factors and cardiovascular disease among primary care patients in Poland : results from the LIPIDOGRAM2015 study

Background and aim: To estimate the prevalence of cardiovascular (CV) disease and CV risk factors among Polish patients. Methods: A nationwide cross-sectional study, LIPIDOGRAM2015, was carried out in Poland in the 4th quarter of 2015 and 1st and 2nd quarters of 2016; 438 primary care physicians enrolled 13,724 adult patients that sought medical care in primary health care practices. Results: Nearly 19% of men and approximately 12% of women had cardiovascular disease (CVD). Over 60% of the recruited patients had hypertension (HTN), >80% had dyslipidaemia and <15% of patients were diagnosed with diabetes (DM). All of these disorders were more frequent in men. In 80% of patients the waist circumference exceed norm for the European population. Less than half of the patients were current smokers or had smoked in the past. Patients with CVD had significantly higher blood pressure and glucose levels but lower low density lipoprotein-cholesterol level. Conclusions: The prevalence of CVD and CV risk factors among patients in Poland is high. CVD is more common in men than in women. The most common CV risk factors are excess waist circumference, dyslipidaemia and HTN. Family physicians should conduct activities to prevent, diagnose early and treat CVD in the primary health care population. © 2021 Elsevier B.V. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Fadi Charchar” is provided in this record*

Hypertension and renin-angiotensin system blockers are not associated with expression of angiotensin-converting enzyme 2 (ACE2) in the kidney

Aims Angiotensin-converting enzyme 2 (ACE2) is the cellular entry point for severe acute respiratory syndrome coronavirus (SARS-CoV-2) - the cause of coronavirus disease 2019 (COVID-19). However, the effect of renin-angiotensin system (RAS)-inhibition on ACE2 expression in human tissues of key relevance to blood pressure regulation and COVID-19 infection has not previously been reported. Methods and results We examined how hypertension, its major metabolic co-phenotypes, and antihypertensive medications relate to ACE2 renal expression using information from up to 436 patients whose kidney transcriptomes were characterized by RNA-sequencing. We further validated some of the key observations in other human tissues and/or a controlled experimental model. Our data reveal increasing expression of ACE2 with age in both human lungs and the kidney. We show no association between renal expression of ACE2 and either hypertension or common types of RAS inhibiting drugs. We demonstrate that renal abundance of ACE2 is positively associated with a biochemical index of kidney function and show a strong enrichment for genes responsible for kidney health and disease in ACE2 coexpression analysis. Conclusion Our results indicate that neither hypertension nor antihypertensive treatment is likely to alter the expression of the key entry receptor for SARS-CoV-2 in the human kidney. Our data further suggest that in the absence of SARS-CoV-2 infection, kidney ACE2 is most likely nephro-protective but the age-related increase in its expression within lungs and kidneys may be relevant to the risk of SARS-CoV-2 infection. © The Author(s) 2020. *Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliates “James Eales", "Priscilla Prestes" and "Fadi Charchar” are provided in this record*