Orthostatic Blood Pressure Dysregulation and Polymorphisms of β-Adrenergic Receptor Genes in Hypertensive Patients

Neuroendocrine Effects on the Risk of Metabolic Syndrome in Children

The endocrine and nervous systems reciprocally interact to manage physiological individual functions and homeostasis. The nervous system modulates hormone release through the hypothalamus, the main cerebrally specialized structure of the neuroendocrine system. The hypothalamus is involved in various metabolic processes, administering hormone and neuropeptide release at different levels. This complex activity is affected by the neurons of various cerebral areas, environmental factors, peripheral organs, and mediators through feedback mechanisms. Therefore, neuroendocrine pathways play a key role in metabolic homeostasis control, and their abnormalities are associated with the development of metabolic syndrome (MetS) in children. The impaired functioning of the genes, hormones, and neuropeptides of various neuroendocrine pathways involved in several metabolic processes is related to an increased risk of dyslipidaemia, visceral obesity, insulin resistance, type 2 diabetes mellitus, and hypertension. This review examines the neuroendocrine effects on the risk of MetS in children, identifying and underlying several conditions associated with neuroendocrine pathway disruption. Neuroendocrine systems should be considered in the complex pathophysiology of MetS, and, when genetic or epigenetic mutations in "hot" pathways occur, they could be studied for new potential target therapies in severe and drug-resistant paediatric forms of MetS.

Monoamino oxidase alleles correlate with the presence of essential hypertension among hypogonadic patients

Background

Monoamine oxidase (MAO) activity has been traditionally implicated in blood pressure through its effects on biogenic amine levels such as catecholamines, serotonin, and dopamine. Nowadays, this role is considered relegated to side‐effects such as orthostatic hypotension and/or hypertensive crisis derived from MAO‐inhibitory treatments in patients with psychiatric disease.

Methods

In the present work we have found an association between a polymorphic variant of MAOB gene and arterial hypertension in obese hypogonadic patients. The study cases comprised a series of 219 nondiabetic males with a body mass index ≥30 kg/m² and aged <45 years. Hypogonadism was defined as subnormal testosterone concentrations, when free testosterone values ranged <65 pg/ml.

Results

MAOB rs3027452‐A allele carriers were significantly over‐represented among hypertensive (HT) patients (25.49%) in comparison to either the non‐HT patients (10%, OR = 3.079 CI₉₅ [1.364–6.952], p = .005, Chi‐square test) and the control population series of nonobese nor hypogonadic males (also 10%, p = .003 Chi‐square test). Upon adjusted, an independent association was shown with the hypogonadic group with hypertension when compared with nonhypertensive hypogonadics (Beta = 3.653, p = .005). When quantitative analysis was performed, hypertensive patients harboring rs3027452‐A allele showed higher systolic blood pressure values (p = .038, Mann–Whitney U‐test) as well as an increased Systolic‐Diastolic range despite following HT treatment (∆mmHg 54 vs. 48 for rs3027452‐A and rs3027452‐G respectively, p‐value .019, Mann–Whitney U‐test). Previous studies on MAOB revealed that rs3027452‐A allele has been correlated to a lower activity of the enzyme, what gives a functional evidence over our observation.

Conclusion

If this result could be extrapolated to other hypertensive patient groups, it would implicate a review of the markers and therapeutic targets on human hypertension.

Genomics of Cardiovascular Measures of Autonomic Tone

The autonomic nervous system exerts broad control over the involuntary functions of the human body through complex equilibrium between sympathetic and parasympathetic tone. Imbalance in this equilibrium is associated with a multitude of cardiovascular outcomes, including mortality. The cardiovascular static state of this equilibrium can be quantified using physiological parameters such as heart rate (HR), blood pressure, and by spectral analysis of HR variability. Here, we review the current state of knowledge of the genetic background of cardiovascular measurements of autonomic tone. For most parameters of autonomic tone, a large portion of variability is explained by genetic heritability. Many of the static parameters of autonomic tone have also been studied through candidate-gene approach, yielding some insight into how genotypes of adrenergic receptors affect variables such as HR. Genome-wide approaches in large cohorts similarly exist for static variables such as HR and blood pressure but less is known about the genetic background of the dynamic and more specific measurements, such as HR variability. Furthermore, because most autonomic measures are likely polygenic, pathway analyses and modeling of polygenic effects are critical. Future work will hopefully explain the control of autonomic tone and guide individualized therapeutic interventions.

Link between depression and cardiovascular diseases due to epigenomics and proteomics: Focus on energy metabolism

Major depression is the most common mental disorder and a leading cause of years lived with disability. In addition to the burden attributed to depressive symptoms and reduced daily life functioning, people with major depression are at increased risk of premature mortality, particularly due to cardiovascular diseases. Several studies point to a bi-directional relation between major depression and cardiovascular diseases, thereby indicating that both diseases may share common pathophysiological pathways. These include lifestyle factors (e.g. physical activity, smoking behavior), dysfunctions of endocrine systems (e.g. hypothalamus-pituitary adrenal axis), and a dysbalance of pro- and anti-inflammatory factors. Furthermore, recent research point to the role of epigenomic and proteomic factors, that are reviewed here with a particular focus on the mitochondrial energy metabolism.

A comparison of the genetic and clinical risk factors for arterial hypertension between indigenous and non-indigenous people of the Shoria Mountain Region

BACKGROUND

This study investigated the non-genetic and genetic risk factors for arterial hypertension (AH) in two ethnic groups living in the Mountain Shoria region: Shors and non-indigenous people.

METHODS

Clinical and epidemiological study of compactly living population in the remote areas of the Mountain Shoria (Orton, Ust-Kabyrza, Sheregesh settlements, Kemerovo region). 1178 residents of these settlements were surveyed with the help of continuous sampling method; the sample consisted of adults (18 years and older).

RESULTS

The prevalence of AH was lower in Shors (39.9% vs. 46.1%), mainly due to differences between men from the different groups: 33.2% vs. 45.8%. The percentage of people with AH, overweight, and obesity (including transabdominal obesity) in the different age groups did not differ between ethnicities. We identified statistically significant differences in the prevalence of hypertension according the two ethic groups according to age, body weight, and abdominal obesity. I/D ACE and ADRA2B polymorphisms were associated with AH. In DD ACE and DD ADRA2B carriers, there were fewer hypertensive patients in Shors than in non-indigenous people: 40.6% vs. 58.6% and 38.3% vs. 64.0%, respectively. In DD ACE carriers, more Shors had AH (60.0% vs. 37.1%).

CONCLUSION

Among Shors, the following factors increased AH risk: female sex, age, hypercholesterolemia, hyperbetacholesterinemia, hypertriglyceridemia, obesity (including transabdominal obesity), glucose intolerance, and the DD ACE, CT MTHFR, and AA ADRB1 genotypes; among the non-indigenous population, the main factors were age, hypercholesterolemia, hyperbetacholesterinemia, hypoalfacholesterinemia, hypertriglyceridemia, obesity (including transabdominal obesity), and ID ACE genotype.

Neuroendocrinological and Epigenetic Mechanisms Subserving Autonomic Imbalance and HPA Dysfunction in the Metabolic Syndrome

Impact of environmental stress upon pathophysiology of the metabolic syndrome (MetS) has been substantiated by epidemiological, psychophysiological, and endocrinological studies. This review discusses recent advances in the understanding of causative roles of nutritional factors, sympathomedullo-adrenal (SMA) and hypothalamic-pituitary adrenocortical (HPA) axes, and adipose tissue chronic low-grade inflammation processes in MetS. Disturbances in the neuroendocrine systems for leptin, melanocortin, and neuropeptide Y (NPY)/agouti-related protein systems have been found resulting directly in MetS-like conditions. The review identifies candidate risk genes from factors shown critical for the functioning of each of these neuroendocrine signaling cascades. In its meta-analytic part, recent studies in epigenetic modification (histone methylation, acetylation, phosphorylation, ubiquitination) and posttranscriptional gene regulation by microRNAs are evaluated. Several studies suggest modification mechanisms of early life stress (ELS) and diet-induced obesity (DIO) programming in the hypothalamic regions with populations of POMC-expressing neurons. Epigenetic modifications were found in cortisol (here HSD11B1 expression), melanocortin, leptin, NPY, and adiponectin genes. With respect to adiposity genes, epigenetic modifications were documented for fat mass gene cluster APOA1/C3/A4/A5, and the lipolysis gene LIPE. With regard to inflammatory, immune and subcellular metabolism, PPARG, NKBF1, TNFA, TCF7C2, and those genes expressing cytochrome P450 family enzymes involved in steroidogenesis and in hepatic lipoproteins were documented for epigenetic modifications.

Arterial Stiffness, Central Pulsatile Hemodynamic Load, and Orthostatic Hypotension

The association between central pulsatile hemodynamic load, arterial stiffness, and orthostatic hypotension (OH) is unclear. The authors recruited 1099 participants from the community. Questionnaire, physical examination, and laboratory tests were performed. To assess the correlation between central pulsatile hemodynamic load, arterial stiffness, and OH, multiple logistic regression analysis was performed, and the discriminatory power was assessed by the area under the receiver operating curve. The prevalence of OH in this population was 5.6%. After adjusting for potential confounders, brachial-ankle pulse wave velocity (BaPWV) was significantly and positively correlated with OH in both the hypertension and nonhypertension groups (all P<.05), while central systolic blood pressure (CSBP) was only significantly associated with OH in the hypertension subgroup. In addition, BaPWV seemed to have a better discriminatory power than CSBP in both subgroups. BaPWV appears to be a better indicator of OH than CSBP in routine clinical practice.

Medical and Psychiatric Causes of Episodic Vestibular Symptoms

Dizziness and vertigo are among the most common presenting patient complaints in ambulatory settings. Specific vestibular causes are often not immediately identifiable. The first task of the clinician is to attempt to rule in specific vestibular disorders, such as benign paroxysmal positional vertigo through physical examination, diagnostic testing, and history taking. A large proportion of patients with dizziness and vertigo will not be easily classified or confirmed as having a specific vestibular cause. As with any undifferentiated patient, the focus in this setting is to attempt to exclude serious or threatening causes.