The association between Alu hypomethylation and the severity of hypertension

Introduction

Epigenetic changes that cause genomic instability may be the basis of pathogenic processes of age-associated noncommunicable diseases (NCDs). Essential hypertension is one of the most common NCDs. Alu hypomethylation is an epigenetic event that is commonly found in elderly individuals. Epigenomic alterations are also found in age-associated NCDs such as osteoporosis and diabetes mellitus. Alu methylation prevents DNA from being damaged. Therefore, Alu hypomethylated DNA accumulates DNA damage and, as a result, causes organ function deterioration. Here, we report that Alu hypomethylation is a biomarker for essential hypertension.

Results

We investigated Alu methylation levels in white blood cells from normal controls, patients with prehypertension, and patients with hypertension. The hypertension group possessed the lowest Alu methylation level when classified by systolic blood pressure and diastolic blood pressure (P = 0.0002 and P = 0.0088, respectively). In the hypertension group, a higher diastolic blood pressure and a lower Alu methylation level were observed (r = -0.6278). Moreover, we found that changes in Alu hypomethylation in the four years of follow-up in the same person were directly correlated with increased diastolic blood pressure.

Conclusions

Similar to other age-associated NCDs, Alu hypomethylation is found in essential hypertension and is directly correlated with severity, particularly with diastolic blood pressure. Therefore, Alu hypomethylation may be linked with the molecular pathogenesis of high blood pressure and can be used for monitoring the clinical outcome of this disease.

Social support as a comfort or an encouragement: A systematic review on the contrasting effects of social support on cardiovascular reactivity

PURPOSE

The stress-buffering hypothesis (Cohen & McKay, 1984, Handbook of psychology and health IV: Social psychological aspects of health (pp. 253-256). Hillsdale, NJ: Lawrence Erlbaum) suggests that one way social support enhances health is by attenuating cardiovascular reactivity (CVR) to stress. Research that has tested this hypothesis has reported inconsistent findings. In this review, we systematically reviewed those findings and proposed a dual-effect model of social support and CVR as a potential explanation for the inconsistency in the literature. Specifically, we proposed that when participants are more engaged during a stressor, social support acts primarily as social comfort, attenuating CVR; and when participants are not engaged, social support acts primarily as social encouragement, elevating CVR.

METHODS

We reviewed 22 previous studies that (1) empirically manipulated social support in a stressful situation, (2) measured CVR, and (3) tested a moderator of social support effects on CVR.

RESULTS

Although a majority of studies reported a CVR-mitigating effect of social support resulting in an overall significant combined p-value, we found that there were different effects of social support on CVR when we considered high- and low-engagement contexts. That is, compared to control conditions, social support lowered CVR in more engaging situations but had no significant effect on CVR in less engaging situations.

CONCLUSION

Our results suggest that a dual-effect model of social support effects on CVR may better capture the nature of social support, CVR, and health associations than the buffering hypothesis and emphasize a need to better understand the health implications of physiological reactivity in various contexts. Statement of contribution What is already known on this subject? According to the stress-buffering hypothesis (Cohen & McKay, ), one pathway social support benefits health is through mitigating the physiological arousal caused by stress. However, previous studies that examined the effects of social support on blood pressure and heart rate changes were not consistently supporting the hypothesis. Some studies reported that social support causes elevations in cardiovascular reactivity (CVR) to stress (Anthony & O'Brien, ; Hilmert, Christenfeld, & Kulik, ; Hilmert, Kulik, & Christenfeld, ) and others showed no effect of social support on CVR (Christian & Stoney, ; Craig & Deichert, ; Gallo, Smith, & Kircher, ). What does this study add? When participants were in more engaging conditions, social support decreased CVR relative to no support. When participants were in less engaging conditions, social support did not have a significant effect on CVR. Provide an alternative way to explain the ways social support affects cardiac health.

Emotional reactivity and blood pressure elevations: anxiety as a mediator

There is a strong link between emotional reactivity and hypertension, yet little research to date has examined mediators of this relationship. Ourstudy  investigated the mediating roleof anxiety on the relationship between emotional reactivity and blood pressure elevations. Participants were226 hypertensive patients (93 men and 133 women, Mean age = 53.09, SD = 13.88 years), purposivelydrawn from the General Outpatient Department in University of Calabar Teaching Hospital, Calabar, , Nigeria. .  Measures for data collection were Emotional Reactivity Scale, State Trait Anxiety Inventory, and the Mercury Sphygmomanometer. Hayes PROCESS macro for SPSS which uses a regression-based, path-analytical framework, was employed in analysing the data. Results showed that emotional reactivity was positively associated with blood pressure elevations. Anxiety was positively associated with blood pressure elevations. Anxiety also fully mediated the relationship between emotional reactivity and blood pressure elevations, even after adjusting for the control variables (e.g., age, family history of hypertension, and educational status). The finding suggests that being less emotionally reactive is associated with a decrease in disabling influences of anxiety, thereby contributing to lower levels of mean arterial blood pressure. The findings may be helpful  in improving prevention, control and management of hypertension in healthcare.

Weighed down by stigma: How weight-based social identity threat contributes to weight gain and poor health

Weight stigma is pervasive, and a number of scholars argue that this profound stigma contributes to the negative effects of weight on psychological and physical health. Some lay individuals and health professionals assume that stigmatizing weight can actually motivate healthier behaviors and promote weight loss. However, as we review, weight stigma is consistently associated with poorer mental and physical health outcomes. In this article we propose a social identity threat model elucidating how weight stigma contributes to weight gain and poorer mental and physical health among overweight individuals. We propose that weight-based social identity threat increases physiological stress, undermines self-regulation, compromises psychological health, and increases the motivation to avoid stigmatizing domains (e.g., the gym) and escape the stigma by engaging in unhealthy weight loss behaviors. Given the prevalence of overweight and obesity in the US, weight stigma thus has the potential to undermine the health and wellbeing of millions of Americans.

Maltreated youth display a blunted blood pressure response to an acute interpersonal stressor

Although there is much evidence of hypothalamic-pituitary-adrenal axis dysfunction among individuals who have experienced child maltreatment, dysregulation of the autonomic nervous system (ANS) has received less attention. Understanding the role of the ANS in maltreated children may help clarify how these children respond to subsequent life stress. We explored ANS reactivity among 111 youth (ages 9-14), 34 of whom had experienced verified child maltreatment. ANS activity was assessed via blood pressure-a convenient, noninvasive physiological index-while youth underwent a social stress task. Blood pressure and subjective mood ratings were obtained prior to and following the task. Nonmaltreated youth experienced an increase in systolic blood pressure following the stressor, whereas maltreated youth did not. Self-reported subjective mood worsened for both groups. The current data suggest that children who experienced early stress exposure demonstrate blunted ANS reactivity. Results are discussed in terms of children's healthy adaptations to transient social stressors. In addition, we discuss the cost-effectiveness and benefits of physiological measures such as blood pressure for understanding risk for psychopathology.