Effects of 5HTTLPR on cardiovascular response to an emotional stressor

Frontiers and Hotspots Evolution in Psycho-cardiology: A Bibliometric Analysis From 2004 to 2022

In the last 20 years, research on the topic of psycho-cardiology has gradually entered the public eye, with more innovations and applications of evidence-based medical research, biological mechanism research, and guideline consensus in the field of psycho-cardiology. This study uses a bibliometric approach to visualize and analyze the literature within the field of psycho-cardiology over the last 20 years to visualize the development process, research hotspots, and cutting-edge trends in clinical practice, mechanisms, and management strategies related to psycho-cardiology. Quantitative description and evaluation of 409 articles published in the field from 2004-2022 were conducted using CiteSpace and VOSviewer, to provide a theoretical reference for the development of psycho-cardiology.

Association of 5-HTTLPR/rs25531 with depressive symptoms in patients with coronary heart disease: A prospective study

BACKGROUND

5-HTTLPR/rs25531 is suspected to be involved in the pathogenesis of both coronary heart disease (CHD)¹ and depression. We aimed to investigate the role of 5-HTTLPR/rs25531 in the development of depressive symptoms among CHD patients in a longitudinal design.

METHODS

N = 265 participants with CHD diagnosis were included while hospitalized in a department of cardiology and genotyped for the 5-HTTLPR/rs25531. Depressive symptoms were measured using the Patient Health Questionnaire (PHQ-9)⁷ at baseline and after 6 and 12 months. Binary logistic regression models were used to analyze the association of 5-HTTLPR/rs25531 with the prevalence of depressive symptoms at each time point as well as with the incidence and persistence of depressive symptoms at follow-up.

RESULTS

"L_AL_A" genotype was associated with a higher prevalence of depressive symptoms 12 months after study inclusion. "L_AL_A" genotype was associated with a higher incidence of depressive symptoms 6 and 12 months after study inclusion. There was no association of 5-HTTLPR/rs25531 with the persistence of depressive symptoms.

LIMITATIONS

Inclusion criteria did not demand a particular cardiac event at baseline, which aggravated the interpretation of the time-specific results. The majority of the participants was of male gender which could cause bias. The present study only vaguely differentiated between ethnical groups which might cause bias regarding nationality-dependent allele distributions.

CONCLUSION

The present study suggests a time-dependent association of the "L_AL_A" genotype with depressive symptoms in CHD patients. 5-HTTLPR/rs25531 might be an important marker to detect risk groups for later onset depressive symptoms among CHD patients.

Meta-analysis of 5-hydroxytryptamine transporter gene promoter region polymorphism and post-stroke depression

OBJECTIVE

To investigate the relationship between 5-hydroxytryptamine transporter gene promoter region (5-HTTLPR) gene polymorphism and post-stroke depression (PSD).

METHODS

We searched the CNKI, China Science and Technology Journal, China WanFang, PubMed, Embase, and Web of Science databases for studies of the relationship between 5-HTTLPR polymorphism and PSD. Data were evaluated using Stata software.

RESULTS

The L allele was significantly related to the S allele (OR = 0.57, 95% confidence interval (CI) 0.49-0.65). The dominant genotype LL + LS was related to SS (OR = 0.48, 95%CI 0.39-0.59), the recessive genotype LL was related to LS + SS (OR = 0.39, 95%CI: 0.30-0.51), the homozygous genotype LL was related to SS (OR = 0.24, 95%CI 0.18-0.33), and the heterozygous genotype LS was related to SS (OR = 0.55, 95 CI 0.44-0.68). All the differences were significant. Ethnicity subgroup analysis showed significant differences among the five genotypes in both Asians and Caucasians. Hardy-Weinberg equilibrium (HWE) subgroup analysis showed that, after removal of a non-HWE-conforming control group, all five genotypes were significant and genotypes LL, LS + LL, and LS and L allele had beneficial effects on recovery from PSD.

CONCLUSION

5-HTTLPR gene polymorphism is strongly associated with PSD, and the LL, LS + LL, and LS genotypes and L allele may protect against this condition.

Association of polymorphisms in serotonin and nitric oxide genes with clinical outcome of dengue in Brazilian northeast population

Serotonin and nitric oxide seem to be involved in Dengue virus infection. The aim of this study was to investigate if SNPs in serotonin and nitric oxide are associated with dengue severity. A retrospective case-control study was conducted, with groups of dengue fever (DF; n = 78) and dengue hemorrhagic fever patients (DHF; n = 49). Genotyping was performed using qPCR and PCR. The power of the sample size was calculated by G*power software. The heterozygous SL for 5-HTTLPR SNP was significantly correlated with protection against progression to DHF in the codominant SS/SL/LL (OR = 0.22, 95% CI = 0.06-0.81, p = 0.011) and overdominant models SL vs SS + LL (OR = 0.19, 95% CI = 0.06-0.65, p = 0.003). For the ENOS (rs1799983) SNP, the genotype GT was positively associated with protection for development of the clinical form in DHF compared to dengue fever (OR = 0.39, 95% CI = (0.13-1.14), p = 0.0058) in codominant GG/GT/TT and overdominant model GT vs GG + TT (OR = 0.35, 95% CI = (0.12-1.02), p = 0.04). To our knowledge, this is the first study to identify the association of the serotonin and nitric oxide SNPs with dengue severity.

The genetics of anxiety-related negative valence system traits

NIMH's Research Domain Criteria (RDoC) domain of negative valence systems (NVS) captures constructs of negative affect such as fear and distress traditionally subsumed under the various internalizing disorders. Through its aims to capture dimensional measures that cut across diagnostic categories and are linked to underlying neurobiological systems, a large number of phenotypic constructs have been proposed as potential research targets. Since "genes" represent a central "unit of analysis" in the RDoC matrix, it is important for studies going forward to apply what is known about the genetics of these phenotypes as well as fill in the gaps of existing knowledge. This article reviews the extant genetic epidemiological data (twin studies, heritability) and molecular genetic association findings for a broad range of putative NVS phenotypic measures. We find that scant genetic epidemiological data is available for experimentally derived measures such as attentional bias, peripheral physiology, or brain-based measures of threat response. The molecular genetic basis of NVS phenotypes is in its infancy, since most studies have focused on a small number of candidate genes selected for putative association to anxiety disorders (ADs). Thus, more research is required to provide a firm understanding of the genetic aspects of anxiety-related NVS constructs. © 2016 Wiley Periodicals, Inc.

Population differences in associations of serotonin transporter promoter polymorphism (5HTTLPR) di- and triallelic genotypes with blood pressure and hypertension prevalence

Based on prior research finding the 5HTTLPR L allele associated with increased cardiovascular reactivity to laboratory stressors and increased risk of myocardial infarction, we hypothesized that the 5HTTLPR L allele will be associated with increased blood pressure (BP) and increased hypertension prevalence in 2 large nationally representative samples in the United States and Singapore.

METHODS

Logistic regression and linear models tested associations between triallelic (L'S', based on rs25531) 5HTTLPR genotypes and hypertension severity and mean systolic and diastolic blood pressure (SBP and DBP) collected during the Wave IV survey of the National Longitudinal Study of Adolescent to Adult Health (Add Health, N=11,815) in 2008-09 and during 2004-07 in 4196 Singaporeans.

RESULTS

In US Whites, L' allele carriers had higher SBP (0.9 mm Hg, 95% CI=0.26-1.56) and greater odds (OR=1.23, 95% CI=1.10-1.38) of more severe hypertension than those with S'S' genotypes. In African Americans, L' carriers had lower mean SBP (-1.27mm Hg, 95% CI=-2.53 to -0.01) and lower odds (OR = 0.78, 95% CI=0.65-0.94) of more severe hypertension than those with the S'S' genotype. In African Americans, those with L'L' genotypes had lower DBP (-1.13mm Hg, 95% CI=-2.09 to -0.16) than S' carriers. In Native Americans, L' carriers had lower SBP (-6.05mm Hg, 95% CI=-9.59 to -2.51) and lower odds of hypertension (OR = 0.34, 95% CI=0.13-0.89) than those with the S'S' genotype. In Asian/Pacific Islanders those carrying the L' allele had lower DBP (-1.77mm Hg, 95% CI=-3.16 to -0.38) and lower odds of hypertension (OR = 0.68, 95% CI=0.48-0.96) than those with S'S'. In the Singapore sample S' carriers had higher SBP (3.02mm Hg, 95% CI=0.54-5.51) and DBP (1.90mm Hg, 95% CI=0.49-3.31) than those with the L'L' genotype.

CONCLUSIONS

These findings suggest that Whites carrying the L' allele, African Americans and Native Americans with the S'S' genotype, and Asians carrying the S' allele will be found to be at higher risk of developing cardiovascular disease and may benefit from preventive measures.

Nonsynonymous HTR2C polymorphism predicts cortisol response to psychosocial stress II: Evidence from two samples

The 5-HT2C receptor is the primary serotonin receptor located in the corticotrophin releasing hormone (CRH) neurons of the hypothalamus. These neurons initiate the signaling cascade that culminates in cortisol release. Therefore, genetic variation in the 5-HT2C receptor gene (HTR2C) is a prime candidate for affecting cortisol reactivity to stress. Accordingly, we examined the association of a nonsynonymous polymorphism (Cys23Ser; rs6318) in HTR2C with stress reactivity in two Trier Social Stress Tests conducted at separate sites. In both Study 1 (N=128) and Study 2 (N=185), Cys23 homozygous females and hemizygous males had greater cortisol reactivity. There was no relation between this polymorphism and self-reported affective response (Studies 1 and 2) or cardiovascular reactivity (Study 2). Additionally, the short/short genotype of a polymorphism (5-HTTLPR) in the serotonin transporter gene was associated with greater cortisol reactivity in Study 1 as well as in Study 2 (previously reported). The Cys23Ser polymorphism and the 5-HTTLPR were independently associated with cortisol reactivity in both studies. These findings emphasize the important role of genetic variation in the serotonin system on regulating cortisol reactivity to social evaluative stress. Comparison of the present associations with those of prior studies underscores the likely importance of situational and psychological factors in determining the direction and magnitude of the association between genotype and phenotype.

Genetic and environmental modulation of neurotrophic and anabolic stress response: Counterbalancing forces

The serotonin transporter genetic variant 5HTTLPR influences activation and feedback control of the hypothalamic-pituitary-adrenal axis, and has been shown to influence the effect of stressful life events on behavioral health. We recently reported that 5HTTLPR modulates cortisol response in healthy military men exposed to intense stress. Less is known of its combined effects with environmental factors in this context, or of its effect on neuroprotective stress responses. In this follow-up study, we examined the unique and combined effects of 5HTTLPR and prior trauma exposure on neuroprotective (salivary nerve growth factor [sNGF]), anabolic (dehydroepiandrosterone sulfate [DHEAS] and testosterone), and catabolic (cortisol) stress responses. Ninety-three healthy, active-duty military men were studied before, during, and 24h after a stressful 12-day survival course. Distinct and interactive effects of 5HTTLPR long allele carriage [L] versus homozygous short allele carriage [SS]) and prior trauma exposure (low versus high) were evaluated, after which a priori group comparisons were performed between hypothesized high resilience (L/low) and low resilience (SS/high) groups. For sNGF, L/low produced the greatest sNGF throughout stress exposure while SS/high demonstrated the smallest; L/high and SS/low bisected these two extremes and were nearly identical to each other (i.e., SS/high < SS/low = L/high < L/low). Thus, 5HTTLPR and prior trauma exposure demonstrated counterbalancing (additive) forces. Similar patterns were found for DHEAS. To our knowledge, this study is the first to report counterbalancing genetic and environmental effects on novel biomarkers related to resilience in humans exposed to real-world stress. These findings have profound implications for health, performance and training in high-stress occupational settings.

Blunted autonomic reactivity to pharmacological panic challenge under long-term escitalopram treatment in healthy men

BACKGROUND

Central serotonergic pathways influence brain areas involved in vagal cardiovascular regulation and, thereby, influence sympathetic efferent activity. Selective serotonin reuptake inhibitors (SSRIs) affect multiple serotonergic pathways, including central autonomic pathways. However, only a few studies have assessed SSRI-mediated effects on autonomic reactivity in healthy individuals using heart rate variability (HRV).

METHODS

The present study assessed the influence of long-term treatment with escitalopram (ESC) on autonomic reactivity to an intravenous application of 50 µg cholecystokinin tetrapeptide (CCK-4) in 30 healthy young men using a double-blind, placebo (PLA)-controlled, randomized, within-subject cross-over design. Main outcome measures were time- and frequency-domain HRV parameters, assessed at both baseline and immediately after CCK-4 application.

RESULTS

Results showed substantial effects for the treatment × CCK-4 challenge interaction with respect to heart rate (p < 0.001; pη(2) = 0.499), SDNN (p < 0.001; pη(2) = 576), RMSSD (p = 0.015; pη(2) = 194), NN50% (p = 0.008; pη(2) = 0.224), and LF% (p = 0.014; pη(2) = 0.196), and moderate effects with respect HF% (p = 0.099; pη(2) = 0.094), with PLA subjects showing a higher increase in HR and SDNN and a higher decrease in RMSSD, NN50, LF and HF than subjects in the ESC condition. Thus, ESC treatment significantly blunted the autonomic reactivity to CCK-4. Secondary analysis indicated no effect of the 5-HTTLPR polymorphism on CCK-4-induced autonomic response.

CONCLUSIONS

Our results support findings suggesting an effect of SSRI treatment on autonomic regulation and provide evidence that ESC treatment is associated with blunted autonomic reactivity in healthy men.

Epigenetic plasticity following early stress predicts long-term health outcomes in rhesus macaques

Early life stress has been linked with poorer lifelong health outcomes across species, including modern and ancient humans. Epigenetic mechanisms, such as DNA methylation patterning of stress pathway genes in stress-responsive tissue, may play an important role in the long-term health effects of early stress across species. The relationships among early maternal care quality, DNA methylation patterns in a candidate stress pathway gene (serotonin transporter, 5-HTT) linked region in blood DNA, and adult health outcomes were examined in male and female rhesus macaques, excellent models of human health. Male (n = 12) and female (n = 32) infants were observed with their mothers for the first 12 weeks of life and 5-HTT linked DNA methylation was measured in blood at 12 weeks of age. Approximately 8 years later, health-related measures were collected for the 25 animals (6 male and 19 female) that were available for study. Health composite scores were generated using factor analysis of body condition, body weight, and diagnosis of diarrhea during the lifespan. Better quality maternal care predicted lower 5-HTT linked methylation at 12 weeks of age. Lower 5-HTT methylation, in turn, predicted better health composite scores in adulthood, including better body condition, greater body weight and absence of lifetime diarrhea. These data suggest that the epigenetic regulation of 5-HTT may be one biomarker of the link between early stress and lifetime health trajectories. Future studies will examine whether epigenetic signatures in modern and ancient human DNA lends insight into stress and health and natural selection in human evolutionary history.

The 5-HTTLPR genotype modulates heart rate variability and its adjustment by pharmacological panic challenge in healthy men

Abnormal serotonin transporter (5-HTT) function and autonomic nervous system (ANS) dysregulation has been proposed in panic disorder. However, in contrast to hypothalamo-pituitary-adrenocortical (HPA) functioning, ANS reactivity during panic response has yet not been investigated in humans with respect to the 5-HTT genotype. The present study assessed the influence of challenging by cholecystokinin tetrapeptide (CCK-4) on heart rate variability (HRV) measures, to monitor autonomic reactivity and its relationship to 5-HTT-linked polymorphic region (5-HTTLPR) genotypes. We hypothesized substantial effects of the 5-HTTLPR genotype on autonomic reactivity. We studied 30 healthy young men, 15 of each with the long/long (l/l) or short/short (s/s) genotype for the 5-HTTLPR. All participants received an intravenous application of 50 μg CCK-4. HRV measures were assessed in both groups at baseline and immediately after CCK-4 application. Our results indicated lower parasympathetic activity in s/s carriers during baseline, time and frequency domain measures. CCK-4 application significantly enhanced the sympathetic tone in both groups, leading to diminished group differences. A significant treatment by genotype effect indicated reduced autonomic reactivity to CCK-4 challenge in the s/s compared to l/l carriers. Our findings show enhanced sympathetic and/or diminished cardiac vagal activity under basal conditions and blunted autonomic reactivity in s/s vs. l/l carriers. Our study provides novel data supporting claims that the s/s genotype represents a genetic vulnerability factor associated with inadequate hyporeactivity to stress and extends current knowledge on the impact of the central serotonergic activity on the sympathoadrenal pathway.

Perceived stress is associated with subclinical cerebrovascular disease in older adults

OBJECTIVE

To examine the association of perceived stress with magnetic resonance imaging (MRI) markers of subclinical cerebrovascular disease in an elderly cohort.

METHODS

Using a cross-sectional study of a community-based cohort in Chicago, 571 adults (57% women; 58.1% African American; 41.9% non-Hispanic white; mean [SD] age: 79.8 [5.9] years) from the Chicago Health and Aging Project, an epidemiologic study of aging, completed questionnaires on perceived stress, medical history, and demographics as part of an in-home assessment and 5 years later underwent a clinical neurologic examination and MRI of the brain. Outcome measures were volumetric MRI assessments of white matter hyperintensity volume (WMHV), total brain volume (TBV), and cerebral infarction.

RESULTS

Stress was measured with six items from the Perceived Stress Scale (PSS); item responses, ranging from never (0) to often (3), were summed to create an overall stress score (mean [SD]: 4.9 [3.3]; range: 0-18). Most participants had some evidence of vascular disease on MRI, with 153 participants (26.8%) having infarctions. In separate linear and logistic regression models adjusted for age, sex, education, race, and time between stress assessment and MRI, each one-point increase in PSS score was associated with significantly lower TBV (coefficient = -0.111, SE = 0.049, t[563] = -2.28, p = 0.023) and 7% greater odds of infarction (odds ratio: 1.07; 95% confidence interval: 1.01, 1.13; Wald χ(2)[1] = 4.90; p = 0.027). PSS scores were unrelated to WMHV. Results were unchanged with further adjustment for smoking, body mass index, physical activity, history of heart disease, stroke, diabetes, hypertension, depressive symptoms, and dementia.

CONCLUSIONS

Greater perceived stress was significantly and independently associated with cerebral infarction and lower brain volume assessed 5 years later in this elderly cohort.

5-HTTLPR and anxiety modulate brain-heart covariation

To date, little is known about genes affecting the interplay of brain and heart activity. Because serotonin (5-HT) is involved in corticovagal neurotransmission, we tested whether the 5-HT transporter polymorphism 5-HTTLPR affects brain-heart covariation. Further, associations with neuroticism/anxiety (NANX) were tested, as anxiety is related to 5-HT and neurogenic changes of heart period (HP). N = 168 participants performed a time-estimation task while EEG and HP were recorded. Brain-heart covariation was measured using time-lagged within-subject correlations of centromedial feedback-evoked single-trial EEG at 300 ms and subsequent changes of HP. EEG-HP correlations were higher in 5-HTTLPR long allele carriers. Moreover, after negative feedback, EEG-HP correlations and feedback-related negativity amplitudes independently correlated with NANX. The results indicate that individual differences in brain-heart covariation relate to 5-HT and NANX.