Circadian rhythms in ischaemic heart disease: key aspects for preclinical and translational research: position paper of the ESC working group on cellular biology of the heart

Exposure to ambient air pollutants during circadian syndrome and subsequent cardiovascular disease and its subtypes and death: A trajectory analysis

BACKGROUND

The association between exposure to air pollutants and cardiovascular disease (CVD) trajectory in individuals with circadian syndrome remains inconclusive.

METHODS

The individual exposure levels of air pollutants, including particulate matter (PM) with aerodynamic diameter ≤ 2.5 μm (PM2.5), PM with aerodynamic diameter ≤ 10 μm (PM10), PM2.5 absorbance, PM with aerodynamic diameter between 2.5 μm and 10 μm, nitrogen dioxide (NO2), nitrogen oxides (NOx), and air pollution score (overall air pollutants exposure), were estimated for 48,850 participants with circadian syndrome from the UK Biobank. Multistate regression models were employed to estimate associations between exposure to air pollutants and trajectories from circadian syndrome to CVD/CVD subtypes (including coronary heart disease [CHD], atrial fibrillation [AF], heart failure [HF], and stroke) and death. Mediation roles of CVD/CVD subtypes in the associations between air pollutants and death were evaluated.

RESULTS

After a mean follow-up time over 12 years, 12,570 cases of CVD occurred, including 8192 CHD, 1693 AF, 1085 HF, and 1600 stroke cases. In multistate model, per-interquartile range increment in PM2.5 (hazard ratio: 1.08; 95 % confidence interval: 1.06, 1.10), PM10 (1.04; 1.01, 1.06), PM2.5 absorbance (1.04; 1.02, 1.06), NO2 (1.07; 1.03, 1.11), NOx (1.08; 1.04, 1.12), or air pollution score (1.06; 1.03, 1.08) was associated with trajectory from circadian syndrome to CVD. Significant associations between the above-mentioned air pollutants and trajectories from circadian syndrome and CVD to death were observed. CVD, particularly CHD, significantly mediated the associations of PM2.5, NO2, NOx, and air pollution score with death.

CONCLUSIONS

Long-term exposure to air pollutants during circadian syndrome was associated with subsequent CVD and death. CHD emerged as the most prominent CVD subtype in CVD progression driven by exposure to air pollutants during circadian syndrome. Our study highlights the importance of controlling air pollutants exposure and preventing CHD in people with circadian syndrome.

Impact of Environmental Factors on Hypertension and Associated Cardiovascular Disease

Hypertension is the primary cause of cardiovascular diseases and is responsible for nearly 9 million deaths worldwide annually. Increasing evidence indicates that in addition to pathophysiologic processes, numerous environmental factors, such as geographic location, lifestyle choices, socioeconomic status, and cultural practices, influence the risk, progression, and severity of hypertension, even in the absence of genetic risk factors. In this review, we discuss the impact of some environmental determinants on hypertension. We focus on clinical data from large population studies and discuss some potential molecular and cellular mechanisms. We highlight how these environmental determinants are interconnected, as small changes in one factor might affect others, and further affect cardiovascular health. In addition, we discuss the crucial impact of socioeconomic factors and how these determinants influence diverse communities with economic disparities. Finally, we address opportunities and challenges for new research to address gaps in knowledge on understanding molecular mechanisms whereby environmental factors influence development of hypertension and associated cardiovascular disease.

Sleep, circadian rhythm characteristics, and melatonin levels in later life adults with and without coronary artery disease

STUDY OBJECTIVES

The purpose of this study was to conduct a comprehensive assessment of sleep and circadian rhythms in individuals with and without coronary artery disease (CAD).

METHODS

This was a cross-sectional study. Participants were 32 individuals, mean age = 70.9, female 46.9%, 19 with CAD, and 13 without CAD. We assessed sleep quality and 24-hour rest-activity rhythms for 14 days using wrist actigraphy and self-report measures, and circadian rhythm using dim light melatonin onset.

RESULTS

Melatonin levels prior to habitual bedtime were significantly lower in individuals with CAD than in those without CAD (median area under the curve = 12.88 vs 26.33 pg/ml × h, P = .049). The median circadian timing measured by dim light melatonin onset was the same for the 2 groups with 20:26 [hours:minutes] for individuals with CAD and 19:53 for the control group (P = .64, r = .14). Compared to the control group, the CAD group had significantly lower amplitude (P = .03, r =-.48), and lower overall rhythmicity (pseudo-F-statistic P = .004, r = -.65) in their 24-hour rest-activity rhythms.

CONCLUSIONS

This is one of the first studies to comprehensively assess both sleep and circadian rhythm in individuals with CAD. Compared to non-CAD controls, individuals with CAD had lower levels of melatonin prior to habitual bedtime and a lower 24-hour rest-activity rhythm amplitude and overall rhythmicity. Future studies using larger sample sizes should further investigate the possibility of suppressed circadian rhythmicity in individuals with CAD.

CITATION

Moon C, Benson CJ, Albashayreh A, Perkhounkova Y, Burgess HJ. Sleep, circadian rhythm characteristics, and melatonin levels in later life adults with and without coronary artery disease. J Clin Sleep Med. 2023;19(2):283-292.

Vascular redox signaling, eNOS uncoupling and endothelial dysfunction in the setting of transportation noise exposure or chronic treatment with organic nitrates

SIGNIFICANCE

Cardiovascular disease and drug-induced health side effects are frequently associated with - or even caused by - an imbalance between the concentrations of reactive oxygen and nitrogen species (RONS) and antioxidants respectively determining the metabolism of these harmful oxidants.

RECENT ADVANCES

According to the "kindling radical" hypothesis, initial formation of RONS may further trigger the additional activation of RONS formation under certain pathological conditions. The present review will specifically focus on a dysfunctional, uncoupled endothelial nitric oxide synthase (eNOS) caused by RONS in the setting of transportation noise exposure or chronic treatment with organic nitrates, especially nitroglycerin. We will further describe the various "redox switches" that are proposed to be involved in the uncoupling process of eNOS.

CRITICAL ISSUES

In particular, the oxidative depletion of tetrahydrobiopterin (BH4), and S-glutathionylation of the eNOS reductase domain will be highlighted as major pathways for eNOS uncoupling upon noise exposure or nitroglycerin treatment. In addition, oxidative disruption of the eNOS dimer, inhibitory phosphorylation of eNOS at threonine or tyrosine residues, redox-triggered accumulation of asymmetric dimethylarginine (ADMA) and L-arginine deficiency will be discussed as alternative mechanisms of eNOS uncoupling.

FUTURE DIRECTIONS

The clinical consequences of eNOS dysfunction due to uncoupling on cardiovascular disease will be summarized also providing a template for future clinical studies on endothelial dysfunction caused by pharmacological or environmental risk factors.

Insight on Cardiac Chronobiology and Latest Developments of Chronotherapeutic Antihypertensive Interventions for Better Clinical Outcomes

Cardiac circadian rhythms are an important regulator of body functions, including cardiac activities and blood pressure. Disturbance of circadian rhythm is known to trigger and aggravate various cardiovascular diseases. Thus, modulating the circadian rhythm can be used as a therapeutic approach to cardiovascular diseases. Through this work, we intend to discuss the current understanding of cardiac circadian rhythms, in terms of quantifiable parameters like BP and HR. We also elaborate on the molecular regulators and the molecular cascades along with their specific genetic aspects involved in modulating circadian rhythms, with specific reference to cardiovascular health and cardiovascular diseases. Along with this, we also presented the latest pharmacogenomic and metabolomics markers involved in chronobiological control of the cardiovascular system along with their possible utility in cardiovascular disease diagnosis and therapeutics. Finally, we reviewed the current expert opinions on chronotherapeutic approaches for utilizing the conventional as well as the new pharmacological molecules for antihypertensive chronotherapy.

Cardiometabolic health impacts of time-restricted eating: implications for type 2 diabetes, cancer and cardiovascular diseases

PURPOSE OF REVIEW

Time-restricted eating (TRE) entails consuming energy intake within a 4- to 10-h window, with the remaining time spent fasting. Although studies have reported health benefits from TRE, little is known about the impact of TRE on common chronic diseases such as type 2 diabetes, cancer and cardiovascular disease. This review summarizes and critically evaluates the most recent TRE research findings relevant to managing and treating these chronic diseases.

RECENT FINDINGS

Most recent TRE studies have been in populations with overweight/obesity or metabolic syndrome; two have been in populations with diabetes, three in cancer survivors and none in populations with cardiovascular disease. Collectively, these studies showed that participants could adhere to TRE and TRE is well tolerated. These studies also showed preliminary efficacy for improved glucose regulation and insulin sensitivity, a reduction in body fat and blood pressure, reduced cardiovascular risk scores and increased quality of life. More research is required to define the most effective TRE protocol (i.e. length and timing of eating window, intervention duration).

SUMMARY

TRE has demonstrated benefits on cardiovascular, metabolic and clinical outcomes relevant to the underlying pathophysiology, but there are limited data on TRE implemented specifically within populations with diabetes, cancer or cardiovascular disease.

Influence of Intermittent Fasting During Ramadan on Circadian Variation of Symptom-Onset and Prehospital Time Delay in Acute ST-Segment Elevation Myocardial Infarction

Ramadan interferes with circadian rhythms mainly by disturbing the routine patterns of feeding and smoking. The objective of this study was to investigate the circadian pattern of ST elevation acute myocardial infarction (STEMI) during the month of Ramadan. We studied consecutive STEMI patients 1 month before and after Ramadan (non-Ramadan group-NRG) and during Ramadan (Ramadan group-RG). The RG group was also divided into two groups, based on whether they chose to fast: fasting (FG) and non-fasting group (NFG). The time of STEMI onset was compared. A total of 742 consecutive STEMI patients were classified into 4 groups by 6 h intervals according to time-of-day at symptom onset. No consistent circadian variation in the onset of STEMI was observed both between the RG (P = .938) and NRG (P = .766) or between the FG (P = .232) and NFG (P = .523). When analyzed for subgroups of the study sample, neither smoking nor diabetes showed circadian rhythm. There was a trend towards a delay from symptom onset to hospital presentation, particularly at evening hours in the RG compared with the control group. In conclusion, there was no significant difference in STEMI onset time, but the time from symptom onset to hospital admission was significantly delayed during Ramadan.

Circadian Dependence of the Acute Immune Response to Myocardial Infarction

Circadian rhythms influence the recruitment of immune cells and the onset of inflammation, which is pivotal in the response to ischemic cardiac injury after a myocardial infarction (MI). The hyperacute immune response that occurs within the first few hours after a MI has not yet been elucidated. Therefore, we characterized the immune response and myocardial damage 3 hours after a MI occurs over a full twenty-four-hour period to investigate the role of the circadian rhythms in this response. MI was induced at Zeitgeber Time (ZT) 2, 8, 14, and 20 by permanent ligation of the left anterior descending coronary artery. Three hours after surgery, animals were terminated and blood and hearts collected to assess the immunological status and cardiac damage. Blood leukocyte numbers varied throughout the day, peaking during the rest-phase (ZT2 and 8). Extravasation of leukocytes was more pronounced during the active-phase (ZT14 and 20) and was associated with greater chemokine release to the blood and expression of adhesion molecules in the heart. Damage to the heart, measured by Troponin-I plasma levels, was elevated during this time frame. Clock gene oscillations remained intact in both MI-induced and sham-operated mice hearts, which could explain the circadian influence of the hyperacute inflammatory response after a MI. These findings are in line with the clinical observation that patients who experience a MI early in the morning (i.e., early active phase) have worse clinical outcomes. This study provides further insight on the immune response occurring shortly after an MI, which may contribute to the development of novel and optimization of current therapeutic approaches.