Deficiency of heme oxygenase 1a causes detrimental effects on cardiac function

Humans lacking heme oxygenase 1 (HMOX1) display growth retardation, haemolytic anaemia, and vulnerability to stress; however, cardiac function remains unclear. We aimed to explore the cardiac function of zebrafish lacking hmox1a at baseline and in response to stress. We generated zebrafish hmox1a mutants using CRISPR/Cas9 genome editing technology. Deletion of hmox1a increases cardiac output and further induces hypertrophy in adults. Adults lacking hmox1a develop myocardial interstitial fibrosis, restrain cardiomyocyte proliferation and downregulate renal haemoglobin and cardiac antioxidative genes. Larvae lacking hmox1a fail to respond to hypoxia, whereas adults are insensitive to isoproterenol stimulation in the heart, suggesting that hmox1a is necessary for cardiac response to stress. Haplodeficiency of hmox1a stimulates non-mitochondrial respiration and cardiac cell proliferation, increases cardiac output in larvae in response to hypoxia, and deteriorates cardiac function and structure in adults upon isoproterenol treatment. Intriguingly, haplodeficiency of hmox1a upregulates cardiac hmox1a and hmox1b in response to isoproterenol. Collectively, deletion of hmox1a results in cardiac remodelling and abrogates cardiac response to hypoxia and isoproterenol. Haplodeficiency of hmox1a aggravates cardiac response to the stress, which could be associated with the upregulation of hmox1a and hmox1b. Our data suggests that HMOX1 homeostasis is essential for maintaining cardiac function and promoting cardioprotective effects.

Case-Fatality Rate in Parkinson's Disease: A Nationwide Registry Study

BACKGROUND

Patients with Parkinson's disease (PD) may have an increased risk of mortality, but robust estimates are lacking.

OBJECTIVE

To compare mortality rates nationally between patients with PD and controls.

METHODS

The case-fatality rates of Finnish PD patients diagnosed in 2004-2018 (n = 23,688; 57% male, mean age at diagnosis = 71 years) and randomly selected sex- and age-matched control subjects (n = 94,752) were compared using data from national registries. The median follow-up duration was 5.8 years (max 17 years).

RESULTS

The case-fatality rate in patients with PD was higher than that in matched controls (HR 2.29; 95% CI 2.24-2.33; P < 0.0001). Excess fatality among PD patients was already present at 1 year from diagnosis and then plateaued at 29% at 12 years after diagnosis. The long-term relative hazard of death in PD patients vs. matched controls did not differ based on sex. Patients with early-onset PD (age at diagnosis <50 years old) had the highest relative hazard of death (HR 3.36) compared to matched control subjects, and the relative hazard decreased with higher age at diagnosis. The seven-year excess risk of death decreased during the study period, especially in men. In patients with PD, male sex, increasing age, and increasing comorbidity burden were associated with an increased risk of death.

CONCLUSIONS

An increased risk of death among PD patients was evident from early on. The increase in risk was greatest among young-onset patients. The excess risk in early PD declined during the study period, particularly in men. The reasons for this are unknown.

Progression and regression of kidney disease in type 1 diabetes

Diabetic kidney disease is distinguished by the presence of albuminuria, hypertension, declining kidney function, and a markedly elevated cardiovascular disease risk. This constellation of clinical features drives the premature mortality associated with type 1 diabetes. The first epidemiological investigations concerning type 1 diabetes-related albuminuria date back to the 1980s. The early studies found that proteinuria - largely equivalent to severe albuminuria - developed in 35 to 45% of individuals with type 1 diabetes, with the diabetes duration-specific incidence rate pattern portraying one or two peaks. Furthermore, moderate albuminuria, the first detectable sign of diabetic kidney disease, was found to nearly inexorably progress to overt kidney disease within a short span of time. Since the early reports, studies presenting more updated incidence rates have appeared, although significant limitations such as study populations that lack broad generalizability, study designs vulnerable to substantive selection bias, and constrained follow-up times have been encountered by many. Nevertheless, the most recent reports estimate that in modern times, moderate - instead of severe - albuminuria develops in one-third of individuals with type 1 diabetes; yet, a considerable part (up to 40% during the first ten years after the initial albuminuria diagnosis) progresses to more advanced stages of the disease over time. An alternative pathway to albuminuria progression is its regression, which affects up to 60% of the individuals, but notably, the relapse rate to a more advanced disease stage is high. Whether albuminuria regression translates into a decline in cardiovascular disease and premature mortality risk is an area of debate, warranting more detailed research in the future. Another unclear but alarming feature is that although the incidence of severe albuminuria has fallen since the 1930s, the decline seems to have reached a plateau after the 1980s. This stagnation may be due to the lack of kidney-protective medicines since the early 1980s, as the recent breakthroughs in type 2 diabetes have not been applicable to type 1 diabetes. Therefore, novel treatment strategies are at high priority within this patient population.

Associations of accelerometer-based sedentary time, light physical activity and moderate-to-vigorous physical activity with resting cardiac structure and function in adolescents according to sex, fat mass, lean mass, BMI, and hypertensive status

BACKGROUND

This study examined the independent relationships of device-based measured sedentary time (ST) and physical activity (PA) in relation to cardiac structural and functional geometry among adolescents.

METHODS

From the Avon Longitudinal Study of Parents and Children, UK birth cohort, 530 (50% female) adolescents aged 17 years had complete ST, PA, cardiac, and covariate measures. Echocardiography cardiac measures were left ventricular mass indexed for height2.7 (LVMI2.7 ), relative wall thickness, LV diastolic function (LVDF), and LV filling pressure (LVFP). Overweight/obesity and elevated systolic/BP hypertension were categorized as body mass index >24.99 kg/m2 and ≥130 mmHg, respectively. Data were analyzed with linear regression models adjusting for cardiometabolic factors and lifestyle factors.

RESULTS

The prevalence of overweight/obesity in males and females was 17.9% and 24.5%, respectively. The prevalence of elevated systolic BP/hypertension was 11.6% in males and 1.1% among females. The average ST was 484 ± 78 min/day, light PA was 274 ± 62 min/day, and moderate-to-vigorous PA (MVPA) was 41 ± 24 min/day, among females. Average ST, LPA, and MVPA were 468 ± 87 min/day, 293 ± 70 min/day, and 56 ± 30 min/day, respectively, among males. Higher ST was associated with higher LVMI2.7 (standardized β = 0.16; p = 0.01) among females, but higher ST was associated with lower LVDF in males (β = -0.14; p = 0.04). Higher ST and MVPA were associated with higher LVMI2.7 in the total cohort, normal weight, and overweight/obese adolescents. Light PA was associated with higher LVDF in the total cohort and normotensives and lower LVFP among adolescents with high lean mass.

CONCLUSIONS

Higher ST and MVPA were associated with higher LVMI; however, ST-associated LVMI increase was threefold higher than MVPA-associated LVMI increase. Higher LPA was associated with better cardiac function. Reducing ST and increasing LPA may attenuate the risk of altered cardiac structure and function in adolescents.

Building blocks of microphysiological system to model physiology and pathophysiology of human heart

Microphysiological systems (MPS) are drawing increasing interest from academia and from biomedical industry due to their improved capability to capture human physiology. MPS offer an advanced in vitro platform that can be used to study human organ and tissue level functions in health and in diseased states more accurately than traditional single cell cultures or even animal models. Key features in MPS include microenvironmental control and monitoring as well as high biological complexity of the target tissue. To reach these qualities, cross-disciplinary collaboration from multiple fields of science is required to build MPS. Here, we review different areas of expertise and describe essential building blocks of heart MPS including relevant cardiac cell types, supporting matrix, mechanical stimulation, functional measurements, and computational modelling. The review presents current methods in cardiac MPS and provides insights for future MPS development with improved recapitulation of human physiology.

Cross-sectional associations between cardiorespiratory fitness and NMR-derived metabolic biomarkers in children - the PANIC study

OBJECTIVE

Cardiorespiratory fitness has been inversely associated with cardiovascular risk across the lifespan. Some studies in adults suggest that higher cardiorespiratory fitness is associated with cardioprotective metabolite profile, but the evidence in children is lacking. Therefore, we investigated the cross-sectional association of cardiorespiratory fitness with serum nuclear magnetic resonance derived metabolic biomarkers in children.

METHODS

A population sample of 450 children aged 6-8 years was examined. Cardiorespiratory fitness was assessed by a maximal exercise test on a cycle ergometer and quantified as maximal power output normalised for lean body mass assessed by dual-energy X-ray absorbtiometry. Serum metabolites were assessed using a high throughput nuclear magnetic resonance platform. The data were analysed using linear regression analyses adjusted for age and sex and subsequently for body fat percentage (BF%) assessed by DXA.

RESULTS

Cardiorespiratory fitness was directly associated with high density lipoprotein (HDL) cholesterol (β=0.138, 95% CI=0.042 to 0.135, p=0.005), average HDL particle diameter (β=0.102, 95% CI=0.004 to 0.199, p=0.041), and the concentrations of extra-large HDL particles (β=0.103, 95% CI=0.006 to 0.201, p=0.038), large HDL particles (β=0.122, 95% CI=0.025 to 0.220, p=0.014), and medium HDL particles (β=0.143, 95% CI=0.047 to 0.239, p=0.004) after adjustment for age and sex. Higher cardiorespiratory fitness was also associated with higher concentrations of ApoA1 (β=0.145, 95% CI=0.047 to 0.242, p=0.003), glutamine (β=0.161, 95% CI=0.064 to 0.257, p=0.001), and phenylalanine (β=0.187, 95% CI=0.091 to 0.283, p<0.001). However, only the direct associations of cardiorespiratory fitness with the concentrations of HDL cholesterol (β=0.114, 95% CI=0.018 to 0.210, p=0.021), medium HDL particles (β=0.126, 95% CI=0.030 to 0.223, p=0.010), ApoA1 (β=0.126, 95% CI=0.030 to 0.223, p=0.011), glutamine (β=0.147, 95% CI=0.050 to 0.224, p=0.003), and phenylalanine (β=0.217, 95% CI=0.122 to 0.311, p<0.001) remained statistically significant after further adjustment for BF%.

CONCLUSIONS

Higher cardiorespiratory fitness was associated with a cardioprotective biomarker profile in children. Most associations were independent of BF% suggesting that the differences in serum metabolites between children are driven by cardiorespiratory fitness and not adiposity.

The Role of Inflammatory Cytokines as Intermediates in the Pathway from Increased Adiposity to Disease

OBJECTIVE

This study aimed to investigate the role of cytokines as intermediates in the pathway from increased adiposity to disease.

METHODS

BMI and circulating levels of up to 41 cytokines were measured in individuals from three Finnish cohort studies (n = 8,293). Mendelian randomization (MR) was used to assess the impact of BMI on circulating cytokines and the impact of BMI-driven cytokines on risk of obesity-related diseases.

RESULTS

Observationally, BMI was associated with 19 cytokines. For every SD increase in BMI, causal effect estimates were strongest for hepatocyte growth factor, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and were as ratios of geometric means 1.13 (95% CI: 1.08-1.19), 1.08 (95% CI: 1.04-1.14), and 1.13 (95% CI: 1.04-1.21), respectively. TRAIL was associated with a small increase in the odds of coronary artery disease (odds ratio: 1.03; 95% CI: 1.00-1.06). There was inconsistent evidence for a protective role of MCP-1 against inflammatory bowel diseases.

CONCLUSIONS

Observational and MR estimates of the effect of BMI on cytokine levels were generally concordant. There was little evidence for an effect of raised levels of BMI-driven cytokines on disease. These findings illustrate the challenges of MR when applied in the context of molecular mediation.

Associations of Sex Hormones and Hormonal Status With Arterial Stiffness in a Female Sample From Reproductive Years to Menopause

OBJECTIVE

Loss of sex hormones has been suggested to underlie menopause-associated increment in cardiovascular risk. We investigated associations of sex hormones with arterial stiffness in 19-58-years-old women. We also studied associations of specific hormonal stages, including natural menstrual cycle, cycle with combined oral contraceptives (COC) and menopausal status with or without hormone therapy (HT), with arterial stiffness.

METHODS

This study includes repeated measurements of 65 healthy women representing reproductive (n=16 natural, n=10 COC-users) and menopause (n=5 perimenopausal, n=26 postmenopausal, n=8 HT-users) stages. Arterial stiffness outcomes were aortic pulse wave velocity (PWVao) and augmentation index (AIx%) assessed using Arteriograph-device. Generalized estimating equation models were constructed to investigate associations of each hormone (wide age-range models) or hormonal stage (age-group focused models) with arterial stiffness. PWVao models with cross-sectional approach, were adjusted for age, relative fitness, fat mass and mean arterial pressure, while models with longitudinal approach were adjusted for mean arterial pressure. AIx% models used the same approach for adjustments and were also adjusted for heart rate.

RESULTS

Negative and positive associations with arterial stiffness variables were observed for estradiol and follicle-stimulating hormone, respectively, until adjustment for confounding effect of age. In naturally menstruating women, AIx% was higher at ovulation (B=3.63, p<0.001) compared to the early follicular phase. In COC-users, PWVao was lower during active (B=-0.33 - -0.57, p<0.05) than inactive pills. In menopausal women, HT-users had higher PWVao (B=1.43, p=0.03) than postmenopausal non-HT-users.

CONCLUSIONS

When using wide age-range assessments covering reproductive to menopausal lifespan it is difficult to differentiate age- and hormone-mediated associations, because age-mediated influence on arterial stiffness seemed to overrule potential hormone-mediated influences. However, hormonal status associated differentially with arterial stiffness in age-group focused analyses. Thus, the role of sex hormones cannot be excluded. Further research is warranted to resolve potential hormone-mediated mechanisms affecting arterial elasticity.