Cardiac MRI shows an association of lower cardiorespiratory fitness with decreased myocardial mass and higher cardiac stiffness in the general population - The Sedentary's Heart

Lower cardiorespiratory fitness is associated with an altered gut microbiome. The Study of Health in Pomerania (SHIP)

Sedentarism is characterized by low levels of physical activity, a risk factor for obesity and cardio-metabolic diseases. It can also adversely affect the composition and diversity of the gut microbiome which may result in harmful consequences for human health. While cardiorespiratory fitness (CRF) is inversely and independently associated with cardiovascular risk factors and diseases and all-cause mortality, the relationship between low CRF and the gut microbiome is not well known. A total of 3,616 individuals from two independent population-based cohorts of the Study of Health in Pomerania (SHIP-START and SHIP-TREND) performed standardized, symptom-limited cardiopulmonary exercise testing (CPET) and had faecal samples collected to determine gut microbiota profiles (16S rRNA gene sequencing). We analysed cross-sectional associations of CRF with the gut microbiome composition controlling for confounding factors. Lower CRF was associated with reduced microbial diversity, loss of beneficial short-chain fatty acid producing bacteria (i.e. Butyricoccus, Coprococcus, unclassified Ruminococcaceae or Lachnospiraceae) and an increase in opportunistic pathogens such as Escherichia/Shigella, or Citrobacter. Decreased cardiorespiratory performance was associated with a gut microbiota pattern that has been previously related to a proinflammatory state. These associations were independent of body weight or glycemic control.

Lower muscular strength is associated with greater liver fat content and higher serum liver enzymes-"The Sedentary's Liver" The Study of Health in Pomerania

We investigated the associations of low handgrip strength (HGS, i.e., a marker of muscular fitness) with liver fat content (LFC) and serum liver enzymes in a population-based setting. We used data from 2700 participants (51.7% women), aged 21-90 years, from two independent cohorts of the population-based Study of Health in Pomerania (SHIP-START-2 and SHIP-TREND-0). Cross-sectional, multivariable adjusted regression models were performed to examine the associations of HGS with LFC, measured by magnetic resonance imaging and serum liver enzymes. We found significant inverse associations of HGS with both LFC and serum liver enzymes. Specifically, a 10-kg lower HGS was associated with a 0.59% (95% confidence interval [CI]: 0.24-0.94; p = 0.001) higher LFC, a 0.051 µkatal/L (95% CI: 0.005-0.097; p = 0.031) higher gamma-glutamyltransferase (GGT) concentration and a 0.010 µkatal/L (95% CI: 0.001-0.020; p = 0.023) higher aspartate aminotransferase (AST) concentration. The adjusted odds-ratio for prevalent hepatic steatosis (defined by a MRI-PDFF ≥5.1%) per 10-kg lower HGS was 1.21 (95% CI: 1.04-1.40; p = 0.014). When considering only obese individuals, those with low HGS had a 1.58% (95% CI: 0.18-2.98; p = 0.027) higher mean LFC and higher chance of prevalent hepatic steatosis (adjusted OR 1.74, 95% CI: 1.15-2.62; p = 0.009) compared to individuals with high HGS. We found similar associations in individuals with overweight, but not in those with normal weight. Lower HGS was strongly associated with both higher LFC and higher serum GGT and AST concentrations. Future studies might clarify whether these findings reflect adverse effects of a sedentary lifestyle or aging on the liver.

Left ventricular hypertrophy as a risk factor for accelerated brain aging: Results from the Study of Health in Pomerania

Previous studies provided evidence for the importance of cardiac structure abnormalities, in particular greater left ventricular (LV) mass, for brain aging, but longitudinal studies are lacking to date. We included 926 individuals (median age 48 years; 53% women) from the TREND cohort of the Study of Health in Pomerania (SHIP) without reduced ejection fraction or a history of myocardial infarction. LV mass index (LVMI) was determined by echocardiography at baseline. Brain morphometric measurements were derived from magnetic resonance images at baseline and 7-year follow-up. Direct effects of baseline LVMI on brain morphometry at follow-up were estimated using linear regression models with adjustment for baseline brain morphometry. At baseline, median LVMI was 40 g/m2.7 and 241 individuals (26%) met the criterion of LV hypertrophy. After correction for multiple testing, baseline LVMI was directly associated with reduced global cortical thickness and increased cortical brain age at follow-up independent from hypertension and blood pressure. Exposure-outcome relations were nonlinear and significantly stronger in the upper half of the exposure distribution. Specifically, an increase in baseline LVMI from the 50% quantile to the 95% quantile was associated additional 2.7 years (95% confidence interval = [1.5 years, 3.8 years]) of cortical brain age at follow-up. Additional regional analyses yielded bilateral effects on multiple frontal cortical regions. Our findings highlight the role of cardiac structure in brain aging. LVMI constitutes an easily measurable marker that might help to identify persons at risk for cognitive impairment and dementia.

Too Little of a Good Thing: Strong Associations Between Cardiac Size and Fitness Among Women

BACKGROUND

Cardiorespiratory fitness (CRF) is associated with functional impairment and cardiac events, particularly heart failure (HF). However, the factors predisposing women to low CRF and HF remain unclear.

OBJECTIVES

This study sought to evaluate the association between CRF and measures of ventricular size and function and to examine the potential mechanism linking these factors.

METHODS

A total of 185 healthy women aged >30 years (51 ± 9 years) underwent assessment of CRF (peak volume of oxygen uptake [Vo2peak]) and biventricular volumes at rest and during exercise by using cardiac magnetic resonance (CMR). The relationships among Vo2peak, cardiac volumes, and echocardiographic measures of systolic and diastolic function were assessed using linear regression. The effect of cardiac size on cardiac reserve (change in cardiac function during exercise) was assessed by comparing quartiles of resting left ventricular end-diastolic volume (LVEDV).

RESULTS

Vo2peak was strongly associated with resting measures of LVEDV and right ventricular end-diastolic volume (R2 = 0.58-0.63; P < 0.0001), but weakly associated with measures of resting left ventricular (LV) systolic and diastolic function (R2 = 0.01-0.06; P < 0.05). Increasing LVEDV quartiles were positively associated with cardiac reserve, with the smallest quartile showing the smallest reduction in LV end-systolic volume (quartile [Q]1: -4 mL vs Q4: -12 mL), smallest augmentation in LV stroke volume (Q1: +11 mL vs Q4: +20 mL) and cardiac output (Q1: +6.6 L/min vs Q4: +10.3 L/min) during exercise (interaction P < 0.001 for all).

CONCLUSIONS

A small ventricle is strongly associated with low CRF because of the combined effect of a smaller resting stroke volume and an attenuated capacity to increase with exercise. The prognostic implications of low CRF in midlife highlight the need for further longitudinal studies to determine whether women with small ventricles are predisposed to functional impairment, exertional intolerance, and HF later in life.

The Role of MR Assessments of Cardiac Morphology, Function, and Tissue Characteristics on Exercise Capacity in Well-Functioning Older Adults

BACKGROUND

The relationship between resting cardiac indices and exercise capacity in older adults was still not well understood. New developments in cardiac magnetic resonance imaging (MRI) enable a much fuller assessment of cardiac characteristics.

PURPOSE/HYPOTHESIS

To assess the association between exercise capacity and specific aspects of resting cardiac structure, function, and tissue.

STUDY TYPE

Cross-sectional study.

POPULATION

A total of 112 well-functioning older adults (mean age 69 years, 52 men).

FIELD STRENGTH/SEQUENCE

All participants underwent 3.0 T MRI, using scan protocols including balanced steady-state free precession cine sequence, modified look-locker inversion recovery, and T2-prepared single-shot balanced steady-state free precession.

ASSESSMENT

Demographic and geriatric characteristics were collected. Blood samples were assayed for lipid and glucose related biomarkers. All participants performed a symptom-limited cardiopulmonary exercise test to achieve peakVO₂ . Cardiac MRI parameters were measured with semi-automatic software by S.Y., an 18-year experienced radiologist.

STATISTICAL TESTS

Demographic, geriatric characteristics and MR measurements were compared among quartiles of peakVO2, with different methods according to the data type. Spearman's partial correlation and least absolute shrinkage selection operator regression were performed to select significant MR features associated with peakVO₂ . Mediation effect analysis was conducted to test any indirect connection between age and peakVO₂ . A two-sided P value of <0.05 was defined statistical significance.

RESULTS

Epicardial fat volume, left atrial volume indexed to height, right ventricular end-systolic volume indexed to body surface area and global circumferential strain (GCS) were correlated with peakVO₂ (regression coefficients were -0.040, -0.093, 0.127, and 0.408, respectively). Mediation analysis showed that the total effect of peakVO₂ change was 43.6% from the change of age. The proportion of indirect effect from epicardial fat volume and GCS were 11.8% and 15.1% in total effect, respectively.

DATA CONCLUSION

PeakVO₂ was associated with epicardial fat volume, left atrial volume, right ventricular volume and GCS of left ventricle.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

Cardiac structural and functional abnormalities in epilepsy: A systematic review and meta-analysis

OBJECTIVE

Epilepsy is associated with an increased risk of cardiovascular disease and mortality. Whether cardiac structure and function are altered in epilepsy remains unclear. To address this, we conducted a systematic review and meta-analysis of studies evaluating cardiac structure and function in patients with epilepsy.

METHODS

We searched the electronic databases MEDLINE, PubMed, COCHRANE, and Web of Science from inception to 31 December 2021. Primary outcomes of interest included left ventricular ejection fraction (LVEF) for studies reporting echocardiogram findings and cardiac weight and fibrosis for postmortem investigations. Study quality was assessed using the National Heart, Lung, and Blood Institute (NHLBI) assessment tools.

RESULTS

Among the 10 case-control studies with epilepsy patients (n = 515) and healthy controls (n = 445), LVEF was significantly decreased in epilepsy group compared with controls (MD: -1.80; 95% confidence interval [CI]: -3.56 to -0.04; P = 0.045), whereas A-wave velocity (MD: 4.73; 95% CI: 1.87-7.60; P = 0.001), E/e' ratio (MD: 0.39; 95% CI: 0.06-0.71; P = 0.019), and isovolumic relaxation time (MD: 10.18; 95% CI: 2.05-18.32; P = 0.014) were increased in epilepsy, compared with controls. A pooled analysis was performed in sudden unexpected death in epilepsy (SUDEP) cases with autopsy data (n = 714). Among SUDEP cases, the prevalence of cardiac hypertrophy was 16% (95% CI: 9%-23%); cardiac fibrosis was 20% (95% CI: 15%-26%). We found no marked differences in cardiac hypertrophy, heart weight, or cardiac fibrosis between SUDEP cases and epilepsy controls.

SIGNIFICANCE

Our findings suggest that epilepsy is associated with altered diastolic and systolic echocardiogram parameters compared with healthy controls. Notably, SUDEP does not appear to be associated with a higher incidence of structural cardiac abnormalities, compared with non-SUDEP epilepsy controls. Longitudinal studies are needed to understand the prognostic significance of such changes. Echocardiography may be a useful noninvasive diagnostic test in epilepsy population.

Low cardiopulmonary fitness is associated with higher liver fat content and higher gamma-glutamyltransferase concentrations in the general population - "The Sedentary's Liver"

BACKGROUND

We investigated the association between low cardiorespiratory fitness and liver fat content (LFC) in the general population.

MATERIALS AND METHODS

We evaluated data from 2151 adults (51.1% women) from two population-based cohorts of the Study of Health in Pomerania (SHIP-2 and SHIP-TREND-0). We analysed the cross-sectional associations of peak oxygen uptake (VO_2peak ) with LFC, assessed by magnetic resonance imaging proton density fat fraction, as well as serum gamma-glutamyltransferase (GGT) and aminotransferase concentrations by multivariable regression models.

RESULTS

We observed significant inverse associations of VO_2peak with LFC and serum GGT, but not with serum aminotransferase levels. Specifically, a 1 L/min lower VO_2peak was associated with a 1.09% (95% confidence interval [CI]: 0.45-1.73; P = .002) higher LFC and a 0.18 μkatal/L (95% CI: 0.09-0.26; P < .001) higher GGT levels. The adjusted odds ratio (OR) for the risk of prevalent hepatic steatosis (HS) by a 1 L/min decrease in VO_2peak was 1.61 (95% CI: 1.22-2.13; P = .001). Compared to subjects with high VO_2peak , obese and overweight individuals with low VO_2peak had 1.78% (95% CI: 0.32-3.25; P = .017) and 0.94% (95% CI: 0.15-1.74; P = .021) higher mean LFC, respectively. Compared to those with high VO_2peak , low VO_2peak was independently associated with a higher risk of prevalent HS in the obese (adjusted-OR 2.29, 95% CI=1.48-3.56; P < .001) and overweight (adjusted OR 1.57, 95% CI=1.16-2.14; P = .04) groups.

CONCLUSIONS

Lower VO_2peak was significantly associated with greater LFC and higher serum GGT levels in a population-based cohort of adult individuals. Our results suggest that low VO_2peak might be a risk factor for HS.

SHIP-MR and Radiology: 12 Years of Whole-Body Magnetic Resonance Imaging in a Single Center

The Study of Health in Pomerania (SHIP), a population-based study from a rural state in northeastern Germany with a relatively poor life expectancy, supplemented its comprehensive examination program in 2008 with whole-body MR imaging at 1.5 T (SHIP-MR). We reviewed more than 100 publications that used the SHIP-MR data and analyzed which sequences already produced fruitful scientific outputs and which manuscripts have been referenced frequently. Upon reviewing the publications about imaging sequences, those that used T1-weighted structured imaging of the brain and a gradient-echo sequence for R2* mapping obtained the highest scientific output; regarding specific body parts examined, most scientific publications focused on MR sequences involving the brain and the (upper) abdomen. We conclude that population-based MR imaging in cohort studies should define more precise goals when allocating imaging time. In addition, quality control measures might include recording the number and impact of published work, preferably on a bi-annual basis and starting 2 years after initiation of the study. Structured teaching courses may enhance the desired output in areas that appear underrepresented.