Sodium Butyrate Protects -Against High Fat Diet-Induced Cardiac Dysfunction and Metabolic Disorders in Type II Diabetic Mice

Histone deacetylases are recently identified to act as key regulators for cardiac pathophysiology and metabolic disorders. However, the function of histone deacetylase (HDAC) in controlling cardiac performance in Type II diabetes and obesity remains unknown. Here, we determine whether HDAC inhibition attenuates high fat diet (HFD)-induced cardiac dysfunction and improves metabolic features. Adult mice were fed with either HFD or standard chow food for 24 weeks. Starting at 12 weeks, mice were divided into four groups randomly, in which sodium butyrate (1%), a potent HDAC inhibitor, was provided to chow and HFD-fed mice in drinking water, respectively. Glucose intolerance, metabolic parameters, cardiac function, and remodeling were assessed. Histological analysis and cellular signaling were examined at 24 weeks following euthanization of mice. HFD-fed mice demonstrated myocardial dysfunction and profound interstitial fibrosis, which were attenuated by HDAC inhibition. HFD-induced metabolic syndrome features insulin resistance, obesity, hyperinsulinemia, hyperglycemia, lipid accumulations, and cardiac hypertrophy, these effects were prevented by HDAC inhibition. Furthermore, HDAC inhibition attenuated myocyte apoptosis, reduced production of reactive oxygen species, and increased angiogenesis in the HFD-fed myocardium. Notably, HFD induced decreases in MKK3, p38, p38 regulated/activated protein kinase (PRAK), and Akt-1, but not p44/42 phosphorylation, which were prevented by HDAC inhibition. These results suggest that HDAC inhibition plays a critical role to preserve cardiac performance and mitigate metabolic disorders in obesity and diabetes, which is associated with MKK3/p38/PRAK pathway. The study holds promise in developing a new therapeutic strategy in the treatment of Type II diabetic-induced heart failure and metabolic disorders. J. Cell. Biochem. 118: 2395-2408, 2017. © 2017 Wiley Periodicals, Inc.

Importance of length and external diameter in left ventricular geometry. Normal values from the HUNT Study

BACKGROUND

We aimed to study left ventricular (LV) geometry assessed by length (LVWL), external diameter (LVEDD) and relative wall thickness (RWT) in relation to age, body size and gender in healthy individuals.

METHODS

1266 individuals underwent echocardiography in the Nord-Trøndelag Health Study (HUNT3), Norway. Septum thickness (IVS), posterior wall thickness (LVPWd) and end-diastolic internal diameter (LVIDD) were measured in M-mode, and LVEDD was calculated as the sum. Myocardial wall lengths were measured in a straight line from apex to the mitral ring in apical views at end diastole and averaged to LVWL. RWT ([IVSd+LVPWd]/LVIDD) and the ratio between length and diameter (L/D) were calculated.

RESULTS

Normal age-related and gender-related values are provided. Conventional measures conform to previous studies. All measures correlated with body surface area (BSA) (r 0.29-0.60), and BSA indexed values were higher in women. Wall thickness (WT) and LVEDD, but not LVIDD, were higher with higher age. LVWL and L/D were lower with increasing age, but L/D was independent of BSA and similar in women and men (1.41 vs 1.40). RWT correlated with BSA and age (r 0.17 and 0.34).

CONCLUSIONS

LV WT increases and LVWL decreases with higher age. Excluding length in LV mass calculations increasingly overestimates mass with ageing. L/D is a BSA independent measure of LV age-related geometry and may be useful as a body size independent measure in LV hypertrophy. RWT depends on body size and age, and a single cut-off value is not warranted.

Novel, single-beat approach for determining both end-systolic pressure-dimension relationship and preload recruitable stroke work

Objective

The end-systolic pressure–dimension relationship (ESPDR) and the preload recruitable stroke work (PRSW) relationship are load-insensitive measures of contractility, but their clinical application has been limited by the need to record multiple beats over a wide volume range. In this study, we therefore sought to validate a new method to concomitantly determine the ESPDR and the PRSW relationship from a single beat.

Methods

Pressure–dimension loops were recorded in 14 conscious dogs under various haemodynamic and pathological conditions. Multiple-beat PRSW relationship was determined for its slope (M_w) and for a dimension-axis intercept (D_w). The ESPDR represented by the formula , was estimated from a steady-state, single-beat late-systolic pressure–dimension relationship. The single-beat M_w was determined as an end-systolic pressure when the end-systolic dimension was equal to D_w.

Results

A strong correlation was observed between multiple-beat and single-beat ESPDRs (zero-stress dimension; r=0.98, p<0.0001). The single-beat estimation of M_w calculated using the wall thickness was strongly correlated with the actual M_w (r=0.93, p<0.0001) and was sensitive enough to detect the change in contractility by dobutamine infusion (p<0.001) and by tachycardia-induced heart failure (p<0.001). Similar results were obtained for M_w estimated without information on wall thickness.

Conclusions

M_w can be interpreted as an end-systolic pressure when the end-systolic dimension is equal to D_w. By using the non-linear ESPDR, accurate single-beat estimation of the ESPDR and M_w is possible even without information on wall thickness. These results should enhance the applicability of pressure–volume framework to clinical medicine.

Bias associated with left ventricular quantification by multimodality imaging: a systematic review and meta-analysis

Purpose

Cardiac MR (CMR) is the gold standard for left ventricular (LV) quantification. However, two-dimensional echocardiography (2DE) is the most common approach, and both three-dimensional echocardiography (3DE) and multidetector CT (MDCT) are increasingly available. The clinical significance and interchangeability of these modalities remains under-investigated. Therefore, we undertook a systemic review to evaluate the accuracy and absolute bias in LV quantification of all the commonly available non-invasive imaging modalities (2DE, CE-2DE, 3DE, MDCT) compared to cardiac MR (CMR).

Methods

Studies were included that reported LV echocardiographic (2DE, CE-2DE, 3DE) and/or MDCT measurements compared to CMR. Only modern CMR (SSFP sequences) was considered. Studies involving small sample size (<10 patients) and unusual cardiac geometry (ie, congenital heart diseases) were excluded. We evaluated LV end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF).

Results

1604 articles were initially considered: 65 studies were included (total of 4032 scans (echo, CT, MRI) performed in 2888 patients). Compared to CMR, significant biased underestimation of LV volumes with 2DE was seen (LVEDV—33.30 mL, LVESV −16.20 mL, p<0.0001). This difference was reduced but remained significant with CE-2DE (LVEDV −18.05, p<0.0001) and 3DE (LVEDV −14.41, p<0.001), while MDCT values were similar to CMR (LVEDV −1.20, p=0.43; LVESV −0.13, p=0.91). However, excellent agreement for echocardiographic LVEF evaluation (2DE LVEF 0.78–1.01%, p=0.37) was observed, especially with 3DE (LVEF 0.14%, p=0.88).

Conclusions

Comparing imaging modalities to CMR as reference standard, 3DE had the highest accuracy in LVEF estimation: 2DE and 3DE-derived LV volumes were significantly underestimated. Newer generation CT showed excellent accuracy for LV volumes.

Subclinical cardiopulmonary dysfunction in stage 3 chronic kidney disease

OBJECTIVE

Reduced exercise capacity is well documented in end-stage chronic kidney disease (CKD), preceded by changes in cardiac morphology in CKD stage 3. However, it is unknown whether subclinical cardiopulmonary dysfunction occurs in CKD stage 3 independently of heart failure.

METHODS

Prospective observational cross-sectional study of exercise capacity assessed by cardiopulmonary exercise testing in 993 preoperative patients. Primary outcome was peak oxygen consumption (VO2peak). Anaerobic threshold (AT), oxygen pulse and exercise-evoked measures of autonomic function were analysed, controlling for CKD stage 3, age, gender, diabetes mellitus and hypertension.

RESULTS

CKD stage 3 was present in 93/993 (9.97%) patients. Diabetes mellitus (RR 2.49 (95% CI 1.59 to 3.89); p<0.001), and hypertension (RR 3.20 (95% CI 2.04 to 5.03); p<0.001)) were more common in CKD stage 3. Cardiac failure (RR 0.83 (95% CI 0.30 to 2.24); p=0.70) and ischaemic heart disease (RR 1.40 (95% CI 0.97 to 2.02); p=0.09) were not more common in CKD stage 3. Patients with CKD stage 3 had lower predicted VO2peak (mean difference: 6% (95% CI 1% to 11%); p=0.02), lower peak heart rate (mean difference:9 bpm (95% CI 3 to 14); p=0.03)), lower AT (mean difference: 1.1 mL/min/kg (95% CI 0.4 to 1.7); p<0.001) and impaired heart rate recovery (mean difference: 4 bpm (95% CI 1 to 7); p<0.001)).

CONCLUSIONS

Subclinical cardiopulmonary dysfunction in CKD stage 3 is common. This study suggests that maladaptive cardiovascular/autonomic dysfunction may be established in CKD stage 3, preceding pathophysiology reported in end-stage CKD.

Cardiac function associated with previous, current and repeated depression and anxiety symptoms in a healthy population: the HUNT study

OBJECTIVE

Symptoms of anxiety and depression often co-exist with cardiovascular disease (CVD), yet little is known about the association with left ventricular (LV) subclinical dysfunction. We aimed to study the cross-sectional associations of previous, current and repeated depression or anxiety symptoms, with sensitive indices of LV systolic and diastolic function, based on tissue Doppler (TD) and speckle tracking (ST) imaging methods.

METHODS

A random selection of 1296 individuals free from known CVD, hypertension and diabetes were examined with echocardiography at baseline of the third Nord-Trøndelag Health Study, (HUNT3, 2006-2008). The primary outcomes were LV diastolic function (e') and LV systolic function (longitudinal global strain). The primary exposures were self-report on the Hospital Anxiety and Depression Scale (HADS). Associations between outcomes and baseline exposures were available for 1034 (80%), and with previous and repeated exposures for 700 participants who also participated in HUNT2 (1995-1997).

RESULTS

Previous and repeated depression symptoms, but not current depression, were linearly associated with a reduction in e'. The average sum of two repeated HADS-D scores 10 years apart had the strongest effect on e' (-8.3%; 95% CI -13.9% to -2.7%) per 5 units. We observed a sex difference between depression symptoms and longitudinal global strain (p for interaction 0.019), where women had a marginal negative effect. Anxiety symptoms, neither previous, current nor repeated were associated with subclinical LV dysfunction.

CONCLUSIONS

In a healthy sample, confirmed free of CVD, past and repeated depression symptoms were associated with subclinical LV dysfunction. Thus, depression symptoms might represent a modifiable risk factor for future CVD.

Subtle increases in heart size persist into adulthood in growth restricted babies: the Cardiovascular Risk in Young Finns Study

Background and objectives

Impaired fetal growth is associated with increased cardiovascular morbidity and mortality in adulthood. We sought to determine whether adults born with intrauterine growth restriction have primary maladaptive changes in cardiac structure.

Methods

Study participants were adults (34–49 years) who attended the 31-year follow-up of the Cardiovascular Risk in Young Finns Study (longitudinal cohort). Transthoracic echocardiograms and demographic and cardiovascular risk surveys were completed for 157 adults born small for gestational age (SGA, birth weight <10th population centile) and 627 born average for gestational age (average for gestational age (AGA), birth weight 50th–90th population centile).

Results

Those born growth restricted had subtly enlarged hearts with indexed left ventricular (LV) end-systolic and end-diastolic diameters slightly greater in the SGA individuals than the AGA group (LVESD 18.7 mm/m² SGA vs 18.1 mm/m² AGA, p<0.01; LVEDD 27.5 mm/m² SGA vs 26.6 mm/m² AGA, p<0.01); LV base-to-apex length (47.4 mm/m² SGA vs 46.0 mm/m² AGA, p<0.01); LV basal diameter (26.4 mm/m² SGA vs 25.7 mm/m² AGA, p<0.01); and right ventricular base-to-apex length (40.1 mm/m² SGA vs 39.2 mm/m² AGA, p=0.02). LV stroke volume was greater in those born AGA (74.5 mL SGA vs 78.8 mL AGA, p<0.01), with no significant difference in cardiac output (5 L/min SGA vs 5.2 L/min AGA, p=0.06), heart rate, diastolic indices or sphericity index.

Conclusions

Adults born SGA have some statistically significant but subtle changes in cardiac structure and function, which are less marked than have been described in childhood, and are unlikely to play a pathogenic role in their elevated cardiovascular risk.

Clinical use of multimodality imaging in the assessment of dilated cardiomyopathy

Learning objectives: =To understand the use of cardiovascular imaging for diagnosis, evaluation of prognosis and for supporting treatment decisions and monitoring therapy in patients with dilated cardiomyopathy by providing morphologic, functional and etiologic information, including refined assessment of ventricular function. =To provide to the clinical cardiologist the information on what to expect from each imaging modality and how to work together with the cardiovascular imaging expert to fully explore the potential of complementary imaging techniques. = To provide a look into the future role of new imaging modalities such as molecular imaging.