“Obesity cardiomyopathy” effects have been widely described; however, the specific contribution of metabolic changes and altered adipokine secretion are still uncharacterized. Moreover, a diagnosis based on body mass index might not be the most accurate to identify increased adiposity and its outcomes. In this study, we aimed to determine the impact of a Western-type diet [hypercaloric diet (HCD)] ingestion on biventricular structure and function, as well as the metabolic and endocrine changes that occur before the establishment of overt obesity. Wistar rats were fed for 6 wk with a regular diet or HCD. At the end of the protocol, metabolic tests, cardiac structure, and functional evaluation were performed, and blood and tissue samples collected to perform histological, molecular biology, and functional studies. The animals that ingested the HCD presented increased adiposity and larger adipocyte cross-sectional area, but similar body weight compared with the regular diet group. At the cardiac level, HCD induced biventricular cardiomyocyte hypertrophy, fibrosis, increased stiffness, and impaired relaxation. Galectin-3 plasma expression was likewise elevated in the same animals. The nutritional modulation also altered the secretory pattern of the adipose tissue, originating a proinflammatory systemic environment. In this study, we observed that before “clinical” overweight or frank obesity is established, the ingestion of a HCD-induced cardiac remodeling manifests by increased biventricular stiffness and diastolic dysfunction. The mechanism triggering the cardiac alterations appears to be the proinflammatory environment promoted by the adipose tissue dysfunction. Furthermore, galectin-3, a profibrotic molecule, might be a potential biomarker for the myocardial alterations promoted by the HCD before overweight or obesity.

Key points: The present study aimed to test whether a chronic intermittent workload could induce an adaptive cardiac phenotype Chronic intermittent workload induced features of adaptive hypertrophy This was paralleled by protection against acute pressure overload insult The heart may adapt favourably to balanced demands, regardless of the nature of the stimuli. The present study aimed to test whether submitting the healthy heart to intermittent and tolerable amounts of workload, independently of its nature, could result in an adaptive cardiac phenotype. Male Wistar rats were subjected to treadmill running (Ex) (n = 20), intermittent cardiac overload with dobutamine (ITO) (2 mg kg^–1, s.c.; n = 20) or placebo administration (Cont) (n = 20) for 5 days week^–1 for 8 weeks. Animals were then killed for histological and biochemical analysis or subjected to left ventricular haemodynamic evaluation under baseline conditions, in response to isovolumetric contractions and to sustained LV acute pressure overload (35% increase in peak systolic pressure maintained for 2 h). Baseline cardiac function was enhanced only in Ex, whereas the response to isovolumetric heartbeats was improved in both ITO and Ex. By contrast to the Cont group, in which rats developed diastolic dysfunction with sustained acute pressure overload, ITO and Ex showed increased tolerance to this stress test. Both ITO and Ex developed cardiomyocyte hypertrophy without fibrosis, no overexpression of osteopontin‐1 or β‐myosin heavy chain, and increased expression of sarcoplasmic reticulum Ca²⁺ protein. Regarding hypertrophic pathways, ITO and Ex showed activation of the protein kinase B/mammalian target of rapamycin pathway but not calcineurin. Mitochondrial complex IV and V activities were also increased in ITO and Ex. Chronic submission to controlled intermittent cardiac overload, independently of its nature, results in an adaptive cardiac phenotype. Features of the cardiac overload, such as the duration and magnitude of the stimuli, may play a role in the development of an adaptive or maladaptive phenotype.

Polyphenols present in some alcoholic beverages have been linked to beneficial effects in preventing cardiovascular diseases. Polyphenols found in beer with anti-proliferative and anti-cancer properties are appealing in the context of the quasi-malignant phenotype of pulmonary arterial hypertension (PAH). Our purpose was to evaluate if the chronic ingestion of a xanthohumol-fortified beer (FB) would be able to modulate the pathophysiology of experimental PAH. Male Wistar rats with monocrotaline (MCT)-induced PAH (60 mg/kg) were allowed to drink either xanthohumol-fortified beer (MCT + FB) or 5.2% ethanol (MCT + SHAM) for a period 4 weeks. At the end of the protocol, cardiopulmonary exercise testing and hemodynamic recordings were performed, followed by sample collection for further analysis. FB intake resulted in a significant attenuation of the pulmonary vascular remodeling in MCT + FB animals. This improvement was paralleled with the downregulation in expression of proteins responsible for proliferation (ERK1/2), cell viability (AKT), and apoptosis (BCL-XL). Moreover, MCT + FB animals presented improved right ventricle (RV) function and remodeling accompanied by VEGFR-2 pathway downregulation. The present study demonstrates that a regular consumption of xanthohumol through FB modulates major remodeling pathways activated in experimental PAH.