Impact of dietary manipulation on cardiac hypertrophy

Left ventricular hypertrophy (LVH) is a significant risk factor for the development of heart failure (HF), the incidence of which is increased by obesity. Diets high in fat and sugar have been linked with the development of the metabolic syndrome and obesity, and may expose the heart to a unique environment via the differential actions of dietary macronutrients. The main objectives of this study were to determine the effect of differing dietary regimens upon (i) the progression of LVH and whole organism morphology (ii) function and metabolism in the hypertrophied heart, and (iii) cardiac ceramide content.Cardiac hypertrophy was surgically induced in male Sprague-Dawley rats via abdominal aortic constriction (AC). Animals were assigned to either a diet containing 5% sucrose/7% fat (standard diet, SD), 9 % sucrose/45 % fat (high-fat diet, HFD), or 14% sucrose/44% fat (western diet, WD) for 9 weeks. LVH was observed in all AC groups but was greatest in those fed a SD or WD. Both HFD and WD resulted in a significant increase in abdominal fat mass, which was positively associated with serum concentrations of leptin.In vitro cardiac function was unaltered by any dietary regimen alone, but was significantly enhanced in hypertrophied hearts from HFD and WD-fed animals, consistent with a compensated phase of hypertrophic remodelling. This was accompanied by a small reduction in palmitate oxidation and increased reliance upon lactate, an effect which was exacerbated in hearts from WD-fed animals. In WD-fed animals, there was a substantial increase in cardiac triglyceride (TG), which was not affected by AC. PPARα protein was reduced following AC in the hearts of animals fed a SD or WD, whereas the HFD prevented this decline. CD36 protein expression was not different between control and AC animals, but was highest in those fed a WD.In addition to elevated TG, WD hearts also exhibited a significant accumulation of long-chain ceramide species (C16-C24) compared with other dietary groups; consistent with metabolic remodelling. This effect was observed independent of AC. In order to simulate a model of HF, WD animals were treated with adriamycin (ADR), and cardiac ceramide content was further increased with the specific accumulation of C16 and C18 ceramide.These findings suggest that dietary macronutrient composition can have a profound effect upon the progression of LVH. Furthermore, the enhanced ceramide content in WD hearts indicates that the macronutrient composition of this dietary profile is most deleterious to the hypertrophied heart. Prolonged exposure of the hypertrophied heart to the WD may lead to increased apoptosis and accelerate the transition to HF

Book of Abstracts: 2019 Health Equity Summer Research Summit Organized by the Center of Excellence in Health Equity, Training and Research, Baylor College of Medicine, Houston, Texas 77030, USA on June 18th, 2019

Copyright © 2020 Harris. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Osteoarthritis Classification Scales: Interobserver Reliability and Arthroscopic Correlation

The MARS Group* Background: Osteoarthritis of the knee is commonly diagnosed and monitored with radiography. However, the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied. Methods: As the Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) Group, we conducted a multicenter, prospective longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction. We followed 632 patients who underwent radiographic evaluation of the knee (an anteroposterior weight-bearing radiograph, a posteroanterior weight-bearing radiograph made with the knee in 45°of flexion [Rosenberg radiograph], or both) and arthroscopic evaluation of the articular surfaces. Three blinded examiners independently graded radiographic findings according to six commonly used systems-the Kellgren-Lawrence, International Knee Documentation Committee, Fairbank, Brandt et al., Ahlbäck, and Jäger-Wirth classifications. Interobserver reliability was assessed with use of the intraclass correlation coefficient. The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient. Results: Overall, 45°posteroanterior flexion weight-bearing radiographs had higher interobserver reliability (intraclass correlation coefficient = 0.63; 95% confidence interval, 0.61 to 0.65) compared with anteroposterior radiographs (intraclass continue