Microbiota and the nitrogen cycle: Implications in the development and progression of CVD and CKD

© 2016 Elsevier Inc. All rights reserved.Chronic kidney disease (CKD) is associated with an increased risk of death from cardiovascular disease (CVD). One factor involved in CVD development is nitric oxide (NO), which acts as a powerful vasodilator. NO is produced via the nitrogen cycle, through the reduction of nitrate to nitrite with the process mainly occurring in the mouth by commensal microbiota. People with CKD have compromised microbiota (dysbiosis) with an increased abundance of potentially pathogenic and pro-inflammatory bacteria capable of producing uremic toxins that contribute to CKD development and reduce enzymatic NO production. However, to date, few studies have comprehensively documented the gut or saliva microbiota in the CKD population or investigated the role of NO in people with CKD. This review will discuss NO pathways that are linked to the progression of CKD and CVD and therapeutic options for targeting these pathways

High intensity interval training favourably affects antioxidant and inflammation mRNA expression in early-stage chronic kidney disease

© 2015 Elsevier Inc. All rights reserved.Increased levels of oxidative stress and inflammation have been linked to the progression of chronic kidney disease. To reduce oxidative stress and inflammation related to chronic kidney disease, chronic aerobic exercise is often recommended. Data suggests high intensity interval training may be more beneficial than traditional aerobic exercise. However, appraisals of differing modes of exercise, along with explanations of mechanisms responsible for observed effects, are lacking. This study assessed effects of eight weeks of high intensity interval training (85% VO₂max), versus low intensity exercise (45-50% VO₂max) and sedentary behaviour, in an animal model of early-stage chronic kidney disease. We examined kidney-specific mRNA expression of genes related to endogenous antioxidant enzyme activity (glutathione peroxidase 1; Gpx1, superoxide dismutase 1; Sod1, and catalase; Cat) and inflammation (kidney injury molecule 1; Kim1 and tumour necrosis factor receptor super family 1b; Tnfrsf1b), as well as plasma F2-isoprostanes, a marker of lipid peroxidation. Compared to sedentary behaviour, high intensity interval training resulted in increased mRNA expression of Sod1 (p=0.01) and Cat (p<0.001). Compared to low intensity exercise, high intensity interval training resulted in increased mRNA expression of Cat (p<0.001) and Tnfrsf1b (p=0.047). In this study, high intensity interval training was superior to sedentary behaviour and low intensity exercise as high intensity interval training beneficially influenced expression of genes related to endogenous antioxidant enzyme activity and inflammation

The effect of dietary sodium modification on blood pressure in adults with systolic blood pressure less than 140 mmHg: a systematic review

Background Modifying dietary sodium intake is a cornerstone of diet advice for lowering blood pressure (BP) under the assumption that it is protective against cardiovascular disease. Previous meta-analyses of normotensive participants have not excluded all studies that recruited participants with systolic blood pressure (SBP) > 140 mmHg, which greatly hinders generalization to the wider normotensive population. Objectives The objective of this review was to identify the effectiveness of reducing or increasing sodium intake on BP in normotensive participants with SBP ≤ 140 mmHg

Shear-wave velocity of the patellar tendon and quadriceps muscle is increased immediately after maximal eccentric exercise

Purpose: To determine whether stiffness of the patellar tendon and quadriceps muscles is altered immediately after and 48 h after a single bout of maximal eccentric exercise of the knee extensor muscles. Methods: Thirteen healthy individuals [group mean (SD) age 22.4 (3.5) years; 7 female] performed a single bout of maximal eccentric exercise of the non-dominant knee extensors, using an isokinetic dynamometer. Shear-wave velocity (an index of tissue stiffness) was recorded from the patellar tendon, vastus medialis (VM), rectus femoris (RF) and vastus lateralis (VL), before, following (post0), and 48 h after (post48) exercise. To investigate features of exercise induced muscle damage, maximal voluntary isometric contraction (MVIC) and self-reported pain and stiffness (numerical rating scales 0 = no pain/stiffness to 100 = worst imaginable pain/stiffness) were measured before, post0, and post48 exercise. Serum creatine kinase (CK) was measured before and post48 exercise. Results: Compared to preexercise, MVIC decreased and self-reported pain and stiffness increased at post0 and post48 and CK levels increased at post48 (all p < 0.01). Compared to preexercise, shear-wave velocity was greater at post0 for the patellar tendon [15.9 (24.6)%, p = 0.01] and RF [23.6 (16.7)%, p < 0.001], each returning to baseline by post48. No significant differences were observed for VL or VM post0 or post48 exercise. Conclusion: Maximal eccentric exercise produced an immediate increase in the stiffness of the patellar tendon and RF, resolving by 48 h. As this change was not observed in VL and VM, future studies may explore heterogeneity within synergist muscles following eccentric exercise. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

High intensity interval training does not result in short- or long-term dietary compensation in cardiac rehabilitation: Results from the FITR heart study

The aim of this study was to investigate short- and long-term compensatory effects on dietary intake following high intensity interval training (HIIT) compared with usual care moderate intensity continuous training (MICT) during and following a cardiac rehabilitation program. This study investigates secondary outcomes of a clinical trial. Ninety-three participants with coronary artery disease enrolled in a 4-week cardiac rehabilitation program, were randomised to 1) 4x4-minute HIIT; or 2) 40-min of MICT (usual care). Patients were instructed to complete 3 weekly sessions (2 supervised, 1 home-based) for 4-weeks, and 3 weekly home-based sessions thereafter for another 48-weeks. Dietary intake was measured by telephone-based 24-h recall over 2 day at baseline, 4-weeks, 3-months, 6-months, and 12-months. Three-Factor Eating Questionnaire was used to measure dietary behaviour and Leeds Food Preference Questionnaire used to measure food preferences. Appetite was assessed by a visual analogue scale and appetite-regulating hormones. There was no change over the study period or differences between groups for daily energy intake at 4-weeks or 12-months. There were also no group differences for any other measures of dietary intake, fasting hunger or appetite-related hormones, dietary behaviour, or food preferences. These findings suggest that compared to moderate intensity exercise, HIIT does not result in compensatory increases of energy intake or indicators of poor diet quality. This finding appears to be the same for patients with normal weight and obesity. HIIT can therefore be included in cardiac rehabilitation programs as an adjunct or alterative to MICT, without concern for any undesirable dietary compensation

Australian guidelines for physical activity in pregnancy and postpartum

Objectives: To develop Australian guidelines on physical activity/exercise during pregnancy and the postpartum period. Design: Critical ‘umbrella’ reviews of the scientific evidence, combined with adaptation of recently published guidelines. Methods: A five stage approach included: identification of key source documents (including national physical activity/exercise guidelines and position statements from professional organisations, published since 2010); narrative review of evidence relating to 27 health outcomes; summarising the evidence; development of draft guidelines and supporting information; and review and consultation to finalise the guidelines. Results: Our evidence review found that physical activity/exercise during pregnancy and the postpartum period is safe, has health benefits for the woman and her unborn child, and may reduce the risks of some pregnancy related complications. Four specific guidelines were developed. These encourage all women without pregnancy complications to: (1) meet the Australian Physical Activity and Sedentary Behaviour Guidelines for Adults before, during and after pregnancy; (2) modify activities to accommodate the physical changes that occur as pregnancy progresses; (3) do pelvic floor exercises during and after pregnancy; and (4) take an active role in shared decision-making about their physical activity/exercise during and after pregnancy. The review also identified warning signs and contraindications for physical activity/exercise during pregnancy. Conclusions: All women who are pregnant or planning a pregnancy should be aware of the benefits of physical activity/exercise, and health professionals should encourage safe levels of activity and be familiar with the contraindications, signs and symptoms which suggest that physical activity/exercise should be modified or avoided

Australian screening tool: Physical activity and exercise during pregnancy

Pre-exercise screening system</p