Joyner, Michael J.

Abstract Lifestyle interventions are pivotal for successful management of type 2 diabetes (T2D), however, the proportion of people with T2D adhering to physical activity advice has not been thoroughly studied. The purpose of this systematic review was to summarise the evidence on adherence to exercise or physical activity components in lifestyle interventions in those with T2D. We searched MEDLINE EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews and Scopus on 12 November 2019. Eligible studies enrolled adults with T2D and reported the proportion of adherence to lifestyle interventions as a primary or secondary outcome. We included 11 studies (nine randomised controlled trials (RCTs) enrolling 1717 patients and two nonrandomised studies enrolling 62 patients). Only one of the studies had low risk of bias. The proportion of participants adhering to physical activity varied from 32% to 100% with a median of 58%. Adherence was higher in interventions using supervised training and lowest in interventions using remote coaching and the adherence rate in observational studies was higher compared to RCTs (92% vs. 55%; p < 0.01). Study duration, risk of bias, or participants' sex, were not associated with adherence to physical activity. The proportion of those with T2D adhering to physical activity interventions for T2D varies widely and most of the included studies had a high risk of bias. These findings have important implications for planning and power analysis of future trials and when counselling patients about lifestyle interventions including physical activity or exercise components.

Antibody therapies such as convalescent plasma and monoclonal antibodies have emerged as major potential therapeutics for coronavirus disease 2019 (COVID-19). Immunoglobulins differ from conventional antimicrobial agents in that they mediate direct and indirect antimicrobial effects that work in concert with other components of the immune system.

While rapid-onset vasodilation (ROV) has been shown to decrease in older individuals, it is unclear if sex contributes to the decline with aging. We sought to identify if sex-related differences exist in the ROV response to single forearm contractions in young and older adults. Our data suggest sex-related differences are present among older but not young individuals, with women having an attenuated response. These data indicate sex plays a role in decreased vasodilation with aging.

Key points Heart failure patients with reduced ejection fraction (HFrEF) exhibit severe limitations in exercise capacity ( peak). One of the primary peripheral mechanisms suggested to underlie exercise intolerance in HFrEF is excessive locomotor muscle group III/IV afferent feedback; however, this has never been investigated in human heart failure. HFrEF patients and controls performed an incremental exercise test to volitional exhaustion to determine peak with lumbar intrathecal fentanyl or placebo. During exercise, cardiac output, leg blood flow and radial artery and femoral venous blood gases were measured. With fentanyl, compared with placebo, patients with HFrEF achieved a higher peak workload, peak, cardiac output, stroke volume and leg blood flow. These findings suggest that locomotor muscle group III/IV afferent feedback in HFrEF leads to increased systemic vascular resistance, which constrains stroke volume, cardiac output and O2 delivery thereby impairing peak and thus exercise capacity. AbstractTo better understand the underlying mechanisms contributing to exercise limitation in heart failure with reduced ejection fraction (HFrEF), we investigated the influence of locomotor muscle group III/IV afferent inhibition via lumbar intrathecal fentanyl on peak exercise capacity ( peak) and the contributory mechanisms. Eleven HFrEF patients and eight healthy matched controls were recruited. The participants performed an incremental exercise test to volitional exhaustion to determine peak with lumbar intrathecal fentanyl or placebo. During exercise, cardiac output and leg blood flow () were measured via open‐circuit acetylene wash‐in technique and constant infusion thermodilution, respectively. Radial artery and femoral venous blood gases were measured. peak was 15% greater with fentanyl compared with placebo for HFrEF (P < 0.01), while no different in the controls. During peak exercise with fentanyl, cardiac output was 12% greater in HFrEF secondary to significant decreases in systemic vascular resistance and increases in stroke volume compared with placebo (all, P < 0.01). From placebo to fentanyl, leg , and O2 delivery were greater for HFrEF during peak exercise (all, P < 0.01), but not control. These findings indicate that locomotor muscle group III/IV afferent feedback in patients with HFrEF leads to increased systemic vascular resistance, which constrains stroke volume, cardiac output and O2 delivery, thereby impairing peak and thus exercise capacity. These findings have important clinical implications as peak is highly predictive of morbidity and mortality in HF.