Testing a self-determination theory-based process model of physical activity behavior change in rheumatoid arthritis: results of a randomized controlled trial.

Physical inactivity is prevalent in rheumatoid arthritis (RA) patients, increasing the risk of poor physical health and compromised well-being. Interventions are therefore required to support physical activity (PA) behavior change in this population. This study examined whether a self-determination theory (SDT) based exercise intervention for people with RA, increased autonomous motivation for PA and in turn, moderate-to-vigorous PA (MVPA) and subjective vitality RA patients (n = 115) were randomized to a 3-month SDT-based psychological intervention + RA-tailored exercise program (experimental group, n = 59) or a RA-tailored exercise program only (control group, n = 56). During the program, the SDT-based intervention group received one-on-one consultations with a PA advisor trained in delivering strategies to promote autonomous motivation for PA. Well-established questionnaires assessed autonomous and controlled motivation for PA, MVPA (min/week), and subjective vitality at baseline (T1) and 3 months (T2). Path analysis examined the hypothesized theoretical process model. The model demonstrated an excellent fit to the data (n = 70, χ2 (26) = 28.69, p = .33, comparative fit index = 0.99, root square mean error of approximation = 0.04). The intervention corresponded to higher autonomous motivation and lower controlled motivation for PA at T2, after controlling for T1 autonomous and controlled motivation. In turn, changes in autonomous motivation from T1 to T2 significantly positively predicted changes in MVPA and subjective vitality. Results suggest an SDT based psychological intervention comprising autonomy-supportive strategies for PA predicted greater reported autonomous reasons for PA in RA patients participating in a tailored 3-month exercise program. Increased autonomous motivation linked to increased engagement in MVPA and feelings of vitality in these patients.

Selective effects of acute low-grade inflammation on human visual attention.

Illness is often accompanied by perceived cognitive sluggishness, a symptom that may stem from immune system activation. The current study used electroencephalography (EEG) to assess how inflammation affected three different distinct attentional processes: alerting, orienting and executive control. In a double-blinded placebo-controlled within-subjects design (20 healthy males, mean age = 24.5, SD = 3.4), Salmonella typhoid vaccination (0.025 mg; Typhim Vi, Sanofi Pasteur) was used to induce transient mild inflammation, while a saline injection served as a placebo-control. Participants completed the Attention Network Test with concurrent EEG recorded 6 h post-injection. Analyses focused on behavioral task performance and on modulation of oscillatory EEG activity in the alpha band (9-12 Hz) for alerting as well as orienting attention and frontal theta band (4-8 Hz) for executive control. Vaccination induced mild systemic inflammation, as assessed by interleukin-6 (IL-6) levels. While no behavioral task performance differences between the inflammation and placebo condition were evident, inflammation caused significant alterations to task-related brain activity. Specifically, inflammation produced greater cue-induced suppression of alpha power in the alerting aspect of attention and individual variation in the inflammatory response was significantly correlated with the degree of alpha power suppression. Notably, inflammation did not affect orienting (i.e., alpha lateralization) or executive control (i.e., frontal theta activity). These results reveal a unique neurophysiological sensitivity to acute mild inflammation of the neural network that underpins attentional alerting functions. Observed in the absence of performance decrements, these novel findings suggest that acute inflammation requires individuals to exert greater cognitive effort when preparing for a task in order to maintain adequate behavioral performance.

Sedentary behaviour in people with multiple sclerosis: Is it time to stand up against MS?

Historically, people with multiple sclerosis (MS) have been considered sedentary, although the actual scientific study of sedentary behaviour in MS did not originate until 2011. Sedentary behaviour, which is conceptually distinct from physical inactivity, is defined as any waking activity characterised by an energy expenditure ⩽ 1.5 metabolic equivalents and in a sitting or reclining posture. In the general population, the volume of sitting time is associated with increased risks of morbidity and mortality, independent of physical activity, and has been suggested to carry a greater risk of mortality than smoking behaviour. There are many symptoms of MS (e.g. mobility disability and fatigue) that could increase the prevalence of sedentary behaviour, and sedentary behaviour may have considerable implications for the development of comorbid conditions prevalent in MS. This review provides a summary of the rates, correlates, consequences and interventions attempting to reduce sedentary behaviour in MS. We provide a research agenda that guides future research on sedentary behaviour in MS. This paper provides a clarion call that it is time to 'stand up against MS'.