Subjects with MS participating in either a 6-month yoga class or exercise class showed significant improvement in measures of fatigue compared to a waiting-list control group. There was no relative improvement of cognitive function in either of the intervention groups.

Expectancy or placebo effects on cognitive function have not been well studied. To determine the effect of taking pills on cognitive function, 40 participants were randomly assigned to a pill or no-pill condition. Healthy seniors who took a 2-week supply of methylcellulose pills, which they were told was an experimental cognitive enhancer, were compared to seniors not taking any pills. There were 2 primary outcome measures defined prior to the study-Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List delayed recall and Stroop color word task time-as well as 7 other cognitive outcome measures. There was a significant effect of pill taking on the 2 primary outcome measures. There was also an effect of pill taking on choice reaction time and Word List immediate recall but not on the other 5 secondary cognitive outcome measures. In an exploratory analysis of potential predictors of the expectancy effect, perceived stress and self-efficacy but not personality traits interacted with the pill-taking effect on cognitive function. Further characterizing and understanding this observed expectancy effect is important to maximize cognitive health and improve clinical trial design.

Alterations in the hypothalamic-pituitary-adrenal axis have been noted in people with Alzheimer disease (AD) and in the people caring for them. In a case-control study, we assessed whether the cortisol response at awakening and diurnal cortisol would reflect these changes. AD patients, their caregivers, and healthy senior noncaregivers collected saliva within 5 minutes of waking, 30 minutes after waking, before lunch, 1 hour after lunch, and at 11 pm or when getting ready for bed. They also completed a Perceived Stress Scale. Total cortisol for the day after adjusting for antidepressant use revealed a group effect [F(2,39)=12.49, P<0.0001], with mild AD patients and caregivers having higher cortisol values. Unlike the noncaregivers (t=-1.15, df=14, P>0.27), both cortisol values of the AD caregivers (t=-2.96, df=16, P<0.03) and the AD patients' (t=-2.5, df=14, P<0.01) increased between awakening and 30 minutes afterward. There were also group differences at awakening [F(2,48)=4.6, P=0.012] adjusting for antidepressant use and 30 minutes after waking adjusting for antidepressant use and awakening cortisol [F(2,46)=4.7, P=0.014<0.02). AD patients (r=0.45, P=0.08) and caregivers (r=0.44, P=0.10) with higher cortisol values 30 minutes after waking also showed a trend toward higher perceived stress scores. Salivary cortisol and cortisol response on awakening may enhance future studies relating free cortisol to subjective psychologic and physiologic markers.

BackgroundTo determine factors that predict adherence to a mind-body intervention in a randomized trial.DesignWe analyzed adherence data from a 3-arm trial involving 135 generally healthy seniors 65–85 years of age randomized to a 6-month intervention consisting of: an Iyengar yoga class with home practice, an exercise class with home practice, or a wait-list control group. Outcome measures included cognitive function, mood, fatigue, anxiety, health-related quality of life, and physical measures. Adherence to the intervention was obtained by class attendance and biweekly home practice logs.ResultsThe drop-out rate was 13%. Among the completers of the two active interventions, average yoga class attendance was 77% and home practice occurred 64% of all days. Average exercise class attendance was 69% and home exercise occurred 54% of all days. There were no clear effects of adherence on the significant study outcomes (quality of life and physical measures). Class attendance was significantly correlated with baseline measures of depression, fatigue, and physical components of health-related quality of life. Significant differences in baseline measures were also found between study completers and drop-outs in the active interventions. Adherence was not related to age, gender, or education level.ConclusionHealthy seniors have good attendance at classes with a physically active intervention. Home practice takes place over half of the time. Decreased adherence to a potentially beneficial intervention has the potential to decrease the effect of the intervention in a clinical trial because subjects who might sustain the greatest benefit will receive a lower dose of the intervention and subjects with higher adherence rates may be functioning closer to maximum ability before the intervention. Strategies to maximize adherence among subjects at greater risk for low adherence will be important for future trials, especially complementary treatments requiring greater effort than simple pill-taking.

AD patients have disproportionate problems shifting spatial attention compared with age-matched controls. Impaired attentional performance in AD cannot be simulated in young subjects by ingestion of a combined antihistamine/anticholinergic agent at a dose sufficient to produce significant changes in alertness.

Visual processing of global and local features differentially engages the right and left hemispheres and requires different allocations of spatial attention. To further understand the decline in visual cognition and visual attention with age, we studied the performance of healthy young subjects and healthy elders on a global-local figures task. The results showed that elders processed global images more quickly when presented in the left visual field and local images in the right visual field, similarly to the young controls. However, we did observe a significant impairment in the elders' ability to process global figures compared with local figures, despite there being no overall difference between global and local processing speed among the young. It is thought that this age-related decline in global processing is related to the narrowed attentional field that can be demonstrated in other age-related visual processing declines such as visual search and useful field of view.

The changes in pulmonary artery (PA) tone that develop during hypoxia are complex and appear to involve multiple vasoregulatory pathways. This study was designed to identify the phases of the response to severe hypoxia in isolated segments of rat PA and to evaluate the mechanisms involved. Exposure of preconstricted PA segments to severe hypoxia (i.e., PO2 < 3 Torr) resulted in transient relaxation followed by vigorous hypoxic vasoconstriction (HVC), which averaged 0.26 +/- 0.02 g (or 43.9 +/- 3.7% of the maximal force developed in response to phenylephrine). HVC was followed by sustained and nearly complete inhibition of existing tone. The first two phases of the response were endothelium dependent and could be blocked by nonspecific inhibitors of endothelium-derived relaxing factor (EDRF) activity and by 500 microM N omega-nitro-L-arginine, a specific inhibitor of nitric oxide (NO) formation. The transient early relaxation could also be inhibited by superoxide dismutase (50 U/ml). In contrast, the late relaxation phase was neither endothelium dependent nor could it be blocked by inhibitors of EDRF/NO activity. Rat PA segments were relaxed by pinacidil and lemakalim, both of which activate ATP-sensitive potassium channels. Preincubation with glibenclamide, a selective inhibitor of these channels, blocked this response and also reduced late hypoxic vasodilation by nearly 40% (P < 0.001). These findings demonstrate that the response of rat PA to hypoxia involves both endothelium-dependent and endothelium-independent components. The initial relaxation results from enhanced EDRF/NO activity, which is likely due to diminished breakdown by superoxide radicals.(ABSTRACT TRUNCATED AT 250 WORDS)

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