Effect of omega-3 and policosanol supplementation on attention and reactivity in athletes.

OBJECTIVE: The purpose of this study was to determine the effect of omega-3 fatty acids and policosanol supplementation on the cognitive processes involved in the control of reactivity in karateka engaged in attention tests. METHODS: Eighteen karateka were randomly assigned to 2 groups. One group (10 subjects) took the supplement of omega-3 fatty acids (2.25 g) plus policosanol (10 mg) (O3 + P) for 21 days, and the other group was supplemented with placebo (oleic sunflower oil). Subjects were tested at the beginning of the experiment (Test 1), after 21 days (Test 2), and after 42 days (Test 3). The experimental procedure consisted of an Alert and a Sustained Attention (SA) reaction time test: the subject had to react by pressing a key of a computer keyboard in Alert and a sequence of 3 keys in SA in response to stimuli, activating a complex go/no-go paradigm. For each test, we recorded the reaction time and the event-related potentials by electroencephalogram and electromyography (EMG) of the forefinger flexor muscle. The Profile of Mood States (POMS) test was also administered. RESULTS: After 21 days of supplementation, subjects who received O3 + P showed a reduced reaction time and increased vigor sensation associated with a reduction of the negative states measured with the POMS test. Analysis of the event-related brain potentials showed a reduced latency of the movement-related brain macropotentials. In particular, the potentials recorded in the premotor period and motor period occurred earlier and the latency of EMG activation was reduced. In the third test, 21 days after the last O3 + P supplementation, the positive effects on the mood state persisted, while the reaction time, EMG, and brain potential latencies increased, although their values remained lower than in the first test. The placebo group did not show any significant differences in Tests 2 and 3 compared to Test 1 for either POMS or reactivity and brain potentials. CONCLUSIONS: Supplementation with O3 + P may be effective in improving mood state and reactivity. The reaction time reduction appears to be due to a central nervous system effect, as shown by the reduced latency of movement-related brain macropotentials and EMG activation. These results are in line with previous experiments.

Changes in salivary cortisol and corticosteroid receptor-alpha mRNA expression following a 3-week multidisciplinary treatment program in patients with fibromyalgia.

The aim of the present study was to investigate the effects of a 3-week residential multidisciplinary non-pharmacological treatment program (including individually prescribed aerobic exercise and cognitive-behavioral therapy) on fibromyalgia symptoms and hypothalamic-pituitary-adrenal (HPA) axis function. Salivary and venous blood samples were collected from 12 female patients with fibromyalgia (age: 25-58) the day before and the day after the treatment period: saliva, eight times (every two hours from 0800 to 2200 h); venous blood, at 0800 h. Peripheral blood mononuclear cells (PBMC) were separated and analyzed for glucocorticoid receptor-alpha (GR-alpha) mRNA expression by semi-quantitative RT-PCR, while the salivary cortisol concentration was determined by RIA. At the same time, pain and aerobic capacity were evaluated. Aerobic capacity improved at the end of the treatment program. The slope of the regression of salivary cortisol values on sampling time was steeper in all patients after treatment, indicating that the cortisol decline was more rapid. Concomitantly, the area under the cortisol curve "with respect to increase" (AUC(i)) was higher and there was a significant increase in GR-alpha mRNA expression in PBMC. The number of positive tender points, present pain, pain area and CES-D score were significantly reduced after the treatment, while the pressure pain threshold increased at most of the tender points. Our findings suggest that one of the active mechanisms underlying the effects of our treatment is an improvement of HPA axis function, consisting in increased resiliency and sensitivity of the stress system probably related to stimulation of GR-alpha synthesis by the components of the treatment.

Attention in athletes of high and low experience engaged in different open skill sports.

In this study were examined differences in attentional style of athletes engaged in two open skill sports requiring high reactivity (karate and volleyball) in groups with high or low experience. 42 healthy men, 24 volleyball players, 12 of High Experience (first division Italian League players whose M age was 28 yr. (SD=5) and 12 of Low Experience (prejunior Italian team athletes whose M age was 19 yr. (SD= 2). and 18 karateka, 9 of High Experience (3rd and 4th dan black belt athletes whose M age was 31 yr., SD=5) and 9 of Low Experience (1st and 2nd dan black belt karateka whose M age was 32 yr., SD=5). Tests involved different types of attention: Alert, Go/No-Go, Divided Attention, and Working Memory. For each one, the reaction time (RT), variability, change in RT, and number of errors were analysed. Karateka of High Experience reacted faster than those of Low Experience on the simple RT test, Alert (M RT: 204 vs 237 msec., p< .01), while on the Divided Attention test, the High Experience subjects performed more poorly and committed more errors (M errors: 4.89 vs 1.44, p <.003). Young volleyball players of Low Experience reacted faster than colleagues of High Experience on the Alert (M RT: 187 vs 210 msec., p<.01) and Divided Attention tests (M RT: 590 vs 688 msec., p<.001) but committed more errors (Divided Attention test, M errors: 6.50 vs 3.08, p<.007). For the Divided Attention and Working Memory tests, correlations were positive among errors, RT, and RT variability but only for volleyball athletes of High Experience, suggesting they showed higher attention and stability in complex reactions than the group with Low Experience. No significant correlations were noted for either group of karateka on complex reactions. Results suggested that the attentional resources were engaged in different ways in the two groups of athletes and, in each group, there were differences between persons of High and Low Experience.

Gender-related effects of chronic non-malignant pain and opioid therapy on plasma levels of macrophage migration inhibitory factor (MIF).

Macrophage migration inhibitory factor (MIF) is a cytokine produced by neuroendocrine and immune tissues that possesses several characteristics of a neuroendocrine mediator. Chronic pain is known to affect and to be affected by neuroendocrine and immune mechanisms. In the present study, the plasma levels of MIF and several hormones (cortisol, estradiol, testosterone) were determined to evaluate their mutual behaviour in controls and in chronic pain patients. Blood samples were collected from males and females divided into groups depending on their age (younger or older than 55) and health condition: (1) pain-free control subjects; (2) chronic non-malignant pain subjects. Moreover, two additional groups were added to evaluate the effects of short- and long-term opioid administration: (3) short-term opioid-treated chronic pain patients and (4) long-term opioid-treated chronic pain patients (longer than 6 months). MIF in control/younger men was higher than in all the other control and chronic pain groups. MIF was lower in pain patients than in controls of both sexes. MIF was not changed by morphine administration; its levels remained lower in opioid-treated subjects than in controls after both short- and long-lasting administration. Chronic pain changed hormone plasma levels differently in male and female patients. MIF was positively correlated with testosterone and negatively with estradiol. These results demonstrate sex differences in the younger men and women and a strong pain-induced decrease of MIF availability. These findings suggest the involvement of this cytokine in the sex differences observed in chronic pain conditions.

Attentional, emotional and hormonal data in subjects of different ages.

The differences in attentional style among subjects of different ages and the influence of emotionality on the attentional components were studied for a limited experimental period. Variation in the hormonal data and its relation to behavioural parameters were also evaluated. The subjects enrolled in the study were divided into four age groups (A 18-29, B 30-45, C 46-59, D 60-77 years). The attentional tests involved different types of attention: alert, go/no-go, divided attention and working memory. Emotionality was assessed on the basis of skin conductance, heart rate and frontalis muscle tone. Testosterone (T), free testosterone (fT), non-specifically bound testosterone (NST), sex hormone binding globulin (sHBG), oestradiol, cortisol and adrenocorticotrophic hormone were determined in the plasma. The data were analysed to identify endocrine and behavioural differences related to sex and age. The results showed an influence of age on reaction time (RT) and RT variability. This was particularly evident for groups C and D with respect to A in the simple (alert) and complex RT tests (go/no-go and working memory). Divided attention, with the highest RT, showed a clear distinction between group A and the other groups. The difference in frontalis electromyography (EMG) (test vs control) increased with age, while the autonomic responses (skin conductance and heart rate) did not vary. In most attentional tests, the age-related reduction of RT was associated with increased T, fT and NST and decreased cortisol.

Platelet adhesion and aggregation on polyethylene: effect of exhaustive exercise.

The aim of the present study was to evaluate the effect of an exhaustive exercise on platelet adhesion and aggregation on polyethylene (PE) in relation to changes in plasma cortisol concentration in order to ascertain the effect of physical stress response in the blood-contacting properties of polymeric materials. Twelve healthy sedentary subjects, six males and six females, were studied. Each subject performed an exercise test on a bicycle ergometer at intensity corresponding to 70% VO2 max until exhaustion. One month after the exercise session, each subject participated in a control rest session. In both sessions, blood samples were drawn every 5 min for cortisol, lactate, hemoglobin, and hematocrit determinations and every 15 min for evaluation of platelet adhesion and aggregation. Individual comparisons between the rest and exercise cortisol patterns identified three categories of cortisol responders to exercise: positive responders (C +, showing higher concentrations during exercise than during rest), negative responders (C -, showing lower concentrations during exercise than during rest), and nonresponders (NR, showing similar concentrations during exercise and rest). The results revealed that C + had lower platelet adhesion and aggregation scores during exercise than during rest; moreover C - had higher scores than C + and NR during exercise. The results obtained demonstrated no effects of sex or exercise on either cortisol plasma levels or platelet adhesion and aggregation on PE surface. With regard to cardiovascular risk, the results suggest that exercise favorably affects platelet functions when mechanisms of metabolic adaptation to prolonged muscular work, expressed by a cortisol increase, are activated during exercise.

IFN-gamma production in rabbits: behavioral and endocrine correlates.

Freely interacting male rabbits were studied to establish the effect of exogenous testosterone on interferon-gamma (IFN-gamma) production in peripheral blood mononuclear cells (PBMCs) and to evaluate if this effect is related to season, social rank, plasma corticosterone and glucocorticoid receptors (GcR) in PBMCs. Dominance behavior increases after testosterone propionate (TP) administration only in rank 1 animals, while submission behavior increases after TP only in rank 4 animals, indicating a reinforcing effect of TP on the behavior. Corticosterone and IFN-gamma production are higher and GcR binding capacity is lower in spring than in autumn, suggesting that seasonal fluctuations in the immune system may be related to the pattern of secretion of immunomodulatory hormones. In autumn, corticosterone decreases after TP treatment and increases after social interaction, while GcR binding capacity decreases after TP treatment and social interaction. IFN-gamma production decreases in spring and increases in autumn after TP treatment plus social interaction, indicating that the modulating action of testosterone is related to the current immune status. The relationship between dominance, testosterone and the immune system in spring is suggested by the finding that GcR binding capacity after TP treatment is directly related to social rank, as confirmed by the positive correlation with dominance behavior frequency. The dominance index is positively correlated with GcR binding capacity and negatively with IFN-gamma production before TP treatment, indicating that high receptor activity in immunocompetent cells and low immunoreactivity could be prerequisites for dominance behavior. The immunosuppressive effect of corticosterone and the mechanism of down-regulation on GcR are confirmed by the negative correlations with IFN-gamma production and GcR binding capacity.

Reactivity and event-related potentials in attentional tests: effect of training.

To study the effects of training on reactivity and event-related potentials a complex attentional shifting test involving reaction time was administered (Test 1) to 24 healthy, young students. After five days, 12 subjects were tested with the same procedure (Test 2) without training (Untrained Subjects) while 12 repeated the test at the fifth day after four days of training (Trained Subjects). During Tests 1 and 2, event-related potentials were recorded by electroencephalogram. The task consisted of each subject responding to a stimulus of a letter appearing in the centre of a geometric figure on the screen of a computer monitor. In the prestimulus period black points were drawn and crowded randomly into a zone of the screen. The geometric figure and the letter were shown in the centre of the crowding. There were two letters and four geometric figures randomly combined in different ways. The subject had to press different keys of the computer keyboard when specific combinations appeared. The averaged event-related potentials were characterized by a negative wave with a close relationship to selective attention before the onset of the stimulus of a geometric figure followed by letters. After the stimulus onset, a P3 complex was recorded. Trained subjects were no different from untrained subjects in Test 1, while in Test 2 they had a shorter reaction time, an earlier peak of the selective attention related wave and P3, and a higher amplitude for the P3 complex. These measures and the correlations between them can be considered an index of the training effect. Thus, these tests could be used for evaluation of the attentional style and its modification with training.