Associations of fatty acids composition and estimated desaturase activities in erythrocyte phospholipids with biochemical and clinical indicators of cardiometabolic risk in non-diabetic Serbian women: the role of level of adiposity.

Introduction: Fatty acids (FAs) composition and desaturase activities can be altered in different metabolic conditions, but the adiposity-independent associations with clinical and biochemical indicators of cardiometabolic risk are still unclear. This study aimed to analyze the associations of FAs composition and estimated desaturase activities with anthropometric, clinical, and biochemical cardiometabolic risk indicators in non-diabetic Serbian women, and to investigate if these associations were independent of the level of adiposity and other confounders. Methods: In 76 non-diabetic, otherwise healthy Serbian women, aged 24-68 years, with or without metabolic syndrome or obesity (BMI=23.6±5.6 kg/m2), FA composition in erythrocyte phospholipids was measured by gas-liquid chromatography. Desaturase activities were estimated from product/precursor FAs ratios (D9D:16:1n-7/16:0; D6D:20:3n-6/18:2n-6; D5D:20:4n-6/20:3n-6). Correlations were made with anthropometric, biochemical (serum glucose, triacylglycerols, LDL-C, HDL-C, ALT, AST, and their ratios) and clinical (blood pressure) indicators of cardiometabolic risk. Linear regression models were performed to test the independence of these associations. Results: Estimated desaturase activities and certain FAs were associated with anthropometric, clinical and biochemical indicators of cardiometabolic risk: D9D, D6D, 16:1n-7 and 20:3n-6 were directly associated, while D5D and 18:0 were inversely associated. However, the associations with clinical and biochemical indicators were not independent of the associations with the level of adiposity, since they were lost after controlling for anthropometric indices. After controlling for multiple confounders (age, postmenopausal status, education, smoking, physical activity, dietary macronutrient intakes, use of supplements, alcohol consumption), the level of adiposity was the most significant predictor of desaturase activities and aforementioned FAs levels, and mediated their association with biochemical/clinical indicators. Vice versa, desaturase activities predicted the level of adiposity, but not other components of cardiometabolic risk (if the level of adiposity was accounted). While the associations of anthropometric indices with 16:1n-7, 20:3n-6, 18:0 and D9D and D6D activities were linear, the associations with D5D activity were the inverse U-shaped. The only adiposity-independent association of FAs profiles with the indicators of cardiometabolic risk was a positive association of 20:5n-3 with ALT/AST ratio, which requires further exploration. Discussion: Additional studies are needed to explore the mechanisms of the observed associations.

Aronia juice consumption prior to half-marathon race can acutely affect platelet activation in recreational runners.

Long-distance running, especially in non-professional runners, can increase cardiac arrest risk by enhancing platelet activation and aggregation. Polyphenols can exert cardioprotective effects by positively influencing platelet function. This study aimed to examine the acute effects of polyphenol-rich aronia juice consumption, before simulation of a half-marathon race, on platelet activation and aggregation with leukocytes in recreational runners. In this acute crossover study,10 healthy male runners (age 30.8 ± 2.3 years) consumed breakfast with 200 mL of aronia juice or 200 mL of placebo. They warmed-up and ran a simulated half-marathon race (21.1 km). Blood was collected at baseline, and at 15 min, 1 h, and 24 h after the run. All variables were analyzed with 4 (time) × 2 (group) ANOVA with repeated measures on both factors. Results revealed a significant effect of group on platelet activation parameters: P-selectin and GPIIb-IIIa expressions significantly decreased in the aronia group compared with the placebo group (F[1,9] = 10.282, p = 0.011 and F[1,9] = 7.860, p = 0.021, respectively). The effect of time was significant on both platelet aggregation markers: platelet-monocyte and platelet-neutrophil aggregates were significantly lower after the race (F[3,7] = 4.227, p = 0.014 and F[3,7] = 70.065, p = 0.000, respectively), with changes more pronounced in the later. All effects remained when platelets were exposed to an agonist. These results suggest that aronia consumption could counteract the half-marathon race-induced changes in platelet function. Novelty Aronia juice consumption significantly decreased the expression of platelet activation markers but did not affect platelet aggregation. The race itself did significantly reduce platelet-neutrophil aggregation. Aronia juice may serve as a supplement beverage for recreational runners to alleviate enhanced platelet reactivity caused by prolonged running.

Sport-Specific Warm-Up Attenuates Static Stretching- Induced Negative Effects on Vertical Jump But Not Neuromuscular Excitability in Basketball Players.

The purpose of this study was to examine the acute effects of static stretching (SS) and dynamic stretching (DS), alone and in combination with specific basketball warm-up (SBWU), on the neuromuscular excitability and vertical jump height in basketball players. Twelve healthy young male basketball players participated in the study (18 ± 0.42 years; 17.4 - 18.6 age range; 188 ± 9 cm; 76.5 ± 9 kg). All participants completed two different stretching treatments (static and dynamic), performed on different days at least seven days apart, in the same period of training microcycle, in a counterbalanced order. Each session consisted of a self-paced jogging warm-up, followed by a 10-minute testing period (T0), which involved eliciting H reflex and M waves, followed by three trials of a vertical jump test. Participants then performed one of the treatment protocols. After another test (T1), participants conducted 8-minute specific basketball warm-up and then one more test (T2). Combined 3 (time) x 2 (stretching protocol) analysis of variance with repeated measures on both factors revealed that SS significantly decreased spinal excitability (H/M ratio) (p = 0.015, d = -0.38, percentage of change = -20.55%) and vertical jump height (p = 0.007, d = -1.91, percentage of change = -2.6%), but after SBWU, vertical jump height increased (p = 0.006, d = 1.13, percentage of change = 3.01%), while H/M ratio continued decreasing (p = 0.019, d = -0.45, percentage of change = -30.23%). Acute effects of DS, alone and in combination with SBWU were not significant. It seems that SBWU attenuates negative acute effects of SS on vertical jump performance in young basketball players, while DS appears to cause no significant acute effect for this population.

Bilateral sequential motor cortex stimulation and skilled task performance with non-dominant hand.

OBJECTIVE: To check whether bilateral sequential stimulation (BSS) of M1 with theta burst stimulation (TBS), using facilitatory protocol over non-dominant M1 followed by inhibitory one over dominant M1, can improve skilled task performance with non-dominant hand more than either of the unilateral stimulations do. Both, direct motor cortex (M1) facilitatory non-invasive brain stimulation (NIBS) and contralateral M1 inhibitory NIBS were shown to improve motor learning. METHODS: Forty right-handed healthy subjects were divided into 4 matched groups which received either ipsilateral facilitatory (intermittent TBS [iTBS] over non-dominant M1), contralateral inhibitory (continuous TBS [cTBS] over dominant M1), bilateral sequential (contralateral cTBS followed by ipsilateral iTBS), or placebo stimulation. Performance was evaluated by Purdue peg-board test (PPT), before (T0), immediately after (T1), and 30min after (T2) an intervention. RESULTS: In all groups and for both hands, the PPT scores increased at T1 and T2 in comparison to T0, showing clear learning effect. However, for the target non-dominant hand only, immediately after BSS (at T1) the PPT scores improved significantly more than after either of unilateral interventions or placebo. CONCLUSION: M1 BSS TBS is an effective intervention for improving motor performance. SIGNIFICANCE: M1 BSS TBS seems as a promising tool for motor learning improvement with potential uses in neurorehabilitation.

Transcranial application of near-infrared low-level laser can modulate cortical excitability.

BACKGROUND AND OBJECTIVE: Near-infrared low-level laser (NIR-LLL) irradiation penetrates scalp and skull and can reach superficial layers of the cerebral cortex. It was shown to improve the outcome of acute stroke in both animal and human studies. In this study we evaluated whether transcranial laser stimulation (TLS) with NIR-LLL can modulate the excitability of the motor cortex (M1) as measured by transcranial magnetic stimulation (TMS). METHODS: TLS was applied for 5 minutes over the representation of the right first dorsal interosseal muscle (FDI) in left primary motor cortex (M1), in 14 healthy subjects. Motor evoked potentials (MEPs) from the FDI, elicited by single-pulse TMS, were measured at baseline and up to 30 minutes after the TLS. RESULTS: The average MEP size was significantly reduced during the first 20 minutes following the TLS. The pattern was present in 10 (71.5%) of the participants. The MEP size reduction correlated negatively with the motor threshold at rest. CONCLUSIONS: TLS with NIR-LLL induced transitory reduction of the excitability of the stimulated cortex. These findings give further insights into the mechanisms of TLS effects in the human cerebral cortex, paving the way for potential applications of TLS in treatment of stroke and in other clinical settings.

Transcranial magnetic stimulation has no placebo effect on motor learning.

OBJECTIVE: Motor learning is the core cognitive function in neurorehabilitation and in various other skill-training activities (e.g. sport, music). Therefore, there is an increasing interest in the use of transcranial magnetic stimulation (TMS) methods for its enhancement. However, although usually assumed, a potential placebo effect of TMS methods on motor learning has never been systematically investigated. METHODS: Improvement of performance on the Purdue Pegboard Task over three test-blocks (T0, T1, and T2), separated by >20 min, was used to evaluate motor learning. In Experiment-1, two groups of 10 participants each were compared: one group immediately before T1 received a sham intermittent theta burst stimulation procedure (P-iTBS group), while another did not have any intervention at all (control - CON group). In Experiment-2, a third group of participants (six subjects) who received sham high-frequency repetitive TMS procedure before T1 (P-rTMS group) was compared with P-iTBS group. RESULTS: All three groups showed significant learning over time, but without any difference between them, either in Experiment-1 between P-iTBS and CON, or in Experiment-2 between P-rTMS and P-iTBS. CONCLUSION: The results suggest lack of any placebo effect of TMS on motor learning. SIGNIFICANCE: The results may help in designing further TMS-motor learning studies and in interpreting their results.